Merge "rdbms: ignore inactive mysql GTIDs in replication position methods"
authorjenkins-bot <jenkins-bot@gerrit.wikimedia.org>
Thu, 12 Apr 2018 01:03:15 +0000 (01:03 +0000)
committerGerrit Code Review <gerrit@wikimedia.org>
Thu, 12 Apr 2018 01:03:15 +0000 (01:03 +0000)
1  2 
includes/libs/rdbms/database/DatabaseMysqlBase.php
tests/phpunit/includes/libs/rdbms/database/DatabaseMysqlBaseTest.php

@@@ -320,7 -320,7 +320,7 @@@ abstract class DatabaseMysqlBase extend
        abstract protected function mysqlFetchObject( $res );
  
        /**
 -       * @param ResultWrapper|resource $res
 +       * @param IResultWrapper|resource $res
         * @return array|bool
         * @throws DBUnexpectedError
         */
        protected function getLagFromPtHeartbeat() {
                $options = $this->lagDetectionOptions;
  
 -              $staleness = $this->trxLevel
 -                      ? microtime( true ) - $this->trxTimestamp()
 -                      : 0;
 -              if ( $staleness > self::LAG_STALE_WARN_THRESHOLD ) {
 -                      // Avoid returning higher and higher lag value due to snapshot age
 -                      // given that the isolation level will typically be REPEATABLE-READ
 -                      $this->queryLogger->warning(
 -                              "Using cached lag value for {db_server} due to active transaction",
 -                              $this->getLogContext( [ 'method' => __METHOD__ ] )
 -                      );
 +              $currentTrxInfo = $this->getRecordedTransactionLagStatus();
 +              if ( $currentTrxInfo ) {
 +                      // There is an active transaction and the initial lag was already queried
 +                      $staleness = microtime( true ) - $currentTrxInfo['since'];
 +                      if ( $staleness > self::LAG_STALE_WARN_THRESHOLD ) {
 +                              // Avoid returning higher and higher lag value due to snapshot age
 +                              // given that the isolation level will typically be REPEATABLE-READ
 +                              $this->queryLogger->warning(
 +                                      "Using cached lag value for {db_server} due to active transaction",
 +                                      $this->getLogContext( [ 'method' => __METHOD__, 'age' => $staleness ] )
 +                              );
 +                      }
  
 -                      return $this->getTransactionLagStatus()['lag'];
 +                      return $currentTrxInfo['lag'];
                }
  
                if ( isset( $options['conds'] ) ) {
                        }
                        // Wait on the GTID set (MariaDB only)
                        $gtidArg = $this->addQuotes( implode( ',', $gtidsWait ) );
-                       $res = $this->doQuery( "SELECT MASTER_GTID_WAIT($gtidArg, $timeout)" );
+                       if ( strpos( $gtidArg, ':' ) !== false ) {
+                               // MySQL GTIDs, e.g "source_id:transaction_id"
+                               $res = $this->doQuery( "SELECT WAIT_FOR_EXECUTED_GTID_SET($gtidArg, $timeout)" );
+                       } else {
+                               // MariaDB GTIDs, e.g."domain:server:sequence"
+                               $res = $this->doQuery( "SELECT MASTER_GTID_WAIT($gtidArg, $timeout)" );
+                       }
                } else {
                        // Wait on the binlog coordinates
                        $encFile = $this->addQuotes( $pos->getLogFile() );
-                       $encPos = intval( $pos->pos[1] );
+                       $encPos = intval( $pos->getLogPosition()[$pos::CORD_EVENT] );
                        $res = $this->doQuery( "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)" );
                }
  
                $row = $res ? $this->fetchRow( $res ) : false;
                if ( !$row ) {
-                       throw new DBExpectedError( $this,
-                               "MASTER_POS_WAIT() or MASTER_GTID_WAIT() failed: {$this->lastError()}" );
+                       throw new DBExpectedError( $this, "Replication wait failed: {$this->lastError()}" );
                }
  
