Added GTID support to slave lag methods

The IDs will be included in MySQLMasterPos objects and,
if specified by config, in slave lag wait methods.

Bug: T135027
Change-Id: I1dfc0210b715b449ec07760c712d0267763f2697

diff --git a/includes/db/DatabaseMysqlBase.php b/includes/db/DatabaseMysqlBase.php
index 3ebc3ec..02a8d30 100644 (file)
--- a/includes/db/DatabaseMysqlBase.php
+++ b/includes/db/DatabaseMysqlBase.php
@@ -36,6 +36,8 @@ abstract class DatabaseMysqlBase extends Database {
        protected $lagDetectionMethod;
        /** @var array Method to detect slave lag */
        protected $lagDetectionOptions = [];
+       /** @var bool bool Whether to use GTID methods */
+       protected $useGTIDs = false;
 
        /** @var string|null */
        private $serverVersion = null;
@@ -43,13 +45,14 @@ abstract class DatabaseMysqlBase extends Database {
        /**
         * Additional $params include:
         *   - lagDetectionMethod : set to one of (Seconds_Behind_Master,pt-heartbeat).
-        *                          pt-heartbeat assumes the table is at heartbeat.heartbeat
-        *                          and uses UTC timestamps in the heartbeat.ts column.
-        *                          (https://www.percona.com/doc/percona-toolkit/2.2/pt-heartbeat.html)
+        *       pt-heartbeat assumes the table is at heartbeat.heartbeat
+        *       and uses UTC timestamps in the heartbeat.ts column.
+        *       (https://www.percona.com/doc/percona-toolkit/2.2/pt-heartbeat.html)
         *   - lagDetectionOptions : if using pt-heartbeat, this can be set to an array map to change
-        *                           the default behavior. Normally, the heartbeat row with the server
-        *                           ID of this server's master will be used. Set the "conds" field to
-        *                           override the query conditions, e.g. ['shard' => 's1'].
+        *       the default behavior. Normally, the heartbeat row with the server
+        *       ID of this server's master will be used. Set the "conds" field to
+        *       override the query conditions, e.g. ['shard' => 's1'].
+        *   - useGTIDs : use GTID methods like MASTER_GTID_WAIT() when possible.
         * @param array $params
         */
        function __construct( array $params ) {
@@ -61,6 +64,7 @@ abstract class DatabaseMysqlBase extends Database {
                $this->lagDetectionOptions = isset( $params['lagDetectionOptions'] )
                        ? $params['lagDetectionOptions']
                        : [];
+               $this->useGTIDs = !empty( $params['useGTIDs' ] );
        }
 
        /**
@@ -788,13 +792,20 @@ abstract class DatabaseMysqlBase extends Database {
                        return 0; // already reached this point for sure
                }
 
-               # Commit any open transactions
+               // Commit any open transactions
                $this->commit( __METHOD__, 'flush' );
 
-               # Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
-               $encFile = $this->addQuotes( $pos->file );
-               $encPos = intval( $pos->pos );
-               $res = $this->doQuery( "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)" );
+               // Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
+               if ( $this->useGTIDs && $pos->gtids ) {
+                       // Wait on the GTID set (MariaDB only)
+                       $gtidArg = implode( ',', $pos->gtids );
+                       $res = $this->doQuery( "SELECT MASTER_GTID_WAIT($gtidArg, $timeout)" );
+               } else {
+                       // Wait on the binlog coordinates
+                       $encFile = $this->addQuotes( $pos->file );
+                       $encPos = intval( $pos->pos );
+                       $res = $this->doQuery( "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)" );
+               }
 
