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Change log

Here is the change lot extracted from the latest release.

version 4.9.0
2014/10/22

- Support SSL-to-proxy: Robots connecting to HTTP forward proxies
  using SSL.

  To configure the new feature, the robot must mention an address of a
  use()d PGL Proxy object. The PGL Proxy object must have an ssl_wraps
  field configured. This tells the robot that the forward proxy is
  accepting SSL connections.

  When a Robot needs to connect to an SSL origin server while using
  SSL-to-proxy, the combination results in two independent "nested"
  SSL layers: One from the robot to the proxy and one from the robot
  to the origin server. The robot sends an HTTP CONNECT request
  (encrypted and, hence, invisible to a 3rd-party observer!) inside
  the outer SSL layer to the proxy.

- Support requesting and/or serving on-disk files. Configured via PGL
  Content.document_root, similar to an Apache httpd document_root.
  Polygraph preloads all regular files from Content.document_root into
  RAM, scanning document_root sub-directories recursively. Empty files
  and files exceeding 2GB in size are currently not supported. When
  configured, Polygraph responds to a request with URI path FOO using
  the content preloaded from the document_root/FOO file on disk.

- Quit ASAP after reaching a negative phase goal instead of waiting
  for server virtual "cold" phase to become idle and time out.

- Exclude the time spent waiting for the first transaction from the
  first phase by adding a virtual "wait" phase before the scheduled
  real phases.

  The wait phase ends when the first transaction begins and should get
  no transaction or connection measurements. Wait phase stats are not
  logged because there should not be any, and because logging them
  would add noise to test reports.

- Added PGL Agent::http_headers field to specify custom HTTP headers.
  PGL constants that look like 'name: value' are now parsed as PGL
  MimeHeader objects:

        MimeHeader B = 'B: valueB';
        MimeHeader C = 'C: valueC';
        MyRobot.http_headers = [ 'A: valueA', [B, C]: 30% ];

  Agent::http_headers is a new kind of PGL "selector" that, for every
  selection, goes through all the listed custom headers and selects
  each header with the specified probability. In the above example,
  Polygraph will emit requests with headers A, B, and C in 30% of all
  agent-generated messages while putting just the header A in the
  remaining 70% of all messages. Note that header A is always added,
  while headers B and C are either added _together_ (30% of cases) or
  not added at all.

  If a PGL-configured header clashes with a Polygraph-generated header
  (or with another PGL-configured header), then the first added header
  wins, and Polygraph logs a warning. PGL-configured headers are added
  first so they should always win against the Polygraph-generated
  headers such as Date, Host, Accept, and Connection. However, this
  feature was not really designed for overwriting Polygraph-generated
  headers but for adding new/different ones.

- Start SMP workers, one per local Bench host, if Bench.*_side.hosts
  are used. To create N SMP workers on host a.b.c.d, use N a.b.c.d
  hosts (the PGL clone operator ** is handy for that).

  If the Bench hosts array contains a single local host, no worker
  processes are started (i.e., the master process becomes the worker
  process). This allows Polygraph to run in "legacy" non-SMP mode in
  simple Bench configurations.

  Changed --worker ID default to zero. The zero value is used for the
  Master process because it may create its own logs that should not
  overwrite worker logs.

- Support running each SMP worker on a configurable set of CPU cores.
  Also usable in a degenerative case of a single worker (no SMP). Not
  supported on systems w/o sched_setaffinity() API, such as FreeBSD.

  The feature is configurable via the new PGL BenchSide::cpu_cores
  field.  Each integer array nested inside cpu_cores represents a list
  of CPU cores (i.e., a CPU affinity mask) for a single worker. If a
  cpu_cores field is defined, the number of its masks must be either
  zero or equal to the number of BenchSide's hosts array elements; any
  other number is a fatal configuration error. Empty array is treated
  as if no cpu_cores array was configured/defined. We may change this
  [rather low-level] configuration approach based on user feedback.

  Without cpu_cores configured, Polygraph does not try to restrict
  workers CPU affinity.

- When generating random content, support optional "data" or "binary"
  format when the new Content.generator field is set to "random_data".

  This is handy when the DUT treats the default mostly-ASCII content
  specially, but the tester does not want to use cdbs to generate
  something other than ASCII content.

  Note that new "random_data" format is virtually uncompressible,
  unlike ASCII that carries more than 25% "fat". Workloads using SSL
  compression or other compression mechanisms may see a substantial
  different in performance, even without a DUT.

  The default behavior is still to use a subset of printable ASCII
  characters.  That algorithm can now be explicitly configured by
  setting Content.generator to "random_text".

- Re-fetch Kerberos TGT ticket if it is needed, but we failed to fetch
  it before. The code already dealt with expired and unusable TGT
  cases by re-fetching, but a missing TGT led to a persistent stream
  of "(c157) missing Kerberos TGT" errors.

- Better reporting of authentication errors: Report such details as
  KDC server address, robot identity, and connection information.

- Better reporting of SSL errors: Minimize the number of logged
  Comments when detailing a single error.

- Simplified table(filename) PGL calls and command line options: Do
  not require explicit distribution type but get it from the loaded
  table instead. Old syntax with an explicit type is still supported.

- Fixed rep.rate evaluation in Phase scripts. Polygraph was returning
  request rate instead of the response rate. The two rates are usually
  similar, which may explain why the bug went unnoticed for years.
  Logged and console-reported stats were not affected.

- Fixed KDC error handling: Polygraph was not switching to the next
  configured KDC server on KDC connection failures.

  Also, final TGT ticket fetch failure (no retries left) now leads to
  the cancellation of all previously queued ticket transactions.
  Prior to this change, the queued ticket transaction waited forever
  if the TGT transactions kept failing.

- Count HTTP authentication errors once, not twice.

- Avoid segfaults when cleaning up Kerberos state, especially after
  many KDC timeouts.

- Prevent InAddress::sockAddr() assertions when deleting IPv6 aliases
  on FreeBSD.

- Avoid year-2038 overflows when running 32bit ltrace --objects time.

- Made modern autotools happier and bootstrap.sh safer.


version 4.8.0
2014/05/20

- Tie Robot.req_rate to "baseline" transactions and report just the
  baseline transactions on console i-lines, avoiding user surprises
  when, for example, enabling authentication doubled perceived request
  rate. A baseline transaction delivers the intended resource to the
  client and may include individual HTTP CONNECT or authentication
  transactions as intermediate steps of a single compound transaction.

  This is a significant change, affecting offered load in
  workloads using HTTP CONNECT requests and/or HTTP authentication.

  Collect and report interval stats for HTTP CONNECT and
  "authenticating" transactions.  Exclude HTTP CONNECT requests from
  "ssl" interval stats so that only transactions actually using SSL
  are recorded there. Report an active i-proto line, even if all its
  transactions have failed.

  Binary log version, some lx object names, and HTML report blobs have
  changed to reflect the new statistics collection approach. More
  related cleanup work is probably needed.

- Negotiate/Kerberos proxy authentication support, configurable via
  PGL KerberosWrap. Both UDP and TCP transports are supported for
  communication with KDC. MIT Kerberos v1.9 or newer is required. No
  Heimdal support.

- Support a configurable cache for successful DNS lookups via the new
  PGL DnsCache type and DnsResolver::cache field. No DNS caching by
  default.

- Added PGL zoneDomains(file_name, ip_addresses) function to load
  domain names from DNS zone files. Only domains that match given IP
  addresses are loaded.  Wildcard domains are ignored.

  DNS zone file interpretation is implemented using libldns. Libldns
  does not allow any leading whitespace in zone files, even on
  otherwise empty lines.  The library supports $ORIGIN directive.
  Tested with libldns v1.6.16.  Polygraph tries [too] hard to fix
  known ldns.h interface bugs. If libldns is not available, cannot be
  fixed, or is not compatible with Polygraph expectations, a
  ./configure warning is printed and any test calling PGL
  zoneDomains() will fail at call time.

- Control SSL compression via the new PGL SslWrap::compression field
  which specifies the probability that the agent using the SslWrap
  configuration will try to use SSL compression. The agent decision is
  sticky. Disabling compressions appears to be required to enable SSL
  (AES-NI) hardware acceleration support, at least in some
  environments. Note: SSL compression is a messy feature in general,
  and Polygraph specifically does not have full control over SSL
  compression.

- Better SMP support (more SMP automation work is still needed):
    * Added --worker command line option to specify SMP worker ID.
    * Support %worker macro in command line option values.
    * The local r.n.g. seed value now defaults to worker ID. This
      change does not affect old test scripts running new Polygraph
      versions because the default worker ID is one, same as the old
      local r.n.g. default.
    * Added worker() PGL function to return the current worker ID.
    * "${worker}" macro support in ips2names, credentials, URL traces.
    * pgl2ldif --worker ID command line option.

- Revised detection of important differences reported by cmp-lx.pl
  based on real-world regression tests to minimize noise. For example,
  very rare (less than 0.1%) errors are no longer considered important
  and absolute differences below 1 millisecond are no longer reported
  for time measurements done with millisecond precision.

- Infect content by appending Request URI information to the response
  body if the newly added PGL Content::inject_object is set to a
  "request_uri" string. This helps caches that do not store multiple
  copies of identical response bodies, especially in tests using cdbs
  with a small number of verbatim entries.

- Accept "A" values for DnsResolver::query_type. They are still the
  default.

- Report an active i-proto line, even if all its transactions have
  failed.

- Revamped Reporter's baseline (a.k.a. executive stats) scope
  formation and use, to better handle cases where client- and
  server-side phases differ.

- Support patches that "register" themselves with Polygraph so that
  Polygraph binaries can report which patches have been applied.

- Do not enable SSL support if libssl is missing or has no
  SSL_connect(), even if OpenSSL headers are present.

- Remove old IPv6 addresses when creating new aliases. Fixed(?)
  primary interface address detection on Linux. We currently define
  "primary" as the address added to the interface first. Also fixed
  IPv6 aliases deletion.

- Fixed handling of concurrent HTTP Negotiate transactions when one
  transaction changes the proxy need for authentication after the
  other transaction has already started with a different assumption.

- Fixed collection of transaction queue time statistics.

- Fixed default libz (compression support) detection for systems with
  AX_CHECK_ZLIB serial 8 macro.

- Fixed StatCycle.cc:82 "0 < cat < count" assertion.

- Avoid division by zero "floating exception" when producing
  dynamize()d domains for empty worlds. If we need to produce a new
  URL but cannot (due to an empty local world), then repeat from a
  non-empty remote world (if possible).

- Fixed dumping of cdbs with "binary" entries. They used to be
  truncated.

- Prevent cdbEntries.cc 'e.model' assertion by rejecting misconfigured
  Content that has content_db containing "markup" objects but lacks a
  may_contain field necessary to generate/pour those objects.

- Fixed computation of histogram percentiles by cml-lx.pl tool.

- Fix segfault in PGL parser on some invalid workloads.

- Install the documentation files during "make install".

- Remove AX_* macros from cfgaux/, use system versions instead.
  Autoconf-archive package is now required for bootstrapping.


version 4.7.0
2013/04/19

- Configurable SSL certificates.

  A new PGL SslWrap::certificates field allows to configure existing
  certificates for Polygraph client and server use.  Each certificate
  file should contain an unencrypted certificate and a private key in
  PEM format.  The key may be followed by intermediate certificates to
  form a chain (see SSL_CTX_use_certificate_chain_file(3)).
  Certificates are assigned to Agents in a round-robin fashion and the
  assignment is sticky.

  This feature is supported on both client and server sides.  If the
  same SslWrap object with certificates is used for both Robots and
  Servers, they would end up using the same certificates.

- Generated client-side SSL certificates.

  Polygraph used to generate server certificates only.  A new PGL
  SslWrap::generate_certificates boolean field now explicitly controls
  whether Polygraph should generate SSL certificates.  The field is
  honored on both client and server sides.  The default behavior has
  not changed: certificates are not generated on the client side and
  are generated on the server side.

  Setting SslWrap::generate_certificates to false allows running
  server without any certificates.  This is a weird but valid
  configuration.

- Collect and report SSL session resumption phase statistics.

  "Count" and "rate" phase stats are available for new and resumed SSL
  sessions.  On client side, both offered (i.e. resumption attempts)
  and measured stats are collected.  On server side, only measured
  stats are collected.  In addition to count and rate stats, SSL
  session resumption probability is reported.

  In the future, we may add offered SSL session stats on the server
  side and collect interval stats.

- Content-driven popularity model support.

  A new ClientBehavior.pop_model PGL field added.  Similar to other
  ClientBehavior properties, it allows setting Robot popularity model
  when requesting a particular Content type.

- Binary log compression.

  Compression is enabled at build time if and only if zlib library is
  available.  All Polygraph tools support reading both compressed and
  uncompressed logs.  A compressed log size for a simple workload is
  less than 20% of the uncompressed log.

  Other than smaller log sizes, no user-visible changes are expected.
  In particular, we do not expect log compression to slow Polygraph
  down, but more experience is needed to confirm that.

- Inherit previous phase factors at runtime (by default).

  If the next phase "begin" factor is not explicitly configured, it is
  inherited from the corresponding "end" factor of the previous phase.
  Before the change, this inheritance was implemented at test start
  time so when a phase would end [by its script] prematurely, the
  factor would jump from the last value in the previous phase to the
  implicitly set "begin" value in the next phase.  Now, the "begin"
  value is computed only when the next phase starts, avoiding the
  jump.

- Polymorphic min() and max() PGL functions.

  Before the change, PGL min() and max() functions converted their
  arguments to float for comparison.  Hence, the functions failed for
  argument types which cannot be converted to float, such as time.
  Now, arguments are compared using PGL '<' and '>' operators,
  allowing min() and max() functions to be applied to such types as
  time and rate.

- More flexible PGL string to int and float conversion.

  Before the change, PGL string to int and float conversion functions
  did not allow any spaces after the number, which resulted in obscure
  errors and inconveniences, especially when dealing with numbers loaded
  using PGL system() calls.  Now any trailing spaces are ignored.
  Note that leading spaces were already ignored before the change.

- Allow unit scales and boolean constants as PGL function and
  object names.

  Before the change, time and size scales and boolean constants were
  not allowed to be PGL function or object names.  In particular, this
  resulted in parsing errors for workloads using min() PGL function or
  scripts using objects like sample.rptm.min.  Now PGL parser can
  distinguish bare constants from function calls and object names.

- Select Robot HTTP version on startup and report it.

  Before the change, Robot HTTP version was selected on session start.
  Hence, Robot HTTP version could be changed during a test with
  multiple sessions and it could not be reported on startup.  Since
  sessions are not meant to model different HTTP clients, such
  behavior is wrong.  Now HTTP version selection for Robots is sticky
  and performed early during startup, the same way it is done for
  Servers.  As a side-effect, Robot HTTP versions are now reported on
  startup.

- Stop Robots when all phases are complete.

  Polygraph client no longer starts new transactions after completing
  the phase schedule and right before exiting.  Such transactions could
  lead to annoying proxy and server errors.

- Support PGL print() call outside of Phase scripts to assist with
  debugging complex workloads and annotating console logs.  For now,
  output printed outside of scripts does not get to binary logs.

- Add printV() function for PGL scripts to print at a given verbosity
  level.  The first argument should be an integer specifying the
  desired verbosity level.  For example:

    printV(1, "An important message ", 123);

- Polish the error message when PGL type conversion fails.

- Polish client error message when a Robot fails to load the
  configured root certificate.

- Improve large table distribution (e.g. array selectors) support.
  Table distributions with up to 10240 entries should be supported
  now.  Larger distributions may still result in failures.

- Refuse to add directories to cdb.

  Before the change, the cdb tool did not check if input file is
  really a file.  It would try to open and process a directory as if
  it was a file, which may succeed on some systems and result in
  unexpected DB content.  Now cdb checks whether input file is a
  regular file and skips it if it is not.  If stat(2) is not
  available, the check is not enabled and cdb behaves as before.

- Fix handling of CONNECT tunnels requiring multiple CONNECT
  transactions.  Do not switch to SSL until CONNECT tunnel is fully
  established.  In particular, this fixes workloads using both HTTPS
  (SSL) and proxy NTLM authentication.

- Fix NTLM authentication statistics for compound transactions.

  During the first authentication Robots cache the authentication
  scheme.  In subsequent requests, Robots send appropriate
  authentication headers right away in the first request.  Before the
  change, a compound transaction was created only during the first
  authentication resulting in missing compound stats for subsequent
  NTLM authentications.

- Fix HTML report generation if a phase name contains spaces.

- Fix segfault for workloads using foreign trace without any Content
  objects (an uncommon but valid configuration).

- Fix segfault on test shutdown before warmup stage is complete.

- Fix potential reporter segfault on some truncated logs.

- Fix errors and warnings when building with GCC v4.7.

- Code cleanup and minor changes.


version 4.6.0
2012/05/07

- Add reachedPositiveGoal() PGL script call, propagate positive
  goals to servers.

  A new reachedPositiveGoal() call allows to stop phases from
  runtime watchdog scripts.  The effects of the call are the same as
  reaching any other positive goal (e.g. Phase duration or
  transaction count).  If multiple client processes are in use,
  calling reachedPositiveGoal() in one client process is not
  sufficient - the synchronized phase will not really stop until all
  clients are done with it.

  Positive goals are now propagated from clients to servers.  This
  means that when all clients reach positive goals, servers would
  also reach a "propagated" positive goal.  This was implemented to
  propagate reachedPositiveGoal() calls from clients to servers in
  the first place (servers do not run watchdog scripts) but it works
  for any positive goal.  Currently, there is no way to disable this
  behavior.  In the future, if we find out that there are cases
  where servers should resist phase changing on client-side positive
  goals, we can probably add a phase.goal.mandatory or similar flag
  to give users more control.

- Per-IP explicit port manager (--ports option) for client and
  server.  Before the change, explicit port manager had a single
  port history for all IP addresses.  This makes explicit port
  manager a poor performer when we use 1000 robots with 1000
  different IP addresses.  Now it does proper per-IP port tracking.

  This change increases Polygraph memory usage for clients and
  servers using explicit port managers.  Each explicit port manager
  for 1024:65535 range uses ~250KB of memory.  A workload with 1000
  IP addresses would require additional ~250MB of RAM.

