rdbms: make MySQLMasterPos handle inactive GTIDs

[lhc/web/wiklou.git] / includes / libs / rdbms / database / position / MySQLMasterPos.php

diff --git a/includes/libs/rdbms/database/position/MySQLMasterPos.php b/includes/libs/rdbms/database/position/MySQLMasterPos.php
index e5bb2c0..62809cd 100644 (file)
--- a/includes/libs/rdbms/database/position/MySQLMasterPos.php
+++ b/includes/libs/rdbms/database/position/MySQLMasterPos.php
@@ -54,14 +54,18 @@ class MySQLMasterPos implements DBMasterPos {
                $thisPosByDomain = $this->getGtidCoordinates();
                $thatPosByDomain = $pos->getGtidCoordinates();
                if ( $thisPosByDomain && $thatPosByDomain ) {
-                       $reached = true;
-                       // Check that this has positions GTE all of those in $pos for all domains in $pos
+                       $comparisons = [];
+                       // Check that this has positions reaching those in $pos for all domains in common
                        foreach ( $thatPosByDomain as $domain => $thatPos ) {
-                               $thisPos = isset( $thisPosByDomain[$domain] ) ? $thisPosByDomain[$domain] : -1;
-                               $reached = $reached && ( $thatPos <= $thisPos );
+                               if ( isset( $thisPosByDomain[$domain] ) ) {
+                                       $comparisons[] = ( $thatPos <= $thisPosByDomain[$domain] );
+                               }
                        }
-
-                       return $reached;
+                       // Check that $this has a GTID for at least one domain also in $pos; due to MariaDB
+                       // quirks, prior master switch-overs may result in inactive garbage GTIDs that cannot
+                       // be cleaned up. Assume that the domains in both this and $pos cover the relevant
+                       // active channels.
+                       return ( $comparisons && !in_array( false, $comparisons, true ) );
                }
 
                // Fallback to the binlog file comparisons
@@ -84,8 +88,11 @@ class MySQLMasterPos implements DBMasterPos {
                $thisPosDomains = array_keys( $this->getGtidCoordinates() );
                $thatPosDomains = array_keys( $pos->getGtidCoordinates() );
                if ( $thisPosDomains && $thatPosDomains ) {
-                       // Check that this has GTIDs for all domains in $pos
-                       return !array_diff( $thatPosDomains, $thisPosDomains );
+                       // Check that $this has a GTID for at least one domain also in $pos; due to MariaDB
+                       // quirks, prior master switch-overs may result in inactive garbage GTIDs that cannot
+                       // easily be cleaned up. Assume that the domains in both this and $pos cover the
+                       // relevant active channels.
+                       return array_intersect( $thatPosDomains, $thisPosDomains ) ? true : false;
                }
 
                // Fallback to the binlog file comparisons