                $row = $res ? $this->fetchRow( $res ) : false;
                if ( !$row ) {
@@ -827,15 +838,23 @@ abstract class DatabaseMysqlBase extends Database {
         * @return MySQLMasterPos|bool
         */
        function getSlavePos() {
-               $res = $this->query( 'SHOW SLAVE STATUS', 'DatabaseBase::getSlavePos' );
+               $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
                $row = $this->fetchObject( $res );
 
                if ( $row ) {
                        $pos = isset( $row->Exec_master_log_pos )
                                ? $row->Exec_master_log_pos
                                : $row->Exec_Master_Log_Pos;
+                       // Also fetch the last-applied GTID set (MariaDB)
+                       if ( $this->useGTIDs ) {
+                               $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_slave_pos'", __METHOD__ );
+                               $gtidRow = $this->fetchObject( $res );
+                               $gtidSet = $gtidRow ? $gtidRow->Value : '';
+                       } else {
+                               $gtidSet = '';
+                       }
 
-                       return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos );
+                       return new MySQLMasterPos( $row->Relay_Master_Log_File, $pos, $gtidSet );
                } else {
                        return false;
                }
@@ -847,11 +866,20 @@ abstract class DatabaseMysqlBase extends Database {
         * @return MySQLMasterPos|bool
         */
        function getMasterPos() {
-               $res = $this->query( 'SHOW MASTER STATUS', 'DatabaseBase::getMasterPos' );
+               $res = $this->query( 'SHOW MASTER STATUS', __METHOD__ );
                $row = $this->fetchObject( $res );
 
                if ( $row ) {
-                       return new MySQLMasterPos( $row->File, $row->Position );
+                       // Also fetch the last-written GTID set (MariaDB)
+                       if ( $this->useGTIDs ) {
+                               $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_binlog_pos'", __METHOD__ );
+                               $gtidRow = $this->fetchObject( $res );
+                               $gtidSet = $gtidRow ? $gtidRow->Value : '';
+                       } else {
+                               $gtidSet = '';
+                       }
+
+                       return new MySQLMasterPos( $row->File, $row->Position, $gtidSet );
                } else {
                        return false;
                }
@@ -1443,20 +1471,43 @@ class MySQLField implements Field {
        }
 }
 
+/**
+ * DBMasterPos class for MySQL/MariaDB
+ *
+ * Note that master positions and sync logic here make some assumptions:
+ *  - Binlog-based usage assumes single-source replication and non-hierarchical replication.
+ *  - GTID-based usage allows getting/syncing with multi-source replication. It is assumed
+ *    that GTID sets are complete (e.g. include all domains on the server).
+ */
 class MySQLMasterPos implements DBMasterPos {
-       /** @var string */
+       /** @var string Binlog file */
        public $file;
-       /** @var int Position */
+       /** @var int Binglog file position */
        public $pos;
+       /** @var string[] GTID list */
+       public $gtids = [];
        /** @var float UNIX timestamp */
        public $asOfTime = 0.0;
 
-       function __construct( $file, $pos ) {
+       /**
+        * @param string $file Binlog file name
+        * @param integer $pos Binlog position
+        * @param string $gtid Comma separated GTID set [optional]
+        */
+       function __construct( $file, $pos, $gtid = '' ) {
                $this->file = $file;
                $this->pos = $pos;
+               $this->gtids = array_map( 'trim', explode( ',', $gtid ) );
                $this->asOfTime = microtime( true );
        }
 
+       /**
+        * @return string <binlog file>/<position>, e.g db1034-bin.000976/843431247
+        */
+       function __toString() {
+               return "{$this->file}/{$this->pos}";
+       }
+
        function asOfTime() {
                return $this->asOfTime;
        }
@@ -1466,10 +1517,29 @@ class MySQLMasterPos implements DBMasterPos {
                        throw new InvalidArgumentException( "Position not an instance of " . __CLASS__ );
                }
 
-               $thisPos = $this->getCoordinates();
-               $thatPos = $pos->getCoordinates();
+               // Prefer GTID comparisons, which work with multi-tier replication
+               $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
+                       foreach ( $thatPosByDomain as $domain => $thatPos ) {
+                               $thisPos = isset( $thisPosByDomain[$domain] ) ? $thisPosByDomain[$domain] : -1;
+                               $reached = $reached && ( $thatPos <= $thisPos );
+                       }
 
