supervisor/CHANGES.txt

Next release
------------

- The ``pid`` command in supervisorctl can now be used to retrieve the PIDs
  of child processes.  See ``help pid``.  Patch by Gregory Wisniewski.

- Added a new ``host_node_name`` expansion that will be expanded to the 
  value returned by Python's ``platform.node`` (see
  http://docs.python.org/library/platform.html#platform.node).  
  Patch by Joseph Kondel.

- Fixed a bug in the web interface where pages over 64K would be truncated.
  Thanks to Drew Perttula and Timothy Jones for reporting this.

- Renamed ``README.txt`` to ``README.rst`` so GitHub renders the file as
  ReStructuredText.

3.0a10 (2011-03-30)
-------------------

- Fixed the stylesheet of the web interface so the footer line won't overlap
  a long process list.  Thanks to Derek DeVries for the patch.

- Allow rpc interface plugins to register new events types.

- Bug fix for FCGI sockets not getting cleaned up when the ``reload`` command
  is issued from supervisorctl.  Also, the default behavior has changed for
  FCGI sockets.  They are now closed whenever the number of running processes
  in a group hits zero.  Previously, the sockets were kept open unless a
  group-level stop command was issued.

- Better error message when HTTP server cannot reverse-resolve a hostname to
  an IP address.  Previous behavior: show a socket error.  Current behavior:
  spit out a suggestion to stdout.

- Environment variables set via ``environment=`` value within
  ``[supervisord]`` section had no effect.  Thanks to Wyatt Baldwin
  for a patch.

- Fix bug where stopping process would cause process output that happened
  after the stop request was issued to be lost.  See
  https://github.com/Supervisor/supervisor/issues/11.

- Moved 2.X change log entries into ``HISTORY.txt``.

- Converted ``CHANGES.txt`` and ``README.txt`` into proper ReStructuredText
  and included them in the ``long_description`` in ``setup.py``.

- Added a tox.ini to the package (run via ``tox`` in the package dir).  Tests
  supervisor on multiple Python versions.

3.0a9 (2010-08-13)
------------------

- Use rich comparison methods rather than __cmp__ to sort process configs and
  process group configs to better straddle Python versions.  (thanks to
  Jonathan Riboux for identifying the problem and supplying an initial
  patch).

- Fixed test_supervisorctl.test_maintail_dashf test for Python 2.7.  (thanks
  to Jonathan Riboux for identifying the problem and supplying an initial
  patch).

- Fixed the way that supervisor.datatypes.url computes a "good" URL
  for compatibility with Python 2.7 and Python >= 2.6.5.  URLs with
  bogus "schemes://" will now be accepted as a version-straddling
  compromise (before they were rejected before supervisor would
  start).  (thanks to Jonathan Riboux for identifying the problem
  and supplying an initial patch).

- Add a ``-v`` / ``--version`` option to supervisord: Print the
  supervisord version number out to stdout and exit.  (Roger Hoover)

- Import iterparse from xml.etree when available (eg: Python 2.6).  Patch
  by Sidnei da Silva.

- Fixed the url to the supervisor-users mailing list.  Patch by
  Sidnei da Silva

- When parsing "environment=" in the config file, changes introduced in
  3.0a8 prevented Supervisor from parsing some characters commonly
  found in paths unless quoting was used as in this example::
  
    environment=HOME='/home/auser'
  
  Supervisor once again allows the above line to be written as::
  
    environment=HOME=/home/auser

  Alphanumeric characters, "_", "/", ".", "+", "-", "(", ")", and ":" can all 
  be used as a value without quoting. If any other characters are needed in 
  the value, please quote it as in the first example above.  Thanks to Paul 
  Heideman for reporting this issue.

- Supervisor will now look for its config file in locations relative to the
  executable path, allowing it to be used more easily in virtual
  environments.  If sys.argv[0] is ``/path/to/venv/bin/supervisorctl``,
  supervisor will now look for it's config file in
  ``/path/to/venv/etc/supervisord.conf`` and
  ``/path/to/venv/supervisord.conf`` in addition to the other standard
  locations.  Patch by Chris Rossi.

3.0a8 (2010-01-20)
------------------

- Don't cleanup file descriptors on first supervisord invocation:
  this is a lame workaround for Snow Leopard systems that use
  libdispatch and are receiving "Illegal instruction" messages at
  supervisord startup time.  Restarting supervisord via
  "supervisorctl restart" may still cause a crash on these systems.

- Got rid of Medusa hashbang headers in various files to ease RPM
  packaging.

- Allow umask to be 000 (patch contributed by Rowan Nairn).

- Fixed a bug introduced in 3.0a7 where supervisorctl wouldn't ask
  for a username/password combination properly from a
  password-protected supervisord if it wasn't filled in within the
  "[supervisorctl]" section username/password values.  It now
  properly asks for a username and password.

