3 * This is the MySQL database abstraction layer.
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 * http://www.gnu.org/copyleft/gpl.html
23 namespace Wikimedia\Rdbms
;
28 use InvalidArgumentException
;
34 * Database abstraction object for MySQL.
35 * Defines methods independent on used MySQL extension.
41 abstract class DatabaseMysqlBase
extends Database
{
42 /** @var MysqlMasterPos */
43 protected $lastKnownReplicaPos;
44 /** @var string Method to detect replica DB lag */
45 protected $lagDetectionMethod;
46 /** @var array Method to detect replica DB lag */
47 protected $lagDetectionOptions = [];
48 /** @var bool bool Whether to use GTID methods */
49 protected $useGTIDs = false;
50 /** @var string|null */
51 protected $sslKeyPath;
52 /** @var string|null */
53 protected $sslCertPath;
54 /** @var string|null */
56 /** @var string|null */
58 /** @var string[]|null */
59 protected $sslCiphers;
60 /** @var string sql_mode value to send on connection */
62 /** @var bool Use experimental UTF-8 transmission encoding */
65 protected $defaultBigSelects = null;
67 /** @var string|null */
68 private $serverVersion = null;
70 private $insertSelectIsSafe = null;
71 /** @var stdClass|null */
72 private $replicationInfoRow = null;
74 // Cache getServerId() for 24 hours
75 const SERVER_ID_CACHE_TTL
= 86400;
77 /** @var float Warn if lag estimates are made for transactions older than this many seconds */
78 const LAG_STALE_WARN_THRESHOLD
= 0.100;
81 * Additional $params include:
82 * - lagDetectionMethod : set to one of (Seconds_Behind_Master,pt-heartbeat).
83 * pt-heartbeat assumes the table is at heartbeat.heartbeat
84 * and uses UTC timestamps in the heartbeat.ts column.
85 * (https://www.percona.com/doc/percona-toolkit/2.2/pt-heartbeat.html)
86 * - lagDetectionOptions : if using pt-heartbeat, this can be set to an array map to change
87 * the default behavior. Normally, the heartbeat row with the server
88 * ID of this server's master will be used. Set the "conds" field to
89 * override the query conditions, e.g. ['shard' => 's1'].
90 * - useGTIDs : use GTID methods like MASTER_GTID_WAIT() when possible.
91 * - insertSelectIsSafe : force that native INSERT SELECT is or is not safe [default: null]
92 * - sslKeyPath : path to key file [default: null]
93 * - sslCertPath : path to certificate file [default: null]
94 * - sslCAFile: path to a single certificate authority PEM file [default: null]
95 * - sslCAPath : parth to certificate authority PEM directory [default: null]
96 * - sslCiphers : array list of allowable ciphers [default: null]
97 * @param array $params
99 function __construct( array $params ) {
100 $this->lagDetectionMethod
= $params['lagDetectionMethod'] ??
'Seconds_Behind_Master';
101 $this->lagDetectionOptions
= $params['lagDetectionOptions'] ??
[];
102 $this->useGTIDs
= !empty( $params['useGTIDs' ] );
103 foreach ( [ 'KeyPath', 'CertPath', 'CAFile', 'CAPath', 'Ciphers' ] as $name ) {
105 if ( isset( $params[$var] ) ) {
106 $this->$var = $params[$var];
109 $this->sqlMode
= $params['sqlMode'] ??
'';
110 $this->utf8Mode
= !empty( $params['utf8Mode'] );
111 $this->insertSelectIsSafe
= isset( $params['insertSelectIsSafe'] )
112 ?
(bool)$params['insertSelectIsSafe'] : null;
114 parent
::__construct( $params );
120 public function getType() {
124 protected function open( $server, $user, $password, $dbName, $schema, $tablePrefix ) {
125 # Close/unset connection handle
128 $this->server
= $server;
130 $this->password
= $password;
132 $this->installErrorHandler();
134 $this->conn
= $this->mysqlConnect( $this->server
, $dbName );
135 } catch ( Exception
$ex ) {
136 $this->restoreErrorHandler();
139 $error = $this->restoreErrorHandler();
141 # Always log connection errors
142 if ( !$this->conn
) {
143 $error = $error ?
: $this->lastError();
144 $this->connLogger
->error(
145 "Error connecting to {db_server}: {error}",
146 $this->getLogContext( [
147 'method' => __METHOD__
,
151 $this->connLogger
->debug( "DB connection error\n" .
152 "Server: $server, User: $user, Password: " .
153 substr( $password, 0, 3 ) . "..., error: " . $error . "\n" );
155 throw new DBConnectionError( $this, $error );
158 if ( strlen( $dbName ) ) {
159 $this->selectDomain( new DatabaseDomain( $dbName, null, $tablePrefix ) );
161 $this->currentDomain
= new DatabaseDomain( null, null, $tablePrefix );
164 // Tell the server what we're communicating with
165 if ( !$this->connectInitCharset() ) {
166 $error = $this->lastError();
167 $this->queryLogger
->error(
168 "Error setting character set: {error}",
169 $this->getLogContext( [
170 'method' => __METHOD__
,
171 'error' => $this->lastError(),
174 throw new DBConnectionError( $this, "Error setting character set: $error" );
177 // Abstract over any insane MySQL defaults
178 $set = [ 'group_concat_max_len = 262144' ];
179 // Set SQL mode, default is turning them all off, can be overridden or skipped with null
180 if ( is_string( $this->sqlMode
) ) {
181 $set[] = 'sql_mode = ' . $this->addQuotes( $this->sqlMode
);
183 // Set any custom settings defined by site config
184 // (e.g. https://dev.mysql.com/doc/refman/4.1/en/innodb-parameters.html)
185 foreach ( $this->sessionVars
as $var => $val ) {
186 // Escape strings but not numbers to avoid MySQL complaining
187 if ( !is_int( $val ) && !is_float( $val ) ) {
188 $val = $this->addQuotes( $val );
190 $set[] = $this->addIdentifierQuotes( $var ) . ' = ' . $val;
194 // Use doQuery() to avoid opening implicit transactions (DBO_TRX)
195 $success = $this->doQuery( 'SET ' . implode( ', ', $set ) );
197 $error = $this->lastError();
198 $this->queryLogger
->error(
199 'Error setting MySQL variables on server {db_server}: {error}',
200 $this->getLogContext( [
201 'method' => __METHOD__
,
205 throw new DBConnectionError( $this, "Error setting MySQL variables: $error" );
209 $this->opened
= true;
215 * Set the character set information right after connection
218 protected function connectInitCharset() {
219 if ( $this->utf8Mode
) {
220 // Tell the server we're communicating with it in UTF-8.
