Merge "Give TestCase::checkHasDiff3 a better name"

[lhc/web/wiklou.git] / includes / db / loadbalancer / LoadBalancer.php

diff --git a/includes/db/loadbalancer/LoadBalancer.php b/includes/db/loadbalancer/LoadBalancer.php
index 85a6bf0..32999f5 100644 (file)
--- a/includes/db/loadbalancer/LoadBalancer.php
+++ b/includes/db/loadbalancer/LoadBalancer.php
@@ -190,11 +190,13 @@ class LoadBalancer {
                                if ( isset( $this->mServers[$i]['max lag'] ) ) {
                                        $maxServerLag = min( $maxServerLag, $this->mServers[$i]['max lag'] );
                                }
+
+                               $host = $this->getServerName( $i );
                                if ( $lag === false ) {
-                                       wfDebugLog( 'replication', "Server #$i is not replicating" );
+                                       wfDebugLog( 'replication', "Server $host (#$i) is not replicating?" );
                                        unset( $loads[$i] );
                                } elseif ( $lag > $maxServerLag ) {
-                                       wfDebugLog( 'replication', "Server #$i is excessively lagged ($lag seconds)" );
+                                       wfDebugLog( 'replication', "Server $host (#$i) has >= $lag seconds of lag" );
                                        unset( $loads[$i] );
                                }
                        }
@@ -679,9 +681,7 @@ class LoadBalancer {
         *
         * @param int $i Server index
         * @param string|bool $wiki Wiki ID, or false for the current wiki
-        * @return DatabaseBase
-        *
-        * @access private
+        * @return DatabaseBase|bool Returns false on errors
         */
        public function openConnection( $i, $wiki = false ) {
                if ( $wiki !== false ) {
@@ -1168,6 +1168,29 @@ class LoadBalancer {
                        || $this->lastMasterChangeTimestamp() > microtime( true ) - $age );
        }
 
+       /**
+        * Get the list of callers that have pending master changes
+        *
+        * @return array
+        * @since 1.27
+        */
+       public function pendingMasterChangeCallers() {
+               $fnames = array();
+
+               $masterIndex = $this->getWriterIndex();
+               foreach ( $this->mConns as $conns2 ) {
+                       if ( empty( $conns2[$masterIndex] ) ) {
+                               continue;
+                       }
+                       /** @var DatabaseBase $conn */
+                       foreach ( $conns2[$masterIndex] as $conn ) {
+                               $fnames = array_merge( $fnames, $conn->pendingWriteCallers() );
+                       }
+               }
+
+               return $fnames;
+       }
+
        /**
         * @param mixed $value
         * @return mixed
@@ -1340,10 +1363,10 @@ class LoadBalancer {
         * function instead of Database::getLag() avoids a fatal error in this
         * case on many installations.
         *
-        * @param DatabaseBase $conn
-        * @return int
+        * @param IDatabase $conn
+        * @return int|bool Returns false on error
         */
-       public function safeGetLag( $conn ) {
+       public function safeGetLag( IDatabase $conn ) {
                if ( $this->getServerCount() == 1 ) {
                        return 0;
                } else {
@@ -1351,6 +1374,41 @@ class LoadBalancer {
                }
        }
 
+       /**
+        * Wait for a slave DB to reach a specified master position
+        *
+        * This will connect to the master to get an accurate position if $pos is not given
+        *
+        * @param IDatabase $conn Slave DB
+        * @param DBMasterPos|bool $pos Master position; default: current position
+        * @param integer $timeout Timeout in seconds
+        * @return bool Success
+        * @since 1.27
+        */
+       public function safeWaitForMasterPos( IDatabase $conn, $pos = false, $timeout = 10 ) {
+               if ( $this->getServerCount() == 1 || !$conn->getLBInfo( 'slave' ) ) {
+                       return true; // server is not a slave DB
+               }
+
+               $pos = $pos ?: $this->getConnection( DB_MASTER )->getMasterPos();
+               if ( !$pos ) {
+                       return false; // something is misconfigured
+               }
+
+               $result = $conn->masterPosWait( $pos, $timeout );
+               if ( $result == -1 || is_null( $result ) ) {
+                       $msg = __METHOD__ . ": Timed out waiting on {$conn->getServer()} pos {$pos}";
+                       wfDebugLog( 'replication', "$msg\n" );
+                       wfDebugLog( 'DBPerformance', "$msg:\n" . wfBacktrace( true ) );
+                       $ok = false;
+               } else {
+                       wfDebugLog( 'replication', __METHOD__ . ": Done\n" );
+                       $ok = true;
+               }
+
+               return $ok;
+       }
+
        /**
         * Clear the cache for slag lag delay times
         *