- Multiplexing queues into groups and for multiple sites.
- Sharing vs breakout configurable per site and per queue via $config['queue']['breakout']
- Detect how many times a message is redelivered, discard if it's killed too many daemons
- count configurable with $config['queue']['max_retries']
- can dump the items to files in $config['queue']['dead_letter_dir']
Queue daemon memory & resource leak fixes:
- avoid unnecessary reconnections to memcached server (switch persistent connections back in on second initialization, assuming it's child process)
- monkey-patch for leaky .ini loads in DB_DataObject::databaseStructure() - was leaking 200k per active switch
- applied leak fixes to Status_network as well, using intermediate base Safe_DataObject for both it and Memcache_DataObject
Misc queue fixes:
- correct handling of child processes exiting due to signal termination instead of regular exit
- shutdown instead of infinite respawn loop if we're already past the soft memory limit at startup
- Added --all option for xmppdaemon... still opens one xmpp connection per site that has xmpp active
Cache updates:
- add Cache::increment() method with native support for memcached atomic increment
statusnet.links.ini file could not be read anymore due to the entry for nonce containing a comma in its key value.
PHP's parse_ini_file() function no longer allows commas in keys, and rejects the *ENTIRE FILE* if it's present, breaking various automatic joins.
* detection of group feeds is currently a nasty hack based on presence of '/groups/' in URL -- should use some property on the feed?
* listing for the remote group is kinda cruddy; needs to be named more cleanly
* still need to establish per-author profiles (easier once we have the updated Atom code in)
* group delivery probably not right yet
* saving of group messages still triggering some weird behavior
Added support for since_id and max_id on group timeline feeds as a free extra. Enjoy!
* Treat linkless feed posts as status updates; drop the "New post:" prefix and quotes on them.
* Use stable user IDs for atom/rss2 feed links instead of unstable nicknames
* Pull Atom feed preferentially when subscribing -- can now put the remote user's profile page straight into the feed subscription form and get to the right place.
* Clean up naming for push endpoints
No change in efficiency for the common case where nothing's deleted: does the same bulk fetch of just the notices we think we'll need as before, then if we turned up short keeps checking one by one until we've filled up to our $limit.
This can leave us with overlap between pages, but we already have that when new messages come in between clicks; seems to be the lesser of evils versus not getting a 'before' button.
More permanent fix for that will be to switch timeline paging in the UI to use notice IDs.
No change in efficiency for the common case where nothing's deleted: does the same bulk fetch of just the notices we think we'll need as before, then if we turned up short keeps checking one by one until we've filled up to our $limit.
This can leave us with overlap between pages, but we already have that when new messages come in between clicks; seems to be the lesser of evils versus not getting a 'before' button.
More permanent fix for that will be to switch timeline paging in the UI to use notice IDs.
queuectl.php --update -s<site>
queuectl.php --stop
queuectl.php --restart
Default control channel is /topic/statusnet-control. For external utilities to send a site update ping direct to the queue server, connect via Stomp and send a message formatted thus:
update:<nickname>
(Nickname here, *not* server hostname! The rest of the queues will be updated to use nicknames later.)
Note that all currently-connected queue daemons will get these notifications, including both queuedaemon.php and xmppdaemon.php. (XMPP will ignore site update requests for sites that it's not handling.)
Limitations:
* only implemented for stomp queue manager so far
* --update may not yet handle a changed server name properly
* --restart won't reload PHP code files that were already loaded at startup. Still need to stop and restart the daemons from 'outside' when updating code base.
$sn->tags() returns tag list as array; $sn->hasTag('blah') to check for a particular tag only
Could be used to control things in config file:
$sn = Status_network::setupSite($_server, $_path, $_wildcard);
if (!$sn) { die("No such site"); }
if ($sn->hasTag('individual')) { /* blah */ }
Note memcached keys are unchanged; if tags are changed from an external tool clear:
statusnet:<dbname>:status_network:<key>:<val>
for <key>s 'nickname', 'hostname', and 'pathname'
Moved much of the writing that happens when posting a notice to a new
queuehandler, distribqueuehandler. This updates tags, groups, replies
and inboxes at queue time (or at Web time, if queues are disabled).