221 // This may engage various charset conversions.
222 return $this->mysqlSetCharset( 'utf8' );
224 return $this->mysqlSetCharset( 'binary' );
229 * Open a connection to a MySQL server
231 * @param string $realServer
232 * @param string|null $dbName
233 * @return mixed Raw connection
234 * @throws DBConnectionError
236 abstract protected function mysqlConnect( $realServer, $dbName );
239 * Set the character set of the MySQL link
241 * @param string $charset
244 abstract protected function mysqlSetCharset( $charset );
247 * @param ResultWrapper|resource $res
248 * @throws DBUnexpectedError
250 public function freeResult( $res ) {
251 if ( $res instanceof ResultWrapper
) {
254 Wikimedia\
suppressWarnings();
255 $ok = $this->mysqlFreeResult( $res );
256 Wikimedia\restoreWarnings
();
258 throw new DBUnexpectedError( $this, "Unable to free MySQL result" );
265 * @param resource $res Raw result
268 abstract protected function mysqlFreeResult( $res );
271 * @param ResultWrapper|resource $res
272 * @return stdClass|bool
273 * @throws DBUnexpectedError
275 public function fetchObject( $res ) {
276 if ( $res instanceof ResultWrapper
) {
279 Wikimedia\
suppressWarnings();
280 $row = $this->mysqlFetchObject( $res );
281 Wikimedia\restoreWarnings
();
283 $errno = $this->lastErrno();
284 // Unfortunately, mysql_fetch_object does not reset the last errno.
285 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
286 // these are the only errors mysql_fetch_object can cause.
287 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
288 if ( $errno == 2000 ||
$errno == 2013 ) {
289 throw new DBUnexpectedError(
291 'Error in fetchObject(): ' . htmlspecialchars( $this->lastError() )
299 * Fetch a result row as an object
301 * @param resource $res Raw result
304 abstract protected function mysqlFetchObject( $res );
307 * @param IResultWrapper|resource $res
309 * @throws DBUnexpectedError
311 public function fetchRow( $res ) {
312 if ( $res instanceof ResultWrapper
) {
315 Wikimedia\
suppressWarnings();
316 $row = $this->mysqlFetchArray( $res );
317 Wikimedia\restoreWarnings
();
319 $errno = $this->lastErrno();
320 // Unfortunately, mysql_fetch_array does not reset the last errno.
321 // Only check for CR_SERVER_LOST and CR_UNKNOWN_ERROR, as
322 // these are the only errors mysql_fetch_array can cause.
323 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
324 if ( $errno == 2000 ||
$errno == 2013 ) {
325 throw new DBUnexpectedError(
327 'Error in fetchRow(): ' . htmlspecialchars( $this->lastError() )
335 * Fetch a result row as an associative and numeric array
337 * @param resource $res Raw result
340 abstract protected function mysqlFetchArray( $res );
343 * @throws DBUnexpectedError
344 * @param ResultWrapper|resource $res
347 function numRows( $res ) {
348 if ( $res instanceof ResultWrapper
) {
351 Wikimedia\
suppressWarnings();
352 $n = !is_bool( $res ) ?
$this->mysqlNumRows( $res ) : 0;
353 Wikimedia\restoreWarnings
();
355 // Unfortunately, mysql_num_rows does not reset the last errno.
356 // We are not checking for any errors here, since
357 // there are no errors mysql_num_rows can cause.
358 // See https://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html.
