Commit Graph

11 Commits

Author SHA1 Message Date
Brion Vibber
c74aea589d Stomp queue restructuring for mass scalability:
- 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
2010-02-16 09:16:51 -08:00
Brion Vibber
b1402896e7 Set default 24-hour expiry on Memcached objects where not specified. 2010-01-27 09:13:21 -08:00
Brion Vibber
775c63b654 Cleanup for memcached host/port split -- apparently we use ';' on purpose, restoring. Keeping fix for the notices spewing into the log. 2010-01-16 13:39:05 -08:00
Brion Vibber
5783874cc2 Clean up host/port separation in memcached plugin -- use : not ; as separator and clean up some warnings 2010-01-14 14:14:32 -08:00
Brion Vibber
b25deaacea queue daemon fixes: path fix for xmpp, suppress warning in memcached init 2010-01-13 21:24:36 -08:00
Brion Vibber
ec145b73fc Major refactoring of queue handlers to support running multiple sites in one daemon.
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
2010-01-12 20:45:09 -08:00
Evan Prodromou
e22af049a8 persistent connection flag, default false on cli 2010-01-08 13:21:29 -08:00
Evan Prodromou
ca3b2d614a add version information to MemcachePlugin 2010-01-07 17:49:39 -08:00
Evan Prodromou
bcddcb38ce make compression threshold and min savings config attrs for MemcachePlugin 2010-01-04 09:09:59 -10:00
Craig Andrews
7a2d72fe28 Enable memcache automatic compression, starting at 20k and only if compression gain is greater than 20%.
Allows storage of larger objects (over 1mb in size uncompressed), such as huge LDAP schemas.
Should also improve cache efficiency (allows more stuff to be stored in same memory) and reduce network latency (less data transfer)

(redo commit 1e9c03e199 which was apparently lost during pluginization)
2010-01-04 12:49:25 -05:00
Evan Prodromou
cc5534d180 First version of Memcache plugin 2010-01-02 21:16:59 -10:00