gnu-social/lib/stompqueuemanager.php
Brion Vibber 155a5d446f Manual failover for stomp queues.
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.
2010-01-28 16:49:32 -08:00

770 lines
24 KiB
PHP

<?php
/**
* StatusNet, the distributed open-source microblogging tool
*
* Abstract class for queue managers
*
* PHP version 5
*
* LICENCE: This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* @category QueueManager
* @package StatusNet
* @author Evan Prodromou <evan@status.net>
* @author Sarven Capadisli <csarven@status.net>
* @copyright 2009 StatusNet, Inc.
* @license http://www.fsf.org/licensing/licenses/agpl-3.0.html GNU Affero General Public License version 3.0
* @link http://status.net/
*/
require_once 'Stomp.php';
require_once 'Stomp/Exception.php';
class StompQueueManager extends QueueManager
{
protected $servers;
protected $username;
protected $password;
protected $base;
protected $control;
protected $useTransactions = true;
protected $sites = array();
protected $subscriptions = array();
protected $cons = array(); // all open connections
protected $disconnect = array();
protected $transaction = array();
protected $transactionCount = array();
protected $defaultIdx = 0;
function __construct()
{
parent::__construct();
$server = common_config('queue', 'stomp_server');
if (is_array($server)) {
$this->servers = $server;
} else {
$this->servers = array($server);
}
$this->username = common_config('queue', 'stomp_username');
$this->password = common_config('queue', 'stomp_password');
$this->base = common_config('queue', 'queue_basename');
$this->control = common_config('queue', 'control_channel');
}
/**
* Tell the i/o master we only need a single instance to cover
* all sites running in this process.
*/
public static function multiSite()
{
return IoManager::INSTANCE_PER_PROCESS;
}
/**
* Record each site we'll be handling input for in this process,
* so we can listen to the necessary queues for it.
*
* @fixme possibly actually do subscription here to save another
* loop over all sites later?
* @fixme possibly don't assume it's the current site
*/
public function addSite($server)
{
$this->sites[] = $server;
$this->initialize();
}
/**
* Optional; ping any running queue handler daemons with a notification
* such as announcing a new site to handle or requesting clean shutdown.
* This avoids having to restart all the daemons manually to update configs
* and such.
*
* Currently only relevant for multi-site queue managers such as Stomp.
*
* @param string $event event key
* @param string $param optional parameter to append to key
* @return boolean success
*/
public function sendControlSignal($event, $param='')
{
$message = $event;
if ($param != '') {
$message .= ':' . $param;
}
$this->_connect();
$result = $this->_send($this->control,
$message,
array ('created' => common_sql_now()));
if ($result) {
$this->_log(LOG_INFO, "Sent control ping to queue daemons: $message");
return true;
} else {
$this->_log(LOG_ERR, "Failed sending control ping to queue daemons: $message");
return false;
}
}
/**
* Instantiate the appropriate QueueHandler class for the given queue.
*
* @param string $queue
* @return mixed QueueHandler or null
*/
function getHandler($queue)
{
$handlers = $this->handlers[$this->currentSite()];
if (isset($handlers[$queue])) {
$class = $handlers[$queue];
if (class_exists($class)) {
return new $class();
} else {
common_log(LOG_ERR, "Nonexistent handler class '$class' for queue '$queue'");
}
} else {
common_log(LOG_ERR, "Requested handler for unkown queue '$queue'");
}
return null;
}
/**
* Get a list of all registered queue transport names.
*
* @return array of strings
*/
function getQueues()
{
$group = $this->activeGroup();
$site = $this->currentSite();
if (empty($this->groups[$site][$group])) {
return array();
} else {
return array_keys($this->groups[$site][$group]);
}
}
/**
* Register a queue transport name and handler class for your plugin.
* Only registered transports will be reliably picked up!
*
* @param string $transport
* @param string $class
* @param string $group
*/
public function connect($transport, $class, $group='queuedaemon')
{
$this->handlers[$this->currentSite()][$transport] = $class;
$this->groups[$this->currentSite()][$group][$transport] = $class;
}
/**
* Saves a notice object reference into the queue item table.
* @return boolean true on success
* @throws StompException on connection or send error
*/
public function enqueue($object, $queue)
{
$this->_connect();
return $this->_doEnqueue($object, $queue, $this->defaultIdx);
}
/**
* Saves a notice object reference into the queue item table
* on the given connection.
