Merge "Defer addAutopromoteOnceGroups to transaction idle"

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

diff --git a/includes/db/LoadBalancer.php b/includes/db/LoadBalancer.php
index b3f9210..5353288 100644 (file)
--- a/includes/db/LoadBalancer.php
+++ b/includes/db/LoadBalancer.php
@@ -1048,8 +1048,22 @@ class LoadBalancer {
                $maxLag = -1;
                $host = '';
                $maxIndex = 0;
-               if ( $this->getServerCount() > 1 ) { // no replication = no lag
+
+               if ( $this->getServerCount() <= 1 ) { // no replication = no lag
+                       return array( $host, $maxLag, $maxIndex );
+               }
+
+               // Try to get the max lag info from the server cache
+               $key = 'loadbalancer:maxlag:cluster:' . $this->mServers[0]['host'];
+               $cache = ObjectCache::newAccelerator( array(), 'hash' );
+               $maxLagInfo = $cache->get( $key ); // (host, lag, index)
+
+               // Fallback to connecting to each slave and getting the lag
+               if ( !$maxLagInfo ) {
                        foreach ( $this->mServers as $i => $conn ) {
+                               if ( $i == $this->getWriterIndex() ) {
+                                       continue; // nothing to check
+                               }
                                $conn = false;
                                if ( $wiki === false ) {
                                        $conn = $this->getAnyOpenConnection( $i );
@@ -1067,9 +1081,11 @@ class LoadBalancer {
                                        $maxIndex = $i;
                                }
                        }
+                       $maxLagInfo = array( $host, $maxLag, $maxIndex );
+                       $cache->set( $key, $maxLagInfo, 5 );
                }
 
-               return array( $host, $maxLag, $maxIndex );
+               return $maxLagInfo;
        }
 
        /**