maintenance/nextJobDB.php

   1 <?php
   2 /**
   3  * Pick a database that has pending jobs
   4  *
   5  * @file
   6  * @ingroup Maintenance
   7  */
   8
   9 $options = array( 'type'  );
  10
  11 require_once( 'commandLine.inc' );
  12
  13 $type = isset($options['type'])
  14                 ? $options['type']
  15                 : false;
  16
  17 $mckey = $type === false
  18             ? "jobqueue:dbs"
  19             : "jobqueue:dbs:$type";
  20
  21 $pendingDBs = $wgMemc->get( $mckey );
  22 if ( !$pendingDBs ) {
  23         $pendingDBs = array();
  24         # Cross-reference DBs by master DB server
  25         $dbsByMaster = array();
  26         foreach ( $wgLocalDatabases as $db ) {
  27                 $lb = wfGetLB( $db );
  28                 $dbsByMaster[$lb->getServerName(0)][] = $db;
  29         }
  30
  31         foreach ( $dbsByMaster as $master => $dbs ) {
  32                 $dbConn = wfGetDB( DB_MASTER, array(), $dbs[0] );
  33                 $stype = $dbConn->addQuotes($type);
  34
  35                 # Padding row for MySQL bug
  36                 $sql = "(SELECT '-------------------------------------------')";
  37                 foreach ( $dbs as $dbName ) {
  38                         if ( $sql != '' ) {
  39                                 $sql .= ' UNION ';
  40                         }
  41                         if ($type === false)
  42                                 $sql .= "(SELECT '$dbName' FROM `$dbName`.job LIMIT 1)";
  43                         else
  44                                 $sql .= "(SELECT '$dbName' FROM `$dbName`.job WHERE job_cmd=$stype LIMIT 1)";
  45                 }
  46                 $res = $dbConn->query( $sql, 'nextJobDB.php' );
  47                 $row = $dbConn->fetchRow( $res ); // discard padding row
  48                 while ( $row = $dbConn->fetchRow( $res ) ) {
  49                         $pendingDBs[] = $row[0];
  50                 }
  51         }
  52
  53         $wgMemc->set( $mckey, $pendingDBs, 300 );
  54 }
  55
  56 if ( $pendingDBs ) {
  57         echo $pendingDBs[mt_rand(0, count( $pendingDBs ) - 1)];
  58 }
  59
  60