                // Result can be NULL (error), -1 (timeout), or 0+ per the MySQL manual
         * @return MySQLMasterPos|bool
         */
        public function getReplicaPos() {
-               $now = microtime( true );
-               if ( $this->useGTIDs ) {
-                       $res = $this->query( "SELECT @@global.gtid_slave_pos AS Value", __METHOD__ );
-                       $gtidRow = $this->fetchObject( $res );
-                       if ( $gtidRow && strlen( $gtidRow->Value ) ) {
-                               return new MySQLMasterPos( $gtidRow->Value, $now );
+               $now = microtime( true ); // as-of-time *before* fetching GTID variables
+               if ( $this->useGTIDs() ) {
+                       // Try to use GTIDs, fallbacking to binlog positions if not possible
+                       $data = $this->getServerGTIDs( __METHOD__ );
+                       // Use gtid_slave_pos for MariaDB and gtid_executed for MySQL
+                       foreach ( [ 'gtid_slave_pos', 'gtid_executed' ] as $name ) {
+                               if ( isset( $data[$name] ) && strlen( $data[$name] ) ) {
+                                       return new MySQLMasterPos( $data[$name], $now );
+                               }
                        }
                }
  
-               $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__ );
-               $row = $this->fetchObject( $res );
-               if ( $row && strlen( $row->Relay_Master_Log_File ) ) {
+               $data = $this->getServerRoleStatus( 'SLAVE', __METHOD__ );
+               if ( $data && strlen( $data['Relay_Master_Log_File'] ) ) {
                        return new MySQLMasterPos(
-                               "{$row->Relay_Master_Log_File}/{$row->Exec_Master_Log_Pos}",
+                               "{$data['Relay_Master_Log_File']}/{$data['Exec_Master_Log_Pos']}",
                                $now
                        );
                }
         * @return MySQLMasterPos|bool
         */
        public function getMasterPos() {
-               $now = microtime( true );
+               $now = microtime( true ); // as-of-time *before* fetching GTID variables
+               $pos = false;
+               if ( $this->useGTIDs() ) {
+                       // Try to use GTIDs, fallbacking to binlog positions if not possible
+                       $data = $this->getServerGTIDs( __METHOD__ );
+                       // Use gtid_binlog_pos for MariaDB and gtid_executed for MySQL
+                       foreach ( [ 'gtid_binlog_pos', 'gtid_executed' ] as $name ) {
+                               if ( isset( $data[$name] ) && strlen( $data[$name] ) ) {
+                                       $pos = new MySQLMasterPos( $data[$name], $now );
+                                       break;
+                               }
+                       }
+                       // Filter domains that are inactive or not relevant to the session
+                       if ( $pos ) {
+                               $pos->setActiveOriginServerId( $this->getServerId() );
+                               $pos->setActiveOriginServerUUID( $this->getServerUUID() );
+                               if ( isset( $data['gtid_domain_id'] ) ) {
+                                       $pos->setActiveDomain( $data['gtid_domain_id'] );
+                               }
+                       }
+               }
  
-               if ( $this->useGTIDs ) {
-                       $res = $this->query( "SELECT @@global.gtid_binlog_pos AS Value", __METHOD__ );
-                       $gtidRow = $this->fetchObject( $res );
-                       if ( $gtidRow && strlen( $gtidRow->Value ) ) {
-                               return new MySQLMasterPos( $gtidRow->Value, $now );
+               if ( !$pos ) {
+                       $data = $this->getServerRoleStatus( 'MASTER', __METHOD__ );
+                       if ( $data && strlen( $data['File'] ) ) {
+                               $pos = new MySQLMasterPos( "{$data['File']}/{$data['Position']}", $now );
                        }
                }
  