- Make retried transactions obey request inter-arrival
  distribution and, hence, Robot::req_rate setting.

  Transactions may be retried due to several reasons like aborts,
  pipeline races, authentication.  Before the change, retried
  transactions did not obey request inter-arrival distribution.
  This resulted in "extra" traffic and higher request rate which
  feels wrong and is confusing.  Retries are now handled in the same
  way as embedded objects: retried transactions are started
  immediately but further requests are delayed to obey configured
  request rate.

- Interactive figures in HTML reports using jqPlot.

  There are two kind of figures now: static and interactive.
  Static figures use regular images as before, while newly added
  interactive figures offer advanced features:

    * resizing
    * zooming
    * line toggling

  By default, all figures are shown in static mode.  One can
  switch between static and interactive figures using the links in
  the top right corner.

  A modern browser is required for interactive figures.

  Interactive figures are implemented using jQuery, jQuery UI, and
  jqPlot Javascript libraries.  The libraries are included in Web
  Polygraph distribution and are installed into the data directory
  (/usr/local/share/polygraph by default).  Web Polygraph must be
  installed (make install) for reporter to work.

- Other fixes and improvements for figures in HTML report.  In
  particular, empty ranges warnings from gnuplot are fixed which
  makes reporter output much less verbose and more readable in some
  cases.

- Enable SSL certificate extensions when making certificates using
  OpenSSL x509.  According to x509(1ssl) manual page, without the
  -extfile option, OpenSSL x509 command will not add extensions to
  the certificate.

- Remove OpenSSL x509 -extensions option as not needed.  The
  section with certificate extensions can be specified in the
  OpenSSL configuration file instead.

- Fix client segfault on shutdown before warmup is complete.

- Fix client and server segfault when PGL string array is use()d.

- Fix reporter segfault on some truncated logs, print warning when
  log is truncated.

- Fix segfault and assert in ltrace introduced by detailed
  content-type stats changes in v4.5.0.

- Fix pgl2ips segfault when there are many hosts or agent types
  configured.

- Fix several segfaults and bugs in polymon tool.

- Add help screen for polymon (press 'h' or 'H' key).

- Fix undefined blob reference errors in reporter for one-sided phases.

- Fix build on FreeBSD 7.2.

- Remove unused --tmp_dir option for reporter and comparator.

- Code cleanup and minor changes.


version 4.5.0
2011/11/01

- Add detailed content-type stats.  Before the change, only
  aggregated size stats were collected for individual content
  types.  Now, Polygraph collects and reports aggregated stats,
  histograms, and traces for content types, including both size
  and response time stats.

- Support longer tests.  Before the change, Polygraph used 32bit
  integers for stats, OIDs, and related code.  When running very
  long and/or very high-load tests (e.g., a few days at 10Gbps
  speeds), 32bit counters could overflow resulting in weird
  errors and assertions.  Now Polygraph uses 64bit integers for
  all counters, OIDs, and related code, avoiding overflows.

  Note: Since Polygraphs prefers to keep URL lengths constant,
  the length of Polygraph URLs and dynamic domain names have
  increased.  Polygraph URL path length changed from 42 (e.g.,
  /w184f4bb3.78a56c48:00000008/t03/_00000001) to 50 (e.g.,
  /w184f4bb3.78a56c48:00000008/t03/_0000000000000001).  Dynamic
  domain name prefix length changed from 7 (wNNNNNN) to 17
  (wNNNNNNNNNNNNNNNN).

- The above changes may result in significant binary log size
  increase for some workloads.

- Increase minimum supported log version due to the above
  changes.

- Replace MINSTD (described in "Random Number Generators: Good
  Ones Are Hard To Find" by Stephen K. Park and Keith W. Miller)
  rng with the Unix rand48().  The rand48() rng allows us to
  generate 32 random bits as opposed to 31 bit from MINSTD.  This
  lets us implement 64bit rng by generating two random 32bit
  numbers.  Besides the rand48() rng demonstrates better results
  in dieharder tests.

  This change affects random variables generated by Polygraph,
  hopefully for the better. For example, we observed more precise
  distribution of protocol choices during a regression test using
  HTTP and FTP transactions.

- Send Host header in HTTP CONNECT requests.  Per RFC 2616, a
  client MUST include a Host header field in all HTTP/1.1
  request messages.  Before the change, Polygraph did not send
  Host header in CONNECT requests.

- Fix multiple bugs related to IPv6 alias creation on Linux (at
  least).  The bugs led to Polygraph assertions and corrupted
  IPv6 addresses being created.  Now, Polygraph can successfully
  create IPv6 aliases on Linux (at least).  Currently, in
  contrast with IPv4, Polygraph does not delete old IPv6 aliases
  before creating new ones.

- Fix IPv6 alias support in the polygraph-aka tool.  Now it can
  successfully create IPv6 aliases (at least on Linux), e.g.:
  polygraph-aka lo '[::3]'.

- Work around a bug on FreeBSD when many IPv6 aliases are
  created on a real network interface.  Polygraph tried to use
  the aliases immediately after creating them and apparently
  before they were fully configured.  The problem affects at
  least FreeBSD 7.2.

- Fix build with OpenSSL libraries with disabled SSLv2 protocol.
  In particular, this fixes build on Debian Weezy.  Workloads
  using SSLv2 will be rejected if Polygraph was built without
  SSLv2 support.

- Fix persistent working set ID reporting when loading the
  stored set.  Before the change, a new ID was generated each
  time the set was loaded.

- Cleanup copyright preamble to make Debian folks happier: add
  copyright statements where missing, remove copyright from
  generated config.h file, update copyright years, replace "(C)"
  with "Copyright".

- Remove files specific to the Windows build which has not been
  supported for a while.

- Code cleanup and minor changes.


version 4.4.0
2011/03/28

- Content-driven recurrence support: ClientBehavior.recurrence
  PGL field added. Similar to other ClientBehavior properties,
  it allows setting Robot recurrence for a particular Content
  type.  For example, a Robot can now be configured to revisit
  images more often than movies. The feature is documented at
  http://www.web-polygraph.org/docs/userman/content-driven-robots.html.

  The object ID (oid) generation and management algorithms have
  been changed to support content-driven robot recurrence.
  Polygraph clients now have to synchronize a larger number of
  smaller distributed oid sets (a.k.a. "worlds"), especially for
  workloads with a large number of distinct content types.

  As a result of these changes, BHR discrimination has fewer
  side-effects now. Before these changes, the BHR discrimination
  algorithm affected content type selection. This could make
  actual content type distribution and recurrence ratio
  different from the configured ones, especially for workloads
  with embedded objects.  After these changes, the traffic
  should better match the PGL configuration.

  No significant changes in traffic patterns are expected for
  high-performance workloads not using BHR discrimination.

- Added PGL system() function. The function accepts a single PGL
  string as an argument, treats that argument as a shell
  command, executes the command, and returns the standard output
  of the command as a PGL string value.

  Outside Phase scripts, the system() function is equivalent to
  a back quoted `command` and is executed only once at startup.
  Inside Phase scripts, the system() function is executed every
  time the script is run, unlike back quotes which are executed
  only once at startup, even in a Phase script context

- Taught PGL int() and float() functions to convert PGL strings
  to integer and floating-point numbers. Implicit conversion
  from strings to numbers are still not allowed.

- Fixed assertion when a container PGL Content type uses an
  embedded PGL Content that was not configured yet.

- Fixed layout of tables printed on the console (e.g. "Server
  content distributions" and "Phases").

- Code cleanup.


version 4.3.2
2011/04/05

- Fixed assertion when a container PGL Content type uses an
  embedded PGL Content that was not configured yet.

- Fix build with OpenSSL libraries with disabled SSLv2 protocol.
  In particular, this fixes build on Debian Weezy. Workloads using
  SSLv2 will be rejected if Polygraph was built without SSLv2
  support.

- Fixed layout of tables printed on the console (e.g. "Server
  content distributions" and "Phases").

- Fix persistent working set ID reporting when loading the stored
  set. Before the change, a new ID was generated each time the set
  was loaded.

- Cleanup copyright preamble to make Debian folks happier: add
  copyright where missing, remove copyright from generated config.h
  file, update copyright years, replace "(C)" with "Copyright".

- Remove files specific to Windows build which has not been
  supported for a while.


version 4.3.1
2011/03/03

- Better support for trace replay: Ignore Robot.origins field
  for PGL Robots with foreign-only interest. Before the change,
  non-empty Robot.origins field was required, even if it was
  unused because the Robot has no interest other than replaying
  the foreign trace.

- Better support for trace replay: Do not "warm up" Robots with
  foreign-only interest. Before the change, many workloads
  containing trace-replaying Robots could get stuck in the first
  phase due to an infinite warmup. Now, foreign-only Robots do
  not affect the warmup, and the first phase ends as expected.

- Print the corresponding workload file line and number for many
  PGL-related warnings and errors.

- Fixed client crash on exit when Robot.accept_content_encodings
  PGL field is set.

- Fixed generation of lifecycle-related entity parameters when
  the same ObjLifeCycle object is used multiple times in the
  workload. The bug resulted in unexpected entity-header (e.g.,
  Last-Modified-Time and Expires) changes when the same URL was
  revisited.

- Fix statistics recording for aborted transactions. Before the
  change, non-basic (e.g. POST) aborted transactions were
  recorded in the wrong category (e.g. post). Now, all aborted
  transactions are recorded in the aborted category.

- OpenSSL 1.0 support (LP:690599).

- Fixed epoll(2)-related bug which could result in "Socket not
  connected" and similar errors.

- Fixed select(2) support in SSL-related workloads.

- Code cleanup.


version 4.3.0
2010/12/10

- Content-driven Robots support: The user may configure Robot
  behavior based on Content. Real HTTP client behavior often
  depends on web site and its content.  Content-driven Robots
  help simulate those dependencies.

  All for-Robot settings in PGL Content objects are grouped
  under the new Content::client_behavior field. A new PGL
  ClientBehavior type is added. Assigning PGL Robot to
  ClientBehavior and vice versa is supported. Once Server and
  Content are selected, Content::client_behavior settings, if
  any, overwrite the corresponding Robot fields.

  For now, the following three Robot behavior properties can be
  specified on per-Content basis: req_types, req_methods, and
  ranges.

- Considerably improved the randomness of distribution values
  tied to URLs, such as response sizes. The old distributions
  could have too many similar values, with too few extreme
  values, especially when non-unique worlds (--unique_world no)
  were used with multiple PGL Servers and table-based
  distributions.

- Linked object blobs from traffic stream tables in report.

- Fixed poll(2)-related bug which could result in "Socket not
  connected" or similar errors on platforms without epoll(2)
  support such as Mac OS X.

- Multiple world support for distr_test tool: The world_count
  option is intended to simulate URL-based value generation in
  workloads with multiple PGL Servers, each Server being a "oid
  world" for the Robot. By default, world_count is 1, and all
  oids are generated from a single world. If world_count is
  greater than 1, distr_test generates oids from multiple
  worlds. The number of oids generated from each world is
  (trials count / worlds count).

- Minor fixes and code cleanup.


version 4.2.2
2010/11/05

- Added custom stats: The user may configure which transactions
  are added to custom stats based on HTTP status code.
  Configuration is done with Agent.custom_stats_scope PGL field:

    custom_stats_scope = ["all", "-2xx", "+30x", "+206"];

  If a transaction finishes before getting a reply, or there is
  no HTTP status code for another reason, the transaction is not
  included in the custom stats.

  The following custom stats are collected: custom.rep,
  custom.live.rep, custom.projected.rep. Custom stats are
  accessible from PGL phase scripts.

- Fixed PGL TblDistr to produce the same results for the same
  seed. For example, if a table distribution is used for
  response body sizes, the response size would stay the same
  when the same URL is visited multiple times.

- Fixed several build and startup problems on Mac OS X.

- Fixed a DummyNet-related build problem on FreeBSD 8.1.

- Fixed IPv6 address parsing in command line arguments.

- Fixed segfault when parsing a PGL array or list with a
  malformed item.

- Allow IPv6 addresses in PGL to start with '[:'.


version 4.2.1
2010/10/14

- Transaction lifetime support: Allow the user to limit the
  lifetime of client and server transactions via the new PGL
  Agent::xact_lifetime field. A transaction aborts when its
  configured lifetime expires. Aborted transactions are treated
  as errors on client and server sides of the test, for now.

  Client transaction lifetime includes both connection slot
  waiting time (if any; see Robot::open_conn_lmt) and regular
  execution time. Server transaction lifetime includes both think
  time (if any; see Agent::xact_think) and regular execution time.


version 4.2.0
2010/10/08

- Allow PGL scripts to monitor in-flight or "live" transactions
  so that they can adjust load even when many transactions get
  stuck or slow down and do not immediately contribute to regular
  postmortem stats.  Measure how long live transactions have
  been running (live.rep.rptm) and how many response bytes they
  have read (live.rep.size). Make these new stats available to
  PGL scripts via the regular stats interfaces
  (currentSample().live.* and currentPhase().live.*).

- Added projected.rep.* statistics that combines live and
  finished transaction stats. Available to PGL scripts only.

- Treat an HTTP CONNECT response as the end of the transaction.
  Collect and report stats dedicated to these new CONNECT-only
  transactions. These CONNECT transactions are often rather
  different from the in-tunnel transactions that follow.
  Isolating them also prevents CONNECT overheads from polluting
  the first in-tunnel transaction stats.


version 4.1.2
2010/11/06

- Fixed PGL TblDistr to produce the same results for the same
  seed. For example, if a table distribution is used for
  response body sizes, the response size would stay the same
  when the same URL is visited multiple times.

- Fixed several build and startup problems on Mac OS X.

- Fixed a DummyNet-related build problem on FreeBSD 8.1.

- Fixed IPv6 address parsing in command line arguments.

- Fixed segfault when parsing a PGL array or list with a
  malformed item.

- Allow IPv6 addresses in PGL to start with '[:'.


version 4.1.1
2010/10/07

- Add dump command to the cdb tool, which stores all verbatim and
  link-only objects into individual files. Cdb dump accepts an
  optional --as "path/prefix${name}.suffix " parameter. Default
  --as value is "./cdb${name}". ${name} macros are substituted with
  1,2,3,4... integers.

- Cdb interface has changed. Commands (add, dump, show) are passed
  as options with database argument, i.e. cdb --show test.cdb.

- Limit PGL load and population factors value to [0%, 100%] range.
  Print error and exit if begin or end factor value is greater than
  100%. If a script changes factor to a negative or greater than
  100% value, print warning and set the factor to 0%/100% instead.

- Set Recursion Desired (RD) flag for outgoing DNS queries because
  some modern resolvers do not accept queries without that flag
  and because we do not recursively resolve ourselves.

- Skip already configured network interface aliases when creating
  new ones if delete_old_addrs option is false.

- Do not send Content-MD5 header with HTTP 206 (Partial Content)
  responses. This fixes segfault and is in line with HTTPbis.
  See http://trac.tools.ietf.org/wg/httpbis/trac/ticket/178

- Fix assertion during network interface alias creation.

- Fix errPersistButNoCLen error on client-side when multi-ranges
  and persistent connections are enabled. Content-Length is not
  required if message uses the media type "multipart/byteranges".

- Fix LP:644813: SSL issues with DNS and embedded objects.

- Fix address space size check for SpreadAs.

- Fix multiple alias range support in the aka tool.

- Fix compilation of the msl_test tool on Linux.

- Make out-of-memory handler more robust.

- Minor fixes and code cleanup.


version 4.1.0
2010/05/13

- Support SOCKS5 proxies for HTTP, HTTPS, and passive FTP
  traffic (socks_proxies and socks_prob PGL Robot fields).  No
  support for Active FTP data connections yet.  "None" and basic
  "username/password" SOCKS authentication methods are
  supported. Chaining SOCKS and HTTP proxies is supported (the
  socks_chaining_prob PGL Robot field).

- Extend the ipsToNames() PGL function to support a domain name
  generation template with ${dashed_ip} and ${port} macros. This
  change allows more flexibility in naming a large number of
  server domains.

- Add a dynamize() PGL function that converts an array of static
  domain names to dynamic names (using the supplied renewal
  percentage), similar to what the dynamicName() function does
  to one static name. This change allows creation of a large
  number of servers, each with a unique dynamic domain name.

- Do not send "100 Continue" control response if we got the
  entire request body already. This fix prevents POST requests
  sent without waiting for 100 Continue response from getting
  stuck because the client sent everything and cannot continue.

- Fix server freeze when "Expect: 100-continue" request headers
  and body (partial or complete) is received in a single read(2)
  call.

- Fix assertion when an HTTP client aborts transaction.

- Fix abort position calculation on the client side. The abort
  size was set bigger than the request size, and client aborted
  after the request was sent, during response reading.


version 4.0.11
2010/11/06

- Limit PGL load and population factors value to [0%, 100%] range.
  Print error and exit if begin or end factor value is greater than
  100%. If a script changes factor to a negative or greater than
  100% value, print warning and set the factor to 0%/100% instead.

- Fixed PGL TblDistr to produce the same results for the same
  seed. For example, if a table distribution is used for
  response body sizes, the response size would stay the same
  when the same URL is visited multiple times.

- Fixed several build and startup problems on Mac OS X.

- Fixed a DummyNet-related build problem on FreeBSD 8.1.

- Skip already configured network interface aliases when creating
  new ones if delete_old_addrs option is false.

- Do not send Content-MD5 header with HTTP 206 (Partial Content)
  responses. This fixes segfault and is in line with HTTPbis.
  See http://trac.tools.ietf.org/wg/httpbis/trac/ticket/178

- Fix assertion during network interface alias creation.

- Fix errPersistButNoCLen error on client-side when multi-ranges
  and persistent connections are enabled. Content-Length is not
  required if message uses the media type "multipart/byteranges".

- Fix assertion when an HTTP client aborts transaction.

- Fix abort position calculation on the client side. The abort
  size was set bigger than the request size, and client aborted
  after the request was sent, during response reading.

- Fix LP:644813: SSL issues with DNS and embedded objects.

- Fix address space size check for SpreadAs.