- Fixed a bug introduced in 3.0a7 where setup.py would not detect the
  Python version correctly.  Patch by Daniele Paolella.

- Fixed a bug introduced in 3.0a7 where parsing a string of key/value
  pairs failed on Python 2.3 due to use of regular expression syntax
  introduced in Python 2.4.

- Removed the test suite for the ``memmon`` console script, which was 
  moved to the Superlance package in 3.0a7.

- Added release dates to CHANGES.txt.

- Reloading the config for an fcgi process group did not close the fcgi
  socket - now, the socket is closed whenever the group is stopped as a unit
  (including during config update). However, if you stop all the processes
  in a group individually, the socket will remain open to allow for graceful
  restarts of FCGI daemons.  (Roger Hoover)

- Rereading the config did not pick up changes to the socket parameter in a
  fcgi-program section.  (Roger Hoover)

- Made a more friendly exception message when a FCGI socket cannot be
  created.  (Roger Hoover)

- Fixed a bug where the --serverurl option of supervisorctl would not
  accept a URL with a "unix" scheme.  (Jason Kirtland)

- Running the tests now requires the "mock" package.  This dependency has 
  been added to "tests_require" in setup.py.  (Roger Hoover)

- Added support for setting the ownership and permissions for an FCGI socket.
  This is done using new "socket_owner" and "socket_mode" options in an
  [fcgi-program:x] section.  See the manual for details.  (Roger Hoover)
  
- Fixed a bug where the FCGI socket reference count was not getting 
  decremented on spawn error.  (Roger Hoover)

- Fixed a Python 2.6 deprecation warning on use of the "sha" module.

- Updated ez_setup.py to one that knows about setuptools 0.6c11.

- Running "supervisorctl shutdown" no longer dumps a Python backtrace
  when it can't connect to supervisord on the expected socket.  Thanks
  to Benjamin Smith for reporting this.

- Removed use of collections.deque in our bundled version of asynchat
  because it broke compatibility with Python 2.3.

- The sample configuration output by "echo_supervisord_conf" now correctly
  shows the default for "autorestart" as "unexpected".  Thanks to
  William Dode for noticing it showed the wrong value.

3.0a7 (2009-05-24)
------------------
 
- We now bundle our own patched version of Medusa contributed by Jason
  Kirtland to allow Supervisor to run on Python 2.6.  This was done 
  because Python 2.6 introduced backwards incompatible changes to 
  asyncore and asynchat in the stdlib.

- The console script ``memmon``, introduced in Supervisor 3.0a4, has
  been moved to Superlance (http://pypi.python.org/pypi/superlance).  
  The Superlance package contains other useful monitoring tools designed
  to run under Supervisor.    

- Supervisorctl now correctly interprets all of the error codes that can
  be returned when starting a process.  Patch by Francesc Alted.

- New ``stdout_events_enabled`` and ``stderr_events_enabled`` config options
  have been added to the ``[program:x]``, ``[fcgi-program:x]``, and
  ``[eventlistener:x]`` sections.  These enable the emitting of new
  PROCESS_LOG events for a program.  If unspecified, the default is False.

  If enabled for a subprocess, and data is received from the stdout or
  stderr of the subprocess while not in the special capture mode used by 
  PROCESS_COMMUNICATION, an event will be emitted.

  Event listeners can subscribe to either PROCESS_LOG_STDOUT or 
  PROCESS_LOG_STDERR individually, or PROCESS_LOG for both.

- Values for subprocess environment variables specified with environment=
  in supervisord.conf can now be optionally quoted, allowing them to 
  contain commas.  Patch by Tim Godfrey.

- Added a new event type, REMOTE_COMMUNICATION, that is emitted by a new
  RPC method, supervisor.sendRemoteCommEvent().

- Patch for bug #268 (KeyError on ``here`` expansion for
  stdout/stderr_logfile) from David E. Kindred.

- Add ``reread``, ``update``, and ``avail`` commands based on Anders
  Quist's ``online_config_reload.diff`` patch.  This patch extends
  the "add" and "drop" commands with automagical behavior::

    In supervisorctl:

      supervisor> status
      bar                              RUNNING    pid 14864, uptime 18:03:42
      baz                              RUNNING    pid 23260, uptime 0:10:16
      foo                              RUNNING    pid 14866, uptime 18:03:42
      gazonk                           RUNNING    pid 23261, uptime 0:10:16
      supervisor> avail
      bar                              in use    auto      999:999
      baz                              in use    auto      999:999
      foo                              in use    auto      999:999
      gazonk                           in use    auto      999:999
      quux                             avail     auto      999:999

    Now we add this to our conf:

      [group:zegroup]
      programs=baz,gazonk

    Then we reread conf:

      supervisor> reread
      baz: disappeared
      gazonk: disappeared
      quux: available
      zegroup: available
      supervisor> avail
      bar                              in use    auto      999:999
      foo                              in use    auto      999:999
      quux                             avail     auto      999:999
      zegroup:baz                      avail     auto      999:999
      zegroup:gazonk                   avail     auto      999:999
      supervisor> status
      bar                              RUNNING    pid 14864, uptime 18:04:18
      baz                              RUNNING    pid 23260, uptime 0:10:52
      foo                              RUNNING    pid 14866, uptime 18:04:18
      gazonk                           RUNNING    pid 23261, uptime 0:10:52

    The magic make-it-so command:

      supervisor> update
      baz: stopped
      baz: removed process group
      gazonk: stopped
      gazonk: removed process group
      zegroup: added process group
      quux: added process group
      supervisor> status
      bar                              RUNNING    pid 14864, uptime 18:04:43
      foo                              RUNNING    pid 14866, uptime 18:04:43
      quux                             RUNNING    pid 23561, uptime 0:00:02
      zegroup:baz                      RUNNING    pid 23559, uptime 0:00:02
      zegroup:gazonk                   RUNNING    pid 23560, uptime 0:00:02
      supervisor> avail
      bar                              in use    auto      999:999
      foo                              in use    auto      999:999
      quux                             in use    auto      999:999
      zegroup:baz                      in use    auto      999:999
      zegroup:gazonk                   in use    auto      999:999

- Fix bug with symptom "KeyError: 'process_name'" when using a logfile name 
  including documented``process_name`` Python string expansions.

- Tab completions in the supervisorctl shell, and a foreground mode for
  Supervisor, implemented as a part of GSoC.  The supervisorctl program now
  has a ``fg`` command, which makes it possible to supply inputs to a
  process, and see its output/error stream in real time.

- Process config reloading implemented by Anders Quist.  The
  supervisorctl program now has the commands "add" and "drop".
  "add <programname>" adds the process group implied by <programname>
  in the config file.  "drop <programname>" removes the process
  group from the running configuration (it must already be stopped).
  This makes it possible to add processes to and remove processes from
  a running supervisord without restarting the supervisord process.

- Fixed a bug where opening the HTTP servers would fail silently
  for socket errors other than errno.EADDRINUSE.

- Thanks to Dave Peticolas, using "reload" against a supervisord
  that is running in the background no longer causes supervisord
  to crash.

- Configuration options for logfiles now accept mixed case reserved 
  words (e.g. "AUTO" or "auto") for consistency with other options.

- childutils.eventdata was buggy, it could not deal with carriage returns
  in data.  See http://www.plope.com/software/collector/257.  Thanks
  to Ian Bicking.

- Per-process exitcodes= configuration now will not accept exit
  codes that are not 8-bit unsigned integers (supervisord will not 
  start when one of the exit codes is outside the range of 0 - 255).

- Per-process ``directory`` value can now contain expandable values like
  ``%(here)s``. (See http://www.plope.com/software/collector/262).

- Accepted patch from Roger Hoover to allow for a new sort of
  process group: "fcgi-program".  Adding one of these to your
  supervisord.conf allows you to control fastcgi programs.  FastCGI
  programs cannot belong to heterogenous groups.

  The configuration for FastCGI programs is the same as regular programs
  except an additional "socket" parameter.  Substitution happens on the
  socket parameter with the ``here`` and ``program_name`` variables::

   [fcgi-program:fcgi_test]
   ;socket=tcp://localhost:8002
   socket=unix:///path/to/fcgi/socket

- Supervisorctl now supports a plugin model for supervisorctl
  commands.

- Added the ability to retrieve supervisord's own pid through
  supervisor.getPID() on the XML-RPC interface or a new
  "pid" command on supervisorctl.

3.0a6 (2008-04-07)
------------------

- The RotatingFileLogger had a race condition in its doRollover
  method whereby a file might not actually exist despite a call to
  os.path.exists on the line above a place where we try to remove
  it.  We catch the exception now and ignore the missing file.

3.0a5 (2008-03-13)
------------------

- Supervisorctl now supports persistent readline history.  To
  enable, add "history_file = <pathname>" to the ``[supervisorctl]``
  section in your supervisord.conf file.

- Multiple commands may now be issued on one supervisorctl command
  line, e.g. "restart prog; tail -f prog".  Separate commands with a
  single semicolon; they will be executed in order as you would
  expect.

3.0a4 (2008-01-30)
------------------

- 3.0a3 broke Python 2.3 backwards compatibility.

- On Debian Sarge, one user reported that a call to
  options.mktempfile would fail with an "[Errno 9] Bad file
  descriptor" at supervisord startup time.  I was unable to
  reproduce this, but we found a workaround that seemed to work for
  him and it's included in this release.  See
  http://www.plope.com/software/collector/252 for more information.
  Thanks to William Dode.

- The fault ``ALREADY_TERMINATED`` has been removed.  It was only raised by
  supervisor.sendProcessStdin().  That method now returns ``NOT_RUNNING``
  for parity with the other methods. (Mike Naberezny)

- The fault TIMED_OUT has been removed.  It was not used.