-               $res = $this->query( 'SHOW MASTER STATUS', __METHOD__ );
-               $row = $this->fetchObject( $res );
-               if ( $row && strlen( $row->File ) ) {
-                       return new MySQLMasterPos( "{$row->File}/{$row->Position}", $now );
+               return $pos;
+       }
+       /**
+        * @return int
+        * @throws DBQueryError If the variable doesn't exist for some reason
+        */
+       protected function getServerId() {
+               return $this->srvCache->getWithSetCallback(
+                       $this->srvCache->makeGlobalKey( 'mysql-server-id', $this->getServer() ),
+                       self::SERVER_ID_CACHE_TTL,
+                       function () {
+                               $res = $this->query( "SELECT @@server_id AS id", __METHOD__ );
+                               return intval( $this->fetchObject( $res )->id );
+                       }
+               );
+       }
+       /**
+        * @return string|null
+        */
+       protected function getServerUUID() {
+               return $this->srvCache->getWithSetCallback(
+                       $this->srvCache->makeGlobalKey( 'mysql-server-uuid', $this->getServer() ),
+                       self::SERVER_ID_CACHE_TTL,
+                       function () {
+                               $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'server_uuid'" );
+                               $row = $this->fetchObject( $res );
+                               return $row ? $row->Value : null;
+                       }
+               );
+       }
+       /**
+        * @param string $fname
+        * @return string[]
+        */
+       protected function getServerGTIDs( $fname = __METHOD__ ) {
+               $map = [];
+               // Get global-only variables like gtid_executed
+               $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_%'", $fname );
+               foreach ( $res as $row ) {
+                       $map[$row->Variable_name] = $row->Value;
+               }
+               // Get session-specific (e.g. gtid_domain_id since that is were writes will log)
+               $res = $this->query( "SHOW SESSION VARIABLES LIKE 'gtid_%'", $fname );
+               foreach ( $res as $row ) {
+                       $map[$row->Variable_name] = $row->Value;
                }
  
-               return false;
+               return $map;
+       }
+       /**
+        * @param string $role One of "MASTER"/"SLAVE"
+        * @param string $fname
+        * @return string[] Latest available server status row
+        */
+       protected function getServerRoleStatus( $role, $fname = __METHOD__ ) {
+               return $this->query( "SHOW $role STATUS", $fname )->fetchRow() ?: [];
        }
  
        public function serverIsReadOnly() {
                return $errno == 2013 || $errno == 2006;
        }
  
 +      protected function wasKnownStatementRollbackError() {
 +              $errno = $this->lastErrno();
 +
 +              if ( $errno === 1205 ) { // lock wait timeout
 +                      // Note that this is uncached to avoid stale values of SET is used
 +                      $row = $this->selectRow(
 +                              false,
 +                              [ 'innodb_rollback_on_timeout' => '@@innodb_rollback_on_timeout' ],
 +                              [],
 +                              __METHOD__
 +                      );
 +                      // https://dev.mysql.com/doc/refman/5.7/en/innodb-error-handling.html
 +                      // https://dev.mysql.com/doc/refman/5.5/en/innodb-parameters.html
 +                      return $row->innodb_rollback_on_timeout ? false : true;
 +              }
 +
 +              // See https://dev.mysql.com/doc/refman/5.5/en/error-messages-server.html
 +              return in_array( $errno, [ 1022, 1216, 1217, 1137 ], true );
 +      }
 +
        /**
         * @param string $oldName
         * @param string $newName
                return 'CAST( ' . $field . ' AS SIGNED )';
        }
  
+       /*
+        * @return bool Whether GTID support is used (mockable for testing)
+        */
+       protected function useGTIDs() {
+               return $this->useGTIDs;
+       }
  }
  
  class_alias( DatabaseMysqlBase::class, 'DatabaseMysqlBase' );
@@@ -29,7 -29,6 +29,7 @@@ use Wikimedia\TestingAccessWrapper
  class DatabaseMysqlBaseTest extends PHPUnit\Framework\TestCase {
  
        use MediaWikiCoversValidator;
 +      use PHPUnit4And6Compat;
  
        /**
         * @dataProvider provideDiapers
                        $db->listViews( '' ) );
        }
  
+       /**
+        * @covers Wikimedia\Rdbms\MySQLMasterPos
+        */
        public function testBinLogName() {
                $pos = new MySQLMasterPos( "db1052.2424/4643", 1 );
  
-               $this->assertEquals( "db1052", $pos->binlog );
+               $this->assertEquals( "db1052", $pos->getLogName() );
                $this->assertEquals( "db1052.2424", $pos->getLogFile() );
-               $this->assertEquals( [ 2424, 4643 ], $pos->pos );
+               $this->assertEquals( [ 2424, 4643 ], $pos->getLogPosition() );
        }
  