- Fixed IPv6 address parsing in command line arguments.

- Fixed segfault when parsing a PGL array or list with a
  malformed item.

- Allow IPv6 addresses in PGL to start with '[:'.

- Fix multiple alias range support in the aka tool.

- Fix compilation of the msl_test tool on Linux.

- Make out-of-memory handler more robust.

- Minor fixes.


version 4.0.10
2010/04/13

- Ignore ssl_wraps for FTP servers because we do not really
  support FTPS yet.

- Servers with ssl_wraps no longer verify SSL peer certificates
  because verification causes an optional peer certificate
  request, which some proxies do not ignore but abandon their
  man-in-the-middle decryption instead.

- In PGL arrays using well-known strings (e.g., protocol names),
  reject unknown names that share a common prefix with the known
  ones.

- Fixed spreading of array probabilities that do not add up to
  100%. Only the first such array in the workload had its
  probabilities adjusted.

- Raised verbosity level of FYI and warning messages from 0 to 1
  to minimize zero-level output.

- Fixed segfault in ltrace that rendered the tool unusable.

- Fixed logging of very long messages.

- Fixed memory leak in pgl2ips.

- Minor man pages and spelling fixes.


version 4.0.9
2010/02/14

- Used newer autotools: automake v1.10.2 to v1.11 and autoconf
  v2.63 to 2.64.

- Added polygraph(7) and individual man pages for each binary.

- Added cmp-lx.pl --precision=percent option to ignore relative
  measurement differences below the specified percentage.  The
  default is 10 percent. Zero percent shows all, including
  identical, measurements. Other fixes for cmp-lx.pl.

- Added header_size/body_size field at the end of "--dump sum"
  log line. This change may be reverted in future releases.

- Added rng_seed option for distr-test tool.

- Allow apostrophe and a few other non-alphanumerical symbols in
  PGL comments.

- Detect the lack of SSL support and quit with an error for SSL
  workloads.

- Fixed HTTP authentication for SSL connections.

- Do not assert if an agent address lacks a netmask.

- Delete old IP aliases by name, not by index, to avoid having
  lo:1 without lo:0. May need more work.

- Warn about duplicate network interface addresses instead of
  asserting that there are none.

- Fixed a segfault when retrieving IPv6 addresses from a network
  interface.

- Removed tcp2xmld as unused.


version 4.0.8
2009/10/01

- New addressing scheme called Spread. It is possibly the
  simplest addressing scheme that distributes the load evenly
  across all hosts, unlike the PolyMix-4 addressing scheme that
  does not add a host until existing hosts are 100% utilized.

- Allow the user to specify alias addresses explicitly,
  overwriting the "concatenate PGL agent addresses" default.
  This allows defining several Server kinds (e.g. plain and SSL)
  and then spreading their aliases across all hosts.

- Add size and response time phase stats for all HTTP response
  status codes received by polyclt and sent by polysrv. The
  measurements are collected for all transactions, including
  failed and non-basic ones. See the new "HTTP reply status..."
  tables in the report.

- Add tools/cmp-lx.pl script to compare two tests and print
  important differences. Test logs must be preprocessed with lx
  first.

- Print warning if Content-MD5 header is present but malformed.

- Polished generated reports: Sort a few tables, number and link
  report generation notes, stretched histogram plots, make
  one-page summary fit.

- Comply with Filesystem Hierarchy Standard (FHS) and Debian
  Policy requirements:
    * set default installation prefix to /usr/local
    * install workloads to share/polygraph/workloads
    * rename polyclt/polysrv to client/server
    * replace '_' with '-' in binaries name (pop_test to pop-test)
    * add polygraph- prefix to all binaries during installation
    * strip .pl prefix from Perl scripts during installation

- Fix "content type mismatch" regression error with reporter log
  processing.

- Fix negative open connection level and ttl stats.

- Fix reporter crash when it is called with the --phases option
  and the phase does not exist. Warn if a phase does not exist.

- Fixed parsing of ":sup" ranges in table distributions.

- Fix "inconsistent computation of unseen_objects" report error.

- Fix "reference to an undefined blob
  'object.all_proxy_validations...'" reporter error.

- Quit nicely when the reporter runs out of memory.

- Fix (potential) double delete errors.

- Made more modern compilers happier.

- Remove gnuplot build dependency.

- Do not link with libnsl on platforms where libnsl is not used.


version 4.0.7
2009/07/15

- Support origin server authentication for Robots. Foreign
  origin servers are supported as well.

  Unlike real browsers, Robots do not support or remember nested
  paths. For example, if the /foo/bar/ path got authenticated,
  the same Robot would go through the entire authentication for
  /foo/bar/baz/ even though a real browser would probably try to
  reuse the first (higher-level directory) authentication
  information instead.

- Support cookie-based Robot authentication, including that with
  foreign URLs. Robots now have their own private cookie storage
  and queue. Cookie Max-Age parameter is parsed and honored.
  Stale cookies are not sent.
  
  Cookie path and domain parameters are still ignored as if they
  were not sent.

- Support active FTP mode (i.e., FTP PORT command). Configured
  using Robot's passive_ftp field. The default is 100% passive.

- Added pgl2ips tool that takes a PGL workload and prints agent
  IP addresses that a test would use.

- Added modulo operator support for PGL integers. Useful for
  flipping coins in PGL Phase scripts.

- Users no longer need to patch system headers to get more file
  descriptors on Linux: Polygraph now ignores FD_SETSIZE limit
  when using poll(2) or epoll(2), which is the default on most
  platforms.

- Exit gracefully on SIGTERM (SIGINT as supported earlier).
  Killall sends SIGTERM by default and we were getting truncated
  console logs because of that.

- Better HTTP cookies support: honor expires/discard options and
  support cookie updates. Do not send cookies that do not fit.

- Better handling of and error reporting in HTTP 401, 403, and
  407 corner cases.

- Polished FTP error reporting.

- Limit SSL error reporting frequency to minimize noise during
  high-performance tests with many SSL errors. Polished
  reporting.

- Better reporting of tests with different client- and
  server-side PGL workloads.

- Better reporting of foreign trace configuration errors.

- Removed some expensive mallocs.

- Removed unseen object blobs and unknown (zero and N/A) rows in
  stream and object tables from the HTML report.

- Allow tabs where were spaces allowed in PGL.

- Fixed memory leaks.

- Fix alias creation bug when workload contains both generated
  and manually configured aliases. Some aliases were created on
  many hosts while others were not created on any hosts.

- Fixed misleading 'unknown log file format' error when the
  named binary log file is not found by lx, ltrace, or reporter.

- Fixed error handling code that was ignoring certain fatal
  errors.

- Made more modern compilers happier.

- Ignore zero-valued Content-Length in GET instead of
  terminating the server transaction with the "unexpected
  Content-Length header" error. Some proxies add that header to
  some GET requests.

- Fixed select(2) support (unused on most platforms by default).

- Report that content types differ and exit instead of asserting
  when a report is generated using logs with mismatched content
  types.

- Do not send body in HTTP HEAD response. This fixes a bug that
  resulted in "malformed HTTP request or response line" errors
  on the client side when Range requests were used.

- Work around crashes in OpenSSL versions older than 0.9.8c:
  http://objectmix.com/apache/674160-apache-start-segmentation-
  fault-emlink-too-many-links.html


version 4.0.6
2009/04/20

- Added support for FTP STOR to robots and servers, triggered by
  selecting the new "Upload" request type in PGL
  Robot::req_types.
  
  STOR transactions use PGL content configuration, including cdb
  support, just like PUT transactions already do.

  Robot::put_contents PGL field is replaced with
  Robot::upload_contents. The old put_contents field is still
  supported, with a deprecated warning.

  Request method selection code adjusted to select PUT/STOR
  method for HTTP/FTP transactions if "Upload" request type is
  chosen.

- When parsing and generating URLs and related addresses, handle
  default port with respect to the protocol scheme (80 for HTTP,
  443 for HTTPS, 21 for FTP).

- Make the test quit when phase error goal is reached.  One of
  the goals here is to prevent automated tests from getting
  stuck forever.

- Added a PGL Phase.primary boolean field. If any of the phases
  have that field set, those phases and only those phases should
  be used for the executive summary and the baseline report. The
  new field is logged when phase stats are logged. This change
  resulted in the log version increase to v17.

- Skip phases without stats when trying to guess which phases
  should be included in the baseline report and the executive
  summary.

- Added initial set of 13 workloads for regression testing to
  workloads/regression/. These workloads need more work.

- Report when phase positive/negative goal is reached for the
  first time.

- When reporting stat phase progress say "waiting for WSS to
  freeze" only when the phase itself is actually locked, waiting
  for WSS to freeze. We used to report when polyclt was waiting,
  which was confusing in a phase progress report context.

- Report more information about locked phases that may continue
  to run after reaching their explicit goal. This should help
  diagnose remaining problems with phases getting stuck when a
  test generates many errors.

- Report IP address counts in addition to dumping (potentially
  huge) address arrays when local and PGL addresses do not
  match. Helps to identify addressing problems quicker.

- Log details about server warmup plan start and completion.

- Fixed nil pointer derefence bug when dealing with rare SSL
  tunnel establishment failures. User-visible bug effects are
  unknown but could include polyclt crashes.

- Fixed epoll support in the presence of some connection errors.
  The bug resulted in some errors not reported to the user and
  an infinite loop.

- Fixed agent alias allocation bug that resulted in identical IP
  aliases created on different hosts. The bug was exposed by
  workloads that randomized generated address order using PGL
  select() or slicing assignment.

- Fixed stats collection for authenticated HTTP transactions.
  User-visible effects could include runtime assertions but the
  exact effects are unknown.

- Deleted a questionable assertion being hit by users (during an
  error-rich test) when SSL tunneled transactions are in use.
  The exact cause of the assertion is still unknown and could be
  already removed by other changes.


version 4.0.5
2009/02/05

- Warn about "unusable" objects as arguments to use(). Skip such
  objects.
  
  Skipping unusable objects simplifies workloads where some
  agents or address maps become unusable if some workload
  parameter leaves them without any addresses. A common use case
  is a workload where agent addresses are selected using slicing
  assignments or select() function calls, with "ratio of
  such-and-such agents" as a configurable parameter.

- Fixed SSL connection level accounting. The level was not 
  decremented properly, resulting in artificially high number of
  open SSL connections being reported.

- Fixed oid management to avoid an assertion when dumping foreign
  request URLs and to dump more oid details.

- Do not blab about configured SSL proxies and/or servers if
  there are none.



version 4.0.4
2009/02/04

- Added Robot.http_proxies and Robot.ftp_proxies PGL fields to
  support HTTP proxies dedicated to ftp:// transactions.
  Specifying an empty ftp_proxies array, disables proxying of
  those transactions.  The Robot.proxies field is now
  deprecated.  The overall logic is similar to how browsers can
  be configured to use different proxies for different origin
  server protocols. Polygraph still supports HTTP proxies only.

- Added setAddrPort(addresses, newPort) PGL function call,
  returning original addresses but with each port is set to
  newPort. The function is useful for assigning a
  protocol-specific port to server addresses, when those
  addresses were selected or sliced from a larger address array
  used for many protocols.

- Support https:// URLs in traces.

- Support ${url_number} macro in URL traces. The substitution
  value is a "URL position in the trace" number that increases
  as the trace wraps. Using this macro, it is possible to create
  a virtually endless sequence of unique URLs using very short
  traces, which is useful for testing using specific URL
  patterns.

- Significantly decreased startup times for workloads with thousands
  of agent addresses.

- Fixed "FtpCltXact.cc:195: assertion failed: 'false'" on data
  connect errors.

- Better handle various FTP RETR-related command sequences and
  server races.

- Do not refuse to create agent aliases if some but not all
  agent addresses lack network interface names. Instead,
  ignore/skip nameless addresses in the alias:host mapping
  algorithm.
  
  This change helps when a workload mixes agents for which
  Polygraph should create aliases dynamically with agents for
  which the addresses are created before the test.

- Complain about the lack of the root certificate once. When the
  number of SslWraps is large, complaining for each takes too
  much time and space, while there is little new information
  with each new complaint.
  
- Do not warn if using non-ALL cipher for SslWrap. The default
  may be ALL:HIGH now and warning for each cipher takes too much
  time and space.


version 4.0.3
2009/01/21

- Support ${target_ip} macro in PGL-configured robot
  credentials. If found, the macro is replaced with the IP
  address of the target (i.e., true origin) server. This is
  especially useful for reverse FTP proxies that distinguish the
  true origin server by FTP user credentials.

- Support empty robot passwords via "username:" credentials
  pattern.


version 4.0.2
2009/01/19

- Added initial support for PWD command. The directory we return
  always ends with a slash ("/") for now.
  
- Revised FTP RETR logic to make 1xx responses required and to
  distinguish FTP 150 "Opening data connection" from the newly
  added "FTP 125 "Data connection already open; transfer
  starting" response.
  
- Added initial support for user-configurable FTP origin server
  authentication. If no credentials are configured, the FTP
  transaction will use anonymous:anonymous@ credentials. For
  now, credentials are always supplied (i.e., the FTP
  transaction always tries to login to the server).
  
- Use "227 Entering Passive Mode (,,,,)" format for PASV
  responses. Some FTP clients expect the parens because that is
  what FTP RFC uses, probably informally.

- Be flexible when parsing FTP PASV response: search for the
  first digit as the start of a,b,c,d,p1,p2 sequence instead of
  assuming a fixed response format.

- Fixed address map support: Agent protocol is determined by the
  target origin server and not by the visible server. Visible
  server may have no Agent configuration at all (e.g., if an
  address map is used in reverse proxy configurations).

- Avoid polysrv assertions when a foreign URL or its size is
  requested without a subsequent request for a Polygraph URL.

- Polished stats maintenance for FTP data connection.  Needs
  more work.

- Made libtool 2.2.4 happier.


version 4.0.1
2009/01/14

- Pause FTP client transactions before writing a RETR command if
  the data connection has not succeeded yet.

- Pause HTTP 100-Continue client writing when we are done
  writing HTTP request headers and are waiting for a 100
  Continue response from the server. Resume writing, if needed,
  when we get a response. Old code would waste CPU cycles and
  occasionally assert when checking whether it is possible to
  write the request body while we were receiving a response. May
  need more work.

- FTP clients may send repeated PASV commands, especially if
  they try unsupported commands. If a PASV command is received
  when we are already listening or even accepted a data
  connection (but have not sent any data!), we simply close the
  data channel and open another one, assuming the client
  considers the old data channel unusable.

- Treat 150 "Data connection opened" response as optional. We
  may not receive it if the server sent all data by the time it
  could generate a RETR response. Or, at least, that is what
  happens with Polygraph FTP server.

- Wait for the data connection if the FTP server got RETR before
  it accepted the data connection: The client sending RETR
  cannot know whether its data connection was already accepted
  by the server. TODO: We need a timeout for this wait.

- Finish with errFtpNoDataXfer ("FTP exchange terminated w/o
  data transfer") error when the FTP client did not RETR
  anything.  This prevents feeding an unclassified (no oid
  even!) but successful transaction to stats collection.

- Fixed logging of request body content type meta-information
  for content types not used as server response content types.
  Partial meta-information led to core dumps during log
  extraction and analysis (also fixed).

- Be more forgiving when encountering an unclassified
  transaction and when encountering a compound transaction
  without an authentication scheme. Both are bugs. We have not
  observed the former, but the latter does happen in some NTLM
  tests (and still needs to be fixed).

- Report FTP port binding errors.

- Report synchronous connect(2) errors for the data channel.
  May need more work handling the errors.
  
- Check for asynchronous connect(2) errors for the data channel
  and terminate the transaction when they happen.
  
- Made GCC v3.4.6 and v4.3.2 happier.


version 4.0.0
2008/11/25

- Added initial FTP client and server support. Robots use FTP
  for talking directly to an FTP server.  When a transaction
  ends at an FTP server via an HTTP proxy, robots use HTTP and
  ftp:// Request-URLs, as most real web clients would. Only
  passive FTP downloads are supported.

  Added a "protocol" field to the PGL Server type to specify
  the distribution of protocols. "HTTP" and "FTP" strings are
  accepted. Multiple protocols make sense if Server specifies
  multiple simulated servers using the addresses field. 

  Many FTP aspects require more work, such as support for more
  FTP commands and responses, FTP uploads, configurable FTP user
  authentication, better correlation with various HTTP-centric
  workload parameters, and a clear definition of an FTP
  transaction boundary for statistics collection.

  The code changes to support FTP were significant and
  widespread.


version 3.6.1
2008/11/25

- Removed unnecessary delays when processing log comments. The
  entire process (or even host) buffers and inodes were flushed
  with every console log message. The bug increased the time to
  process a single log comment significantly. The sync(2) delays
  become a noticeable problem when PGL watchdogs print a lot of
  custom statistics while Polygraph is working at the bench
  performance limit. The same probably happens when many errors
  are reported.

- Fixed (enabled) statistics collection for socket write(2)
  calls.

- Fixed assert failure when repeating foreign URLs from a trace.


version 3.6.0
2008/09/22

- Fixed URL selection algorithm: A change in URL selection code
  accidentally exposed an ancient bug that led to incorrect
  offered hit ratios. The bug remained unnoticed because the
  effect was negligible in most standard workloads. However, a
  significant difference in offered hit ratios can be observed
  in some custom workloads that used large portion of private
  URLs.

  Removed support for private URL worlds. Adding dynamic DNS
  feature (Polygraph v3.4.0) broke this support, offering false
  hits among private URLs. Hopefully, removing private URL
  worlds has no significant effect on standard workloads as this
  feature should only affect URL paths, which most DUTs treat as
  opaque.
  
  We may resurrect support for private URL worlds. The problem
  here is how to make private URLs use the same set of dynamic
  domain names as public URLs use. Since new names in public and
  private slices usually appear at a different speed, one
  category of URLs may use domain names that the other category
  stopped using long time ago.

- Added authentication scheme stats. Response time and size
  stats are collected for each auth scheme separately. HTML
  report now includes "all auth-ing" (all authenticating) and
  "all auth-ed" (all authenticated) categories for individual
  HTTP transactions.  There is also "all auth" stats combining
  all categories.  The following log objects introduced:
  auth.none auth.ing.basic auth.ing.ntlm auth.ing.negotiate
  auth.ed.basic auth.ed.ntlm auth.ed.negotiate auth.none.

