1. 03 Jun, 2010 1 commit
  2. 29 Jan, 2010 1 commit
    • Brion Vibber's avatar
      Manual failover for stomp queues. · 155a5d44
      Brion Vibber authored
      If an array of multiple servers is put in $config['queue']['stomp_server'], enqueues will pick a random server to send to (failing over automatically if any are down).
      Queue handling daemons connect all servers so they get events no matter where they were delivered.
      In case of disconnection, daemons should now handle it gracefully and attempt to reconnect every 60 seconds or so, automatically resubscribing to all queues once it's back up.
      
      Can put to 'native' failover for reads as well by disabling $config['stomp']['manual_failover'] = false; but this is untested and may explode in addition to requiring that your ActiveMQ cluster actually be set up to handle its own data distribution.
      
      Additionally, can choose which queues to mark as persistent by setting $config['stomp']['persistent'] to an array of queue names.
      155a5d44
  3. 13 Jan, 2010 1 commit
    • Brion Vibber's avatar
      Major refactoring of queue handlers to support running multiple sites in one daemon. · ec145b73
      Brion Vibber authored
      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
      ec145b73