-               return ( $thisPos && $thatPos && $thisPos >= $thatPos );
+                       return $reached;
+               }
+
+               // Fallback to the binlog file comparisons
+               $thisBinPos = $this->getBinlogCoordinates();
+               $thatBinPos = $pos->getBinlogCoordinates();
+               if ( $thisBinPos && $thatBinPos && $thisBinPos['binlog'] === $thatBinPos['binlog'] ) {
+                       return ( $thisBinPos['pos'] >= $thatBinPos['pos'] );
+               }
+
+               // Comparing totally different binlogs does not make sense
+               return false;
        }
 
        function channelsMatch( DBMasterPos $pos ) {
@@ -1477,36 +1547,56 @@ class MySQLMasterPos implements DBMasterPos {
                        throw new InvalidArgumentException( "Position not an instance of " . __CLASS__ );
                }
 
-               $thisBinlog = $this->getBinlogName();
-               $thatBinlog = $pos->getBinlogName();
+               // Prefer GTID comparisons, which work with multi-tier replication
+               $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 );
+               }
 
-               return ( $thisBinlog !== false && $thisBinlog === $thatBinlog );
-       }
+               // Fallback to the binlog file comparisons
+               $thisBinPos = $this->getBinlogCoordinates();
+               $thatBinPos = $pos->getBinlogCoordinates();
 
-       function __toString() {
-               // e.g db1034-bin.000976/843431247
-               return "{$this->file}/{$this->pos}";
+               return ( $thisBinPos && $thatBinPos && $thisBinPos['binlog'] === $thatBinPos['binlog'] );
        }
 
        /**
-        * @return string|bool
+        * @note: this returns false for multi-source replication GTID sets
+        * @see https://mariadb.com/kb/en/mariadb/gtid
+        * @see https://dev.mysql.com/doc/refman/5.6/en/replication-gtids-concepts.html
+        * @return array Map of (domain => integer position) or false
         */
-       protected function getBinlogName() {
-               $m = [];
-               if ( preg_match( '!^(.+)\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
-                       return $m[1];
+       protected function getGtidCoordinates() {
+               $gtidInfos = [];
+               foreach ( $this->gtids as $gtid ) {
+                       $m = [];
+                       // MariaDB style: <domain>-<server id>-<sequence number>
+                       if ( preg_match( '!^(\d+)-\d+-(\d+)$!', $gtid, $m ) ) {
+                               $gtidInfos[(int)$m[1]] = (int)$m[2];
+                       // MySQL style: <UUID domain>:<sequence number>
+                       } elseif ( preg_match( '!^(\w{8}-\w{4}-\w{4}-\w{4}-\w{12}):(\d+)$!', $gtid, $m ) ) {
+                               $gtidInfos[$m[1]] = (int)$m[2];
+                       } else {
+                               $gtidInfos = [];
+                               break; // unrecognized GTID
+                       }
+
                }
 
-               return false;
+               return $gtidInfos;
        }
 
        /**
-        * @return array|bool (int, int)
+        * @see http://dev.mysql.com/doc/refman/5.7/en/show-master-status.html
+        * @see http://dev.mysql.com/doc/refman/5.7/en/show-slave-status.html
+        * @return array|bool (binlog, (integer file number, integer position)) or false
         */
-       protected function getCoordinates() {
+       protected function getBinlogCoordinates() {
                $m = [];
-               if ( preg_match( '!\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
-                       return [ (int)$m[1], (int)$m[2] ];
+               if ( preg_match( '!^(.+)\.(\d+)/(\d+)$!', (string)$this, $m ) ) {
+                       return [ 'binlog' => $m[1], 'pos' => [ (int)$m[2], (int)$m[3] ] ];
                }
 
                return false;