- Added recurrence ratio stats. Put unique URL count and
  recurrence ratio to the executive summary table in the
  reporter.  Added url.unique.count and url.recurrence.ratio log
  objects.

- Report various stats for compound transactions such as
  authentication transactions that may require several
  individual transactions before the final response is received.

- Added SslWrap.ssl_config_file PGL field to set config file
  path for SSL certificate generation. The old 'myssl.conf'
  default is honored but deprecated.

- Added SSL stats reporting. New SSL Load blob, similar to the
  old [HTTP] Load blob.  Added SSL hits and misses to stream and
  object tables. Made SSL stats available in scripts. The
  following objects added:
      ssl.xact.* - successful SSL transactions HR and levels
      ssl.conn.* - open SSL connections level stats
      ssl.err_xact.count - failed SSL transactions count

- Added --hushed_error_tout option to polysrv and polyclt to
  configure error reporting frequency. This reduced log sizes
  for long tests designed to produce many errors.

- Added stats for HTTP transactions exchanged using a CONNECT
  tunnel.

- Polished generated HTML reports.

- Fixed CONNECT regression bug introduced by NTLM authentication
  changes.

- Fixed reporter initialization bug causing occasional coredumps
  and bogus results.

- Fixed occasional parsing errors of chunked encoded message
  bodies.

- Fixed assertion failure when handling an errors response to an
  "Expect: 100-Continue" request.

- Updated running-out-of-RAM handling code that has not been
  tested for a while. This should remove a PolyApp.cc warning
  when Polygraph process starts.


version 3.5.0
2008/06/22

- Recognized authentication errors as transaction errors. It is
  now possible to write workloads that stop the test or decrease
  the load when there are too many authentication errors (using
  PGL phase goals or watchdogs).

- Added epoll(2) level-triggered interface support. Epoll is now
  default on systems that support it (e.g., Linux). It should be
  faster than poll(2), the old default. Use the --file_scan
  command-line option to force poll if epoll gives you troubles.

- Fix gcc 4.3 warnings and errors.

- Removed deprecated acconfig.h that was causing ./configure
  warnings. Removed autotools-generated files from VCS control.


version 3.4.2
2008/05/27

- Fixed NTLM authentication of CONNECT requests.


version 3.4.1
2008/05/22

- Fixed 407 Authentication Required response handling: A v3.3.0
  regression bug resulted in "misdirected" errors for
  authenticated requests.


version 3.4.0
2008/05/16

- Support dynamic domain name generation using masks like
  '*.example.com:80'. The speed of new name generation is
  configurable and proportional to the miss rate. The number of
  names is frozen if the working set size is. Details at
  http://www.web-polygraph.org/test/docs/userman/dns.html
  
- Added proxy authentication support for CONNECT requests.

- Fixed CONNECT requests support (v3.3 regression bugs).


version 3.3.1
2008/04/29

- Report gzip-specific headers correctly for range responses.

- Fix assert failures when using gzip encoding or range requests
  with bodies from a content database. Mixing range requests,
  gzip-compressed content, and cdbs now works correctly.

- Fixed v3.1 regression bug: Uninitialized theBodyParser member
  led to occasional polyclt segfaults.


version 3.3.0
2008/04/17

- Support configurable POST/PUT content. Request body content
  configuration is very similar to how response content is
  configured. Content databases (cdbs) are supported. Actual
  request content type properties are measured runtime and
  reported by the reporter.

  Standard workloads have been updated. Custom workloads must be
  updated if you are using POST or PUT request types. Use
  cntSimpleRequest content defined in contents.pg to mimic old
  behavior.

  Details and configuration examples at
  http://www.web-polygraph.org/docs/userman/req_bodies.html

- Detect proxy validation requests (i.e., transactions where the
  proxy converts a regular GET request into an If-Modified-Since
  request, most likely because it has the content cached but
  considers it stale).  Collect stats for useful and useless
  proxy validation requests. Useless validation requests are
  those resulting in a 304 Not Modified response (i.e., the
  cached content is still fresh).

  Added "Validation effectiveness" table to generated reports.
  This helps to analyze the effectiveness of proxy validations.

  Added "Cheap proxy validation hit ratio" table to the
  generated reports. The reported hit ratios are calculated as
  if useless proxy validation requests are so cheap that they
  should not be counted as server accesses for the purpose of
  hit ratio calculation.

- Added basic statistics for messages without bodies and
  messages with unknown body content types. Requests with body
  have an "unknown" content type on server side. Messages with a
  non 2xx status and a body also have an "unknown" content type.

- Fixed report generation bug leading to occasional garbage in
  the report text.


version 3.2.1
2008/03/25

- Polished stat object names related to Range request
  generation.

- Fix segfault when server replies to HEAD request and attempts
  to pour body.

- Fixed Proxy-Authenticate scheme parsing bug that was causing
  random segfaults during authentication tests (Qiao Yang at
  IronPort)


version 3.2.0
2008/03/19

- Added support for generation of Range requests and responses,
  including configurable single- and multi-range Range requests,
  single Content-Range responses, and multipart/byterange 
  responses.

- Fixed "undefined assert()" compilation error on Ubuntu Gutsy.


version 3.1.5
2008/03/13

- Initial and mostly untested support for NTLM/GSSAPI proxy
  authentication. We need to find a proxy that supports
  NTLM/GSSAPI to test this feature.

- Added support for recycling or sharing SSL certificates that
  have identical generation parameters. The support is enabled
  by setting PGL SslWrap::sharing_group to a non-empty string.
  The certificates within the same group will be shared if their
  openssl generation commands are the same.
  
  Sharing provides significant speedup in Polygraph start times
  when hundreds of servers require certificate generation.
  
- Some Linux kernels have gettimeofday bugs that cause time
  jumps of approximately 72 minutes, especially on SMP systems.
  We saw it on an 8-CPU box running 2.6.18-8.el5. For 2002
  discussion, start at
  http://www.kernel-traffic.org/kernel-traffic/kt20020708_174.html#1
  
  We now try to ignore individual jumps exceeding 60 minutes. If
  the time did change, the change will be honored during the
  second gettimeofday() call.

- Make NTLM code compile when SSL is disabled. Polygraph will
  assert if NTLM is used without SSL support because it needs
  SSL code for NTLM.

- Removed extra terminating CRLF after CONNECT headers.


version 3.1.4
2007/11/12

- Use the first (top) supported Proxy-Authenticate method
  instead of the last one.

- Use the last '@' in NTLM credentials to separate the host name
  from the user name because the user name itself may contain '@'.

- Robots were not parsing some CONNECT responses correctly.

- Send full Request URL only if we are talking directly to a
  proxy. Sending an HTTP request inside the CONNECT transaction
  is not talking directly to a proxy.

- Do not try to parse content as markup if we are not going to
  request embedded objects due to non-positive embed_recur.


version 3.1.3
2007/06/13
- Tolerate binary log "level" statistics with negative mean level
  data, which may be caused by level sum overflow.

- Fixed --log and --sample_log command-line option descriptions.
  (Mikhail Fedotov).

- Removed no longer used or maintained nmake-specific Makefiles.


version 3.1.1
2007/03/07
- Fixed the 'theInOff <= theCapacity' assertion.


version 3.1.0
2007/03/05
- Support client-side NTLM authentication with proxies.

- Fixed a bug resulting in a stuck client transaction when the
  HTTP request did not fit into a single I/O.

- Make GCC4 on Ubuntu6 happier (Mikhail Fedotov).


version 3.0.5
2006/09/25

- Changed license to Apache v2.0.

- Support gzip Content-Encoding: Build fails if gzip content
  encoding is requested but an appropriate zlib library is not
  found. Added encoding PGL field to PGL Content type to specify
  supported encodings for a given content type.  Added
  accept_content_encodings field to PGL Robot type to control
  Accept-Encoding request header generation. When parsing
  Content-Encoding values, only gzip encoding is recognized for
  now, and q=0 parameter (if any) is ignored. Generate 406 "Not
  Acceptable" responses and record transaction errors when
  content coding negotiation fails. Send Vary:  Accept-Encoding
  header when multiple codings are possible, depending on client
  acceptance rules.

- Use autotools to generate Makefiles instead of relying on
  custom generators that are too costly to maintain.

- Removed licensing terms acknowledgment from ./configure

- Do not simulate cached DNS responses for embedded objects if
  embedded URL points to a foreign server.

- Set pipelining depth for each newly opened connection; the
  default is the depth of 1 (i.e., no pipelining)

- Added initial support for HTTP cookies. Generate cookies based
  on probability, count, and size params supplied by the user
  via PGL (cookie_set_prob, cookie_set_count). Added
  Agent::cookie_sender PGL field to specify sticky probability
  that an agent supports (generates or returns) cookies. Added
  Server::cookie_size PGL field to specify the size distribution
  for generated cookies.  Added Robot::cookie_keep_lmt PGL field
  to control how many cookies (per server) are kept on the
  client side.

- Added hostedUrls() PGL function to convert a URL trace to an
  array of extracted host addresses.

- Added pipeline_depth PGL field to control the maximum number
  of concurrent (pipelined) HTTP requests per connection.

- Allow for more names than there are IP addresses in the PGL
  address map and use round-robin mapping to assign IPs. This is
  needed to support URL traces that may have a lot more real
  host names than the IP addresses the tester is willing to
  create.

- Support "." or root zone when configuring PGL address maps for
  BIND configuration generation.

- Disabled recursion in named config file, just in case.

- When generating a BIND configuration file, comment out records
  for names with underscores: BIND will not use the entire zone
  if it has invalid names.

- Speedup warmup phase: If we sent two requests to the server,
  the server is considered warmed-up even if there were no
  first-hand responses.

- Raised log version to 11.

- Complain if response to a reload request was generated before
  the reload request.

- Allow content database (cdb) to co-exist with may_contain PGL
  content option and use container information to configure the
  database.

- Allow the number of embedded objects in a page to exceed 255
  with a slight chance an embedded object ID colliding with
  another object ID. Warn if the number of embedded objects
  increases beyond 500.

- Added "linkonly" input format to cdb. With this format, cdb
  manipulates embedded URIs (links) as if markup format was used
  but preserves the entire file as a single object as if
  verbatim format was used.

- Added tagname-independent catch-all rules for common
  attributes such as background and src so that we can find more
  embedded URLs.

- Presence of the Xact-Id header field is now sufficient for the
  response to be considered as generated by Polygraph.

- Do not cancel a server-side transaction if the request lacks
  Polygraph headers because it may be a prefetch.  Count such
  requests as errors, for now.

- When generating IP aliases, avoid interfaces that have no inet
  family information at all (e.g., teql0 on a Linux laptop).
  Thanks to Adrian Chadd.

- Enabled recovering partial phase statistics from interval
  stats.

- Deal with duplicate phase names by appending unique suffixes
  instead of crashing.

- Added page-related stats such as page response time and page
  size.  Page download accounting starts with the first
  "container" transaction and ends with the last transaction
  among those that fetch the container and embedded objects.
  Client-side only.

- Added a "mean response time versus load" scattered plot figure
  to the report.

- Added traces of offered and measured hit ratios, based on
  client-side measurements.

- Report pipelining statistics.

- Switched to Gnuplot 4.x command conventions. PNG terminal in
  Gnuplot 4.x does not have a 'color' option.  All "set *style"
  commands are now "set style *"

- Be more robust when reading strings from a corrupted test log.

- Fixed --unique_world handling when persistent working set
  feature is enabled.

- Fixed seed generation when computing random request bodies.
  Old generated request content sequences were probably not
  random enough because they were probably always started at the
  beginning of the precomputed random-content source instead of
  starting at random offsets.

- Fixed handling of timed out DNS queries. The queries were
  probably not retried unless the timeout was reported on the
  console.

- Content checksums were not generated for some URLs.

- Newer FreeBSD versions require (/32, /128) netmasks for
  aliases on public interfaces. Warn, but do not quit if the
  explicit mask is too small.

- The "real." and "cachable."  prefixes of PGL stat objects were
  not recognized. Thanks to Wu S.N.  <wsn@21cncorp.com> (a.k.a.
  Searock)

- Various GCC3 and GCC4 portability fixes, including the use of
  the newer stringstream interface instead of strstream, to
  avoid "deprecated header" warnings in GCC3 and compilation
  errors in GCC4. The code will no longer work with GCC2 though
  because GCC2 does not support stringstreams.

     - Applied FreeBSD 5.2-CURRENT / gcc-3.3.3 compatibility patches
  from Sergey A. Osokin <osa/at/freebsd.org.ru>

- Give priority to new <header>s but still load <old.h> headers
  if new headers do not exist. Loading old headers is unlikely
  to help anyway because many interfaces have changed.

- Fixed network socket handling code on Solaris.



version 2.8.1
2004/10/11
- GCC 3.4 compatibility fixes
- GCC 3.3 compatibility fixes backported from Polygraph 3.0
- guard SIOCGIFINDEX-dependent code (Linux compatibility)
- String does not have a reset() method
- include <strstream> as a last resort when compiling string.h
  wrapper; ideally, it too should be guarded by ./configure
- make sure configure fails if SSL support is not disabled and
  SSL files are not found
- fixed ReportGen installation, although new reporter should
  be used instead; ReportGen is deprecated and will not be
  available in 3.x


version 2.8.0
2003/11/17
- SSL/TLS (https) support, including CONNECT requests 
- HTTP Authentication support, including support for very 
  large user databases (e.g., via LDAP directory) and loadable 
  modules for custom authentication schemes (e.g., RADIUS) 
- IPv6 support 
- Automatic adjustment of offered load based on real-time 
  measurements, such as response time or throughput (aka 
  peakfinder or watchdog) 
- Persistent working set and ability to continue/resume tests 
- Support for checking decisions of URL- and content-based 
  filtering proxies to allow, deny, or modify content during 
  a performance test 
- Better integrated, more detailed, and robust result reporter
- GCC 3.2 support


2.7.4 -> 2.7.5
20011231
- removed "you can modify" clause from the default end-user
  license to comply with University of California license
- changed default PopModel.bhr_discrimination from 100% to zero
  to remain backward compatible with earlier versions and workloads
  that did not use BHR discrimination algorithm
- removed "under construction" warnings from -4 workload files
- log statistics about transactions involving foreign URLs
- make all accept(2) errors on the server side non-fatal;
  continue to report previously fatal errors
- make errors when creating a UDP socket to send a DNS query non-fatal
- report current load factor level when rptmstat is in use
- better handle very large console messages (some errors may 
  generate output exceeding internal buffer capacity)
- fixed phase synchronization bug; reordered requests from
  robots could sometimes confuse phase synchronization
  algorithm and lead to incorrect phase schedule 
- BSDI portability fix
- fixed lx segmentation fault bug that was especially likely
  in the presence of large number of different errors logged
  during the test
- do not print millions of "fyi: populus reached max level"
  messages when (often incorrectly configured) test attempts
  to increase the number of robots when all robots are already
  in use
- fixed other minor bugs that probably remained invisible in 2.7
  branch but were exposed by ongoing code changes

2.7.3 -> 2.7.4
20010922
- synchronized packet delay/loss parameters with on-line
  workloads documentation (PolyMix-4 and WebAxe-4): 40msec delay
  and 0.05% packet loss in both directions, on one side
- changed plateau phase duration back to 4 hours until more
  evidence is collected to support the theory that shorter
  measurement phase is OK. (WebAxe-4)
- set final populus factor to zero and added "synchronize =
  false" flag to last phase (dec2) in PolyMix-4 and WebAxe-4
  workloads to ensure smooth test termination
- do not perform DNS lookups for embedded objects
- added "synchronize" flag to Phase type (PGL); by default,
  phases try to synchronize their finishes with remote
  schedules; if set to false, the phase will quit when its local
  schedule tells it so; the latter is handy for the very last
  phase of the test when request rate may be almost zero,
  leaving few chances for synchronization; this per-phase flag
  replaces the global --sync_phases option
- emit progress reports on the console every 5 minutes; handy
  when a phase seem to be stuck for no apparent reason; the
  report frequency is currently hard-coded
- do not report "premature end of message body" errors when
  transaction is aborted by the other side due to PGL abort_prob
  settings
- ignore stale objects that became stale while in-transit;
  report more info about stale objects
- update clock more often at startup
- replaced several assertions with warnings and workarounds to
  be robust in the presence of yet unknown internal and external
  errors
- fixed waiting transaction accounting bug: when robots were
  made idle to meet (smaller) populus goal or for other reasons,
  waiting transaction queue was silently flushed instead of
  "killing" each individual queued xaction and updating
  appropriate counters/tables; the bug led to wrong wait.level
  statistics and to memory leaks
- robot transactions were not resetting calculated Object
  Lifecycle timestamps leading to false "stale object" errors
- different embedded object IDs were sometimes generated for the
  same container, screwing MD5 checksums and probably some
  supersmart intermediaries because generated content for the
  same oid may not be the same
- optimized address map searching; linear search was too slow
  for large scale configuration, leading to worse response times
  for servers closer to the end of the robots' origins array
- make sure that no more than scheduled abort size gets
  written/read on a connection; old code would read/write as
  much as possible, and many scheduled aborts would not happen
  until the object is fully written/read, when it is too late
  for the other side to notice/experience an abort
- a CRLF sequence was getting appended to a host name in the
  Host: header if that header happened to be the last HTTP
  header in the request/response; Polygraph servers would report
  "foreign host name" errors because of that extra CRLF in the
  host name; other headers in the same [last] position were
  getting extra CRLF as well, but, apparently, their parser
  would ignore those extra characters (or, at least, no
  side-effects were noticed)
- initialize OS-dependent libraries in aka to prevent aka from
  quitting due to WSAStartup() not being called on MS Windows;
  alias handling code still needs more work on Windows