- Supervisor now depends on meld3 0.6.4, which does not compile its
  C extensions by default, so there is no more need to faff around
  with NO_MELD3_EXTENSION_MODULES during installation if you don't
  have a C compiler or the Python development libraries on your
  system.

- Instead of making a user root around for the sample.conf file,
  provide a convenience command "echo_supervisord_conf", which he can
  use to echo the sample.conf to his terminal (and redirect to a file 
  appropriately).  This is a new user convenience (especially one who
  has no Python experience).

- Added ``numprocs_start`` config option to ``[program:x]`` and
  ``[eventlistener:x]`` sections.  This is an offset used to compute
  the first integer that ``numprocs`` will begin to start from.
  Contributed by Antonio Beamud Montero.

- Added capability for ``[include]`` config section to config format.
  This section must contain a single key "files", which must name a
  space-separated list of file globs that will be included in
  supervisor's configuration.  Contributed by Ian Bicking.

- Invoking the ``reload`` supervisorctl command could trigger a bug in
  supervisord which caused it to crash.  See
  http://www.plope.com/software/collector/253 .  Thanks to William Dode for
  a bug report.

- The ``pidproxy`` script was made into a console script.

- The ``password`` value in both the ``[inet_http_server]`` and
  ``[unix_http_server]`` sections can now optionally be specified as a SHA
  hexdigest instead of as cleartext.  Values prefixed with ``{SHA}`` will be
  considered SHA hex digests.  To encrypt a password to a form suitable for
  pasting into the configuration file using Python, do, e.g.::

     >>> import sha
     >>> '{SHA}' + sha.new('thepassword').hexdigest()
     '{SHA}82ab876d1387bfafe46cc1c8a2ef074eae50cb1d'

- The subtypes of the events PROCESS_STATE_CHANGE (and
  PROCESS_STATE_CHANGE itself) have been removed, replaced with a
  simpler set of PROCESS_STATE subscribable event types.

  The new event types are:

    PROCESS_STATE_STOPPED
    PROCESS_STATE_EXITED
    PROCESS_STATE_STARTING
    PROCESS_STATE_STOPPING
    PROCESS_STATE_BACKOFF
    PROCESS_STATE_FATAL
    PROCESS_STATE_RUNNING
    PROCESS_STATE_UNKNOWN
    PROCESS_STATE # abstract

  PROCESS_STATE_STARTING replaces:

    PROCESS_STATE_CHANGE_STARTING_FROM_STOPPED
    PROCESS_STATE_CHANGE_STARTING_FROM_BACKOFF
    PROCESS_STATE_CHANGE_STARTING_FROM_EXITED
    PROCESS_STATE_CHANGE_STARTING_FROM_FATAL

  PROCESS_STATE_RUNNING replaces
  PROCESS_STATE_CHANGE_RUNNING_FROM_STARTED

  PROCESS_STATE_BACKOFF replaces
  PROCESS_STATE_CHANGE_BACKOFF_FROM_STARTING

  PROCESS_STATE_STOPPING replaces:

    PROCESS_STATE_CHANGE_STOPPING_FROM_RUNNING
    PROCESS_STATE_CHANGE_STOPPING_FROM_STARTING

  PROCESS_STATE_EXITED replaces
  PROCESS_STATE_CHANGE_EXITED_FROM_RUNNING

  PROCESS_STATE_STOPPED replaces
  PROCESS_STATE_CHANGE_STOPPED_FROM_STOPPING

  PROCESS_STATE_FATAL replaces
  PROCESS_STATE_CHANGE_FATAL_FROM_BACKOFF

  PROCESS_STATE_UNKNOWN replaces PROCESS_STATE_CHANGE_TO_UNKNOWN

  PROCESS_STATE replaces PROCESS_STATE_CHANGE

  The PROCESS_STATE_CHANGE_EXITED_OR_STOPPED abstract event is gone.

  All process state changes have at least "processname",
  "groupname", and "from_state" (the name of the previous state) in
  their serializations.

  PROCESS_STATE_EXITED additionaly has "expected" (1 or 0) and "pid"
  (the process id) in its serialization.

  PROCESS_STATE_RUNNING, PROCESS_STATE_STOPPING,
  PROCESS_STATE_STOPPED additionally have "pid" in their
  serializations.

  PROCESS_STATE_STARTING and PROCESS_STATE_BACKOFF have "tries" in
  their serialization (initially "0", bumped +1 each time a start
  retry happens).

- Remove documentation from README.txt, point people to
  http://supervisord.org/manual/ .

- The eventlistener request/response protocol has changed.  OK/FAIL
  must now be wrapped in a RESULT envelope so we can use it for more
  specialized communications.