359 // See https://phabricator.wikimedia.org/T44430
364 * Get number of rows in result
366 * @param resource $res Raw result
369 abstract protected function mysqlNumRows( $res );
372 * @param ResultWrapper|resource $res
375 public function numFields( $res ) {
376 if ( $res instanceof ResultWrapper
) {
380 return $this->mysqlNumFields( $res );
384 * Get number of fields in result
386 * @param resource $res Raw result
389 abstract protected function mysqlNumFields( $res );
392 * @param ResultWrapper|resource $res
396 public function fieldName( $res, $n ) {
397 if ( $res instanceof ResultWrapper
) {
401 return $this->mysqlFieldName( $res, $n );
405 * Get the name of the specified field in a result
407 * @param ResultWrapper|resource $res
411 abstract protected function mysqlFieldName( $res, $n );
414 * mysql_field_type() wrapper
415 * @param ResultWrapper|resource $res
419 public function fieldType( $res, $n ) {
420 if ( $res instanceof ResultWrapper
) {
424 return $this->mysqlFieldType( $res, $n );
428 * Get the type of the specified field in a result
430 * @param ResultWrapper|resource $res
434 abstract protected function mysqlFieldType( $res, $n );
437 * @param ResultWrapper|resource $res
441 public function dataSeek( $res, $row ) {
442 if ( $res instanceof ResultWrapper
) {
446 return $this->mysqlDataSeek( $res, $row );
450 * Move internal result pointer
452 * @param ResultWrapper|resource $res
456 abstract protected function mysqlDataSeek( $res, $row );
461 public function lastError() {
463 # Even if it's non-zero, it can still be invalid
464 Wikimedia\
suppressWarnings();
465 $error = $this->mysqlError( $this->conn
);
467 $error = $this->mysqlError();
469 Wikimedia\restoreWarnings
();
471 $error = $this->mysqlError();
474 $error .= ' (' . $this->server
. ')';
481 * Returns the text of the error message from previous MySQL operation
483 * @param resource|null $conn Raw connection
486 abstract protected function mysqlError( $conn = null );
488 protected function wasQueryTimeout( $error, $errno ) {
489 return $errno == 2062;
493 * @param string $table
494 * @param array $uniqueIndexes
496 * @param string $fname
498 public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__
) {
499 $this->nativeReplace( $table, $rows, $fname );
502 protected function isInsertSelectSafe( array $insertOptions, array $selectOptions ) {
503 $row = $this->getReplicationSafetyInfo();
504 // For row-based-replication, the resulting changes will be relayed, not the query
505 if ( $row->binlog_format
=== 'ROW' ) {
508 // LIMIT requires ORDER BY on a unique key or it is non-deterministic
509 if ( isset( $selectOptions['LIMIT'] ) ) {
512 // In MySQL, an INSERT SELECT is only replication safe with row-based
513 // replication or if innodb_autoinc_lock_mode is 0. When those
514 // conditions aren't met, use non-native mode.
515 // While we could try to determine if the insert is safe anyway by
516 // checking if the target table has an auto-increment column that
517 // isn't set in $varMap, that seems unlikely to be worth the extra
520 in_array( 'NO_AUTO_COLUMNS', $insertOptions ) ||
521 (int)$row->innodb_autoinc_lock_mode
=== 0
526 * @return stdClass Process cached row
528 protected function getReplicationSafetyInfo() {
529 if ( $this->replicationInfoRow
=== null ) {
530 $this->replicationInfoRow
= $this->selectRow(
533 'innodb_autoinc_lock_mode' => '@@innodb_autoinc_lock_mode',
534 'binlog_format' => '@@binlog_format',
541 return $this->replicationInfoRow
;
545 * Estimate rows in dataset
546 * Returns estimated count, based on EXPLAIN output
547 * Takes same arguments as Database::select()
549 * @param string|array $table
550 * @param string|array $var
551 * @param string|array $conds
552 * @param string $fname
553 * @param string|array $options
554 * @param array $join_conds
557 public function estimateRowCount( $table, $var = '*', $conds = '',
558 $fname = __METHOD__
, $options = [], $join_conds = []
560 $conds = $this->normalizeConditions( $conds, $fname );
561 $column = $this->extractSingleFieldFromList( $var );
562 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
563 $conds[] = "$column IS NOT NULL";
566 $options['EXPLAIN'] = true;
567 $res = $this->select( $table, $var, $conds, $fname, $options, $join_conds );
568 if ( $res === false ) {
571 if ( !$this->numRows( $res ) ) {
576 foreach ( $res as $plan ) {
577 $rows *= $plan->rows
> 0 ?
$plan->rows
: 1; // avoid resetting to zero
583 public function tableExists( $table, $fname = __METHOD__
) {
584 // Split database and table into proper variables as Database::tableName() returns
585 // shared tables prefixed with their database, which do not work in SHOW TABLES statements
586 list( $database, , $prefix, $table ) = $this->qualifiedTableComponents( $table );
587 $tableName = "{$prefix}{$table}";
589 if ( isset( $this->sessionTempTables
[$tableName] ) ) {
590 return true; // already known to exist and won't show in SHOW TABLES anyway
593 // We can't use buildLike() here, because it specifies an escape character
594 // other than the backslash, which is the only one supported by SHOW TABLES
595 $encLike = $this->escapeLikeInternal( $tableName, '\\' );
597 // If the database has been specified (such as for shared tables), use "FROM"
598 if ( $database !== '' ) {
599 $encDatabase = $this->addIdentifierQuotes( $database );
600 $query = "SHOW TABLES FROM $encDatabase LIKE '$encLike'";
602 $query = "SHOW TABLES LIKE '$encLike'";
605 return $this->query( $query, $fname )->numRows() > 0;
609 * @param string $table
610 * @param string $field
611 * @return bool|MySQLField
613 public function fieldInfo( $table, $field ) {
614 $table = $this->tableName( $table );
615 $res = $this->query( "SELECT * FROM $table LIMIT 1", __METHOD__
, true );
619 $n = $this->mysqlNumFields( $res->result
);
620 for ( $i = 0; $i < $n; $i++
) {
621 $meta = $this->mysqlFetchField( $res->result
, $i );
622 if ( $field == $meta->name
) {
623 return new MySQLField( $meta );
631 * Get column information from a result
633 * @param resource $res Raw result
637 abstract protected function mysqlFetchField( $res, $n );
640 * Get information about an index into an object
641 * Returns false if the index does not exist
643 * @param string $table
644 * @param string $index
645 * @param string $fname
646 * @return bool|array|null False or null on failure
648 public function indexInfo( $table, $index, $fname = __METHOD__
) {
649 # SHOW INDEX works in MySQL 3.23.58, but SHOW INDEXES does not.