2.7.2 -> 2.7.3
20010830
- submit requests to foreign URLs if needed; the corresponding
  responses are read but not counted/analyzed as
  hits/misses/etc; the only current valid source of foreign URLs
  are redirect (HTTP 302 Found) responses that have foreign URLs
  in the Location: field
- use relative URLs in container objects because most embedded
  URLs that point to the same Web site are relative and because
  it solves problems with group of "identical" servers
  implementing one Web site (each server should not put its own
  address into a URL, but should put its visible name, but one
  server may, in theory have multiple visible names)
- attempt to handle more errors gracefully, without terminating
  a connection and aborting the transaction; still report
  errors as they are detected (polyclt)
- handle [large] string ranges efficiently (PGL)
- all open square brackets ('[') in strings must now be escaped
  with a backslash ("\[") for the string to be interpreted as a
  string rather than a range (PGL)
- compute MD5 checksum for selected objects
- WSS of 1GB is now required for cache-off entries (WebAxe-4)
- default port for HTTP surrogates should be 80 (WebAxe-4)
- client and server-side .hosts values where swapped (WebAxe-4)
- minimized the number of differences in parameters and layout
  between PolyMix-4 and WebAxe-4
- added proxy IP:port address to webaxe-4.pg and address map to
  webaxe-4-guts.pg; robots should send requests directly to the
  proxy address as if it were an origin server
- added port numbers for WebAxe-4 servers (via
  server-side.hosts array)
- replaced "foreign HTTP request/reply" errors with "foreign
  HTTP request or response" (response without Polygraph-specific
  headers while those headers were expected) and "foreign URL"
  (a URL that does not belong to Polygraph URL space) errors
- added "foreign URL without host name" error to complain about
  relative foreign URLs when they are not expected
- warn if popularity model is not set and rep_types are used
  because some reply types require popularity model
- added X-* extension headers to HTTP 302 responses
- use WSAEMFILE on W2K instead of EMFILE when indicating
  out-of-sockets condition to make that error reporting on W2K
  work
- webaxe-4-guts.pg file was not installed on "make install"
- fixed order-dependency bug in polymix-4-guts.pg and synced
  webaxe-4-guts.pg
- polished polymix-4-guts file to eliminate non-differences
  with webaxe-4 guts file
- lx should not read standard input by default
- fixed yet another bug affecting reported "level" stats; old
  reports could have much higher per-phase level stats than
  what could be inferred from ltrace plots; per-phase level
  stats were incorrect
- set GET method for redirected requests; old code would assert
  on redirects


2.7.1 -> 2.7.2
20010813
- calculate values for If-Modified-Since header fields using
  Object Life Cycle configuration of the corresponding object
  content type instead of using cached last-modified values;
  robots could not cache enough objects to generate reasonable
  number of IMS requests with "sane" IMS headers; the new method
  solves the problem and eliminates requirement for maintaining
  a private cache on each robot (saving lots of RAM for large
  scale configurations); now we can specify the number of
  IMS-200s and IMS-304s and should be able to meet the specs;
  this is a yet another change that makes it crucial to have
  identical client- and server- side PGL configurations
- select object birthday as a random point within the object
  life cycle starting at "time zero" instead of allowing
  relative or absolute birthdays; birthday point should not
  matter for any current practical purpose, and having relative
  birthdays made it impossible(?) to re-generate OLC timestamps
  in non-authoritative processes (e.g., clients); the latter was
  needed for robots to generate sane IMS requests; PGL object
  birthday settings are now deprecated and ignored
- removed private_cache_cap settings (i.e., disabled robots'
  private caches) from all standard workloads; we no longer
  need a private cache to generate IMS requests and, hopefully,
  the latter was the only reason to have it; private caches
  consumed a lot of memory on large scale configurations
- added "bhr_discrimination" field to the PopModel type to
  control the aggressiveness of the byte hit ratio (BHR)
  discrimination algorithm; 100% makes algorithm the most
  aggressive (default); 0% disables the algorithm; internally,
  bhr_discrimination is actually a probability of applying the
  discrimination algorithm when oid selection is made
- added bhr_discrimination to generation-4 workloads
- make request body size of PUT and POST requests random rather
  than 8192 bytes; 8192 bytes is now an upper limit given 16KB
  I/O buffers
- moved WebAxe-4 details into include/webaxe-4-guts.pg and
  synchronized WebAxe-4 specs with recent PolyMix-4 changes to
  keep the two workloads similar (needs more work)
- removed "recurrence" field from content types in contents.pg
  since Polygraph does not use it anymore; warn if "recurrence"
  is set
- increased public_interest from 50% to 75% because we now have
  robots that are not active until after the [private] working
  set size is frozen and, thus, some robots will not be able to
  request objects from their private working set, violating the
  old goal of 50% of request submitted to private subsets;
  while no drastic changes are expected due to this change, we
  need more measurements to understand its effect
- removed birthday settings from standard OLC configs; OLC now
  ignores birthday settings
- decreased the ratio of IMS requests in PolyMix-4 from 20% to
  15%
- configured PolyMix-4 robots and servers to abort 0.1% of
  transactions
- added 1.5% of POST and 0.1% of HEAD request methods to
  PolyMix-4 and WebAxe-4 workloads
- added zone name back to AddrMap in PolyMix-4; dns_cfg should
  work with polymix-4.pg now
- increased supported and required log version to 10 due to
  transaction logging changes; older logs cannot be read with newer
  readers and vice-versa
- IpsToNames() now preserves port numbers (PGL)
- supply more information about DNS timeout errors
- DNS answers were allocated but not freed, leaking a memory on
  every DNS request
- try other DNS servers (if any) when DNS query times out
- cloned addresses are now iterated depth first when agent
  aliases are created, because alias creation code tries to
  allocate n-th chunk of addresses rather than every k
  addresses; the old code would create twice as many aliases for
  addressing schemes with more than one agent per address; the
  new code creates the same alias twice; needs more work to
  avoid extra creation
- "--names" option was treated as "--addresses" option (dns_cfg)
- improved old IP alias deletion on OSes with numbered virtual
  interfaces (e.f., Linux and Solaris); this needs more work;
  for example, one cannot have both polyclt and polysrv creating
  aliases on the same Linux box
- fixed netmasks and broadcast address settings on systems with
  "numbered" virtual interfaces and without ifaliasreq structure
  (e.g., Linux and Solaris); old code did not set netmasks and
  broadcast addresses at all (effectively), and defaults were
  probably assigned by OS
- when creating aliases, we were opening a new socket instead of
  closing an old one, creating thousands of "extra" sockets when
  aliases were created on a box; this led to "too many open
  files" errors on some systems, at least

2.7.0 -> 2.7.1
20010803
- added "recurrence" field to PGL's Content type; recurrence
  value affects the probability of the content type being
  selected when Polygraph decides which object should be
  revisited among a set of candidates; recurrence is a "weight"
  rather than "probability" because several objects of the same
  type may be present in the selection group and the sum of all
  weights can exceed 1.0; in other words, the selection group is
  formed first, recurrence weights are applied second;
  recurrence weight defaults to 1.00
- added "zone" field to AddrMap type (PGL); the zone name is
  not used by Polygraph run-time, but can be used by external
  programs such as dns_cfg to build zone files based on PGL
  configuration
- added ipsToNames() PGL function to convert an array of IP
  addresses into host names using a simple 1:1 mapping
- added "--config" and "--cfg_dirs" options to dns_cfg to
  extract required information from a PGL file; old
  command-line options interface is still supported and is
  mutually exclusive with the new PGL interface
- added DNS resolver address as a parameter for PolyMix-4
  workload; set DNS resolver timeout to 5 seconds
- use ipsToNames() to generate DNS names for PolyMix-4 servers
  PolyMix-4 workloads are now using DNS names; this can be
  disabled (in violation of PolyMix-4 rules) by setting AddrMap
  "names" to server "addresses"
- polished PolyMix-4 workload files to explicitly list address
  space and real hosts settings; /22 subnet must be specified
  for address space or PGL will compute the smallest subnet
  given the bench configuration (smaller subnet will lead to a
  different agent addresses compared to the required /22 subnet,
  screwing up routing)
- added recurrence weights to content types used in PolyMix-4;
  this should improve byte hit ratio (BHR) simulation, but it
  looks like more work is needed to actually make that happen
- polished dns_cfg output to better match BIND files format
- renamed "--domain" to "--zone" (dns_cfg)
- renamed Session's heartbit_notif_rate to heartbeat_notif_rate
  (PGL)
- reduce the number of "labeled logs have no object named X"
  messages when generating reports
- account for the number of agents per address when computing
  minimum (smallest) subnet in version-4 addressing schemes;
  old code incorrectly complained about /22 being too small for
  PolyMix-4 workloads because it did not account for the fact
  that two PolyMix-4 robots may share an IP address
- plot_traces was using unportable regular expression feature
  that led to "Character class syntax [: :] is reserved for
  future extensions" Perl errors when generating reports; use a
  more portable expression instead
- delete old IP aliases before creating new ones; old code
  was not calling the delete method

2.6.5 -> 2.7.0
20010729
- added "req_methods" field to Robot (PGL) to specify
  distribution of HTTP request methods for a robot to use;
  supported methods are GET, HEAD, POST, and PUT; methods that
  allow request bodies (POST and PUT) use constant body size of
  8192Bytes, for now.

- added "abort_prob" field to robot and server PGL
  configurations to abort transactions based on on a given abort
  probability; robots may abort while receiving response body,
  and no aborts while sending headers, waiting for a response,
  or reading response headers are supported; servers may abort
  while sending response body, and no aborts while sending
  headers, waiting for a request, or reading request headers are
  supported

- added "addr_space" field that deprecates "addr_mask" field;
  version-4 addressing schemes use "addr_space" addresses to
  generate robot and server addresses; older schemes used only
  two first octets of, now deprecated, addr_mask, making agent
  address configuration too rigid; "addr_space" can list any IP
  addresses as long as they comply with the addressing schemes
  in use; this is a big change so there may be bugs in
  implementations of addressing schemes that now use addr_space

- rewrote PGL arrays to allow array members to be arrays; the
  nesting is almost transparent to the end-user as far as member
  iteration is concerned (i.e., nested arrays are flattened
  automagically), but does affect probabilities assignment
  because each container can have its own [sub-]probabilities in
  addition to a member probability specified in the array;
  doing something like "[ a: 5%, [b: 10%, c]: 50%, d]" is now
  possible and equivalent to "[a: 5%, b: 5%, c: 45%, d]"

- added a binary "+" operator for arrays so that two arrays
  can be concatenated without nesting

- added "--delete_old_addrs <bool>" option to polyclt/srv to
  specify whether old IP addresses should be deleted when
  creating new IP addresses; defaults to "yes"; may allow to
  run polyclt on the same box as polysrv _and_ create aliases
  run-time (bit more work would be needed for OSes that number
  their alias interfaces for system call purposes)

- do not send Last-Modified and Expires headers for uncachable
  objects; some proxies (e.g., Apache's mod_proxy 1.3)
  completely ignore "Cache-control no-=cache,private" and
  "Pragma: no-cache" response headers and cache an object if
  a response has, say, a valid Last-Modified header

- use interface names and subnets directly from agent.addresses
  arrays instead of addr_mask when creating new aliases; now, in
  theory, one can have agents bound to several interfaces and
  still be able to create aliases automatically

- added PolyMix-4 workload (first draft) and 
  synchronized them with PGL changes

- use 2 robots per IP for WebAxe-4 and PolyMix-4; this allows to
  support higher request rates with reasonable number of IP
  aliases

- bumped log version to 9 due to new stats (HEAD/POST/PUT and
  aborts) being logged

- reduced memory footprint of large address ranges and large
  "**" clones (PGL)

- renamed option "--addrs" to "--addresses" (dns_cfg)

- "something/0" expressions were interpreted as rate because
  zero is convertible to time (e.g., 0 seconds); forced PGL to
  just complain about division by zero instead


2.6.4 -> 2.6.5
20010729
- use "binary" mode for log files; required on MS Windows for
  the logging to work; previous versions produced corrupted
  log files on MS Windows or any platform that treats binary
  files specially
- changed Unix makefiles to stop after the first error

2.6.3 -> 2.6.4
20010709
- added "proxies" field to robot PGL configuration; proxies
  must not be used together with the --proxy command line
  option as they are mutually exclusive; a robot selects a
  random proxy at the configuration time and uses that proxy
  for the entire duration of the test (sticky proxy
  assignment); proxy addresses are distributed evenly (if
  possible) among all robots in the test; individual groups of
  robots (e.g., all robots on one host) may not get an even
  distribution.
- support "make install" in workload files; "make install"
  will overwrite existing files in the destination directory
  (/usr/local/polygraph/workloads by default); users are not
  supposed to modify original workload files and should
  create copies when modifications are needed
- made aka robust when no primary IP is present on the interface
- lognormal mean and standard deviation were not reported
  correctly (Johnson Lee <jl03@gte.com>)
- synced comments in polymix-3.pg with Bench type changes
- clientHostCount in PolyMix-3 on 2.6 branch was not computed
  correctly, leading to ridiculously small working set sizes
  and shorter fill phases


2.6.2 -> 2.6.3
20010627
- emit (errUnreachContType) "unreachable content type" when an
  embedded content type cannot be found on the [visible] server that
  hosts the container object; Polygraph can only handle embedded
  objects that reside on the same visible server as the container
- use the same content distribution for all L7 servers (except
  for the URL extension) so that all servers will get similar
  load
- when server's direct_access probabilities are specified manually,
  use them and do not compute our own
- added "byte.rptm.mean", [milliseconds / kilobyte] object to Report
  Generator. The object value is visible in make_report as "byte"
  table entry in the Response Time table and as the byte_rptms plot.
- replaced --rng_seed option with two new options:  --global_rng_seed
  and --local_rnd_seed. Both default to 1.  All processes within a
  test must have the same --global_rng_seed value to correctly
  generate "global" information such as a URL extension for the same
  object ID.  All processes within a test should have different
  --local_rnd_seed settings to avoid lock-step behavior of things that
  should not be synchronized.
- do not print "Potential problems" header if no problems are detected
  by make_report
- when generating a public miss, use local public world slice
  only; using remote slices creates race condition for
  generating a miss with the corresponding remote agent; these
  race conditions lead to buggy offered hit ratio
- W2K select(2) fails if no FDs are passed to it (i.e., all FDs sets
  are empty)
- fixed fixed a very old bug (again) that, under certain conditions,
  left some FDs ignored by select(2); the earlier fix was ineffective
- fixed ceil() workaround once again: the earlier fix was ineffective

2.6.1 -> 2.6.2
20010613
- polished SrvLB workloads; added SrvLb4As addressing scheme;
  same as WebAxe4 but uses server_side.hosts for server
  addresses instead of building them using a
  server_side.addr_mask
- try to select appropriate target if content type is known so
  that embedded objects will be directed to the right targets;
  this feature is needed for L7 SLB tests; needs more work to
  randomize target selection when more than one target server
  has the required content type
- if no command is given to forsome, just print addresses in the
  specified host group
- check that the content type in the request URI belongs to the
  server that the request was sent to; generate a misdirected
  request error if it does not; previously, a server would
  happily serve any content type that belonged to at least one
  server in a PGL configuration
- open DNS/UDP socket for a robot only when the first DNS query
  needs to be sent out; this will prevent polyclt from creating
  one socket for every robot even when no DNS queries are
  needed; also do not select(2) DNS/UDP socket for reading when
  there are no pending transactions to reduce CPU overhead when
  some DNS queries are present
- public URL worlds were erroneously updated with stale data
  when hot set position of the stale snapshot differed from the
  current one; the bug led to incorrect (higher than what should
  have been offered) offered hit ratios
- fixed a very old bug that, under certain conditions, left some
  FDs ignored by select(2)/poll(2); most likely, the bug was
  never or infrequently triggered by Polygraph code before;
  noticed the bug when adding BEEP support that has somewhat
  different FD registration/scanning pattern from the rest of
  the code.
- libc's ceil(700/0.7) returns 1001; the old workaround was not
  good enough, and led to creation of 1001 agents where only
  1000 agents were needed; added a better workaround
- made interface aliases / primary address detection code more
  robust on Linux
- changed recur_factor to recur_factor_{beg,end} in webaxe-1.pg

2.6.0 -> 2.6.1
20010605
- fixed "version three" addressing scheme bug that led to incorrect
  addresses being auto-generated for PolyMix-3 and other -3 workloads
  that used addressing scheme PGL feature
- a server now checks for requested URL to belong to that server; if
  request is misdirected, the connection is closed with an xaction
  error message dumped to the console; no 404 HTTP error is generated
  at this time
- added --load_balancer option to make_report to generate slightly
  different reports for load balancing tests

