…where the transaction is committed) Galera prevents writing conflicts to these pending transactions while they are inflight in the form of deadlock errors…no effect on standard MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL replication? It’s …
Post: Percona XtraDB Cluster: Multi-node writing and Unexpected deadlocks
August 17, 2012 By 17 Comments
… first transaction, but it does not. Let’s go back to node1 and see what happened: node1 mysql> commit; ERROR 1213 (40001): Deadlock found when trying to get lock; try restarting transaction node1 mysql> select * from autoinc…
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 11 Comments
…. The pmp-check-mysql-deadlocks plugin can help you detect such problems, in conjunction with Percona Toolkit’s pt-deadlock-logger tool. Open…. InnoDB is getting stuck, has long-running transactions, or other problems. The pmp-check-mysql-innodb plugin checks for several indicators of…
Post: Understanding Multi-node writing conflict metrics in Percona XtraDB Cluster and Galera
November 20, 2012 By 17 Comments
… is a conflict, the deadlock on COMMIT error happens (which shouldn’t happen in normal Innodb), the transaction is rolled back, and… local transaction triggering the failure on commit, this is triggered by Galera replication threads applying replicated transactions. To be clearer: a transaction was…
Post: Pitfalls of converting to InnoDB
February 25, 2007 By 16 Comments
…_TIMEOUT) Lock wait timeout expired. Transaction was rolled back. 1213 (ER_LOCK_DEADLOCK) Transaction deadlock. You should rerun the transaction. It is not hard to…” $DBNAME; done There is the standard script mysql_convert_table_format in the MySQL distribution, but it requires Perl and DBI package…
Post: MySQL Limitations Part 1: Single-Threaded Replication
October 20, 2010 By 16 Comments
… to write a series of blog posts on MySQL‘s unsolved severe limitations. I mean limitations …for all situations. For example, mixtures of transactional and non-transactional tables are a nightmare. Here are a…order. If any error occurred, such as a deadlock or lock wait timeout, then the coordinator …
Comment: Checking for a live database connection considered harmful
May 5, 2010 By 38 Comments
… thought I’d post my reply here. MySQL used to roll back the whole transaction on a lock wait timeout, but since 5.0 it only rolls back the latest statement: http://dev.mysql.com…_timeout There are cases where it rolls back the whole transaction (deadlock is one). I don’t think we need to care…
Post: Differences between READ-COMMITTED and REPEATABLE-READ transaction isolation levels
August 28, 2012 By 3 Comments
… rows it is modifying. It must do this to prevent deadlocks and maintain the isolation level. If you run an UPDATE…; —TRANSACTION 1EAB04, ACTIVE 7 sec 633 lock struct(s), heap size 96696, 218786 row lock(s), undo log entries 1 MySQL thread… internals day covers MVCC and locking in detail The SET TRANSACTION ISOLATION LEVEL MySQL manual page
Post: MySQL 5.6: Improvements in the Nutshell
January 27, 2013 By 16 Comments
… January I have created the outline of improvements available in MySQL 5.6 which I thought was worth sharing to give… update the page Scalability – Scalable Read Only Transactions – Concurrent Innodb data file extension – Non-Recursive Deadlock Detection – Faster Locking Primitives – Improved Innodb…
Post: MVCC: Transaction IDs, Log Sequence numbers and Snapshots
December 19, 2007 By 3 Comments
MySQL Storage Engines implementing Multi Version Concurrency Control have several internal … it in case of deadlock, for proper isolation mode handling – transaction should see its own uncommitted changes but other transactions typically do not…