650 # SHOW INDEX should work for 3.x and up:
651 # https://dev.mysql.com/doc/mysql/en/SHOW_INDEX.html
652 $table = $this->tableName( $table );
653 $index = $this->indexName( $index );
655 $sql = 'SHOW INDEX FROM ' . $table;
656 $res = $this->query( $sql, $fname );
664 foreach ( $res as $row ) {
665 if ( $row->Key_name
== $index ) {
670 return $result ?
: false;
677 public function strencode( $s ) {
678 return $this->mysqlRealEscapeString( $s );
685 abstract protected function mysqlRealEscapeString( $s );
687 public function addQuotes( $s ) {
688 if ( is_bool( $s ) ) {
689 // Parent would transform to int, which does not play nice with MySQL type juggling.
690 // When searching for an int in a string column, the strings are cast to int, which
691 // means false would match any string not starting with a number.
692 $s = (string)(int)$s;
694 return parent
::addQuotes( $s );
698 * MySQL uses `backticks` for identifier quoting instead of the sql standard "double quotes".
703 public function addIdentifierQuotes( $s ) {
704 // Characters in the range \u0001-\uFFFF are valid in a quoted identifier
705 // Remove NUL bytes and escape backticks by doubling
706 return '`' . str_replace( [ "\0", '`' ], [ '', '``' ], $s ) . '`';
710 * @param string $name
713 public function isQuotedIdentifier( $name ) {
714 return strlen( $name ) && $name[0] == '`' && substr( $name, -1, 1 ) == '`';
717 public function getLag() {
718 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
719 return $this->getLagFromPtHeartbeat();
721 return $this->getLagFromSlaveStatus();
728 protected function getLagDetectionMethod() {
729 return $this->lagDetectionMethod
;
735 protected function getLagFromSlaveStatus() {
736 $res = $this->query( 'SHOW SLAVE STATUS', __METHOD__
);
737 $row = $res ?
$res->fetchObject() : false;
738 // If the server is not replicating, there will be no row
739 if ( $row && strval( $row->Seconds_Behind_Master
) !== '' ) {
740 return intval( $row->Seconds_Behind_Master
);
749 protected function getLagFromPtHeartbeat() {
750 $options = $this->lagDetectionOptions
;
752 $currentTrxInfo = $this->getRecordedTransactionLagStatus();
753 if ( $currentTrxInfo ) {
754 // There is an active transaction and the initial lag was already queried
755 $staleness = microtime( true ) - $currentTrxInfo['since'];
756 if ( $staleness > self
::LAG_STALE_WARN_THRESHOLD
) {
757 // Avoid returning higher and higher lag value due to snapshot age
758 // given that the isolation level will typically be REPEATABLE-READ
759 $this->queryLogger
->warning(
760 "Using cached lag value for {db_server} due to active transaction",
761 $this->getLogContext( [
762 'method' => __METHOD__
,
764 'trace' => ( new RuntimeException() )->getTraceAsString()
769 return $currentTrxInfo['lag'];
772 if ( isset( $options['conds'] ) ) {
773 // Best method for multi-DC setups: use logical channel names
774 $data = $this->getHeartbeatData( $options['conds'] );
776 // Standard method: use master server ID (works with stock pt-heartbeat)
777 $masterInfo = $this->getMasterServerInfo();
778 if ( !$masterInfo ) {
779 $this->queryLogger
->error(
780 "Unable to query master of {db_server} for server ID",
781 $this->getLogContext( [
782 'method' => __METHOD__
786 return false; // could not get master server ID
789 $conds = [ 'server_id' => intval( $masterInfo['serverId'] ) ];
790 $data = $this->getHeartbeatData( $conds );
793 list( $time, $nowUnix ) = $data;
794 if ( $time !== null ) {
795 // @time is in ISO format like "2015-09-25T16:48:10.000510"
796 $dateTime = new DateTime( $time, new DateTimeZone( 'UTC' ) );
797 $timeUnix = (int)$dateTime->format( 'U' ) +
$dateTime->format( 'u' ) / 1e6
;
799 return max( $nowUnix - $timeUnix, 0.0 );
802 $this->queryLogger
->error(
803 "Unable to find pt-heartbeat row for {db_server}",
804 $this->getLogContext( [
805 'method' => __METHOD__
812 protected function getMasterServerInfo() {
813 $cache = $this->srvCache
;
814 $key = $cache->makeGlobalKey(
817 // Using one key for all cluster replica DBs is preferable
818 $this->getLBInfo( 'clusterMasterHost' ) ?
: $this->getServer()
822 return $cache->getWithSetCallback(
824 $cache::TTL_INDEFINITE
,
825 function () use ( $cache, $key, $fname ) {
826 // Get and leave a lock key in place for a short period
827 if ( !$cache->lock( $key, 0, 10 ) ) {
828 return false; // avoid master connection spike slams
831 $conn = $this->getLazyMasterHandle();
833 return false; // something is misconfigured
836 // Connect to and query the master; catch errors to avoid outages
838 $res = $conn->query( 'SELECT @@server_id AS id', $fname );
839 $row = $res ?
$res->fetchObject() : false;
840 $id = $row ?
(int)$row->id
: 0;
841 } catch ( DBError
$e ) {
845 // Cache the ID if it was retrieved
846 return $id ?
