maintenance/nextJobDB.php

   1 <?php
   2 /**
   3  * Pick a database that has 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  * @ingroup Maintenance
  21  */
  22
  23 require_once( "Maintenance.php" );
  24
  25 class nextJobDB extends Maintenance {
  26         public function __construct() {
  27                 parent::__construct();
  28                 $this->mDescription = "Pick a database that has pending jobs";
  29                 $this->addOption( 'type', "The type of job to search for", false, true );
  30         }
  31         public function execute() {
  32                 global $wgMemc;
  33                 $type = $this->getOption( 'type', false );
  34                 $mckey = $type === false
  35                                         ? "jobqueue:dbs"
  36                                         : "jobqueue:dbs:$type";
  37                 $pendingDBs = $wgMemc->get( $mckey );
  38
  39                 # If we didn't get it from the cache
  40                 if( !$pendingDBs ) {
  41                         $pendingDBs = $this->getPendingDbs( $type );
  42                         $wgMemc->get( $mckey, $pendingDBs, 300 );
  43                 }
  44                 # If we've got a pending job in a db, display it.
  45                 if ( $pendingDBs ) {
  46                         $this->output( $pendingDBs[mt_rand(0, count( $pendingDBs ) - 1)] );
  47                 }
  48         }
  49
  50         /**
  51          * Get all databases that have a pending job
  52          * @param $type String Job type
  53          * @return array
  54          */
  55         private function getPendingDbs( $type ) {
  56                 global $wgLocalDatabases;
  57                 $pendingDBs = array();
  58                 # Cross-reference DBs by master DB server
  59                 $dbsByMaster = array();
  60                 foreach ( $wgLocalDatabases as $db ) {
  61                         $lb = wfGetLB( $db );
  62                         $dbsByMaster[$lb->getServerName(0)][] = $db;
  63                 }
  64
  65                 foreach ( $dbsByMaster as $master => $dbs ) {
  66                         $dbConn = wfGetDB( DB_MASTER, array(), $dbs[0] );
  67                         $stype = $dbConn->addQuotes($type);
  68                         $jobTable = $dbConn->getTable( 'job' );
  69
  70                         # Padding row for MySQL bug
  71                         $sql = "(SELECT '-------------------------------------------')";
  72                         foreach ( $dbs as $dbName ) {
  73                                 if ( $sql != '' ) {
  74                                         $sql .= ' UNION ';
  75                                 }
  76                                 if ($type === false)
  77                                         $sql .= "(SELECT '$dbName' FROM `$dbName`.$jobTable LIMIT 1)";
  78                                 else
  79                                         $sql .= "(SELECT '$dbName' FROM `$dbName`.$jobTable WHERE job_cmd=$stype LIMIT 1)";
  80                         }
  81                         $res = $dbConn->query( $sql, __METHOD__ );
  82                         $row = $dbConn->fetchRow( $res ); // discard padding row
  83                         while ( $row = $dbConn->fetchRow( $res ) ) {
  84                                 $pendingDBs[] = $row[0];
  85                         }
  86                 }
  87         }
  88 }
  89
  90 $maintClass = "nextJobDb";
  91 require_once( DO_MAINTENANCE );