… that uses a separate service for a message queue, not MySQL at all. E.g. ActiveMQ, RabbitMQ, Resque, etc. All applications… the MQ and then apply them to the database. Possibly committing sets of events in a single transaction to reduce the…
Comment: trx descriptors: MySQL performance improvements in Percona Server 5.5.30-30.2
April 12, 2013 By 3 Comments
… one is the default sysbench mode, i.e. “BEGIN; SELECT …; COMMIT” which is expected to provide lower TPS values than the…. 2) There was no fix from Percona at the time MySQL bug #49169 was closed. However, as you can see from…
Post: How Does Semisynchronous MySQL Replication Work?
January 19, 2012 By 24 Comments
… you commit a transaction, the commit does not complete until all replicas have also committed successfully. In MySQL‘s semi-synchronous replication, the commit completes… the relevant section of the MySQL manual. But read carefully, for example, the following sentences: When a commit returns successfully, it is…
Post: Percona XtraDB Cluster: Multi-node writing and Unexpected deadlocks
August 17, 2012 By 17 Comments
…: 1 Changed: 1 Warnings: 0 node3 mysql> commit; Query OK, 0 rows affected (0.00 sec) node3 mysql> select * from autoinc; +—+——-+ | i | j… what happened: node1 mysql> commit; ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction node1 mysql> select * from autoinc…
Post: Testing the Group Commit Fix
July 13, 2011 By 13 Comments
… are the results of my testing of the new Group Commit in Percona Server 5.1. As background information, the problem… improves performance substantially when both innodb_flush_log_at_trx_commit=1 and sync_binlog=1 options are set and write… enabled and disabled. All results are for binaries with group commit fix. Results with disabled write cache thread trx=1, No…
Post: Ultimate MySQL variable and status reference list
January 8, 2011 By 4 Comments
…constantly referring to the amazing MySQL manual, especially the option and variable reference table. But… innodb_change_bufferingblogpercona.commanual innodb_checksumsblogpercona.commanual innodb_commit_concurrencyblogpercona.commanual innodb_concurrency_ticketsblogpercona.commanual innodb_data_…
Post: Percona Server 5.5.18-23.0: Now with Group Commit!
December 19, 2011 By 3 Comments
… available here and from the Percona Software Repositories). Based on MySQL 5.5.18, including all the bug fixes in it… milestone at Launchpad. New Features Percona Server now supports group commit between XtraDB and the replication binlog. Percona has imported the group commit patch from MariaDB and is making the performance improvements that…
Post: Implications of Metadata Locking Changes in MySQL 5.5
February 1, 2013 By 9 Comments
… Locking behavior prior to MySQL 5.5.3 Metadata Locking behavior prior to MySQL 5.5.3 Prior to MySQL 5.5.3…:39 server id 1 end_log_pos 856 Xid = 85 COMMIT/*!*/; Note how ALTER is logged before the UPDATE, because ALTER… for the transaction to commit. For the reasons described above the implementation of Metadata Locking was changed, starting MySQL 5.5.3…
Post: Helgrinding MySQL with InnoDB for Synchronisation Errors, Fun and Profit
November 24, 2011 By 2 Comments
…. Now, Valgrind does not need much introduction, especially to the MySQL server developers. The Valgrind Memcheck tool, which is synonymous with…: mutex_spin_wait (sync0sync.c:441) ==9090== by 0x6B751FC: mtr_commit (sync0sync.ic:221) ==9090== by 0x6B39223: fsp_fill_free_list…: log_write_low (log0log.c:330) ==9090== by 0x6B75144: mtr_commit (mtr0mtr.c:153) ==9090== by 0x6BD7F87: trx_sys_create_doublewrite…
Post: Multiple purge threads in Percona Server 5.1.56 and MySQL 5.6.2
May 3, 2011 By 13 Comments
… CONSISTENT SNAPSHOT. In the middle of the workload this transaction commits and so the purge begins. The tests were performed on… innodb_log_file_size=1900M innodb_flush_log_at_trx_commit=2 innodb_doublewrite=1 innodb_flush_method=O_DIRECT innodb… to not to penalize further TPS. MySQL 5.6.2 Results Now let’s test MySQL 5.6.2. It is important…