[ 'serverId' => $id, 'asOf' => time() ] : false;
852 * @param array $conds WHERE clause conditions to find a row
853 * @return array (heartbeat `ts` column value or null, UNIX timestamp) for the newest beat
854 * @see https://www.percona.com/doc/percona-toolkit/2.1/pt-heartbeat.html
856 protected function getHeartbeatData( array $conds ) {
857 // Query time and trip time are not counted
858 $nowUnix = microtime( true );
859 // Do not bother starting implicit transactions here
860 $this->clearFlag( self
::DBO_TRX
, self
::REMEMBER_PRIOR
);
862 $whereSQL = $this->makeList( $conds, self
::LIST_AND
);
863 // Use ORDER BY for channel based queries since that field might not be UNIQUE.
864 // Note: this would use "TIMESTAMPDIFF(MICROSECOND,ts,UTC_TIMESTAMP(6))" but the
865 // percision field is not supported in MySQL <= 5.5.
867 "SELECT ts FROM heartbeat.heartbeat WHERE $whereSQL ORDER BY ts DESC LIMIT 1",
870 $row = $res ?
$res->fetchObject() : false;
872 $this->restoreFlags();
875 return [ $row ?
$row->ts
: null, $nowUnix ];
878 protected function getApproximateLagStatus() {
879 if ( $this->getLagDetectionMethod() === 'pt-heartbeat' ) {
880 // Disable caching since this is fast enough and we don't wan't
881 // to be *too* pessimistic by having both the cache TTL and the
882 // pt-heartbeat interval count as lag in getSessionLagStatus()
883 return parent
::getApproximateLagStatus();
886 $key = $this->srvCache
->makeGlobalKey( 'mysql-lag', $this->getServer() );
887 $approxLag = $this->srvCache
->get( $key );
889 $approxLag = parent
::getApproximateLagStatus();
890 $this->srvCache
->set( $key, $approxLag, 1 );
896 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
897 if ( !( $pos instanceof MySQLMasterPos
) ) {
898 throw new InvalidArgumentException( "Position not an instance of MySQLMasterPos" );
901 if ( $this->getLBInfo( 'is static' ) === true ) {
902 return 0; // this is a copy of a read-only dataset with no master DB
903 } elseif ( $this->lastKnownReplicaPos
&& $this->lastKnownReplicaPos
->hasReached( $pos ) ) {
904 return 0; // already reached this point for sure
907 // Call doQuery() directly, to avoid opening a transaction if DBO_TRX is set
908 if ( $pos->getGTIDs() ) {
909 // Ignore GTIDs from domains exclusive to the master DB (presumably inactive)
910 $rpos = $this->getReplicaPos();
911 $gtidsWait = $rpos ? MySQLMasterPos
::getCommonDomainGTIDs( $pos, $rpos ) : [];
913 $this->queryLogger
->error(
914 "No GTIDs with the same domain between master ($pos) and replica ($rpos)",
915 $this->getLogContext( [
916 'method' => __METHOD__
,
920 return -1; // $pos is from the wrong cluster?
922 // Wait on the GTID set (MariaDB only)
923 $gtidArg = $this->addQuotes( implode( ',', $gtidsWait ) );
924 if ( strpos( $gtidArg, ':' ) !== false ) {
925 // MySQL GTIDs, e.g "source_id:transaction_id"
926 $res = $this->doQuery( "SELECT WAIT_FOR_EXECUTED_GTID_SET($gtidArg, $timeout)" );
928 // MariaDB GTIDs, e.g."domain:server:sequence"
929 $res = $this->doQuery( "SELECT MASTER_GTID_WAIT($gtidArg, $timeout)" );
932 // Wait on the binlog coordinates
933 $encFile = $this->addQuotes( $pos->getLogFile() );
934 $encPos = intval( $pos->getLogPosition()[$pos::CORD_EVENT
] );
935 $res = $this->doQuery( "SELECT MASTER_POS_WAIT($encFile, $encPos, $timeout)" );
938 $row = $res ?
$this->fetchRow( $res ) : false;
940 throw new DBExpectedError( $this, "Replication wait failed: {$this->lastError()}" );
943 // Result can be NULL (error), -1 (timeout), or 0+ per the MySQL manual
944 $status = ( $row[0] !== null ) ?
intval( $row[0] ) : null;
945 if ( $status === null ) {
946 if ( !$pos->getGTIDs() ) {
947 // T126436: jobs programmed to wait on master positions might be referencing
948 // binlogs with an old master hostname; this makes MASTER_POS_WAIT() return null.
949 // Try to detect this case and treat the replica DB as having reached the given
950 // position (any master switchover already requires that the new master be caught
951 // up before the switch).
