maintenance/runJobs.php

   1 <?php
   2 /**
   3  * Run pending jobs.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License along
  16  * with this program; if not, write to the Free Software Foundation, Inc.,
  17  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  18  * http://www.gnu.org/copyleft/gpl.html
  19  *
  20  * @file
  21  * @ingroup Maintenance
  22  */
  23
  24 require_once __DIR__ . '/Maintenance.php';
  25
  26 /**
  27  * Maintenance script that runs pending jobs.
  28  *
  29  * @ingroup Maintenance
  30  */
  31 class RunJobs extends Maintenance {
  32         public function __construct() {
  33                 parent::__construct();
  34                 $this->mDescription = "Run pending jobs";
  35                 $this->addOption( 'maxjobs', 'Maximum number of jobs to run', false, true );
  36                 $this->addOption( 'maxtime', 'Maximum amount of wall-clock time', false, true );
  37                 $this->addOption( 'type', 'Type of job to run', false, true );
  38                 $this->addOption( 'procs', 'Number of processes to use', false, true );
  39         }
  40
  41         public function memoryLimit() {
  42                 if ( $this->hasOption( 'memory-limit' ) ) {
  43                         return parent::memoryLimit();
  44                 }
  45                 // Don't eat all memory on the machine if we get a bad job.
  46                 return "150M";
  47         }
  48
  49         public function execute() {
  50                 if ( wfReadOnly() ) {
  51                         $this->error( "Unable to run jobs; the wiki is in read-only mode.", 1 ); // die
  52                 }
  53
  54                 if ( $this->hasOption( 'procs' ) ) {
  55                         $procs = intval( $this->getOption( 'procs' ) );
  56                         if ( $procs < 1 || $procs > 1000 ) {
  57                                 $this->error( "Invalid argument to --procs", true );
  58                         } elseif ( $procs != 1 ) {
  59                                 $fc = new ForkController( $procs );
  60                                 if ( $fc->start() != 'child' ) {
  61                                         exit( 0 );
  62                                 }
  63                         }
  64                 }
  65
  66                 $type = $this->getOption( 'type', false );
  67                 $maxJobs = $this->getOption( 'maxjobs', false );
  68                 $maxTime = $this->getOption( 'maxtime', false );
  69                 $startTime = time();
  70
  71                 $group = JobQueueGroup::singleton();
  72                 // Handle any required periodic queue maintenance
  73                 $count = $group->executeReadyPeriodicTasks();
  74                 if ( $count > 0 ) {
  75                         $this->runJobsLog( "Executed $count periodic queue task(s)." );
  76                 }
  77
  78                 $backoffs = $this->loadBackoffs(); // map of (type => UNIX expiry)
  79                 $startingBackoffs = $backoffs; // avoid unnecessary writes
  80                 $backoffExpireFunc = function( $t ) { return $t > time(); };
  81
  82                 $jobsRun = 0; // counter
  83                 $flags = JobQueueGroup::USE_CACHE;
  84                 $lastTime = time(); // time since last slave check
  85                 do {
  86                         if ( $type === false ) {
  87                                 $backoffs = array_filter( $backoffs, $backoffExpireFunc );
  88                                 $blacklist = array_keys( $backoffs );
  89                                 $job = $group->pop( JobQueueGroup::TYPE_DEFAULT, $flags, $blacklist );
  90                         } else {
  91                                 $job = $group->pop( $type ); // job from a single queue
  92                         }
  93                         if ( $job ) { // found a job
  94                                 ++$jobsRun;
  95                                 $this->runJobsLog( $job->toString() . " STARTING" );
  96
  97                                 // Set timer to stop the job if too much CPU time is used
  98                                 set_time_limit( $maxTime ?: 0 );
  99                                 // Run the job...
 100                                 wfProfileIn( __METHOD__ . '-' . get_class( $job ) );
 101                                 $t = microtime( true );
 102                                 try {
 103                                         $status = $job->run();
 104                                         $error = $job->getLastError();
 105                                 } catch ( MWException $e ) {
 106                                         $status = false;
 107                                         $error = get_class( $e ) . ': ' . $e->getMessage();
 108                                         $e->report(); // write error to STDERR and the log
 109                                 }
 110                                 $timeMs = intval( ( microtime( true ) - $t ) * 1000 );
 111                                 wfProfileOut( __METHOD__ . '-' . get_class( $job ) );
 112                                 // Disable the timer
 113                                 set_time_limit( 0 );
 114
 115                                 // Mark the job as done on success or when the job cannot be retried
 116                                 if ( $status !== false || !$job->allowRetries() ) {
 117                                         $group->ack( $job ); // done
 118                                 }
 119
 120                                 if ( $status === false ) {
 121                                         $this->runJobsLog( $job->toString() . " t=$timeMs error={$error}" );
 122                                 } else {
 123                                         $this->runJobsLog( $job->toString() . " t=$timeMs good" );
 124                                 }
 125
 126                                 // Back off of certain jobs for a while
 127                                 $ttw = $this->getBackoffTimeToWait( $job );
 128                                 if ( $ttw > 0 ) {
 129                                         $jType = $job->getType();
 130                                         $backoffs[$jType] = isset( $backoffs[$jType] ) ? $backoffs[$jType] : 0;
 131                                         $backoffs[$jType] = max( $backoffs[$jType], time() + $ttw );
 132                                 }
 133
 134                                 // Break out if we hit the job count or wall time limits...