To make this work well, I had to break up the monolithic
Notice::blowCaches() and make cache blowing happen closer to where
data is updated.
Squashed commit of the following:
commit 5257626c62750ac4ac1db0ce2b71410c5711cfa3
Author: Evan Prodromou <evan@status.net>
Date: Mon Jan 25 14:56:41 2010 -0500
slightly better handling of blowing tag memory cache
commit 8a22a3cdf6ec28685da129a0313e7b2a0837c9ef
Author: Evan Prodromou <evan@status.net>
Date: Mon Jan 25 01:42:56 2010 -0500
change 'distribute' to 'distrib' so not too long for dbqueue
commit 7a063315b0f7fad27cb6fbd2bdd74e253af83e4f
Author: Evan Prodromou <evan@status.net>
Date: Mon Jan 25 01:39:15 2010 -0500
change handle_notice() to handle() in distributqueuehandler
commit 1a39ccd28b9994137d7bfd21bb4f230546938e77
Author: Evan Prodromou <evan@status.net>
Date: Mon Jan 25 16:05:25 2010 -0500
error with queuemanager
commit e6b3bb93f305cfd2de71a6340b8aa6fb890049b7
Author: Evan Prodromou <evan@status.net>
Date: Mon Jan 25 01:11:34 2010 -0500
Blow memcache at different point rather than one big function for Notice class
commit 94d557cdc016187d1d0647ae1794cd94d6fb8ac8
Author: Evan Prodromou <evan@status.net>
Date: Mon Jan 25 00:48:44 2010 -0500
Blow memcache at different point rather than one big function for Notice class
commit 1c781dd08c88a35dafc5c01230b4872fd6b95182
Author: Evan Prodromou <evan@status.net>
Date: Wed Jan 20 08:54:18 2010 -0500
move broadcasting and distributing to new queuehandler
commit da3e46d26b84e4f028f34a13fd2ee373e4c1b954
Author: Evan Prodromou <evan@status.net>
Date: Wed Jan 20 08:53:12 2010 -0500
Move distribution of notices to new distribute queue handler
I made a bad merge on Jan 10th from master to 0.9.x. This lost a number
of memcache enhancements made on the 0.9.x branch. I've been able to
re-do the manual merge, and this represents the changes. Most of them
are related to caching on insert.
Queue handlers for XMPP individual & firehose output now send their XML stanzas
to another output queue instead of connecting directly to the chat server. This
lets us have as many general processing threads as we need, while all actual
XMPP input and output go through a single daemon with a single connection open.
This avoids problems with multiple connected resources:
* multiple windows shown in some chat clients (psi, gajim, kopete)
* extra load on server
* incoming message delivery forwarding issues
Database changes:
* queue_item drops 'notice_id' in favor of a 'frame' blob.
This is based on Craig Andrews' work branch to generalize queues to take any
object, but conservatively leaving out the serialization for now.
Table updater (preserves any existing queued items) in db/rc3to09.sql
Code changes to watch out for:
* Queue handlers should now define a handle() method instead of handle_notice()
* QueueDaemon and XmppDaemon now share common i/o (IoMaster) and respawning
thread management (RespawningDaemon) infrastructure.
* The polling XmppConfirmManager has been dropped, as the message is queued
directly when saving IM settings.
* Enable $config['queue']['debug_memory'] to output current memory usage at
each run through the event loop to watch for memory leaks
To do:
* Adapt XMPP i/o to component connection mode for multi-site support.
* XMPP input can also be broken out to a queue, which would allow the actual
notice save etc to be handled by general queue threads.
* Make sure there are no problems with simply pushing serialized Notice objects
to queues.
* Find a way to improve interactive performance of the database-backed queue
handler; polling is pretty painful to XMPP.
* Possibly redo the way QueueHandlers are injected into a QueueManager. The
grouping used to split out the XMPP output queue is a bit awkward.