952 $replicationPos = $this->getReplicaPos();
953 if ( $replicationPos && !$replicationPos->channelsMatch( $pos ) ) {
954 $this->lastKnownReplicaPos
= $replicationPos;
958 } elseif ( $status >= 0 ) {
959 // Remember that this position was reached to save queries next time
960 $this->lastKnownReplicaPos
= $pos;
967 * Get the position of the master from SHOW SLAVE STATUS
969 * @return MySQLMasterPos|bool
971 public function getReplicaPos() {
972 $now = microtime( true ); // as-of-time *before* fetching GTID variables
974 if ( $this->useGTIDs() ) {
975 // Try to use GTIDs, fallbacking to binlog positions if not possible
976 $data = $this->getServerGTIDs( __METHOD__
);
977 // Use gtid_slave_pos for MariaDB and gtid_executed for MySQL
978 foreach ( [ 'gtid_slave_pos', 'gtid_executed' ] as $name ) {
979 if ( isset( $data[$name] ) && strlen( $data[$name] ) ) {
980 return new MySQLMasterPos( $data[$name], $now );
985 $data = $this->getServerRoleStatus( 'SLAVE', __METHOD__
);
986 if ( $data && strlen( $data['Relay_Master_Log_File'] ) ) {
987 return new MySQLMasterPos(
988 "{$data['Relay_Master_Log_File']}/{$data['Exec_Master_Log_Pos']}",
997 * Get the position of the master from SHOW MASTER STATUS
999 * @return MySQLMasterPos|bool
1001 public function getMasterPos() {
1002 $now = microtime( true ); // as-of-time *before* fetching GTID variables
1005 if ( $this->useGTIDs() ) {
1006 // Try to use GTIDs, fallbacking to binlog positions if not possible
1007 $data = $this->getServerGTIDs( __METHOD__
);
1008 // Use gtid_binlog_pos for MariaDB and gtid_executed for MySQL
1009 foreach ( [ 'gtid_binlog_pos', 'gtid_executed' ] as $name ) {
1010 if ( isset( $data[$name] ) && strlen( $data[$name] ) ) {
1011 $pos = new MySQLMasterPos( $data[$name], $now );
1015 // Filter domains that are inactive or not relevant to the session
1017 $pos->setActiveOriginServerId( $this->getServerId() );
1018 $pos->setActiveOriginServerUUID( $this->getServerUUID() );
1019 if ( isset( $data['gtid_domain_id'] ) ) {
1020 $pos->setActiveDomain( $data['gtid_domain_id'] );
1026 $data = $this->getServerRoleStatus( 'MASTER', __METHOD__
);
1027 if ( $data && strlen( $data['File'] ) ) {
1028 $pos = new MySQLMasterPos( "{$data['File']}/{$data['Position']}", $now );
1037 * @throws DBQueryError If the variable doesn't exist for some reason
1039 protected function getServerId() {
1040 $fname = __METHOD__
;
1041 return $this->srvCache
->getWithSetCallback(
1042 $this->srvCache
->makeGlobalKey( 'mysql-server-id', $this->getServer() ),
1043 self
::SERVER_ID_CACHE_TTL
,
1044 function () use ( $fname ) {
1045 $res = $this->query( "SELECT @@server_id AS id", $fname );
1046 return intval( $this->fetchObject( $res )->id
);
1052 * @return string|null
1054 protected function getServerUUID() {
1055 return $this->srvCache
->getWithSetCallback(
1056 $this->srvCache
->makeGlobalKey( 'mysql-server-uuid', $this->getServer() ),
1057 self
::SERVER_ID_CACHE_TTL
,
1059 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'server_uuid'" );
1060 $row = $this->fetchObject( $res );
1062 return $row ?
$row->Value
: null;
1068 * @param string $fname
1071 protected function getServerGTIDs( $fname = __METHOD__
) {
1073 // Get global-only variables like gtid_executed
1074 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'gtid_%'", $fname );
1075 foreach ( $res as $row ) {
1076 $map[$row->Variable_name
] = $row->Value
;
1078 // Get session-specific (e.g. gtid_domain_id since that is were writes will log)
1079 $res = $this->query( "SHOW SESSION VARIABLES LIKE 'gtid_%'", $fname );
1080 foreach ( $res as $row ) {
1081 $map[$row->Variable_name
] = $row->Value
;
1088 * @param string $role One of "MASTER"/"SLAVE"
1089 * @param string $fname
1090 * @return string[] Latest available server status row
1092 protected function getServerRoleStatus( $role, $fname = __METHOD__
) {
1093 return $this->query( "SHOW $role STATUS", $fname )->fetchRow() ?
: [];
1096 public function serverIsReadOnly() {
1097 $res = $this->query( "SHOW GLOBAL VARIABLES LIKE 'read_only'", __METHOD__
);
1098 $row = $this->fetchObject( $res );
1100 return $row ?
( strtolower( $row->Value
) === 'on' ) : false;
1104 * @param string $index
1107 function useIndexClause( $index ) {
1108 return "FORCE INDEX (" . $this->indexName( $index ) . ")";
1112 * @param string $index
1115 function ignoreIndexClause( $index ) {
1116 return "IGNORE INDEX (" . $this->indexName( $index ) . ")";
1122 function lowPriorityOption() {
1123 return 'LOW_PRIORITY';
1129 public function getSoftwareLink() {
1130 // MariaDB includes its name in its version string; this is how MariaDB's version of
1131 // the mysql command-line client identifies MariaDB servers (see mariadb_connection()
1132 // in libmysql/libmysql.c).
1133 $version = $this->getServerVersion();
1134 if ( strpos( $version, 'MariaDB' ) !== false ||
strpos( $version, '-maria-' ) !== false ) {
1135 return '[{{int:version-db-mariadb-url}} MariaDB]';
1138 // Percona Server's version suffix is not very distinctive, and @@version_comment
1139 // doesn't give the necessary info for source builds, so assume the server is MySQL.
1140 // (Even Percona's version of mysql doesn't try to make the distinction.)
1141 return '[{{int:version-db-mysql-url}} MySQL]';
1147 public function getServerVersion() {
1148 // Not using mysql_get_server_info() or similar for consistency: in the handshake,
1149 // MariaDB 10 adds the prefix "5.5.5-", and only some newer client libraries strip
1150 // it off (see RPL_VERSION_HACK in include/mysql_com.h).