  Previously, to signify success, an event listener would write the string
  ``OK\n`` to its stdout.  To signify that the event was seen but couldn't
  be handled by the listener and should be rebuffered, an event listener
  would write the string ``FAIL\n`` to its stdout.

  In the new protocol, the listener must write the string::

    RESULT {resultlen}\n{result}

  For example, to signify OK::

    RESULT 2\nOK

  To signify FAIL::

    RESULT 4\nFAIL

  See the scripts/sample_eventlistener.py script for an example.

- To provide a hook point for custom results returned from event
  handlers (see above) the [eventlistener:x] configuration sections
  now accept a "result_handler=" parameter,
  e.g. "result_handler=supervisor.dispatchers:default_handler" (the
  default) or "handler=mypackage:myhandler".  The keys are pkgutil
  "entry point" specifications (importable Python function names).
  Result handlers must be callables which accept two arguments: one
  named "event" which represents the event, and the other named
  "result", which represents the listener's result.  A result
  handler either executes successfully or raises an exception.  If
  it raises a supervisor.dispatchers.RejectEvent exception, the
  event will be rebuffered, and the eventhandler will be placed back
  into the ACKNOWLEDGED state.  If it raises any other exception,
  the event handler will be placed in the UNKNOWN state.  If it does
  not raise any exception, the event is considered successfully
  processed.  A result handler's return value is ignored.  Writing a
  result handler is a "in case of emergency break glass" sort of
  thing, it is not something to be used for arbitrary business code.
  In particular, handlers *must not block* for any appreciable
  amount of time.

  The standard eventlistener result handler
  (supervisor.dispatchers:default_handler) does nothing if it receives an
  "OK" and will raise a supervisor.dispatchers.RejectEvent exception if it
  receives any other value.

- Supervisord now emits TICK events, which happen every N seconds.
  Three types of TICK events are available: TICK_5 (every five
  seconds), TICK_60 (every minute), TICK_3600 (every hour).  Event
  listeners may subscribe to one of these types of events to perform
  every-so-often processing.  TICK events are subtypes of the EVENT
  type.

- Get rid of OSX platform-specific memory monitor and replace with
  memmon.py, which works on both Linux and Mac OS.  This script is
  now a console script named "memmon".

- Allow "web handler" (the handler which receives http requests from 
  browsers visiting the web UI of supervisor) to deal with POST requests.

- RPC interface methods stopProcess(), stopProcessGroup(), and
  stopAllProcesses() now take an optional "wait" argument that defaults
  to True for parity with the start methods.  

3.0a3 (2007-10-02)
------------------

- Supervisorctl now reports a better error message when the main supervisor
  XML-RPC namespace is not registered.  Thanks to Mike Orr for reporting
  this. (Mike Naberezny)

- Create ``scripts`` directory within supervisor package, move
  ``pidproxy.py`` there, and place sample event listener and comm event
  programs within the directory.

- When an event notification is buffered (either because a listener rejected
  it or because all listeners were busy when we attempted to send it
  originally), we now rebuffer it in a way that will result in it being
  retried earlier than it used to be.

- When a listener process exits (unexpectedly) before transitioning from the
  BUSY state, rebuffer the event that was being processed.

- supervisorctl ``tail`` command now accepts a trailing specifier: ``stderr``
  or ``stdout``, which respectively, allow a user to tail the stderr or
  stdout of the named process.  When this specifier is not provided, tail
  defaults to stdout.

- supervisor ``clear`` command now clears both stderr and stdout logs for the
  given process.

- When a process encounters a spawn error as a result of a failed execve or
  when it cannot setuid to a given uid, it now puts this info into the
  process' stderr log rather than its stdout log.

- The event listener protocol header now contains the ``server`` identifier,
  the ``pool`` that the event emanated from, and the ``poolserial`` as well
  as the values it previously contained (version, event name, serial, and
  length).  The server identifier is taken from the config file options value
  ``identifier``, the ``pool`` value is the name of the listener pool that
  this event emanates from, and the ``poolserial`` is a serial number
  assigned to the event local to the pool that is processing it.

- The event listener protocol header is now a sequence of key-value
  pairs rather than a list of positional values.  Previously, a
  representative header looked like::

    SUPERVISOR3.0 PROCESS_COMMUNICATION_STDOUT 30 22\n

  Now it looks like::

    ver:3.0 server:supervisor serial:21 ... 

- Specific event payload serializations have changed.  All event
  types that deal with processes now include the pid of the process
  that the event is describing.  In event serialization "header"
  values, we've removed the space between the header name and the
  value and headers are now separated by a space instead of a line
  feed.  The names of keys in all event types have had underscores
  removed.

- Abandon the use of the Python stdlib ``logging`` module for speed
  and cleanliness purposes.  We've rolled our own.

- Fix crash on start if AUTO logging is used with a max_bytes of
  zero for a process.

- Improve process communication event performance.

