gnu-social/lib/stompqueuemanager.php
2013-10-28 12:44:06 +01:00

765 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;
protected $useAcks;
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');
$this->breakout = common_config('queue', 'breakout');
$this->useTransactions = common_config('queue', 'stomp_transactions');
$this->useAcks = common_config('queue', 'stomp_acks');
}
/**
* 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;
}
/**
* 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();
$con = $this->cons[$this->defaultIdx];
$result = $con->send($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;
}
}
/**
* Saves an object into the queue item table.
*
* @param mixed $object
* @param string $queue
* @param string $siteNickname optional override to drop into another site's queue
*
* @return boolean true on success
* @throws StompException on connection or send error
*/
public function enqueue($object, $queue, $siteNickname=null)
{
$this->_connect();
if (common_config('queue', 'stomp_enqueue_on')) {
// We're trying to force all writes to a single server.
// WARNING: this might do odd things if that server connection dies.
$idx = array_search(common_config('queue', 'stomp_enqueue_on'),
$this->servers);
if ($idx === false) {
common_log(LOG_ERR, 'queue stomp_enqueue_on setting does not match our server list.');
$idx = $this->defaultIdx;
}
} else {
$idx = $this->defaultIdx;
}
return $this->_doEnqueue($object, $queue, $idx, $siteNickname);
}
/**
* Saves a notice object reference into the queue item table
* on the given connection.
*
* @return boolean true on success
* @throws StompException on connection or send error
*/
protected function _doEnqueue($object, $queue, $idx, $siteNickname=null)
{
$rep = $this->logrep($object);
$envelope = array('site' => $siteNickname ? $siteNickname : common_config('site', 'nickname'),
'handler' => $queue,
'payload' => $this->encode($object));
$msg = serialize($envelope);
$props = array('created' => common_sql_now());
if ($this->isPersistent($queue)) {
$props['persistent'] = 'true';
}
$con = $this->cons[$idx];
$host = $con->getServer();
$target = $this->queueName($queue);
$result = $con->send($target, $msg, $props);
if (!$result) {
$this->_log(LOG_ERR, "Error sending $rep to $queue queue on $host $target");
return false;
}
$this->_log(LOG_DEBUG, "complete remote queueing $rep for $queue on $host $target");
$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();
$this->defaultIdx = $idx;
$ok = true;
try {
$frames = $con->readFrames();
} catch (StompException $e) {
$this->_log(LOG_ERR, "Lost connection to $host: " . $e->getMessage());
fclose($socket); // ???
$this->cons[$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($frame)) {
// We got a control event that requests a shutdown;
// close out and stop handling anything else!
break;
}
} else {
$ok = $this->handleItem($frame) && $ok;
}
$this->ack($idx, $frame);
$this->commit($idx);
$this->begin($idx);
}
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);
$this->_connectAll();
foreach ($this->cons as $i => $con) {
if ($con) {
$this->doSubscribe($con);
$this->begin($i);
}
}
return true;
}
/**
* Close out any active connections.
*
* @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->disconnect();
$this->cons[$i] = null;
}
}
return true;
}
/**
* 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;
}
}
}
/**
* Attempt to manually reconnect to the Stomp server for the given
* slot. If successful, set up our subscriptions on it.
*/
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;
$this->doSubscribe($con);
$this->begin($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;
}
/**
* Set up all our raw queue subscriptions on the given connection
* @param LiberalStomp $con
*/
protected function doSubscribe(LiberalStomp $con)
{
$host = $con->getServer();
foreach ($this->subscriptions() as $sub) {
$this->_log(LOG_INFO, "Subscribing to $sub on $host");
$con->subscribe($sub);
}
}
/**
* Grab a full list of stomp-side queue subscriptions.
* Will include:
* - control broadcast channel
* - shared group queues for active groups
* - per-handler and per-site breakouts from $config['queue']['breakout']
* that are rooted in the active groups.
*
* @return array of strings
*/
protected function subscriptions()
{
$subs = array();
$subs[] = $this->control;
foreach ($this->activeGroups as $group) {
$subs[] = $this->base . $group;
}
foreach ($this->breakout as $spec) {
$parts = explode('/', $spec);
if (count($parts) < 2 || count($parts) > 3) {
common_log(LOG_ERR, "Bad queue breakout specifier $spec");
}
if (in_array($parts[0], $this->activeGroups)) {
$subs[] = $this->base . $spec;
}
}
return array_unique($subs);
}
/**
* 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 StompFrame $frame
* @return bool success
*/
protected function handleItem($frame)
{
$host = $this->cons[$this->defaultIdx]->getServer();
$message = unserialize($frame->body);
if ($message === false) {
$this->_log(LOG_ERR, "Can't unserialize frame: {$frame->body}");
$this->_log(LOG_ERR, "Unserializable frame length: " . strlen($frame->body));
return false;
}
$site = $message['site'];
$queue = $message['handler'];
if ($this->isDeadletter($frame, $message)) {
$this->stats('deadletter', $queue);
return false;
}
// @fixme detect failing site switches
$this->switchSite($site);
try {
$item = $this->decode($message['payload']);
} catch (Exception $e) {
$this->_log(LOG_ERR, "Skipping empty or deleted item in queue $queue from $host");
$this->stats('baditem', $queue);
return false;
}
$info = $this->logrep($item) . " posted at " .