1151 if ( $this->serverVersion
=== null ) {
1152 $this->serverVersion
= $this->selectField( '', 'VERSION()', '', __METHOD__
);
1154 return $this->serverVersion
;
1158 * @param array $options
1160 public function setSessionOptions( array $options ) {
1161 if ( isset( $options['connTimeout'] ) ) {
1162 $timeout = (int)$options['connTimeout'];
1163 $this->query( "SET net_read_timeout=$timeout" );
1164 $this->query( "SET net_write_timeout=$timeout" );
1169 * @param string &$sql
1170 * @param string &$newLine
1173 public function streamStatementEnd( &$sql, &$newLine ) {
1174 if ( strtoupper( substr( $newLine, 0, 9 ) ) == 'DELIMITER' ) {
1175 preg_match( '/^DELIMITER\s+(\S+)/', $newLine, $m );
1176 $this->delimiter
= $m[1];
1180 return parent
::streamStatementEnd( $sql, $newLine );
1184 * Check to see if a named lock is available. This is non-blocking.
1186 * @param string $lockName Name of lock to poll
1187 * @param string $method Name of method calling us
1191 public function lockIsFree( $lockName, $method ) {
1192 if ( !parent
::lockIsFree( $lockName, $method ) ) {
1193 return false; // already held
1196 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1197 $result = $this->query( "SELECT IS_FREE_LOCK($encName) AS lockstatus", $method );
1198 $row = $this->fetchObject( $result );
1200 return ( $row->lockstatus
== 1 );
1204 * @param string $lockName
1205 * @param string $method
1206 * @param int $timeout
1209 public function lock( $lockName, $method, $timeout = 5 ) {
1210 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1211 $result = $this->query( "SELECT GET_LOCK($encName, $timeout) AS lockstatus", $method );
1212 $row = $this->fetchObject( $result );
1214 if ( $row->lockstatus
== 1 ) {
1215 parent
::lock( $lockName, $method, $timeout ); // record
1219 $this->queryLogger
->info( __METHOD__
. " failed to acquire lock '{lockname}'",
1220 [ 'lockname' => $lockName ] );
1227 * https://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_release-lock
1228 * @param string $lockName
1229 * @param string $method
1232 public function unlock( $lockName, $method ) {
1233 $encName = $this->addQuotes( $this->makeLockName( $lockName ) );
1234 $result = $this->query( "SELECT RELEASE_LOCK($encName) as lockstatus", $method );
1235 $row = $this->fetchObject( $result );
1237 if ( $row->lockstatus
== 1 ) {
1238 parent
::unlock( $lockName, $method ); // record
1242 $this->queryLogger
->warning( __METHOD__
. " failed to release lock '$lockName'\n" );
1247 private function makeLockName( $lockName ) {
1248 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1249 // Newer version enforce a 64 char length limit.
1250 return ( strlen( $lockName ) > 64 ) ?
sha1( $lockName ) : $lockName;
1253 public function namedLocksEnqueue() {
1257 public function tableLocksHaveTransactionScope() {
1258 return false; // tied to TCP connection
1261 protected function doLockTables( array $read, array $write, $method ) {
1263 foreach ( $write as $table ) {
1264 $items[] = $this->tableName( $table ) . ' WRITE';
1266 foreach ( $read as $table ) {
1267 $items[] = $this->tableName( $table ) . ' READ';
1270 $sql = "LOCK TABLES " . implode( ',', $items );
1271 $this->query( $sql, $method );
1276 protected function doUnlockTables( $method ) {
1277 $this->query( "UNLOCK TABLES", $method );
1283 * @param bool $value
1285 public function setBigSelects( $value = true ) {
1286 if ( $value === 'default' ) {
1287 if ( $this->defaultBigSelects
=== null ) {
1288 # Function hasn't been called before so it must already be set to the default
1291 $value = $this->defaultBigSelects
;
1293 } elseif ( $this->defaultBigSelects
=== null ) {
1294 $this->defaultBigSelects
=
1295 (bool)$this->selectField( false, '@@sql_big_selects', '', __METHOD__
);
1297 $encValue = $value ?
'1' : '0';
1298 $this->query( "SET sql_big_selects=$encValue", __METHOD__
);
1302 * DELETE where the condition is a join. MySql uses multi-table deletes.
1303 * @param string $delTable
1304 * @param string $joinTable
1305 * @param string $delVar
1306 * @param string $joinVar
1307 * @param array|string $conds
1308 * @param bool|string $fname
1309 * @throws DBUnexpectedError
1311 public function deleteJoin(
1312 $delTable, $joinTable, $delVar, $joinVar, $conds, $fname = __METHOD__
1315 throw new DBUnexpectedError( $this, __METHOD__
. ' called with empty $conds' );
1318 $delTable = $this->tableName( $delTable );
1319 $joinTable = $this->tableName( $joinTable );
1320 $sql = "DELETE $delTable FROM $delTable, $joinTable WHERE $delVar=$joinVar ";
1322 if ( $conds != '*' ) {
1323 $sql .= ' AND ' . $this->makeList( $conds, self
::LIST_AND
);
1326 $this->query( $sql, $fname );
1330 * @param string $table
1331 * @param array $rows
1332 * @param array $uniqueIndexes
1334 * @param string $fname
1337 public function upsert( $table, array $rows, array $uniqueIndexes,
1338 array $set, $fname = __METHOD__
1340 if ( $rows === [] ) {
1341 return true; // nothing to do
1344 if ( !is_array( reset( $rows ) ) ) {
1348 $table = $this->tableName( $table );
1349 $columns = array_keys( $rows[0] );
1351 $sql = "INSERT INTO $table (" . implode( ',', $columns ) . ') VALUES ';
1353 foreach ( $rows as $row ) {
1354 $rowTuples[] = '(' . $this->makeList( $row ) . ')';
1356 $sql .= implode( ',', $rowTuples );
1357 $sql .= " ON DUPLICATE KEY UPDATE " . $this->makeList( $set, self
::LIST_SET
);
1359 $this->query( $sql, $fname );
1365 * Determines how long the server has been up
1369 public function getServerUptime() {
1370 $vars = $this->getMysqlStatus( 'Uptime' );
1372 return (int)$vars['Uptime'];
1376 * Determines if the last failure was due to a deadlock
1380 public function wasDeadlock() {
1381 return $this->lastErrno() == 1213;
1385 * Determines if the last failure was due to a lock timeout
1389 public function wasLockTimeout() {
1390 return $this->lastErrno() == 1205;
1394 * Determines if the last failure was due to the database being read-only.