*
* @return boolean true on success
* @throws StompException on connection or send error
*/
protected function _doEnqueue($object, $queue, $idx)
{
$msg = $this->encode($object);
$rep = $this->logrep($object);
$props = array('created' => common_sql_now());
if ($this->isPersistent($queue)) {
$props['persistent'] = 'true';
}
$con = $this->cons[$idx];
$host = $con->getServer();
$result = $con->send($this->queueName($queue), $msg, $props);
if (!$result) {
common_log(LOG_ERR, "Error sending $rep to $queue queue on $host");
return false;
}
common_log(LOG_DEBUG, "complete remote queueing $rep for $queue on $host");
$this->stats('enqueued', $queue);
return true;
}
/**
* Determine whether messages to this queue should be marked as persistent.
* Actual persistent storage depends on the queue server's configuration.
* @param string $queue
* @return bool
*/
protected function isPersistent($queue)
{
$mode = common_config('queue', 'stomp_persistent');
if (is_array($mode)) {
return in_array($queue, $mode);
} else {
return (bool)$mode;
}
}
/**
* Send any sockets we're listening on to the IO manager
* to wait for input.
*
* @return array of resources
*/
public function getSockets()
{
$sockets = array();
foreach ($this->cons as $con) {
if ($con) {
$sockets[] = $con->getSocket();
}
}
return $sockets;
}
/**
* Get the Stomp connection object associated with the given socket.
* @param resource $socket
* @return int index into connections list
* @throws Exception
*/
protected function connectionFromSocket($socket)
{
foreach ($this->cons as $i => $con) {
if ($con && $con->getSocket() === $socket) {
return $i;
}
}
throw new Exception(__CLASS__ . " asked to read from unrecognized socket");
}
/**
* We've got input to handle on our socket!
* Read any waiting Stomp frame(s) and process them.
*
* @param resource $socket
* @return boolean ok on success
*/
public function handleInput($socket)
{
$idx = $this->connectionFromSocket($socket);
$con = $this->cons[$idx];
$host = $con->getServer();
$ok = true;
try {
$frames = $con->readFrames();
} catch (StompException $e) {
common_log(LOG_ERR, "Lost connection to $host: " . $e->getMessage());
$this->cons[$idx] = null;
$this->transaction[$idx] = null;
$this->disconnect[$idx] = time();
return false;
}
foreach ($frames as $frame) {
$dest = $frame->headers['destination'];
if ($dest == $this->control) {
if (!$this->handleControlSignal($idx, $frame)) {
// We got a control event that requests a shutdown;
// close out and stop handling anything else!
break;
}
} else {
$ok = $ok && $this->handleItem($idx, $frame);
}
}
return $ok;
}
/**
* Attempt to reconnect in background if we lost a connection.
*/
function idle()
{
$now = time();
foreach ($this->cons as $idx => $con) {
if (empty($con)) {
$age = $now - $this->disconnect[$idx];
if ($age >= 60) {
$this->_reconnect($idx);
}
}
}
return true;
}
/**
* Initialize our connection and subscribe to all the queues
* we're going to need to handle... If multiple queue servers
* are configured for failover, we'll listen to all of them.
*
* Side effects: in multi-site mode, may reset site configuration.
*
* @param IoMaster $master process/event controller
* @return bool return false on failure
*/
public function start($master)
{
parent::start($master);
$this->_connectAll();
common_log(LOG_INFO, "Subscribing to $this->control");
foreach ($this->cons as $con) {
if ($con) {
$con->subscribe($this->control);
}
}
if ($this->sites) {
foreach ($this->sites as $server) {
StatusNet::init($server);
$this->doSubscribe();
}
} else {
$this->doSubscribe();
}
foreach ($this->cons as $i => $con) {
if ($con) {
$this->begin($i);
}
}
return true;
}
/**
* Subscribe to all the queues we're going to need to handle...
*
* Side effects: in multi-site mode, may reset site configuration.
*
* @return bool return false on failure
*/
public function finish()
{
// If there are any outstanding delivered messages we haven't processed,
// free them for another thread to take.
foreach ($this->cons as $i => $con) {
if ($con) {
$this->rollback($i);
$con->unsubscribe($this->control);
}
}
if ($this->sites) {
foreach ($this->sites as $server) {
StatusNet::init($server);
$this->doUnsubscribe();
}
} else {
$this->doUnsubscribe();
}
return true;
}
/**
* Get identifier of the currently active site configuration
* @return string
*/
protected function currentSite()
{
return common_config('site', 'server'); // @fixme switch to nickname
}
/**
* Lazy open a single connection to Stomp queue server.
* If multiple servers are configured, we let the Stomp client library
* worry about finding a working connection among them.
*/
protected function _connect()
{
if (empty($this->cons)) {
$list = $this->servers;
if (count($list) > 1) {
shuffle($list); // Randomize to spread load
$url = 'failover://(' . implode(',', $list) . ')';
} else {
$url = $list[0];
}
$con = $this->_doConnect($url);
$this->cons = array($con);
$this->transactionCount = array(0);
$this->transaction = array(null);
$this->disconnect = array(null);
}
}
/**
* Lazy open connections to all Stomp servers, if in manual failover
* mode. This means the queue servers don't speak to each other, so
* we have to listen to all of them to make sure we get all events.
