Merge "Fix default handling in LoadBalancer::getRandomNonLagged()"

diff --git a/includes/db/loadbalancer/LoadBalancer.php b/includes/db/loadbalancer/LoadBalancer.php
index d29f05a..71286a9 100644 (file)
--- a/includes/db/loadbalancer/LoadBalancer.php
+++ b/includes/db/loadbalancer/LoadBalancer.php
@@ -78,7 +78,7 @@ class LoadBalancer {
        /** @var integer Warn when this many connection are held */
        const CONN_HELD_WARN_THRESHOLD = 10;
        /** @var integer Default 'max lag' when unspecified */
-       const MAX_LAG = 10;
+       const MAX_LAG_DEFAULT = 10;
        /** @var integer Max time to wait for a replica DB to catch up (e.g. ChronologyProtector) */
        const POS_WAIT_TIMEOUT = 10;
        /** @var integer Seconds to cache master server read-only status */
@@ -189,19 +189,21 @@ class LoadBalancer {
         * @param int $maxLag Restrict the maximum allowed lag to this many seconds
         * @return bool|int|string
         */
-       private function getRandomNonLagged( array $loads, $wiki = false, $maxLag = self::MAX_LAG ) {
+       private function getRandomNonLagged( array $loads, $wiki = false, $maxLag = INF ) {
                $lags = $this->getLagTimes( $wiki );
 
                # Unset excessively lagged servers
                foreach ( $lags as $i => $lag ) {
                        if ( $i != 0 ) {
-                               $maxServerLag = $maxLag;
-                               if ( isset( $this->mServers[$i]['max lag'] ) ) {
-                                       $maxServerLag = min( $maxServerLag, $this->mServers[$i]['max lag'] );
-                               }
+                               # How much lag this server nominally is allowed to have
+                               $maxServerLag = isset( $this->mServers[$i]['max lag'] )
+                                       ? $this->mServers[$i]['max lag']
+                                       : self::MAX_LAG_DEFAULT; // default
+                               # Constrain that futher by $maxLag argument
+                               $maxServerLag = min( $maxServerLag, $maxLag );
 
                                $host = $this->getServerName( $i );
-                               if ( $lag === false ) {
+                               if ( $lag === false && !is_infinite( $maxServerLag ) ) {
                                        wfDebugLog( 'replication', "Server $host (#$i) is not replicating?" );
                                        unset( $loads[$i] );
                                } elseif ( $lag > $maxServerLag ) {