- The process config parameters ``stdout_capturefile`` and
  ``stderr_capturefile`` are no longer valid.  They have been replaced with
  the ``stdout_capture_maxbytes`` and ``stderr_capture_maxbytes`` parameters,
  which are meant to be suffix-multiplied integers.  They both default to
  zero.  When they are zero, process communication event capturing is not
  performed.  When either is nonzero, the value represents the maximum number
  of bytes that will be captured between process event start and end tags.
  This change was to support the fact that we no longer keep capture data in
  a separate file, we just use a FIFO in RAM to maintain capture info.  For
  users whom don't care about process communication events, or whom haven't
  changed the defaults for ``stdout_capturefile`` or ``stderr_capturefile``,
  they needn't do anything to their configurations to deal with this change.

- Log message levels have been normalized.  In particular, process
  stdin/stdout is now logged at ``debug`` level rather than at ``trace``
  level (``trace`` level is now reserved for output useful typically for
  debugging supervisor itself).  See "Supervisor Log Levels" in the
  documentation for more info.

- When an event is rebuffered (because all listeners are busy or a
  listener rejected the event), the rebuffered event is now inserted
  in the head of the listener event queue.  This doesn't guarantee
  event emission in natural ordering, because if a listener rejects
  an event or dies while it's processing an event, it can take an
  arbitrary amount of time for the event to be rebuffered, and other
  events may be processed in the meantime.  But if pool listeners
  never reject an event or don't die while processing an event, this
  guarantees that events will be emitted in the order that they were
  received because if all listeners are busy, the rebuffered event
  will be tried again "first" on the next go-around.

- Removed EVENT_BUFFER_OVERFLOW event type.

- The supervisorctl xmlrpc proxy can now communicate with
  supervisord using a persistent HTTP connection.

- A new module "supervisor.childutils" was added.  This module
  provides utilities for Python scripts which act as children of
  supervisord.  Most notably, it contains an API method
  "getRPCInterface" allows you to obtain an xmlrpxlib ServerProxy
  that is willing to communicate with the parent supervisor.  It
  also contains utility functions that allow for parsing of
  supervisor event listener protocol headers.  A pair of scripts
  (loop_eventgen.py and loop_listener.py) were added to the script
  directory that serve as examples about how to use the childutils
  module.

- A new envvar is added to child process environments:
  SUPERVISOR_SERVER_URL.  This contains the server URL for the
  supervisord running the child.

- An ``OK`` URL was added at ``/ok.html`` which just returns the string
  ``OK`` (can be used for up checks or speed checks via plain-old-HTTP).

- An additional command-line option ``--profile_options`` is accepted
  by the supervisord script for developer use::

    supervisord -n -c sample.conf --profile_options=cumulative,calls

  The values are sort_stats options that can be passed to the
  standard Python profiler's PStats sort_stats method.

  When you exit supervisor, it will print Python profiling output to
  stdout.

- If cElementTree is installed in the Python used to invoke
  supervisor, an alternate (faster, by about 2X) XML parser will be
  used to parse XML-RPC request bodies.  cElementTree was added as
  an "extras_require" option in setup.py.

- Added the ability to start, stop, and restart process groups to
  supervisorctl.  To start a group, use ``start groupname:*``.  To start
  multiple groups, use ``start groupname1:* groupname2:*``.  Equivalent
  commands work for "stop" and "restart". You can mix and match short
  processnames, fullly-specified group:process names, and groupsplats on the
  same line for any of these commands.

- Added ``directory`` option to process config.  If you set this
  option, supervisor will chdir to this directory before executing
  the child program (and thus it will be the child's cwd).

- Added ``umask`` option to process config.  If you set this option,
  supervisor will set the umask of the child program.  (Thanks to
  Ian Bicking for the suggestion).

- A pair of scripts ``osx_memmon_eventgen.py`` and `osx_memmon_listener.py``
  have been added to the scripts directory.  If they are used together as
  described in their comments, processes which are consuming "too much"
  memory will be restarted.  The ``eventgen`` script only works on OSX (my
  main development platform) but it should be trivially generalizable to
  other operating systems.

- The long form ``--configuration`` (-c) command line option for
  supervisord was broken.  Reported by Mike Orr.  (Mike Naberezny)

- New log level: BLAT (blather).  We log all
  supervisor-internal-related debugging info here.  Thanks to Mike
  Orr for the suggestion.

- We now allow supervisor to listen on both a UNIX domain socket and an inet
  socket instead of making them mutually exclusive.  As a result, the options
  "http_port", "http_username", "http_password", "sockchmod" and "sockchown"
  are no longer part of the ``[supervisord]`` section configuration. These
  have been supplanted by two other sections: ``[unix_http_server]`` and
  ``[inet_http_server]``.  You'll need to insert one or the other (depending
  on whether you want to listen on a UNIX domain socket or a TCP socket
  respectively) or both into your supervisord.conf file.  These sections have
  their own options (where applicable) for port, username, password, chmod,
  and chown.  See README.txt for more information about these sections.

