From ec145b73fc91dd54695dd374c8a71a11e233b8c0 Mon Sep 17 00:00:00 2001 From: Brion Vibber Date: Tue, 12 Jan 2010 19:57:15 -0800 Subject: 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 --- classes/Memcached_DataObject.php | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'classes/Memcached_DataObject.php') diff --git a/classes/Memcached_DataObject.php b/classes/Memcached_DataObject.php index 9c9994cea..4ecab9db6 100644 --- a/classes/Memcached_DataObject.php +++ b/classes/Memcached_DataObject.php @@ -331,6 +331,29 @@ class Memcached_DataObject extends DB_DataObject $exists = false; } + // @fixme horrible evil hack! + // + // In multisite configuration we don't want to keep around a separate + // connection for every database; we could end up with thousands of + // connections open per thread. In an ideal world we might keep + // a connection per server and select different databases, but that'd + // be reliant on having the same db username/pass as well. + // + // MySQL connections are cheap enough we're going to try just + // closing out the old connection and reopening when we encounter + // a new DSN. + // + // WARNING WARNING if we end up actually using multiple DBs at a time + // we'll need some fancier logic here. + if (!$exists && !empty($_DB_DATAOBJECT['CONNECTIONS'])) { + foreach ($_DB_DATAOBJECT['CONNECTIONS'] as $index => $conn) { + if (!empty($conn)) { + $conn->disconnect(); + } + unset($_DB_DATAOBJECT['CONNECTIONS'][$index]); + } + } + $result = parent::_connect(); if ($result && !$exists) { -- cgit v1.2.3-54-g00ecf