1398 public function wasReadOnlyError() {
1399 return $this->lastErrno() == 1223 ||
1400 ( $this->lastErrno() == 1290 && strpos( $this->lastError(), '--read-only' ) !== false );
1403 public function wasConnectionError( $errno ) {
1404 return $errno == 2013 ||
$errno == 2006;
1407 protected function wasKnownStatementRollbackError() {
1408 $errno = $this->lastErrno();
1410 if ( $errno === 1205 ) { // lock wait timeout
1411 // Note that this is uncached to avoid stale values of SET is used
1412 $row = $this->selectRow(
1414 [ 'innodb_rollback_on_timeout' => '@@innodb_rollback_on_timeout' ],
1418 // https://dev.mysql.com/doc/refman/5.7/en/innodb-error-handling.html
1419 // https://dev.mysql.com/doc/refman/5.5/en/innodb-parameters.html
1420 return $row->innodb_rollback_on_timeout ?
false : true;
1423 // See https://dev.mysql.com/doc/refman/5.5/en/error-messages-server.html
1424 return in_array( $errno, [ 1022, 1216, 1217, 1137 ], true );
1428 * @param string $oldName
1429 * @param string $newName
1430 * @param bool $temporary
1431 * @param string $fname
1434 public function duplicateTableStructure(
1435 $oldName, $newName, $temporary = false, $fname = __METHOD__
1437 $tmp = $temporary ?
'TEMPORARY ' : '';
1438 $newName = $this->addIdentifierQuotes( $newName );
1439 $oldName = $this->addIdentifierQuotes( $oldName );
1440 $query = "CREATE $tmp TABLE $newName (LIKE $oldName)";
1442 return $this->query( $query, $fname );
1446 * List all tables on the database
1448 * @param string|null $prefix Only show tables with this prefix, e.g. mw_
1449 * @param string $fname Calling function name
1452 public function listTables( $prefix = null, $fname = __METHOD__
) {
1453 $result = $this->query( "SHOW TABLES", $fname );
1457 foreach ( $result as $table ) {
1458 $vars = get_object_vars( $table );
1459 $table = array_pop( $vars );
1461 if ( !$prefix ||
strpos( $table, $prefix ) === 0 ) {
1462 $endArray[] = $table;
1470 * @param string $tableName
1471 * @param string $fName
1472 * @return bool|ResultWrapper
1474 public function dropTable( $tableName, $fName = __METHOD__
) {
1475 if ( !$this->tableExists( $tableName, $fName ) ) {
1479 return $this->query( "DROP TABLE IF EXISTS " . $this->tableName( $tableName ), $fName );
1483 * Get status information from SHOW STATUS in an associative array
1485 * @param string $which
1488 private function getMysqlStatus( $which = "%" ) {
1489 $res = $this->query( "SHOW STATUS LIKE '{$which}'" );
1492 foreach ( $res as $row ) {
1493 $status[$row->Variable_name
] = $row->Value
;
1500 * Lists VIEWs in the database
1502 * @param string|null $prefix Only show VIEWs with this prefix, eg.
1503 * unit_test_, or $wgDBprefix. Default: null, would return all views.
1504 * @param string $fname Name of calling function
1508 public function listViews( $prefix = null, $fname = __METHOD__
) {
1509 // The name of the column containing the name of the VIEW
1510 $propertyName = 'Tables_in_' . $this->getDBname();
1512 // Query for the VIEWS
1513 $res = $this->query( 'SHOW FULL TABLES WHERE TABLE_TYPE = "VIEW"' );
1515 foreach ( $res as $row ) {
1516 array_push( $allViews, $row->$propertyName );
1519 if ( is_null( $prefix ) ||
$prefix === '' ) {
1523 $filteredViews = [];
1524 foreach ( $allViews as $viewName ) {
1525 // Does the name of this VIEW start with the table-prefix?
1526 if ( strpos( $viewName, $prefix ) === 0 ) {
1527 array_push( $filteredViews, $viewName );
1531 return $filteredViews;
1535 * Differentiates between a TABLE and a VIEW.
1537 * @param string $name Name of the TABLE/VIEW to test
1538 * @param string|null $prefix
1542 public function isView( $name, $prefix = null ) {
1543 return in_array( $name, $this->listViews( $prefix ) );
1546 protected function isTransactableQuery( $sql ) {
1547 return parent
::isTransactableQuery( $sql ) &&
1548 !preg_match( '/^SELECT\s+(GET|RELEASE|IS_FREE)_LOCK\(/', $sql );
1552 * @param string $field Field or column to cast
1555 public function buildIntegerCast( $field ) {
1556 return 'CAST( ' . $field . ' AS SIGNED )';
1560 * @return bool Whether GTID support is used (mockable for testing)
1562 protected function useGTIDs() {
1563 return $this->useGTIDs
;
1568 * @deprecated since 1.29
1570 class_alias( DatabaseMysqlBase
::class, 'DatabaseMysqlBase' );