- All supervisord command-line options related to "http_port",
  "http_username", "http_password", "sockchmod" and "sockchown" have
  been removed (see above point for rationale).

- The option that *used* to be ``sockchown`` within the ``[supervisord]``
  section (and is now named ``chown`` within the ``[unix_http_server]``
  section) used to accept a dot-separated user.group value.  The separator
  now must be a colon ":", e.g. "user:group".  Unices allow for dots in
  usernames, so this change is a bugfix.  Thanks to Ian Bicking for the bug
  report.

- If a '-c' option is not specified on the command line, both supervisord and
  supervisorctl will search for one in the paths ``./supervisord.conf`` ,
  ``./etc/supervisord.conf`` (relative to the current working dir when
  supervisord or supervisorctl is invoked) or in ``/etc/supervisord.conf``
  (the old default path).  These paths are searched in order, and supervisord
  and supervisorctl will use the first one found.  If none are found,
  supervisor will fail to start.

- The Python string expression ``%(here)s`` (referring to the directory in
  which the the configuration file was found) can be used within the
  following sections/options within the config file::

      unix_http_server:file
      supervisor:directory
      supervisor:logfile
      supervisor:pidfile
      supervisor:childlogdir
      supervisor:environment
      program:environment
      program:stdout_logfile
      program:stderr_logfile
      program:process_name
      program:command

- The ``--environment`` aka ``-b`` option was removed from the list of
  available command-line switches to supervisord (use "A=1 B=2
  bin/supervisord" instead).

- If the socket filename (the tail-end of the unix:// URL) was
  longer than 64 characters, supervisorctl would fail with an
  encoding error at startup.

- The ``identifier`` command-line argument was not functional.

- Fixed http://www.plope.com/software/collector/215 (bad error
  message in supervisorctl when program command not found on PATH).

- Some child processes may not have been shut down properly at
  supervisor shutdown time.

- Move to ZPL-derived (but not ZPL) license availble from
  http://www.repoze.org/LICENSE.txt; it's slightly less restrictive
  than the ZPL (no servicemark clause).

- Spurious errors related to unclosed files ("bad file descriptor",
  typically) were evident at supervisord "reload" time (when using
  the "reload" command from supervisorctl).

- We no longer bundle ez_setup to bootstrap setuptools installation.

3.0a2 (2007-08-24)
------------------

- Fixed the README.txt example for defining the supervisor RPC
  interface in the configuration file.  Thanks to Drew Perttula.

- Fixed a bug where process communication events would not have the
  proper payload if the payload data was very short.

- when supervisord attempted to kill a process with SIGKILL after
  the process was not killed within "stopwaitsecs" using a "normal"
  kill signal, supervisord would crash with an improper
  AssertionError.  Thanks to Calvin Hendryx-Parker.

- On Linux, Supervisor would consume too much CPU in an effective
  "busywait" between the time a subprocess exited and the time at
  which supervisor was notified of its exit status.  Thanks to Drew
  Perttula.

- RPC interface behavior change: if the RPC method
  "sendProcessStdin" is called against a process that has closed its
  stdin file descriptor (e.g. it has done the equivalent of
  "sys.stdin.close(); os.close(0)"), we return a NO_FILE fault
  instead of accepting the data.

- Changed the semantics of the process configuration ``autorestart``
  parameter with respect to processes which move between the RUNNING and
  EXITED state.  ``autorestart`` was previously a boolean.  Now it's a
  trinary, accepting one of ``false``, ``unexpected``, or ``true``.  If it's
  ``false``, a process will never be automatically restarted from the EXITED
  state.  If it's ``unexpected``, a process that enters the EXITED state will
  be automatically restarted if it exited with an exit code that was not
  named in the process config's ``exitcodes`` list.  If it's ``true``, a
  process that enters the EXITED state will be automatically restarted
  unconditionally.  The default is now ``unexpected`` (it was previously
  ``true``).  The readdition of this feature is a reversion of the behavior
  change note in the changelog notes for 3.0a1 that asserted we never cared
  about the process' exit status when determining whether to restart it or
  not.

- setup.py develop (and presumably setup.py install) would fail under Python
  2.3.3, because setuptools attempted to import ``splituser`` from urllib2,
  and it didn't exist.

- It's now possible to use ``setup.py install`` and ``setup.py develop`` on
  systems which do not have a C compiler if you set the environment variable
  "NO_MELD3_EXTENSION_MODULES=1" in the shell in which you invoke these
  commands (versions of meld3 > 0.6.1 respect this envvar and do not try to
  compile optional C extensions when it's set).

- The test suite would fail on Python versions <= 2.3.3 because
  the "assertTrue" and "assertFalse" methods of unittest.TestCase
  didn't exist in those versions.