*/
protected function _connectAll()
{
if (!common_config('queue', 'stomp_manual_failover')) {
return $this->_connect();
}
if (empty($this->cons)) {
$this->cons = array();
$this->transactionCount = array();
$this->transaction = array();
foreach ($this->servers as $idx => $server) {
try {
$this->cons[] = $this->_doConnect($server);
$this->disconnect[] = null;
} catch (Exception $e) {
// s'okay, we'll live
$this->cons[] = null;
$this->disconnect[] = time();
}
$this->transactionCount[] = 0;
$this->transaction[] = null;
}
if (empty($this->cons)) {
throw new ServerException("No queue servers reachable...");
return false;
}
}
}
protected function _reconnect($idx)
{
try {
$con = $this->_doConnect($this->servers[$idx]);
} catch (Exception $e) {
$this->_log(LOG_ERR, $e->getMessage());
$con = null;
}
if ($con) {
$this->cons[$idx] = $con;
$this->disconnect[$idx] = null;
// now we have to listen to everything...
// @fixme refactor this nicer. :P
$host = $con->getServer();
$this->_log(LOG_INFO, "Resubscribing to $this->control on $host");
$con->subscribe($this->control);
foreach ($this->subscriptions as $site => $queues) {
foreach ($queues as $queue) {
$this->_log(LOG_INFO, "Resubscribing to $queue on $host");
$con->subscribe($queue);
}
}
$this->begin($idx);
} else {
// Try again later...
$this->disconnect[$idx] = time();
}
}
protected function _doConnect($server)
{
$this->_log(LOG_INFO, "Connecting to '$server' as '$this->username'...");
$con = new LiberalStomp($server);
if ($con->connect($this->username, $this->password)) {
$this->_log(LOG_INFO, "Connected.");
} else {
$this->_log(LOG_ERR, 'Failed to connect to queue server');
throw new ServerException('Failed to connect to queue server');
}
return $con;
}
/**
* Subscribe to all enabled notice queues for the current site.
*/
protected function doSubscribe()
{
$site = $this->currentSite();
$this->_connect();
foreach ($this->getQueues() as $queue) {
$rawqueue = $this->queueName($queue);
$this->subscriptions[$site][$queue] = $rawqueue;
$this->_log(LOG_INFO, "Subscribing to $rawqueue");
foreach ($this->cons as $con) {
if ($con) {
$con->subscribe($rawqueue);
}
}
}
}
/**
* Subscribe from all enabled notice queues for the current site.
*/
protected function doUnsubscribe()
{
$site = $this->currentSite();
$this->_connect();
if (!empty($this->subscriptions[$site])) {
foreach ($this->subscriptions[$site] as $queue => $rawqueue) {
$this->_log(LOG_INFO, "Unsubscribing from $rawqueue");
foreach ($this->cons as $con) {
if ($con) {
$con->unsubscribe($rawqueue);
}
}
unset($this->subscriptions[$site][$queue]);
}
}
}
/**
* Handle and acknowledge an event that's come in through a queue.
*
* If the queue handler reports failure, the message is requeued for later.
* Missing notices or handler classes will drop the message.
*
* Side effects: in multi-site mode, may reset site configuration to
* match the site that queued the event.
*
* @param int $idx connection index
* @param StompFrame $frame
* @return bool
*/
protected function handleItem($idx, $frame)
{
$this->defaultIdx = $idx;
list($site, $queue) = $this->parseDestination($frame->headers['destination']);
if ($site != $this->currentSite()) {
$this->stats('switch');
StatusNet::init($site);
}
$host = $this->cons[$idx]->getServer();
if (is_numeric($frame->body)) {
$id = intval($frame->body);
$info = "notice $id posted at {$frame->headers['created']} in queue $queue from $host";
$notice = Notice::staticGet('id', $id);
if (empty($notice)) {
$this->_log(LOG_WARNING, "Skipping missing $info");
$this->ack($idx, $frame);
$this->commit($idx);
$this->begin($idx);
$this->stats('badnotice', $queue);
return false;
}
$item = $notice;
} else {
// @fixme should we serialize, or json, or what here?
$info = "string posted at {$frame->headers['created']} in queue $queue from $host";
$item = $frame->body;
}
$handler = $this->getHandler($queue);
if (!$handler) {
$this->_log(LOG_ERR, "Missing handler class; skipping $info");
$this->ack($idx, $frame);
$this->commit($idx);
$this->begin($idx);
$this->stats('badhandler', $queue);
return false;
}
$ok = $handler->handle($item);
if (!$ok) {
$this->_log(LOG_WARNING, "Failed handling $info");
// FIXME we probably shouldn't have to do
// this kind of queue management ourselves;
// if we don't ack, it should resend...