$frame->headers['created'] . " in queue $queue from $host";
$this->_log(LOG_DEBUG, "Dequeued $info");
$handler = $this->getHandler($queue);
if (!$handler) {
$this->_log(LOG_ERR, "Missing handler class; skipping $info");
$this->stats('badhandler', $queue);
return false;
}
try {
$ok = $handler->handle($item);
} catch (Exception $e) {
$this->_log(LOG_ERR, "Exception on queue $queue: " . $e->getMessage());
$ok = false;
}
if ($ok) {
$this->_log(LOG_INFO, "Successfully handled $info");
$this->stats('handled', $queue);
} else {
$this->_log(LOG_WARNING, "Failed handling $info");
// Requeing moves the item to the end of the line for its next try.
// @fixme add a manual retry count
$this->enqueue($item, $queue);
$this->stats('requeued', $queue);
}
return $ok;
}
/**
* Check if a redelivered message has been run through enough
* that we're going to give up on it.
*
* @param StompFrame $frame
* @param array $message unserialized message body
* @return boolean true if we should discard
*/
protected function isDeadLetter($frame, $message)
{
if (isset($frame->headers['redelivered']) && $frame->headers['redelivered'] == 'true') {
// Message was redelivered, possibly indicating a previous failure.
$msgId = $frame->headers['message-id'];
$site = $message['site'];
$queue = $message['handler'];
$msgInfo = "message $msgId for $site in queue $queue";
$deliveries = $this->incDeliveryCount($msgId);
if ($deliveries > common_config('queue', 'max_retries')) {
$info = "DEAD-LETTER FILE: Gave up after retry $deliveries on $msgInfo";
$outdir = common_config('queue', 'dead_letter_dir');
if ($outdir) {
$filename = $outdir . "/$site-$queue-" . rawurlencode($msgId);
$info .= ": dumping to $filename";
file_put_contents($filename, $message['payload']);
}
common_log(LOG_ERR, $info);
return true;
} else {
common_log(LOG_INFO, "retry $deliveries on $msgInfo");
}
}
return false;
}
/**
* Update count of times we've re-encountered this message recently,
* triggered when we get a message marked as 'redelivered'.
*
* Requires a CLI-friendly cache configuration.
*
* @param string $msgId message-id header from message
* @return int number of retries recorded
*/
function incDeliveryCount($msgId)
{
$count = 0;
$cache = Cache::instance();
if ($cache) {
$key = 'statusnet:stomp:message-retries:' . $msgId;
$count = $cache->increment($key);
if (!$count) {
$count = 1;
$cache->set($key, $count, null, 3600);
$got = $cache->get($key);
}
}
return $count;
}
/**
* 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");
}
return $shutdown;
}
/**
* Switch site, if necessary, and reset current handler assignments
* @param string $site
*/
function switchSite($site)
{
if ($site != StatusNet::currentSite()) {
$this->stats('switch');
StatusNet::switchSite($site);
$this->initialize();
}
}
/**
* (Re)load runtime configuration for a given site by nickname,
* triggered by a broadcast to the 'statusnet-control' topic.
*
* Configuration changes in database should update, but config
* files might not.
*
* @param array $frame Stomp frame
* @return bool true to continue; false to stop further processing.
*/
protected function updateSiteConfig($nickname)
{
$sn = Status_network::getKV('nickname', $nickname);
if ($sn) {
$this->switchSite($nickname);
if (!in_array($nickname, $this->sites)) {
$this->addSite();
}
$this->stats('siteupdate');
} else {
$this->_log(LOG_ERR, "Ignoring ping for unrecognized new site $nickname");
}
}
/**
* Combines the queue_basename from configuration with the
* group name for this queue to give eg:
*
* /queue/statusnet/main
* /queue/statusnet/main/distrib
* /queue/statusnet/xmpp/xmppout/site01
*
* @param string $queue
* @return string
*/
protected function queueName($queue)
{
$group = $this->queueGroup($queue);
$site = StatusNet::currentSite();
$specs = array("$group/$queue/$site",
"$group/$queue");
foreach ($specs as $spec) {
if (in_array($spec, $this->breakout)) {
return $this->base . $spec;
}
}
return $this->base . $group;
}
/**
* Get the breakout mode for the given queue on the current site.
*
* @param string $queue
* @return string one of 'shared', 'handler', 'site'
*/
protected function breakoutMode($queue)
{
$breakout = common_config('queue', 'breakout');
if (isset($breakout[$queue])) {
return $breakout[$queue];
} else if (isset($breakout['*'])) {
return $breakout['*'];
} else {
return 'shared';
}
}
protected function begin($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->useAcks) {
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;
}
}
}