- The ``supervisorctl`` and ``supervisord`` wrapper scripts were disused in
  favor of using setuptools' ``console_scripts`` entry point settings.

- Documentation files and the sample configuration file are put into
  the generated supervisor egg's ``doc`` directory.

- Using the web interface would cause fairly dramatic memory
  leakage.  We now require a version of meld3 that does not appear
  to leak memory from its C extensions (0.6.3).

3.0a1 (2007-08-16)
------------------

- Default config file comment documented 10 secs as default for ``startsecs``
  value in process config, in reality it was 1 sec.  Thanks to Christoph
  Zwerschke.

- Make note of subprocess environment behavior in README.txt.
  Thanks to Christoph Zwerschke.

- New "strip_ansi" config file option attempts to strip ANSI escape
  sequences from logs for smaller/more readable logs (submitted by
  Mike Naberezny).

- The XML-RPC method supervisor.getVersion() has been renamed for 
  clarity to supervisor.getAPIVersion().  The old name is aliased 
  for compatibility but is deprecated and will be removed in a
  future version (Mike Naberezny).

- Improved web interface styling (Mike Naberezny, Derek DeVries)

- The XML-RPC method supervisor.startProcess() now checks that
  the file exists and is executable (Mike Naberezny).

- Two environment variables, "SUPERVISOR_PROCESS_NAME" and
  "SUPERVISOR_PROCESS_GROUP" are set in the environment of child
  processes, representing the name of the process and group in
  supervisor's configuration.

- Process state map change: a process may now move directly from the
  STARTING state to the STOPPING state (as a result of a stop
  request).

- Behavior change: if ``autorestart`` is true, even if a process exits with
  an "expected" exit code, it will still be restarted.  In the immediately
  prior release of supervisor, this was true anyway, and no one complained,
  so we're going to consider that the "officially correct" behavior from now
  on.

- Supervisor now logs subprocess stdout and stderr independently.
  The old program config keys "logfile", "logfile_backups" and
  "logfile_maxbytes" are superseded by "stdout_logfile",
  "stdout_logfile_backups", and "stdout_logfile_maxbytes".  Added
  keys include "stderr_logfile", "stderr_logfile_backups", and
  "stderr_logfile_maxbytes".  An additional "redirect_stderr" key is
  used to cause program stderr output to be sent to its stdin
  channel.  The keys "log_stderr" and "log_stdout" have been
  removed.

- ``[program:x]`` config file sections now represent "homgeneous process
  groups" instead of single processes.  A "numprocs" key in the section
  represents the number of processes that are in the group.  A "process_name"
  key in the section allows composition of the each process' name within the
  homogeneous group.

- A new kind of config file section, ``[group:x]`` now exists, allowing users
  to group heterogeneous processes together into a process group that can be
  controlled as a unit from a client.

- Supervisord now emits "events" at certain points in its normal
  operation.  These events include supervisor state change events,
  process state change events, and "process communication events".

- A new kind of config file section ``[eventlistener:x]`` now exists.  Each
  section represents an "event listener pool", which is a special kind of
  homogeneous process group.  Each process in the pool is meant to receive
  supervisor "events" via its stdin and perform some notification (e.g. send
  a mail, log, make an http request, etc.)

- Supervisord can now capture data between special tokens in
  subprocess stdout/stderr output and emit a "process communications
  event" as a result.

- Supervisor's XML-RPC interface may be extended arbitrarily by programmers.
  Additional top-level namespace XML-RPC interfaces can be added using the
  ``[rpcinterface:foo]`` declaration in the configuration file.

- New ``supervisor``-namespace XML-RPC methods have been added:
  getAPIVersion (returns the XML-RPC API version, the older
  "getVersion" is now deprecated), "startProcessGroup" (starts all
  processes in a supervisor process group), "stopProcessGroup"
  (stops all processes in a supervisor process group), and
  "sendProcessStdin" (sends data to a process' stdin file
  descriptor).

- ``supervisor``-namespace XML-RPC methods which previously accepted
  ony a process name as "name" (startProcess, stopProcess,
  getProcessInfo, readProcessLog, tailProcessLog, and
  clearProcessLog) now accept a "name" which may contain both the
  process name and the process group name in the form
  ``groupname:procname``.  For backwards compatibility purposes,
  "simple" names will also be accepted but will be expanded
  internally (e.g. if "foo" is sent as a name, it will be expanded
  to "foo:foo", representing the foo process within the foo process
  group).

- 2.X versions of supervisorctl will work against supervisor 3.0
  servers in a degraded fashion, but 3.X versions of supervisorctl
  will not work at all against supervisor 2.X servers.

Known issues
~~~~~~~~~~~~

- supervisorctl and the web interface do not yet allow you to stop
  / start / restart a process group as a unit.

- supervisorctl and the web interface do not allow you to tail or
  otherwise examine stderr log files of processes.

- buffered event notifications may be lost at supervisor shutdown
  or restart time.