2.5.5 -> 2.6.0
20010522
- changed licensing terms and added not-for-publication clause
- updated README
- added DNS/FQDN client-side support; robots can now send
  [non-blocking asynchronous] DNS queries to specified DNS servers to
  resolve destination addresses; DNS responses are currently not
  cached
- added pxylb-4.pg and srvlb-l4-4.pg workload drafts to test proxy
  and origin server load balancing, respectfully
- added webaxe-3.pg configuration file for WebAxe workload; this
  file was distributed with Polygraph version 2.5.4 under the name
  webaxe-2.5.pg
- create IP aliases upon startup, based on the PGL bench
  configuration; warn if aliases are not being created and explain
  why
- log PGL configuration upon startup
- added support for URL prefixes; arbitrary string(s) can be
  specified to be included as a URL "prefix", right after the first
  '/' following the host name or host address; use Mime.prefixes for
  now (just like Mime.extensions)
- added "special_msg_factor_beg" and "special_msg_factor_end" fields
  to Phase specs to control the presence of special messages (IMS,
  Reload, 302 Found, etc.) in the generated stream (PGL); useful to
  speedup fill phase and to test the influence of those special
  requests on the cache
- handle ``302 Found'' replies: treat them as special valid kind of
  an HTTP response and follow URIs in the Location: field; 302s may
  be foreign replies, but 302 takes priority when it comes to
  redirection handling and statistics logging
- added client-side support for HTTP 300, 303, and 307 responses; a
  Robot would request the Uri found in the Location: field of the
  response after processing the original transaction
- use new client-centric PubWorld interface instead of old
  server-centric object ID (oid) exchange; use/maintain related
  global indexes; broadcast/update PubWorld info
- added support to flip-flop debugging (--dump hdrs) status on USR1
  signal
- try to flush logs when process is running out of memory;
  pre-allocate a 16KB buffer to be freed when we are running out of
  memory, in hope to get enough memory to flush the logs; this trick
  may help to save some of the logs when Polygraph quits with
  "virtual memory exhausted in new"; may need more work
- added phase name reporting to ltrace; when multiple logs with
  different phases are merged, the printed phase name can be the
  name of any then-current phase.
- added polyprobe -- a traffic-volume-oriented network test tool
  that will, eventually, replace netperf for many-to-many raw
  network bandwidth tests used before PolyMix tests
- added polyrrd tool to supply run-time Polygraph stats to the rrd
  tool; rrd tool is a "better MRTG" software for displaying run-time
  stats in graphical form:
  http://ee-staff.ethz.ch/~oetiker/webtools/rrdtool/
- added rrd-cgi.sh as a sample file to use with polyrrd and rrd tool
- pgl_test now accepts include directories as parameters (after the
  PGL file to test)
- assume URLs starting with "/health" are health checks and reply as
  if --ignore_urls was set
- added "Rptmstat" PGL type to store response-time-stat (as in
  thermo-stat) configuration; a rptmstat attempts to keep response
  time within the specified bounds by adjusting offered request rate
  (just as a thermostat attempts to keep temperature within the
  specified bounds by adjusting the furnace or A/C operation)
- added "rptmstat" field to Phase type; rptmstats are activated on a
  per-phase basis
- added "rep_types" field to Server agent type (PGL); "Basic" and
  "302 Found" reply types are supported
- added "client.hosts" and "server.hosts" fields to Bench object to
  specify real machine addresses (as opposed to "virtual" aliases for
  agents) (PGL);
- added DnsResolver PGL type to configure DNS resolver for robots
- skip insane/corrupted entries in the trace and warn about them;
  trace corruption may happen when Polygraph process or the host OS
  is killed without a chance to flush the binary logs
- added dns_resolver field to Robot type
- support port ranges in PGL addresses
- added use(Bench) PGL call to specify the bench configuration for
  the test
- added minimize_new_conn field to Robot to specify probability of
  an attempt to use idle connections to address' substitutes when no
  idle connections to the address are available; added
  note_substitutes() procedure call to register known substitute
  groups (PGL); substitutes are useful to approximate connection
  reuse pattern of a single-destination workload in a no-proxy or
  no-balancer setup
- added dns_cfg tool to generate configuration files for named, a
  DNS server, needs more work
- use a new tool to generate Makefiles for Unix (gmake) and MS
  Windows (nmake). Temporary lost ability to built out of the source
  directory.
- renamed --*log_size to --*log_buf_size so better reflect the true
  meaning of the option
- removed the --new_oids* options as unused
- renamed popularity distributions pmUnif and pmZipf to popUnif and
  popZipf to avoid conflict with popularity models (pm*)
- polished simple.pg and moved simple server to port 9090 to avoid
  strange port 8080 hijacking problems on some Windows installations
- synced standard workloads with PGL changes
- changed HotSet algorithm to avoid storing theObjLmt: change hot
  position when it is no longer in the working set; when WSS is
  unknown, keep hot position in the middle of the URL set
  (constantly sliding position); the rationale is to reduce memory
  overhead and, maybe, to simplify remote synchronization of hot
  positions
- changed Bench definition to use BenchSides instead of client_ and
  server_ prefixes
- added new "Addressing Scheme" PGL types to calculate agent
  addresses for various workloads
- PGL agents should always bind(2) to specified addresses
- removed "Rptm vs Size" and "Conn Life Time vs Use Count"
  statistics; (they were huge and rarely used; similar data can
  probably be derived from stats samples)
- changed binary log format and version
- moved pop_model PGL field from Robot to Agent because Server agent
  needs it to generate ``302 Found'' responses
- replaced "agent.hosts" fields with "agent.addresses" to be more
  consistent; "hosts" in PGL usually means "real, permanent
  address" while "addresses" are often used for IP aliases that are
  created run-time
- use address ranges when printing arrays of addresses, if possible
- when checking for "clocks out of sync" errors, ignore replies that
  took a long time; slow replies is usually an indication of
  problems other/bigger than clock synchronization
- embedded objects should inherit request type property from the
  container (not ideal, but better than using default req type for
  all embedded objects)
- removed old place() PGL function
- increased client-group-count-dependent hash capacities from 11 to
  37 old limits did not allow to use more than 11 clients or server
  machines in a test
- changed default value of polysrv's --idle_tout to 5 minutes
- removed piper tool -- it was not used and caused compilation
  problems on FreeBSD 4.x due to new DummyNet interface
- tried to make alias manipulation with aka work again on Linux
- added port of msl_test to linux, based, in part, on code donated
  by Andrew Schultz from Mission Critical Linux, Inc. More work is
  required to make msl_test more portable
- provide traces of conn.open.rate and conn.estb.rate in the report
- improved report generation tools
- AIX portability fixes
- HP-UX (aCC) portability fixes
- Linux portability fixes
- MS W2K (VC++) portability fixes
- Solaris portability fixes
- added config.bat script to compile sources with nmake on Windows
- reduce default optimization level on Linux to 1 (-O1) to avoid
  coredumps
- lots of polypxy fixes to make it more robust; needs more work
- a yet another attempt to fix code that merges level stats
- adjusted alias creation code to extract and honor individual
  subnets of the alias addresses
- when merging (not concatenating) stats, the duration should be set
  to the maximum duration of the two intervals being merged so that
  merging 10 req/sec for 1 sec and 1 req/sec for 1 hour does not
  result in 11 req/sec mean; will this screw anything that used to
  work?
- when merging or concatenating phase stats, do not change the phase
  name if phases with the same are joined
- fixed ./CdbBodyIter.cc:43: assertion failed: '!theInjector';
  a common problem with realistic content simulation module
- fixed an old ltrace bug: sampling windows were sometimes getting
  huge, leading to excessive memory consumption and possibly somewhat
  incorrect trace plots
- "ceil(700/0.7)" returns 1001(!!); added a workaround; old IP
  calculation tools were generating wrong values when 700
  req/sec/host and 0.7req/sec/agent combination was used
- aka was not setting subnets right


2.5.4 -> 2.5.5
20010501
- updated copyright/license statements
- added licensing terms acknowledgment to ./configure script
- resurrected support for user-defined or "table-based" distributions;
  e.g., ``SimpleContent.size = table("/tmp/t.distr", "size");'' where
  /tmp/t.distr contains the distribution of type size_distr
- added webaxe-3.pg configuration file for WebAxe workload; this file
  was distributed with Polygraph version 2.5.4 under the name
  webaxe-2.5.pg
- Red Hat 7.0 compatibility fixes
- AIX compatibility fixes
- fixes for platforms with unsigned chars (e.g. AIX); PGL parser would
  quit on those platforms with error location pointing to the end of a
  file being parsed
- fixed an old ltrace bug: sampling windows were sometimes getting
  huge, leading to excessive memory consumption and possibly somewhat
  incorrect trace plots
- fixed local time detection bug on Solaris; the bug caused Polygraph
  to complain about client/server clocks being out of sync even if
  both processes were running on the same host
- replaced "MB/sec" column heading produced by make_report 
  with less confusing Mbit/sec


2.5.3 -> 2.5.4
20000724
- added "special_req_factor_beg" and "special_req_factor_end"
  fields to Phase specs to control the presence of special
  requests (IMS, Reload, etc.) in the generated stream (PGL)
- identify cases when HTTP race conditions lead to connectivity
  errors on used-to-idle persistent connections; retry
  transactions when such errors occur; log the number of retried
  transactions (that otherwise do not affect statistics)
- eliminated most of the special (non-Basic) requests during the
  fill to shorten the fill phase (PolyMix-3)
- when a phase meets its goal, wait until all remote phases are
  ready before proceeding
- added the "--sync_phases <bool>" option to disable auto phase
  synchronization if needed
- log statistics about oid generation algorithm
- distinguish "hot" requests in stats samples
- polished stats samples and made them smaller
- report WSS in terms of bytes (in addition to object count); be
  careful when interpreting the values -- adjust for embedded
  objects and other hosts in the bench
- complain if server agent port is not specified
- upgraded current and required log versions from 2 to 3; log
  versions were not upgraded for a while despite format changes,
  unfortunately
- warn about log extractor <--> log producer versions mismatch
  when reading a log
- fixed typo in X-Srv-Sets header parsing code that led to
  growing WSS for public (shared) objects, resulting in
  lower-than-expected HR
- fixed ./CdbBodyIter.cc:43: assertion failed: '!theInjector'
- fixed coredumps when all configured phases are ended and
  Polygraph adds a "cold" phase for the last transactions to
  finish and coredumpts with segmentation fault
- made reportgen.cfg dependent on ./configure parameters


2.5.2 -> 2.5.3
20000719
- ProxyCacheSize in polymix-3.pg should now be set to the
  *total* proxy cache size, without adjusting for the number of
  polyclt processes; all adjustments are now done in
  polymix-3-guts.pg, without user participation (the patch
  with the above functionality was posted shortly after 2.5.2
  was released)
- added the clientHostCount() function to compute the number of
  client hosts based on the PolyMix-3 rules (PGL)
- added client_host_count to benchPolyMix3; if not defined by
  the user, its value will be computed on-the-fly in
  polymix-3-guts.pg:  TheBench.client_host_count will be set to
  clientHostCount(TheBench)
- added the "fexit" phase to PolyMix-3; fexit increases hit
  ratio to peak level while decreasing request rate; this phase
  may be required for proxies that get overwhelmed by high loads
  with low hit ratio; the latter were possible during "inc1"
  when hit ratio was increased along with request rate, but not
  "fast enough".
- adjust Robot's recurrence ratio for Reload requests (we are still
  unsure what to do with IMSes)
- collect small transaction sample during the fill phase (PolyMix-3)
- polypxy can now handle misses (not yet robust in error-rich
  environments)
- a Robot that did not request any private objects from a server
  before WSS was frozen should try not to request new private
  oids from that server; doing otherwise populates the working
  set with oids that cannot be requested again in the future
  (because the corresponding WSS is zero) but may consume cache
  space, etc.  Generating a new private oid is always the last
  resort, but it should not be the second best choice.
- hot set objects may have been sometimes chosen outside of the
  working set, leading to false false hits and lower hit ratio;
  other objects may have been subjected to this as well
- request embedded objects during the initial server scan (not
  requesting them makes Polygraph think that an embedded object
  was requested before when it was not, decreasing HR)
- made polymon report Network Bandwidth usage again (untested)
- moved foreign request error reporting so that we still have
  request headers to dump
- marking a freshly accepted socket as a non-blocking or
  not-naggling socket may fail when poly* is overloaded; do not
  exit the program but rather continue after reporting the error
- fixed two coredump-inducing bugs in the polypxy module
- aka was exiting silently when no "anonymous" options where
  specified
- support the "log_dir" option to label_results


2.5.1 -> 2.5.2
20000713
- accept more than one alias range (aka); useful for running
  robots and servers on the same machine (but do not do that for
  production tests!)
- do not attempt to extract the broadcast address of the
  interface, we do not need it and some interfaces (e.g., lo0 on
  FreeBSD) may not have one (aka)
- added tools/pmix3-ips.pl script which is identical to
  pmix2-ips.pl except that it also prints IP ranges for each
  host in the bench (in default, verbose mode)
- added IMS/reload statistics collection and reporting IMS and
  reload transactions are now treated separately from "basic"
  transactions and do not affect hit ratios, fill rates and
  other statistics that is hard to define for IMS and reloads
  (e.g., what IMS response can be count as a hit?); The
  "Contribution" table in generated reports needs more work as it
  is not 100% in sync with the above change
- added working_set_cap() function to freeze WSS based on the
  number of transactions rather than run time (PGL)
- added min() and max() functions to PGL
- split polymix-3.pg into [modifiable] polymix-3.pg and
  [read-only] include/polymix-3-guts.pg
- specify WSS in terms of fill responses rather than time (the
  calculation is still time-based, just like in Polymix-2); WSS
  is meant to be equal to 4 hours of fill traffic during a "top"
  phase, approximately (polymix-3.pg)
- specify ramp durations as a fraction of plateau durations to
  ease scaling of a test (polymix-3.pg)
- added "wait_wss_freeze" boolean field to PGL's Phase; if set,
  the phase will finish only if the working set size is frozen
  (and all other goals are satisfied, of course)
- make sure that fill phase stops only if working set is frozen
- do not request embedded objects while in the initial
  server-scan mode
- shortened launch window because we no longer request embedded
  objects
- decreased warmup phase goal to a single launch window
- detect malformed HTTP request or response lines and complain
- check that embedded object type makes sense and complain if it
  does not (instead of dumping core)
- Polygraph was erroneously reporting "hit on reload requests"
  for some embedded objects
- removed "http." prefix from some lx object names
- report the number of local private objects in the working set
  size
- obey RFC 2616: do not send any extension-headers with 304s
- Zip files should have ".zip" extension, not "zip"
  (contents.pg)
- yet another attempt to make oid exchange algorithm more robust
  (needs more work)
- increased new_oids_history default to from 1024 to 2*1024
- increased new_oids_prefetch default to from 128 to 256


2.5.0 -> 2.5.1
20000626
- added support for realistic HTML simulation
- added aka support for IP alias manipulation on systems that
  use virtual interfaces such as eth0:1, including Solaris
  (untested) and Linux (tested)
- polished the code that searches for local interface addresses
  in hope to make it work on more OSes
- added robotAddrs() and serverAddrs() functions: PGL now knows
  how to compute PolyMix-2,3 IP addresses, given the peak
  request rate (and other parameters); make use of that feature
  so that people do not have to spell out IP addresses in
  polymix-3.pg; explicit addresses are still supported, of
  course; IP aliases still need to be created before the test
- added "Bench" type to describe parameters for the IP
  allocation schemes and include/benches.pg to describe standard
  IP allocation schemes
- support variable recurrence ratio: replaced "recur_factor" in
  Robot with recur_factor_beg / recur_factor_end pair for smooth
  change in recurrence ratio (PGL)
- polished definitions of fill-related phases to make use of
  variable recurrence in PolyMix-3
- polished launch window calculations in PolyMix-3 (needs more
  work)
- added the "--ign_bad_cont_tags" option to ignore content tags
  that a Robot cannot parse; useful with realistic HTML
  simulation
- added the "--ign_urls" option to generate content regardless
  of the URL being requested; useful when running polysrv in a
  "demo" mode
- fixed logging of ICP statistics
- added reporting of ICP measurements to the Report Generator;
  the above reporting is enabled only when ICP stats are present
  in the logs
- make sure IMS timestamp is always at least 00:00:00 UTC,
  January 1, 1970
- fixed type unification compile-time bugs
- Solaris portability fixes (IP aliasing improvements are
  untested due to the lack of root access to a Solaris box)
- "everything expires when modified" should use "nmt" not "lmt"
  in olcStatic in contents.pg
- replaced pop_model settings to make old workloads "compile"
  with new PopModel type (PGL)
- support number/rate operation (returns time) (PGL)


2.2.8 -> 2.2.9
20000113
- added downtime-2.pg workload specs for the "power-off" test
- when transaction fails, it may take a while for polysrv to
  stop waiting on the corresponding object id; the latter may
  lead to a situation when hits are generated only using oids
  that are smaller than the lost oid, preventing WSS algorithm
  from "sliding"; we now attempt to report "lost" oids back to
  the server so it does not wait for them; the latter may
  improve hit ratio for "small" caches in the presence of
  errors
- freeze WSS based on last object id sent to the server rather
  than last object id confirmed by the server (to prevent
  funny tiny working sets in the presence of errors when oids
  may get lost)
- groups with working set size of zero were not handled
  correctly; a group has zero size if it was never used prior
  to the working set freezing time
- on the client side, distinguish closed connection with no
  headers sent from a closed connection with some headers
  sent; that is, distinguish "connection closed before sending
  headers" from "premature end of msg headers"; the former may
  by due to HTTP race condition, the latter is definitely a
  bug.
- added "Errors Total Count x 1000" screen to polymon
- assume BB/*.pm files are in /usr/local/polygraph/BB or in
  the current dir
- polished bb.pl output
- added tools/pmix2-ips.pl and tool/BB/forsome scripts that
  help in configuring and running [large scale] experiments
- removed most defaults values for options of Report Generator
  tools; reportgen.cfg should be used instead; needs more work
- allow up to 0.1% difference between fill count measured and
  computed based on hit and cachability ratios (Report
  Generator)
- do not complain about too many waiting requests because it
  is not clear what "too many" is (Report Generator)
- plot cachability ratio along with hit ratios (Report
  Generator)
- ported Report Generator to Solaris (the patch was available
  for 2.2.8)
- do not dump core if a requested phase is not found in the
  log (lx)
- do not quit on logs with [very] different absolute times
  (ltrace)
- made log merging algorithm less susceptible to minor local
  time differences between machines where the logs where
  generated (lx, ltrace); "level" traces (e.g., those produced
  by Report Generator) no longer have weird slight downward
  slopes
- statistics about "waiting" (queued for connections)
  transactions was not collected appropriately resulting in
  zero readings
- fixed "request rate for robot X is not positive"
  configuration time bug (the patch was available for 2.2.8)
- compile IpSocket.cc even when IPFW is not supported (the
  patch was available for 2.2.8)
- prevent "invalid type X for default argument to Y"
  compilation errors