$this->ack($idx, $frame);
$this->enqueue($item, $queue);
$this->commit($idx);
$this->begin($idx);
$this->stats('requeued', $queue);
return false;
}
$this->_log(LOG_INFO, "Successfully handled $info");
$this->ack($idx, $frame);
$this->commit($idx);
$this->begin($idx);
$this->stats('handled', $queue);
return true;
}
/**
* Process a control signal broadcast.
*
* @param int $idx connection index
* @param array $frame Stomp frame
* @return bool true to continue; false to stop further processing.
*/
protected function handleControlSignal($idx, $frame)
{
$message = trim($frame->body);
if (strpos($message, ':') !== false) {
list($event, $param) = explode(':', $message, 2);
} else {
$event = $message;
$param = '';
}
$shutdown = false;
if ($event == 'shutdown') {
$this->master->requestShutdown();
$shutdown = true;
} else if ($event == 'restart') {
$this->master->requestRestart();
$shutdown = true;
} else if ($event == 'update') {
$this->updateSiteConfig($param);
} else {
$this->_log(LOG_ERR, "Ignoring unrecognized control message: $message");
}
$this->ack($idx, $frame);
$this->commit($idx);
$this->begin($idx);
return $shutdown;
}
/**
* Set us up with queue subscriptions for a new site added at runtime,
* triggered by a broadcast to the 'statusnet-control' topic.
*
* @param array $frame Stomp frame
* @return bool true to continue; false to stop further processing.
*/
protected function updateSiteConfig($nickname)
{
if (empty($this->sites)) {
if ($nickname == common_config('site', 'nickname')) {
StatusNet::init(common_config('site', 'server'));
$this->doUnsubscribe();
$this->doSubscribe();
} else {
$this->_log(LOG_INFO, "Ignoring update ping for other site $nickname");
}
} else {
$sn = Status_network::staticGet($nickname);
if ($sn) {
$server = $sn->getServerName(); // @fixme do config-by-nick
StatusNet::init($server);
if (empty($this->sites[$server])) {
$this->addSite($server);
}
$this->_log(LOG_INFO, "(Re)subscribing to queues for site $nickname / $server");
$this->doUnsubscribe();
$this->doSubscribe();
$this->stats('siteupdate');
} else {
$this->_log(LOG_ERR, "Ignoring ping for unrecognized new site $nickname");
}
}
}
/**
* Combines the queue_basename from configuration with the
* site server name and queue name to give eg:
*
* /queue/statusnet/identi.ca/sms
*
* @param string $queue
* @return string
*/
protected function queueName($queue)
{
return common_config('queue', 'queue_basename') .
$this->currentSite() . '/' . $queue;
}
/**
* Returns the site and queue name from the server-side queue.
*
* @param string queue destination (eg '/queue/statusnet/identi.ca/sms')
* @return array of site and queue: ('identi.ca','sms') or false if unrecognized
*/
protected function parseDestination($dest)
{
$prefix = common_config('queue', 'queue_basename');
if (substr($dest, 0, strlen($prefix)) == $prefix) {
$rest = substr($dest, strlen($prefix));
return explode("/", $rest, 2);
} else {
common_log(LOG_ERR, "Got a message from unrecognized stomp queue: $dest");
return array(false, false);
}
}
function _log($level, $msg)
{
common_log($level, 'StompQueueManager: '.$msg);
}
protected function begin($idx)
{
if ($this->useTransactions) {
if (!empty($this->transaction[$idx])) {
throw new Exception("Tried to start transaction in the middle of a transaction");
}
$this->transactionCount[$idx]++;
$this->transaction[$idx] = $this->master->id . '-' . $this->transactionCount[$idx] . '-' . time();
$this->cons[$idx]->begin($this->transaction[$idx]);
}
}
protected function ack($idx, $frame)
{
if ($this->useTransactions) {
if (empty($this->transaction[$idx])) {
throw new Exception("Tried to ack but not in a transaction");
}
$this->cons[$idx]->ack($frame, $this->transaction[$idx]);
} else {
$this->cons[$idx]->ack($frame);
}
}
protected function commit($idx)
{
if ($this->useTransactions) {
if (empty($this->transaction[$idx])) {
throw new Exception("Tried to commit but not in a transaction");
}
$this->cons[$idx]->commit($this->transaction[$idx]);
$this->transaction[$idx] = null;
}
}
protected function rollback($idx)
{
if ($this->useTransactions) {
if (empty($this->transaction[$idx])) {
throw new Exception("Tried to rollback but not in a transaction");
}
$this->cons[$idx]->commit($this->transaction[$idx]);
$this->transaction[$idx] = null;
}
}
}