        /**
                        ],
                        // MySQL GTID style
                        [
-                               new MySQLMasterPos( '3E11FA47-71CA-11E1-9E33-C80AA9429562:23', $now ),
-                               new MySQLMasterPos( '3E11FA47-71CA-11E1-9E33-C80AA9429562:24', $now ),
+                               new MySQLMasterPos( '3E11FA47-71CA-11E1-9E33-C80AA9429562:1-23', $now ),
+                               new MySQLMasterPos( '3E11FA47-71CA-11E1-9E33-C80AA9429562:5-24', $now ),
                                true,
                                false
                        ],
                        [
-                               new MySQLMasterPos( '3E11FA47-71CA-11E1-9E33-C80AA9429562:99', $now ),
-                               new MySQLMasterPos( '3E11FA47-71CA-11E1-9E33-C80AA9429562:100', $now ),
+                               new MySQLMasterPos( '3E11FA47-71CA-11E1-9E33-C80AA9429562:5-99', $now ),
+                               new MySQLMasterPos( '3E11FA47-71CA-11E1-9E33-C80AA9429562:1-100', $now ),
                                true,
                                false
                        ],
                        [
-                               new MySQLMasterPos( '3E11FA47-71CA-11E1-9E33-C80AA9429562:99', $now ),
-                               new MySQLMasterPos( '1E11FA47-71CA-11E1-9E33-C80AA9429562:100', $now ),
+                               new MySQLMasterPos( '3E11FA47-71CA-11E1-9E33-C80AA9429562:1-99', $now ),
+                               new MySQLMasterPos( '1E11FA47-71CA-11E1-9E33-C80AA9429562:1-100', $now ),
                                false,
                                false
                        ],
                        ],
                        [
                                new MySQLMasterPos(
-                                       '2E11FA47-71CA-11E1-9E33-C80AA9429562:5,' .
-                                       '3E11FA47-71CA-11E1-9E33-C80AA9429562:99,' .
-                                       '7E11FA47-71CA-11E1-9E33-C80AA9429562:30',
+                                       '2E11FA47-71CA-11E1-9E33-C80AA9429562:1-5,' .
+                                       '3E11FA47-71CA-11E1-9E33-C80AA9429562:20-99,' .
+                                       '7E11FA47-71CA-11E1-9E33-C80AA9429562:1-30',
                                        1
                                ),
                                new MySQLMasterPos(
-                                       '1E11FA47-71CA-11E1-9E33-C80AA9429562:100,' .
-                                       '3E11FA47-71CA-11E1-9E33-C80AA9429562:66',
+                                       '1E11FA47-71CA-11E1-9E33-C80AA9429562:30-100,' .
+                                       '3E11FA47-71CA-11E1-9E33-C80AA9429562:30-66',
                                        1
                                ),
-                               [ '3E11FA47-71CA-11E1-9E33-C80AA9429562:99' ]
+                               [ '3E11FA47-71CA-11E1-9E33-C80AA9429562:20-99' ]
                        ]
                ];
        }
                ];
        }
  
