…of a particular MySQL schema and then reload it with a different schema name on the same server….on larger schemas. One of the downsides to mysqldump is the need to scan the full tables and in turn…streaming the redo-logs to ensure that all transactions are also captured. The –apply-logs phase …
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
… want this transaction to persist after a crash, it has to get to disk. This has no effect on standard MySQL replication from… turns out transaction ordering really, really matters (really!). By enforcing replication to all nodes, we can (simultaneously) establish global ordering for the transaction…
Post: Follow these basics when migrating to Percona XtraDB Cluster for MySQL
May 1, 2013 By 10 Comments
… XtraDB Cluster (PXC) for MySQL is a hot thing right now and some users…basic support, primarily because the storage engine is non-transactional and so PXC cannot guarantee the data will remain…the latter, make sure to not forget turning the feature back on when you switch to the new cluster …
Post: Memory allocators: MySQL performance improvements in Percona Server 5.5.30-30.2
April 15, 2013 By
…, there is another issue in InnoDB transaction processing that notably affects MySQL performance – for every transaction InnoDB creates a read view and allocates… notably slowdown MySQL-transaction creation and many threads will get stuck on glibc/kernel syscalls, which will in turn result in contention on kernel_mutex…
Post: Emulating global transaction ID with pt-heartbeat
November 4, 2011 By 6 Comments
Global transaction IDs are being considered for a future version of MySQL. A global transaction ID lets you determine a server’s replication… some of the benefits of a global transaction ID, but it works on any version of MySQL. Now why would we want this… to figure out C’s position relative to A. It turned out to be tedious, but not impossible, because pt-heartbeat…
Post: Replication checksums in MySQL 5.6
February 15, 2013 By 3 Comments
…transactions mixing transactional and non-transactional tables The real problem is that replication may keep on…turn on replication checksums on the slave: slave1 [localhost] {msandbox} ((none)) > set global slave_sql_verify_checksum=ON…
Post: Understanding Multi-node writing conflict metrics in Percona XtraDB Cluster and Galera
November 20, 2012 By 17 Comments
… local transaction getting aborted and rolled back, and the difference comes down to when and how that transaction conflict was detected. It turns… local transaction triggering the failure on commit, this is triggered by Galera replication threads applying replicated transactions. To be clearer: a transaction was open on… writeset being applied by a slave thread and an open transaction on the node, not by a Galera writeset comparison as in…
Post: Percona XtraDB Cluster: Failure Scenarios with only 2 nodes
July 25, 2012 By 6 Comments
… mysql> insert into percona values (0,’percona1′,’peter’); ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction percona1 mysql…-0800-b8b68845d409, ‘tcp://0.0.0.0:4567′) turning message relay requesting on, nonlive peers: tcp://192.168.70.3:4567 2012…
Comment: Percona XtraDB Cluster Feature 2: Multi-Master replication
April 2, 2012 By 22 Comments
… keeping track of global transaction ID and caching the writesets for potential IST. This overhead can be turned off by either unloading Galera wsrep provider or setting wsrep_on=0 globally. But that of course will effectively turn it…, you probably should compare single Galera node with plain mysql with binlog turned on. Having said that, 20% may be not really justified…
Post: MySQL Sizing questions
June 23, 2006 By 4 Comments
… frequently get questions along the lines of “how many transactions per second MySQL can do” or “how many servers I need to… not accept any responsibilty for estimates being wrong. On the contrary – underestimates would turn extra license sales, while overestimates would typically mean…