2.2.7 -> 2.2.8
19991227
- added "req_inter_arrival" field to Robot to specify other
  than Poisson inter-arrival time distributions; for example,
  downtime test will use constant distribution (PGL)
- redesigned lx to concentrate on phase-related statistics and
  support multiple log files; phases with equal names are
  merged, and phases with different names are concatenated to
  produce correct "totals"
- added `ltrace', a tool to generate traces based on binary
  logs; this functionality was moved from `lx' that no longer
  supports trace extraction
- changed naming scheme for log objects to be more consistent
  and scalable, added a few new objects
- log statistics about transactions waiting for resources to
  become available (e.g., requests waiting for a robot
  connection pool to allocate a connection); this changed log
  format, unfortunately
- dump more information on "foreign content <tag>" and
  "malformed content <tag>" errors
- added a cool "summary" screen to polymon
- do not quit when all phases met their goals when there is a
  positive idle timeout; wait for that timeout to expire (so
  that servers do not quit while clients are running)
- do not log ascii representation of addresses when storing
  current state
- "level" statistics was not maintained properly between
  phases
- "fill" stream was measured as "miss" stream instead of
  "cachable miss"; polyfill-2.pg was not affected because all
  polyfill objects were cachable
- gettimeofday(2) system call is broken on FreeBSD; make sure
  internal Polygraph clocks never go backwards and show sane
  values
- avoid infinite recursion coredumps when we fail to write a
  log entry; report and try to salvage logging errors instead
- do not dump core if a phase has no name, use "" name instead


2.2.6 -> 2.2.7
19991215
- added "--time_scale" option to lx; positive values make lx to
  print relative [to the run start] time for traces, scaled by the
  specified amount
- added "Traces" macro to represent all "traceable" objects in lx
- added rptm_mean:hit and rptm_mean:miss to lx's All micro
- only redirect standard output when --out option is used (lx); used
  to redirect error streams as well
- try to skip corrupted entries in [otherwise valid] binary logs
- implementation of lognormal distribution used incorrect standard
  deviation leading to occasional huge objects and
  smaller-than-configured means
- changed content sizes for cntOther and cntDownload after fixing
  the lognormal distribution bug to get the right mean object size
- removed percents from Server.direct_access specs; those values are
  ignored by Polygraph because servers calculate them from scratch
  to match "global" content distribution
- the sum of squared values was not computed correctly leading to
  incorrect readings for standard and relative deviations for
  samples with sampled values larger than 46341

2.2.5 -> 2.2.6
19991207
- PolyMix-2 workload now uses 0.4/sec per-robot request rate; use
  cloning or IP aliases to get more robots (and hence higher
  request rates)
- added "rep_sz_mean" object to lx
- added polyfill-2.pg to workloads/
- added pmix2 blob to tools/BB/bb.pl and polished bb.pl's comments
- when using --dump, dump transaction meta-info even if there is
  no message data to dump
- recognize KB scale for command line size options
- two meant-to-be-independent random number generators used for
  simulating object sizes got "in-sync", producing wrong size
  distributions
- phases with decreasing request rate were dropping request rate
  too fast
- public_interest for PolyMix-1 and DataComm-1 workloads should be
  set to 0%, not 50%.
- added now-required hit ratio and popularity model specs to
  datacomm-1.pg
- avoid division by zero on corrupted log files


2.2.4 -> 2.2.5
19991129
- added "idle_pconn_tout" field to Agent to specify the maximum
  time an idle (no pending transactions) persistent connection
  should remain open (PGL)
- support phase-dependent recurrence ratio; useful for populating
  the cache (fast, with only a few hits) and then doing
  measurement phase with appropriate hit ratio, all in one run
- added "recur_factor" field to Phase (PGL)
- added support for priority scheduling: Polygraph runs (N-1) file
  scans for file descriptors (connections) that require urgent
  action and then one scan for all file descriptors; N is
  configurable using the --priority_sched option
- added "--priority_sched" option to control priority level for
  somewhat urgent socket I/O operations; giving higher priority to
  some operations may improve performance in environments with
  lots of probably idle connections as Polygraph will spend less
  time processing those connections; "over-optimized" setting are
  likely to cause noticeable increase in response time; the
  default priority is 5; to disable the optimization, set to 1
- added support for assigning the same value to several variables
  with one assignment operator (PGL): [ a1, a2, a3 ] = 100%;
- added support for randomly distributing values of an array among
  several arrays, each with an optional "portion" quantifier; for
  example:
        [ arr1 : 60%, arr2 : 20%, arr3 ] = '10.0.1.1-255';
  this feature is very convenient when distributing network
  addresses among several objects (e.g., servers or pipes) (PGL)
- grow storage area for new oids when clients start to run out of
  them (to make prefetching more aggressive)
- optimized initial server scan (when robots are "touching" all
  servers to make sure robots can later generate hits on every
  server); the scan is now much faster and has more random access
  pattern
- added reporting of server scan progress
- "lock" first phase until all robots are ready to hit all servers
- when an advertised oid has not been requested for a while, see
  if we should grow the bitmap to store more oids (and hence keep
  an oid for a longer time) instead of reclaiming that stuck oid
- changed default for "--new_oids_prefetch" from 256 to 128
  because Polygraph is not capable of dynamically adjusting
  prefetch amount
- if load factor reaches zero, stop submitting requests
- check for late alarms and other timers and report if we are
  getting behind the schedule
- server now accepts new connections for at most 10msec at a time
- do not quit when running out of file descriptors in accept()
  call
- destroy PGL objects after use to reduce memory footprint for
  large scale configurations
- use idle_pconn_tout of 15 seconds for PolyMix-2 servers
- changed Robot.open_conn_lmt to 4 in polymix-2.pg
- polished phase definitions in polymix-2.pg
- check for error status when deleting rules and pipes (piper)
- re-ordered screens in polymon
- resurrected err_cnt_tbl in lx
- the "--phase" option was not supported for non-traceable objects
  (lx)
- fixed introduced in 2.2.4 typo that made servers "blocking" and
  hence unusable (they would get stuck in the accept(2) call);
  client-side sockets were also affected but that was not visible
  to an end-user because blocking robots may still work; the patch
  was posted to the Polygraph list
- portability star, ncurses, #defines timeout causing namespace
  havoc
- bad guys #defined `select' in Solaris system files causing
  namespace havoc
- I/O buffer pool was not reporting memory growth correctly (err..
  at all)
- prevent coredumps when printing a histogram with max value less
  than 1 (lx)
- True64 requires a special setsysinfo(2) call to raise FD limit
  beyond the default hard limit of 4K


2.2.3 -> 2.2.4
19991109
- added "piper", a program to configure DummyNet network pipes
  based on PGL
- added 'bwidth' -- a basic PGL type to represent [network]
  bandwidth small set of operations are supported for now
- added NetPipe PGL type to describe network pipes; a pipe
  specifies maximum network bandwidth, packet delay and loss,
  and other low -level network parameters/conditions
- added pipes.pg with definitions of commonly used network pipes,
  including modems and various kinds of origin servers
- added configure-time check for DummyNet and IPFW interfaces
- reduced start-up time in configurations with large number of
  robots and servers; reduced memory footprint for large
  configurations (more work may be needed)
- print aggregate statistics (min/mean/max/etc) for histograms
  produced by lx and distr_test
- report agent creation progress every 5 seconds rather than
  every 50 agents
- report system resource usage before and after run
- adjusted the way stat intervals (i- lines on the console) are
  printed in a blocking or overloaded environment
- increase the maximum number of FD ./configure script can
  detect to 2^16 (65K)
- fixed configuration bug in environments with no rlim_t type
- include limits.h file to avoid compilation errors on Solaris
- do not print "array probabilities (above) add up to .. less
  than 100%" if they add up to more than 99%
- cntDownload in contents.pg was named cntDowload; some found it
  funny
- lx could not handle logs with combination of duration-based
  and non-duration based phases
- some environments do not know better than #define getc and
  putc macros causing namespace havoc
- rptm_hist was printed twice by lx --objects All
- a typo caused size type to do multiplication instead of
  division (PGL)


2.2.2 -> 2.2.3
19991026
- added "--sample_log" and "--sample_log_size" options to
  configure sample log; sample log defaults to the general
  purpose log; if separate log is specified, it is not flushed
  to disk on periodic basis as general log (to avoid potential
  run-time overhead)
- added "StatsSample" object to PGL to describe the time and
  size of a statistical sample; Samples must be scheduled(),
  just like Phases; more work needed to make scheduling more
  convenient (phase related?)
- added "kind" field to label Content object (PGL)
- added "cntDowload" content to represent relatively large
  downloads; use cntDowload in PolyMix-2
- disabled sharing of embedded objects among containers; with no
  sharing, we have to rely on user specified content
  configuration with no tools to "tune" the model internally --
  resulting (actual) global content distribution may not match
  the planned one; a likely global distribution is reported so a
  user can check their specs without running an experiment
- disabled client side cache in PolyMix-2
- set embedded recurrence to 100% in PolyMix-2
- added initial support to save experiment "state"; eventually
  we will use state information to resume experiments from a
  given point and also for stats analysis; needs more work
- added support for collecting low-level statistics in the form
  of samples; sample collection is controlled using PGL
  "StatsSample" type and "schedule()" call
- for large configurations, inform about the progress in
  creating agents at startup
- prevent int overflows when generating very large files
- several bug fixes related to size constants (PGL)
- try to handle "unlimited" resources reported by getrlimit(2)
  correctly


2.2.1 -> 2.2.2
19991020
- added "cache_cap" field to Robot (PGL); the cache is currently used
  for embedded objects only; it prevents robots from requesting the
  same embedded objects many times, emulating browser behavior
- added "conn_lvl_mean" lx object to report average number of opened
  concurrent connections; because of Polygraph does not update time on
  every open() and close(), this statistics may not be accurate
- robots now scan all servers (in a semi-random manner) before
  proceeding with truly random accesses; the initial scan ensures
  that all connectivity problems are detected early and also helps
  reach stable HR earlier
- inform user when all robots are ready to generate hits on all
  servers
- no "wait_xact_lmt" by default, a robot can queue as many
  transactions as needed; this is potentially dangerous because a user
  does not see those queued transactions (yet) and may think that
  everything is OK; more work is needed
- generate new oids only when we know that the xaction will not be
  queued; this rule prevents robots from thinking an oid has already
  been seen by a proxy while it was not (because it got queued); the
  latter used to decreases offered hit ratio
- agents should share random number generators to avoid a
  hard-to-detect artificial condition when all agents are "doing the
  same" all the time (e.g., all robots send requests to the same
  subset of servers for a while)
- if no new alias is specified, just delete old ones (aka)
- make sure that we always #include sys/types.h before inet.h because
  old BSD systems may not include sys/types.h in inet.h, and they
  should
- removed --out option from aka
- fixed a bug that led to an occasional assertion if the FD limit is
  reached on server side
- fixed bugs leading to occasional segv and assertions when poll(2)
  system call is used
- fixed parsing of the --dump option; now all tag combinations are
  parsed correctly
- request rate field of a Robot was misinterpreted unless N/sec format
  was used (PGL)
- due to ioctl(2) interface differences, aka does not work on Linux
  and probably some other OSes; more work is needed
- fixed IP range parsing bug; some valid ranges were declared
  malformed
- logging modifications; binary logs are not compatible with previous
  versions (again)
- updated polymix-2.pg and contents.pg; changed content weights to
  ensure that an "average" object has 80% chance of being cachable

2.2.0 -> 2.2.1
19991012
- added support for IP ranges using a-b.c-d.e-f.g-h notation,
  for example '10.0.1-2.50-99' constant specifies an array of
  100 addresses; the old range operator (A .. B) is still
  supported but is less flexible; subnet and/or port
  specification is also allowed
- added "aka", an ingeniously named tool to create [large]
  number of IP aliases for a given interface; aka accepts IP
  specs in the PGL format (a-b.c-d.e-f.g-h/subnet) which allows
  for specifying hundreds of aliases in a compact form; aka will
  _delete_ all aliases for the interface before setting new
  ones; aka requires superuser access, of course
- added "new_oids_per_msg_max", "new_oids_prefetch", and
  "new_oids_history" options to control synchronization between robots
  and servers; may be useful if you get many oid-related errors in
  large scale experiments and/or when a proxy gets too slow or drops
  requests
- added "open_conn_lmt" and "wait_xact_lmt" fields to Robot
  (PGL) to limit the number of concurrent connections a single
  Robot may have at a time, emulating browser behavior (the code
  was written for version 2.2.0, but lacked PGL hook-ups and was
  not tested)
- removed place() function call and replaced 'host' field in
  Agent with 'hosts' field to reduce memory footprint when
  configuring lots of agents on a single machine; place() call
  used to clone lots of agent specs that would differ only in
  'host' field setting; we now specify all the hosts directly
  (in 'hosts' field) bypassing the cloning step (PGL)
- added "conn_close_act_use_hist" and "conn_close_act_ttl_hist"
  lx objects to filter stats for "actively" closed connections
  only (i.e., all connections except those that were closed in
  an "idle" state)
- agents where not binding to their addresses when they were
  supposed to
- robots used to maintain one private object space as if there
  was only one origin server; the bug led to lower than expected
  hit ratios when robot's public_interest was less than 100%
- robots were not setting server world id (wid) for embedded
  requests
- statistics for idle persistent connections closed by Polygraph
  was not maintained
- synchronized workload specs


2.1.0 -> 2.2.0
19990928
- added support for embedded objects: a server populates content with
  special tags that point to embedded objects (based on PGL Content
  specs); a robot parses server responses for those tags; a robot
  requests embedded objects as it detects them; we try to keep average
  request rate at the specified level (if any) despite these "extra"
  requests requests for embedded objects do cause bursts in traffic,
  just like in the real worlds
- added may_contain and embedded_obj_cnt fields to Content type (PGL)
- added "embed_recur" ratio to Robot; the ratio specifies the portion
  of embedded objects in a container that are re-requested, on average
- added "choice_space" field to Content type (PGL); Choice space
  specifies the number of oids considered when selecting next embedded
  oid for a container oid:
    embedded_oid = uniform(k*container_oid, k*container_oid + choice_space)
- added "direct_access" field to Server (PGL); direct_access selector
  specifies (a) objects that can be accessed not as an embedded part of
  other object and (b) relative frequency of such an accesses (e.g. 1%
  of all direct accesses are images and 95% of all direct accesses are
  HTML pages)
- added tools/msl_test tool that attempts to estimate the maximum time
  a proxy keeps a TCP connection in a TIME_WAIT state. (Glenn Chisholm
  <glenn at ircache dot net>)
- added rng_test to test the quality of various random number
  generators that Polygraph is using
- added the "--dump" option to control what type of messages and what
  message parts must be dumped to console. The option accepts a list of
  flags; the old --prn_* interface was not flexible enough or required
  too many options; new interface needs more work
- renamed "--prn_dump_size" to "--dump_size"
- removed "--prn_reqs", "--prn_reps", and "--prn_errs" options
- robots must bind(2) to the IP addresses they are running on except
  when all robots are running on the same address
- report approximate time a server waited for an advertised oid to be
  requested
- always randomize IO buffers before use
- use agent id along with object id when seeding r.n.g; this prevents
  skew in pseudo-random numbers when many agents are dealing with the
  same small subset of oids
- use one port manager for all addresses to reduce memory footprint for
  big scale runs
- install SIG_INT (^C) handler _after_ polyclt/srv has configured
  itself; makes possible to kill a program if configuration takes
  forever
- workload files were missing server side delays (Becky Larsen
  <balarsen at novell dot com>)
- polymix-2.pg file comments were saying that it is a PolyMix-1 file
- fixed typo in [client] "closed conn w/o sending data" error message
- polymon.cc::TheSelHostCnt was not defined properly, causing
  compilation warnings (Ron Jones <ronjones at himalaya dot fc dot hp
  dot com>)
- udp2tcpd.cc was using `int' instead of `socklen_t' causing
  compilation errors on Linux and others OSes that require socklen_t
  (Ron Jones <ronjones at himalaya dot fc dot hp dot com>)
- a kludge to prevent mysterious (compiler?) bug causing segmentation
  faults in RecSym::getDistr on some platforms

2.0.0 -> 2.1.0
19990917
- added pop_test program that simulates an LRU-based cache and can be
  used to estimate [memory] hit ratios depending on popularity model
  and other related workload parameters
- added "pop_model" field to Robot; two popularity models are
  supported:  pmUnif() and pmZipf(skew_factor).
- added "public_interest", "recurrence", and "unique_urls" fields to
  Robot
- added working_set_length() procedure call to PGL; use it to limit
  working set size and hence prevent hit ratio decline during long
  tests
- added a "--prn_dump_size" option to limit the size of HTTP message
  dumps
- added a "--prn_errs" option to print HTTP messages that caused
  xaction errors
- recognize 'All' macro in --phase option (lx)
- removed "--unique_urls" option (polyclt) -- it is now Robot's field
- removed unused `world' options (polyclt): world_type, world_id,
  world_urls, unique_urls, order, recur, pop_model, tmp_loc,
  tmp_loc_delta, tmp_loc_depth, exp_oids, prefilled_cnt; some of these
  option were already implemented via PGL, and some wait till be
  implemented/ported/tuned
- removed the "dhr" field from Robot specs (the field was ignored
  anyway)
- share URL space among all robots and servers; robots may have a
  "private" URL subset while "public" subset is shared by all; servers
  send robots information about the current global state; current
  limitation is that all polyclt processes should emit request streams
  with similar rate (per robot differences are OK), otherwise the
  servers start complaining that some clients are not doing their
  share in creating the load; solving the latter problem would require
  more heavy negotiations among clients and servers
- make IO buffer content "more random" than it used to be; servers now
  produce Web objects filled with more random content. Note that
  servers still may produce different content for the same URL, even
  if the headers imply that the object has not changed. The latter is
  probably OK under "normal testing conditions" though.
- do NOT make relative URIs artificially long by prepending them with
  an '/http:/ip-address' prefix; transparent proxies usually receive
  relative URIs so they do have and advantage of handling shorter
  request-lines, and we probably should simulate that
- HTTP/1.0 connections are non-persistent by default, no need to send
  *Connection: close header.
- write all 'unique ids' (e.g., world id) using hex notation and fixed
  length fields
- write oids in URLs using hex notation and fixed length fields
- console now displays minutes since the start of an experiment rather
  than absolute time; absolute time is logged and is available to lx
- when building executables, use CXXFLAGS instead of CFLAGS in
  Makefiles
- "conn_ttl_vs_use" was erroneously named "conn_ttl_vs_sz"
- fixed parsing bug that caused assertions on a "''" expression
- offered (ideal) hit ratio was not recorded properly