+       /**
+        * @dataProvider provideGtidData
+        * @covers Wikimedia\Rdbms\MySQLMasterPos
+        * @covers Wikimedia\Rdbms\DatabaseMysqlBase::getReplicaPos
+        * @covers Wikimedia\Rdbms\DatabaseMysqlBase::getMasterPos
+        */
+       public function testServerGtidTable( $gtable, $rBLtable, $mBLtable, $rGTIDs, $mGTIDs ) {
+               $db = $this->getMockBuilder( DatabaseMysqli::class )
+                       ->disableOriginalConstructor()
+                       ->setMethods( [
+                               'useGTIDs',
+                               'getServerGTIDs',
+                               'getServerRoleStatus',
+                               'getServerId',
+                               'getServerUUID'
+                       ] )
+                       ->getMock();
+               $db->method( 'useGTIDs' )->willReturn( true );
+               $db->method( 'getServerGTIDs' )->willReturn( $gtable );
+               $db->method( 'getServerRoleStatus' )->willReturnCallback(
+                       function ( $role ) use ( $rBLtable, $mBLtable ) {
+                               if ( $role === 'SLAVE' ) {
+                                       return $rBLtable;
+                               } elseif ( $role === 'MASTER' ) {
+                                       return $mBLtable;
+                               }
+                               return null;
+                       }
+               );
+               $db->method( 'getServerId' )->willReturn( 1 );
+               $db->method( 'getServerUUID' )->willReturn( '2E11FA47-71CA-11E1-9E33-C80AA9429562' );
+               if ( is_array( $rGTIDs ) ) {
+                       $this->assertEquals( $rGTIDs, $db->getReplicaPos()->getGTIDs() );
+               } else {
+                       $this->assertEquals( false, $db->getReplicaPos() );
+               }
+               if ( is_array( $mGTIDs ) ) {
+                       $this->assertEquals( $mGTIDs, $db->getMasterPos()->getGTIDs() );
+               } else {
+                       $this->assertEquals( false, $db->getMasterPos() );
+               }
+       }
+       public static function provideGtidData() {
+               return [
+                       // MariaDB
+                       [
+                               [
+                                       'gtid_domain_id' => 100,
+                                       'gtid_current_pos' => '100-13-77',
+                                       'gtid_binlog_pos' => '100-13-77',
+                                       'gtid_slave_pos' => null // master
+                               ],
+                               [
+                                       'Relay_Master_Log_File' => 'host.1600',
+                                       'Exec_Master_Log_Pos' => '77'
+                               ],
+                               [
+                                       'File' => 'host.1600',
+                                       'Position' => '77'
+                               ],
+                               [],
+                               [ '100' => '100-13-77' ]
+                       ],
+                       [
+                               [
+                                       'gtid_domain_id' => 100,
+                                       'gtid_current_pos' => '100-13-77',
+                                       'gtid_binlog_pos' => '100-13-77',
+                                       'gtid_slave_pos' => '100-13-77' // replica
+                               ],
+                               [
+                                       'Relay_Master_Log_File' => 'host.1600',
+                                       'Exec_Master_Log_Pos' => '77'
+                               ],
+                               [],
+                               [ '100' => '100-13-77' ],
+                               [ '100' => '100-13-77' ]
+                       ],
+                       [
+                               [
+                                       'gtid_current_pos' => '100-13-77',
+                                       'gtid_binlog_pos' => '100-13-77',
+                                       'gtid_slave_pos' => '100-13-77' // replica
+                               ],
+                               [
+                                       'Relay_Master_Log_File' => 'host.1600',
+                                       'Exec_Master_Log_Pos' => '77'
+                               ],
+                               [],
+                               [ '100' => '100-13-77' ],
+                               [ '100' => '100-13-77' ]
+                       ],
+                       // MySQL
+                       [
+                               [
+                                       'gtid_executed' => '2E11FA47-71CA-11E1-9E33-C80AA9429562:1-77'
+                               ],
+                               [
+                                       'Relay_Master_Log_File' => 'host.1600',
+                                       'Exec_Master_Log_Pos' => '77'
+                               ],
+                               [], // only a replica
+                               [ '2E11FA47-71CA-11E1-9E33-C80AA9429562'
+                                       => '2E11FA47-71CA-11E1-9E33-C80AA9429562:1-77' ],
+                               // replica/master use same var
+                               [ '2E11FA47-71CA-11E1-9E33-C80AA9429562'
+                                       => '2E11FA47-71CA-11E1-9E33-C80AA9429562:1-77' ],
+                       ],
+                       [
+                               [
+                                       'gtid_executed' => '2E11FA47-71CA-11E1-9E33-C80AA9429562:1-49,' .
+                                               '2E11FA47-71CA-11E1-9E33-C80AA9429562:51-77'
+                               ],
+                               [
+                                       'Relay_Master_Log_File' => 'host.1600',
+                                       'Exec_Master_Log_Pos' => '77'
+                               ],
+                               [], // only a replica
+                               [ '2E11FA47-71CA-11E1-9E33-C80AA9429562'
+                                       => '2E11FA47-71CA-11E1-9E33-C80AA9429562:51-77' ],
+                               // replica/master use same var
+                               [ '2E11FA47-71CA-11E1-9E33-C80AA9429562'
+                                       => '2E11FA47-71CA-11E1-9E33-C80AA9429562:51-77' ],
+                       ],
+                       [
+                               [
+                                       'gtid_executed' => null, // not enabled?
+                                       'gtid_binlog_pos' => null
+                               ],
+                               [
+                                       'Relay_Master_Log_File' => 'host.1600',
+                                       'Exec_Master_Log_Pos' => '77'
+                               ],
+                               [], // only a replica
+                               [], // binlog fallback
+                               false
+                       ],
+                       [
+                               [
+                                       'gtid_executed' => null, // not enabled?
+                                       'gtid_binlog_pos' => null
+                               ],
+                               [], // no replication
+                               [], // no replication
+                               false,
+                               false
+                       ]
+               ];
+       }
        /**
         * @covers Wikimedia\Rdbms\MySQLMasterPos
         */