Conflicts:
scripts/xmppdaemon.php
Queue handlers for XMPP individual & firehose output now send their XML stanzas
to another output queue instead of connecting directly to the chat server. This
lets us have as many general processing threads as we need, while all actual
XMPP input and output go through a single daemon with a single connection open.
This avoids problems with multiple connected resources:
* multiple windows shown in some chat clients (psi, gajim, kopete)
* extra load on server
* incoming message delivery forwarding issues
Database changes:
* queue_item drops 'notice_id' in favor of a 'frame' blob.
This is based on Craig Andrews' work branch to generalize queues to take any
object, but conservatively leaving out the serialization for now.
Table updater (preserves any existing queued items) in db/rc3to09.sql
Code changes to watch out for:
* Queue handlers should now define a handle() method instead of handle_notice()
* QueueDaemon and XmppDaemon now share common i/o (IoMaster) and respawning
thread management (RespawningDaemon) infrastructure.
* The polling XmppConfirmManager has been dropped, as the message is queued
directly when saving IM settings.
* Enable $config['queue']['debug_memory'] to output current memory usage at
each run through the event loop to watch for memory leaks
To do:
* Adapt XMPP i/o to component connection mode for multi-site support.
* XMPP input can also be broken out to a queue, which would allow the actual
notice save etc to be handled by general queue threads.
* Make sure there are no problems with simply pushing serialized Notice objects
to queues.
* Find a way to improve interactive performance of the database-backed queue
handler; polling is pretty painful to XMPP.
* Possibly redo the way QueueHandlers are injected into a QueueManager. The
grouping used to split out the XMPP output queue is a bit awkward.
- NOTICE_INBOX_SOURCE_* constants moved to common.php since Notice_inbox.php not always loaded
- fixed typo in User::staticGet() call which caused user #1 to receive messages once for each subscriber instead of for him/herself
- 'continue' -> 'continue 2' inside switch() statement to fix loop escape (PHP considers switch() a looping construct for break & continue)
Key changes:
* Initialization code moved from common.php to StatusNet class;
can now switch configurations during runtime.
* As a consequence, configuration files must now be idempotent...
Be careful with constant, function or class definitions.
* Control structure for daemons/QueueManager/QueueHandler has been refactored;
the run loop is now managed by IoMaster run via scripts/queuedaemon.php
IoManager subclasses are woken to handle socket input or polling, and may
cover multiple sites.
* Plugins can implement notice queue handlers more easily by registering a
QueueHandler class; no more need to add a daemon.
The new QueueDaemon runs from scripts/queuedaemon.php:
* This replaces most of the old *handler.php scripts; they've been refactored
to the bare handler classes.
* Spawns multiple child processes to spread load; defaults to CPU count on
Linux and Mac OS X systems, or override with --threads=N
* When multithreaded, child processes are automatically respawned on failure.
* Threads gracefully shut down and restart when passing a soft memory limit
(defaults to 90% of memory_limit), limiting damage from memory leaks.
* Support for UDP-based monitoring: http://www.gitorious.org/snqmon
Rough control flow diagram:
QueueDaemon -> IoMaster -> IoManager
QueueManager [listen or poll] -> QueueHandler
XmppManager [ping & keepalive]
XmppConfirmManager [poll updates]
Todo:
* Respawning features not currently available running single-threaded.
* When running single-site, configuration changes aren't picked up.
* New sites or config changes affecting queue subscriptions are not yet
handled without a daemon restart.
* SNMP monitoring output to integrate with general tools (nagios, ganglia)
* Convert XMPP confirmation message sends to use stomp queue instead of polling
* Convert xmppdaemon.php to IoManager?
* Convert Twitter status, friends import polling daemons to IoManager
* Clean up some error reporting and failure modes
* May need to adjust queue priorities for best perf in backlog/flood cases
Detailed code history available in my daemon-work branch:
http://www.gitorious.org/~brion/statusnet/brion-fixes/commits/daemon-work