diff --git a/tests/phpunit/includes/db/DatabaseMysqlBaseTest.php b/tests/phpunit/includes/db/DatabaseMysqlBaseTest.php
index bb747c7..bb7eb79 100644 (file)
--- a/tests/phpunit/includes/db/DatabaseMysqlBaseTest.php
+++ b/tests/phpunit/includes/db/DatabaseMysqlBaseTest.php
@@ -250,26 +250,71 @@ class DatabaseMysqlBaseTest extends MediaWikiTestCase {
        /**
         * @dataProvider provideComparePositions
         */
-       function testHasReached( MySQLMasterPos $lowerPos, MySQLMasterPos $higherPos ) {
-               $this->assertTrue( $higherPos->hasReached( $lowerPos ) );
-               $this->assertTrue( $higherPos->hasReached( $higherPos ) );
-               $this->assertTrue( $lowerPos->hasReached( $lowerPos ) );
-               $this->assertFalse( $lowerPos->hasReached( $higherPos ) );
+       function testHasReached( MySQLMasterPos $lowerPos, MySQLMasterPos $higherPos, $match ) {
+               if ( $match ) {
+                       $this->assertTrue( $lowerPos->channelsMatch( $higherPos ) );
+
+                       $this->assertTrue( $higherPos->hasReached( $lowerPos ) );
+                       $this->assertTrue( $higherPos->hasReached( $higherPos ) );
+                       $this->assertTrue( $lowerPos->hasReached( $lowerPos ) );
+                       $this->assertFalse( $lowerPos->hasReached( $higherPos ) );
+               } else { // channels don't match
+                       $this->assertFalse( $lowerPos->channelsMatch( $higherPos ) );
+
+                       $this->assertFalse( $higherPos->hasReached( $lowerPos ) );
+                       $this->assertFalse( $lowerPos->hasReached( $higherPos ) );
+               }
        }
 
        function provideComparePositions() {
                return [
+                       // Binlog style
                        [
                                new MySQLMasterPos( 'db1034-bin.000976', '843431247' ),
-                               new MySQLMasterPos( 'db1034-bin.000976', '843431248' )
+                               new MySQLMasterPos( 'db1034-bin.000976', '843431248' ),
+                               true
                        ],
                        [
                                new MySQLMasterPos( 'db1034-bin.000976', '999' ),
-                               new MySQLMasterPos( 'db1034-bin.000976', '1000' )
+                               new MySQLMasterPos( 'db1034-bin.000976', '1000' ),
+                               true
                        ],
                        [
                                new MySQLMasterPos( 'db1034-bin.000976', '999' ),
-                               new MySQLMasterPos( 'db1035-bin.000976', '1000' )
+                               new MySQLMasterPos( 'db1035-bin.000976', '1000' ),
+                               false
+                       ],
+                       // MySQL GTID style
+                       [
+                               new MySQLMasterPos( 'db1-bin.2', '1', '3E11FA47-71CA-11E1-9E33-C80AA9429562:23' ),
+                               new MySQLMasterPos( 'db1-bin.2', '2', '3E11FA47-71CA-11E1-9E33-C80AA9429562:24' ),
+                               true
+                       ],
+                       [
+                               new MySQLMasterPos( 'db1-bin.2', '1', '3E11FA47-71CA-11E1-9E33-C80AA9429562:99' ),
+                               new MySQLMasterPos( 'db1-bin.2', '2', '3E11FA47-71CA-11E1-9E33-C80AA9429562:100' ),
+                               true
+                       ],
+                       [
+                               new MySQLMasterPos( 'db1-bin.2', '1', '3E11FA47-71CA-11E1-9E33-C80AA9429562:99' ),
+                               new MySQLMasterPos( 'db1-bin.2', '2', '1E11FA47-71CA-11E1-9E33-C80AA9429562:100' ),
+                               false
+                       ],
+                       // MariaDB GTID style
+                       [
+                               new MySQLMasterPos( 'db1-bin.2', '1', '255-11-23' ),
+                               new MySQLMasterPos( 'db1-bin.2', '2', '255-11-24' ),
+                               true
+                       ],
+                       [
+                               new MySQLMasterPos( 'db1-bin.2', '1', '255-11-99' ),
+                               new MySQLMasterPos( 'db1-bin.2', '2', '255-11-100' ),
+                               true
+                       ],
+                       [
+                               new MySQLMasterPos( 'db1-bin.2', '1', '255-11-999' ),
+                               new MySQLMasterPos( 'db1-bin.2', '2', '254-11-1000' ),
+                               false
                        ],
                ];
        }