1.3.2 -> 2.0.0
19990907
- new copyright file header and polished licensing terms
- added support for PGL configuration language; most experiment
  parameters are now set via a configuration file
- "--pop_model" option defaults to "unif"orm now (used to be "zipf")
- added the "--idle_tout" option to the client side; "idle" in
  "--idle_tout" now means "no network I/O activity" -- Polygraph may
  still be trying to do something
- added the "--stats_cycle" option to specify the duration of a cycle
  that collects and logs "cheap" stats (defaults to 5 seconds)
- added "fill size" experiment goal
- removed accept_lmt, rep_sz, obj_bday, obj_life_cycle,
  obj_life_cycle_var, obj_with_lmt, obj_expire, cool_phase, goal,
  launch_win, rep_cachable, maximize_req_rate, and perhaps other
  options; similar functionality is usually provided in PGL
- renamed "--dhr" to "--recur" (recurrence ratio or how often a URL is
  revisited by a robot); in Polygraph 2.0.0 the actual DHR is
  recurrence/cachability ratio; DHR may be affected by popularity
  model and other factors; we had to rename "--dhr" because Polygraph
  can no longer simulate any given DHR independent from other config
  parameters -- the models are becoming too complex; this is still
  work in progress and changes are likely
- removed `ephemeral' string as a valid port range in --ports
- the "--file_scan" option now defaults to poll if poll(2) is
  supported; Polygraph used to call select(2) by default
- added conn_close_frgn_use_hist,conn_close_frgn_ttl_hist,
  conn_close_lcl_use_hist,conn_close_lcl_ttl_hist, soread_sz_hist,
  sowrite_sz_hist, and phase_name objects to lx
- made 'All' macro a default "object" to be extracted by lx
- honor --phase option in trace mode of lx
- changed binary log format; new format is not backwards compatible
- log errno strings along with errnos; makes error logging portable
  across OSes
- modified logging procedure to flush binary log data periodically
- removed "X-ETag" header field
- send Proxy-Connection: header when talking to a proxy (used to send
  Connection: which was a terrible idea and was not honored by some
  proxies)
- added support for Content-Type header field in responses
- added support for arbitrary number of user-defined simulation
  "phases"
- cachability is now determined on the server side (again!)
- added ./configure script to preconfigure the distribution before
  `make'
- added INSTALL file with generic package installation instructions
- added root-level Makefile
- added distclean goal to Makefiles to remove most auto-generated
  files
- changed Perl interpreter name in scripts to '/usr/bin/perl'; ideally
  we need to determine the location at ./configure time
- explicitly require Perl version 5.003 or higher in Perl scripts
- added DataComm-1 specs to bb.pl
- added workloads directory with standard workloads specs written in
  PGL.
- added polymix-1.pg, polymix-2.pg, and datacomm-1.pg workload specs
- added simple.pg, a minimalistic workload to use as a "Hello World"
  example
- complain about "uncachable hits"
- ignore "false hits" by default
- removed hard coded limits on the reply content size; the change may
  have performance effect for workloads with zipf popularity model
- removed 'loop' tool until it gets fixed
- applied some HPUX compatibility patches (submitted by James Murphy
  <murphy@fc.hp.com>)
- 'max' values printed by distr_test was greater than real max by one
- lots of other additions, modifications, and bug fixes


1.3.1 -> 1.3.2
19990830
- this minor release incorporates all previously released patches for
  1.3.1; the pathces fix a few logging bugs and, to the best of our
  knowledge, do not affect Polygraph run-time performance
- replaced the "--prn_trace" lx switch with the "--trace" option; now
  trace stats can be averaged at a specified time interval; small
  window sizes emulate old behavior
- added "conn_use_mean" object to lx
- added datacomm-1 workload specs to bb.pl script
- increment error count on each phase/log
- fixed generation of class-based object names
- fixed lx coredump when extracting class-based stats like 
  class_rptm_mean:hit

1.3.0 -> 1.3.1
19990616
- added the "--notify" option that enables notification messages to be
  sent to a monitoring program; messages (currently less than 100
  bytes) are sent via UDP every 20 seconds.
- added "--label" option to specify a [short] run description; the
  label gets included into notification messages if any.
- added udp2tcpd, a daemon that runs on port 18256 (default), listens
  to notification messages (UDP), and forwards them to polymon(s) via
  TCP; the intention is to support multiple monitoring programs for
  the same notification stream without using IP multicast or broadcast
- added polymon; a ncurses-based program that monitors run-time status
  of Polygraph experiments using udp2tcpd daemon
- added the err_cnt_tbl option to lx to print error table; note that
  Unix error codes are not standardized so you may get different
  descriptions of error messages if you move binary logs around (this
  is a bug)
- fixed "invalid port" assertion in ExpPortMgr
- fixed logging of error table (it probably was not logged before)
- fixed compile-time warnings reported on Linux
- fixed compile-time poll(2) errors on Linux
- fixed a few compile-time problems on Solaris
- maybe improved timegm() port to True64 and other environments with
  tm_gmtoff
- removed custom polyVersion dependency from Makefile; it caused too
  many re-compilations and we never used the $CompileTime$ feature
  anyway
- polished comments in Makefiles


1.2.2 -> 1.3.0
19990608
- added poll(2) support; users must add -DLACK_POLL to DEFINES
  in src/xstd/Makefile in the environments without poll(2);
- added the "--file_scan" option to select between poll(2) and
  select(2); the default is still select, but that is likely to change
- added the "--maximize_req_rate" option that enables "maximum request
  rate" searching mode; must be used together with the "--req_rate"
  option which specified initial rate; search is done by incrementing
  or decrementing actual request rate depending on the reply rate;
  support is rudimental, more work needed
- added the "--prn_rep_cnt" option to lx; similar to --prn_time;
  prepends trace lines with number of replies received since log start
- added response time statistics for major request classes:
  hits, misses, cachable, uncachable, etc.
- added several lx objects to extract new stats: conn_use_hist,
  conn_ttl_vs_use, resp_tm_vs_class, class_rptm_mean
- added stats for persistent connections (xactions per connection)
- "rep_rate" and "req_rate" objects are now traceable via lx
- log errors "histogram"
- scan the port range and mark used ports at start-up if port manager
  is enabled via the "--ports" option; the scan adds about 2.5 seconds
  to polyclt start but avoids some of the run-time port binding errors
- improved random number generation; do not use object ids as r.n.g
  seeds directly; generate a "good" "uncorrelated" random value and
  use that instead; prevents "loops" in reply size generation and
  other oid-dependent models; the loops were visible only on some
  micro-level workloads though; 
  the fix adds a few seconds to polyclt/srv start time and about 4MB
  to memory footprint
- adjusted histogram dumps so that max column in the output
  corresponds to max rather than max+1
- avoid floating point exceptions when reading bogus log data
- improved handling of incomplete or old binary logs in lx
- fixed FP exception error due to wrong double->int cast
  (a patch was available for 1.2.2)
- use "linux" #define to prevent "FD_SETSIZE already defined"
  warnings on Linux (one can also add -DLINUX in Makefiles)

1.2.1 -> 1.2.2
19990521
- added distr_test tool that can print a histogram for any
  distribution recognized by Polygraph
- added the "--prn_trace" lx option to print trace stats
  rather than totals; not all object values can be computed in
  the middle of a log; those that can, will be printed; others
  will be silently ignored; log files are not joined when trace
  mode is on
- added the "--prn_time" lx option to show log time as a first
  column of the output (useful together with --prn_trace)
- added support for accumulating large sizes (over 2GB);
  yet untested; old counters used to overflow leading to 
  bogus byte hit ratios; current counters can hold up to
  about 4 exabytes which should be enough for a while
- timegm is missing on Solaris; Solaris users should add 
  -DLACK_TIMEGM to DEFINES in xstd/Makefile to enable a
  workaround
- several bug fixes in Histogram module; trace stats
  (collected at 90 second intervals) that were based on
  histograms (e.g., response time percentiles) where not
  recorded correctly; aggregate stats (e.g., means) and stats
  averaged over entire phase were not affected
- Zipf distribution was not generating the value of '1' when
  used for persistent connection limits; other zipf fixes
- fixed "ambiguous overload for `bool ? Size : int'" compilation
  errors
- zipf distribution now reports "world size" parameter only to
  be consistent with the way zipf is specified on the command
  line (used to print alpha=1 as a first parameter)
- other minor bug fixes


1.2.0 -> 1.2.1
19990513
- added the "--obj_bday" option to specify object creation
  times; used to be hard-coded to a randomly (per object) chosen
  day in the 70s; negative birthdays are relative to program
  start time; non-negative birthdays are relative to 0, UTC;
- accept "zipf" distribution on command line
- time parsing routines now accept "year" scale
  (e.g., const:1.5year)
- report Polygraph version in the configuration dump
- internal lmt and expires time must be rounded using second
  resolution for HTTP date comparisons to work correctly
- polished last-modified-time calculations to better handle lmts
  that are close to current time
- renamed XSTD_INCLUDE to LIB_INCLUDE in xstd/Makefile


1.1.0 -> 1.2.0
19990501
- added Object Life Cycle model to simulate object modification and
  expiration; the model is controlled by the following server side
  options: --obj_life_cycle, --obj_life_cycle_var, --obj_with_lmt,
  and --obj_expire
- support If-Modified-Since requests on server side
- Poly-server now adds the Date: header field to all replies
- removed "max-age" option from cachable replies because it had
  priority over the more common Expires: header. As a side effect
  not all cachable replies have expiration information
- Last-Modified header field is now added to replies only if
  --obj_life_cycle option is enabled; some proxies will not cache
  replies without a Last-Modified header field -- watch out!
- Expires header fields are not added to cachable replies by default;
  see --obj_expire option to control Expires fields
- reordered HTTP reply header fields to follow HTTP recommendations
- always use the minimum of FD_SETSIZE and getrlimit(RLIMIT_NOFILE);
  warn if FD_SETSIZE is smaller; we got tired of coredumps when
  a tester would forget to increase FD_SETSIZE after increasing
  kernel limits
- date manipulation functions now use "timegm()" call which may
  not be portable; portability problems will be fixed on-demand
- distinguish between "premature end of msg body" and "premature end
  of msg headers"; useful to diagnose proxy connection resets
- detect premature end of headers on client side (we probably would
  wait forever prior to this fix)
- reorganized and optimized HTTP header parsing; parsing speed is
  increasingly important as we have to recognize more header fields;
  current improvement (on 2.5 fields) is negligible (about 3%).
- fixed a bug with HTTP header parsing (a patch was available for
  1.1.0)


1.0p7 -> 1.1p0
19990425
- added a "--version" option to print package version and (c) info
- ident-like routines may extract version info from Poly binaries now
- added a "--pconn_use_lmt" option to control the number of
  transactions executed over a single [persistent] connection; Poly
  generates (and understands) Connection: close/keep-alive headers,
  and will honor Proxy-Connection: header as well; mutli-token
  Connection: headers are not supported; the option makes sense on
  both client and server sides; TCP may need "--nagle off" to utilize
  the advantage of pconns
- added support for user-defined (tabulated) distributions;
  "tab:filename" or "tab(filename)" can be used wherever a
   distribution is expected on the command line
- changed the default of the "--origin" option to "127.0.0.1:8080"
- the "--proxy" option has no default now and implies proxied
  connection if present; with no "--proxy" option, a direct connection
  is assumed
- removed the "--abs_urls" option; absolute (relative) urls are now
  generated only for proxied (direct) traffic
- added libs target to Makefile to ease re-build of libraries
- make will now clean src/xstd directory when making clean in src
- the "--rng_seed" option is now honored by all rnd number generators
- complain if units (KB, sec, etc.) are specified where none expected
- added reporting of source code location in error messages
- check for connect errors during first IO on a socket; Poly 1.0 would
  do an I/O and only then check for an error leading to imprecise
  error diagnostics
- set socket options for accept(2)-ed sockets (server side), do not
  rely on inheritance; BSD OSes silently suppress inheritance of some
  flags like TCP_NODELAY (Nagle algorithm)
- response time now includes connection setup time
- fixed member initialization bug in StatPhase.cc that caused 
  coredumps on Linux


1.0p6 -> 1.0p7
19990405
- added rep_sz_hist, rep_sz_mean, resp_tm_vs_sz, req_bhr, rep_bhr
  objects to 'lx' (byte HRs are broken for long experiments)
- added --track_rports and --rport_wait_min options to track TCP port
  usage on the proxy side; unfortunately tracking is complicated by
  known TCP violations of most BSD implementations
- fixed 'lx' bug with aggregating reply rate from logs with
  different phase durations
- applied bake-off mods to bb.pl


1.0p5 -> 1.0p6
19990310
- added "lx", a routine to eXtract objects from binary logs; also
  mergers logs to support multiple client/server experiments
- added "exprep.pl" script to generate reports from binary logs
  of several experiments (needs more work)
- replaced all ETag: headers with X-ETag (requests and replies); 
  ETag is not a request header and gets filtered out on some proxies
- added "Last-Modified: Wed, 18 Feb 1998 17:53:58 GMT" reply header 
  to cachable replies; some proxies may not cache replies otherwise
  (a magic constant value should be eventually eliminated)
- changed the default for the "--log_size" option to 10KB
  with no logging and 10MB with logging enabled
- various fixes to handle log buffer overflows; we now ignore all
  new entries if the buffer is full (needs more work)
- fixed a lot of bugs in interpreting logged data (recording was OK?)
  no program was interpreting logs so bugs stayed undetected
- mandatory phases should not stop even when too many errors;
  we used to abort if that happens (needs more work to detect
  error flood early as we used to)
- increased required verbosity level for "got N xactions..." message
  to 2; a more detailed but less readable progress/goal message is
  printed with a verbose level of 0.


1.0p3 -> 1.0p5
19990223
- added "--prefilled_cnt" option
- added Uniform Popularity Model
- minor polish and bug fixes


1.0p3 -> 1.0p4
19990222
- added "--ign_false_hits" option; by default false hits are
  now treated as xaction errors
- added "--prn_false_misses" option; handy to see what hits
  a proxy has "missed"
- added the "--tmp_loc_depth" option that specifies a soft limit
  on inter-request distances in tmp locality model
- added "--tmp_loc_delta" option to specify fuzziness of temporal 
  locality choices
- added "--cool_phase" option to specify minimal cool-off phase;
  handy when you run more than one polyclt and do not want one
  of them to stop when others are still in their measurement phase
- added "--fd_limit" option to lower FD limit supplied by OS 
  (as a safeguard for OSes that crash when we run out of FDs)
- added "--phase" option to log reader to show more stats about
  a particular phase (needs more work)
- added support for error limit (given in the --goal option)
- added ETag headers to pass object specific info from the client 
  to the server
- better facilities for logging and reporting various errors
- record ideal (i.e, offered) Hit Ratio
- record actual cachability ratio
- added lognormal distribution to the list of distributions
  available on the command line (logn:mean,sdev)
- print number of hits, misses, errors, etc. in lr
- enforce a safeguard FD limit of (0.97*rcur - 10), where "rcur"
  is the FD limit enforced by OS according to getrlimit(2)
  the "--fd_limit" option can be used to lower this value
- shutdown nicely on exit or fatal external error
- count and report the number of open sockets; the last column
  of the console output now shows number of open FDs, not just
  pending xactions
- revised traffic model operation and simplified the interface
  now traffic characteristics are controlled individually rather
  than via an ugly --world_oids option
- constant hit ratio now works correctly regardless of cachability
  ratio and other traffic parameters
- moved --rep_cachable option from the server side to the client 
  side
- changed tmp locality model to use future "plan" instead of past
  "history"; old model was emitting too many too close requests;
  current model follows the --tmp_loc distribution much better
- complain if cachability status of a reply has changed
- print various FD limits on start
- r.n.g. seed was not properly changed when calculating reply sizes,
  resulting in same object ids having different content length if
  requested more than once by a proxy


1.0p2 -> 1.0p3
19990215
- added initial support for Constant Hit Ratio; we have several
  models (Object Ids distributions) to choose from, see
  --world_oids
- added --world_oids option to specify Object Ids
  "distribution"; currently supported "distributions" meaningful
  for --world_oids are:
    . sequential ("seq"),
    . MemoryLess Zipf ("MLZipf"),
    . Hot/Cold ("HoCo");
  names will change if we find better ones
- changed default behavior when no --world_oids is specified: we
  used to generate Zipf-like stream of Object Ids by default,
  now the default is Sequential stream (hence, no hits by default)
- removed --world_cap option; we no longer need/use World Capacity
- added "Expires: Wed, 17 Feb 2000 03:35:25 GMT" header to
  cachable responses; this constant should be good enough in
  most cases and will be changed to a dynamic value in next
  releases
- added "Pragma: no-cache" to uncachable responses
- better explanation for errors with distribution specs on the
  command line
- fixed zero Content-Length bug
- fixed time accounting bug (visible at least on FreeBSD 3.0)
- define _BSD_SIGNALS to make IRIX happy (needs more work)


1.0p1 -> 1.0p2
19990212
- added support for specifying distributions on the command line;
  currently available distributions: unif, exp, norm, and const
- added support for specifying ratios and such on the command line;
- "--rep-size" is now of type Size Distribution (default: exp(13KB))
- "--xact_think" is now of type Time Distribution
- "--rep_cachable" is now of type Ratio (e.g. 80%)
- renamed "--users" to "--robots"
- value "0" does not require scale any more ("0" == "0sec" == "0min")
- report number of outstanding xactions in i-stats (new last column)
- increased verbosity level required for i-stats to 2
- fixed parsing of floating point values on the command line
  (used to be truncated to int)
- #warn, not #err if FD_SETSIZE is #defined suspiciously early


1.0p0 -> 1.0p1
19990207
- added time support in goal option
- enabled --launch_win support
- enabled --xact_think support 
  (per xaction think times on both sides)
- added constant req submission rate mode (--req_rate)
- replaced --req_ccl with --users (just a name change)
- added support for absolute/relative urls (--abs_urls option)
- added Host: header (all requests)
- many binary logs fixes and improvements
- many stats fixes
- disable SO_LINGER if linger_tout == 0
- drastically improved memory management; 
  now Poly runs out of filedescriptors before running 
  out of memory on high loads
- account for BSD select(2)'s magic limit on timeout value
- internal alarms now use Heap instead of LinkedList

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