…. Bugs Fixed: Using Perl’s DBD::MySQL package for server communication instead of spawning the MySQL command line client introduced a regression… wsrep_last_committed. Bug fixed #1181222. innobackupex automatic version detection did not work correctly for latest Percona Server and MySQL 5.1… option on the server to prevent server from closing connections if the global wait_timeout value is set too low. Bug…
Post: Repair MySQL 5.6 GTID replication by injecting empty transactions
March 26, 2013 By 1 Comment
… for a simple reason, it doesn’t work anymore if you are using MySQL GTID. Then the question is: Is there any…; SET GTID_NEXT=”7d72f9b4-8577-11e2-a3d7-080027635ef5:5″; BEGIN; COMMIT; SET GTID_NEXT=”AUTOMATIC”; START SLAVE; [...] Retrieved_Gtid_Set: 7d72f9b4… is found in Percona Toolkit for MySQL. Last week I gave a talk at Percona MySQL University @Toronto about GTID. It includes…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
… no effect on standard MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL replication? It’s actually…’t even commit and you have to take some action you normally wouldn’t have had to do. Workarounds If your hotspots were really bad in standalone Innodb, you might consider relaxing the fsync: set innodb_flush_log_at_trx_commit…
Post: Galera Flow Control in Percona XtraDB Cluster for MySQL
May 2, 2013 By 5 Comments
… replication feedback mechanism, unlike anything you find in standard async MySQL replication. It is my belief that the lack of understanding… can be behind committing transactions from the cluster. gcs.fc_master_slave The fc_limit is modified dynamically if you have fc… of certification by keeping the window between new transactions being committed and the oldest unapplied transaction small. The larger the queue…
Post: More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
… results across all 3 boxes to see if different hardware has any notable impact: Still…100M:autoextend innodb_flush_log_at_trx_commit = 2 innodb_flush_method = O_DIRECT … –percentile=99 –mysql-user=root –mysql-db=sbtest8t1M –mysql-table-engine=INNODB –mysql-socket=/tmp/mysql.sock –oltp-point…
Post: trx descriptors: MySQL performance improvements in Percona Server 5.5.30-30.2
April 12, 2013 By 3 Comments
…) and copies IDs of transactions that have not yet been committed at the current point in time, and thus should not… magnitudes faster than a list scan. You may be curious if MySQL 5.6 brings any notable improvements in this area. It… to the following kinds of transactions: MySQL transactions started with START TRANSACTION READ ONLY MySQL transactions created by a non-locking SELECT…
Post: Memory allocators: MySQL performance improvements in Percona Server 5.5.30-30.2
April 15, 2013 By
… that the heap for that allocation is destroyed on each commit and thus the read view memory is reallocated on the… an costly operation and if memory allocator has scalability problems (like allocator from glibc) this will notably slowdown MySQL-transaction creation and… test for glibc and jemalloc allocators. Observations: = MySQL 5.5.30 – throughput of MySQL 5.5.30 with glibc is limited first…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
… PCIe SSD, would it make more sense to configure MySQL as if it were using SSD storage or to just use an…-time=7200 –max-requests=0 –percentile=95 \ –mysql-user=root –mysql-socket=/tmp/mysql.sock –mysql-table-engine=innodb \ –oltp-read-only=off run… innodb_log_buffer_size = 128M innodb_flush_log_at_trx_commit = 1 innodb_log_file_size = 1G innodb_log_files_in…
Post: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
…) ON DUPLICATE KEY UPDATE k=VALUES(k)+k; COMMIT; So this workload produces SEQUENTIAL inserts into Primary…will interesting how both InnoDB and TokuDB performs if PK is (`id`,`hid`,`mid`). This also…_repair_threads = 1 myisam_recover socket=/var/lib/mysql/mysql.sock user=root skip-grant-tables TokuDB-…
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… places (on the master and at least one slave). If the master commits but a crash occurs while the master is waiting…