 135                                 if ( $maxJobs && $jobsRun >= $maxJobs ) {
 136                                         break;
 137                                 } elseif ( $maxTime && ( time() - $startTime ) > $maxTime ) {
 138                                         break;
 139                                 }
 140
 141                                 // Don't let any of the main DB slaves get backed up
 142                                 $timePassed = time() - $lastTime;
 143                                 if ( $timePassed >= 5 || $timePassed < 0 ) {
 144                                         wfWaitForSlaves();
 145                                         $lastTime = time();
 146                                 }
 147                                 // Don't let any queue slaves/backups fall behind
 148                                 if ( $jobsRun > 0 && ( $jobsRun % 100 ) == 0 ) {
 149                                         $group->waitForBackups();
 150                                 }
 151
 152                                 // Bail if near-OOM instead of in a job
 153                                 $this->assertMemoryOK();
 154                         }
 155                 } while ( $job ); // stop when there are no jobs
 156                 // Sync the persistent backoffs for the next runJobs.php pass
 157                 $backoffs = array_filter( $backoffs, $backoffExpireFunc );
 158                 if ( $backoffs !== $startingBackoffs ) {
 159                         $this->syncBackoffs( $backoffs );
 160                 }
 161         }
 162
 163         /**
 164          * @param Job $job
 165          * @return integer Seconds for this runner to avoid doing more jobs of this type
 166          * @see $wgJobBackoffThrottling
 167          */
 168         private function getBackoffTimeToWait( Job $job ) {
 169                 global $wgJobBackoffThrottling;
 170
 171                 if ( !isset( $wgJobBackoffThrottling[$job->getType()] ) ) {
 172                         return 0; // not throttled
 173                 }
 174                 $itemsPerSecond = $wgJobBackoffThrottling[$job->getType()];
 175                 if ( $itemsPerSecond <= 0 ) {
 176                         return 0; // not throttled
 177                 }
 178
 179                 $seconds = 0;
 180                 if ( $job->workItemCount() > 0 ) {
 181                         $seconds = floor( $job->workItemCount() / $itemsPerSecond );
 182                         $remainder = $job->workItemCount() % $itemsPerSecond;
 183                         $seconds += ( mt_rand( 1, $itemsPerSecond ) <= $remainder ) ? 1 : 0;
 184                 }
 185
 186                 return (int)$seconds;
 187         }
 188
 189         /**
 190          * Get the previous backoff expiries from persistent storage
 191          *
 192          * @return array Map of (job type => backoff expiry timestamp)
 193          */
 194         private function loadBackoffs() {
 195                 $section = new ProfileSection( __METHOD__ );
 196
 197                 $backoffs = array();
 198                 $file = wfTempDir() . '/mw-runJobs-backoffs.json';
 199                 if ( is_file( $file ) ) {
 200                         $handle = fopen( $file, 'rb' );
 201                         flock( $handle, LOCK_SH );
 202                         $content = stream_get_contents( $handle );
 203                         flock( $handle, LOCK_UN );
 204                         fclose( $handle );
 205                         $backoffs = json_decode( $content, true ) ?: array();
 206                 }
 207
 208                 return $backoffs;
 209         }
 210
 211         /**
 212          * Merge the current backoff expiries from persistent storage
 213          *
 214          * @param array $backoffs Map of (job type => backoff expiry timestamp)
 215          */
 216         private function syncBackoffs( array $backoffs ) {
 217                 $section = new ProfileSection( __METHOD__ );
 218
 219                 $file = wfTempDir() . '/mw-runJobs-backoffs.json';
 220                 $handle = fopen( $file, 'wb+' );
 221                 flock( $handle, LOCK_EX );
 222                 $content = stream_get_contents( $handle );
 223                 $cBackoffs = json_decode( $content, true ) ?: array();
 224                 foreach ( $backoffs as $type => $timestamp ) {
 225                         $cBackoffs[$type] = isset( $cBackoffs[$type] ) ? $cBackoffs[$type] : 0;
 226                         $cBackoffs[$type] = max( $cBackoffs[$type], $backoffs[$type] );
 227                 }
 228                 ftruncate( $handle, 0 );
 229                 fwrite( $handle, json_encode( $backoffs ) );
 230                 flock( $handle, LOCK_UN );
 231                 fclose( $handle );
 232         }
 233
 234         /**
 235          * Make sure that this script is not too close to the memory usage limit.
 236          * It is better to die in between jobs than OOM right in the middle of one.
 237          * @throws MWException
 238          */
 239         private function assertMemoryOK() {
 240                 static $maxBytes = null;
 241                 if ( $maxBytes === null ) {
 242                         $m = array();
 243                         if ( preg_match( '!^(\d+)(k|m|g|)$!i', ini_get( 'memory_limit' ), $m ) ) {
 244                                 list( , $num, $unit ) = $m;
 245                                 $conv = array( 'g' => 1073741824, 'm' => 1048576, 'k' => 1024, '' => 1 );
 246                                 $maxBytes = $num * $conv[strtolower( $unit )];
 247                         } else {
 248                                 $maxBytes = 0;
 249                         }
 250                 }
 251                 $usedBytes = memory_get_usage();
 252                 if ( $maxBytes && $usedBytes >= 0.95 * $maxBytes ) {
 253                         throw new MWException( "Detected excessive memory usage ($usedBytes/$maxBytes)." );
 254                 }
 255         }
 256
 257         /**
 258          * Log the job message
 259          * @param $msg String The message to log
 260          */
 261         private function runJobsLog( $msg ) {
 262                 $this->output( wfTimestamp( TS_DB ) . " $msg\n" );
 263                 wfDebugLog( 'runJobs', $msg );
 264         }
 265 }
 266
 267 $maintClass = "RunJobs";
 268 require_once RUN_MAINTENANCE_IF_MAIN;