… set up replication filters on the slave, as described in the MySQL manual. You can configure the slave to only replicate a specific…-based replication, it looks like you’ll need to wait for the next release of MHA. Q: How do you monitor MySQL… the MySQL world, except maybe MyISAM files on top of a clustered filesystem with an external lock manager. You might say that MySQL…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
… has no effect on standard MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL replication? It’s actually much worse… will take the 1 RTT). The other transactions will lock wait until the lock(s) they need are available. The application just…
Post: Galera Flow Control in Percona XtraDB Cluster for MySQL
May 2, 2013 By 5 Comments
… to Galera is existence of a replication feedback mechanism, unlike anything you find in standard async MySQL replication. It is my belief that… allow replication to resume as soon as possible. An example configuration tuning flow control in a master/slave cluster might be: mysql… node by simply by running “FLUSH TABLES WITH READ LOCK“, or perhaps by “LOCK TABLE”, in which case flow control will kick…
Post: Managing Slave Lag with MySQL Replication
October 12, 2007 By 15 Comments
… cause replication lag spikes as well. Locks – MySQL Replication SQL Thread executes queries same as any other thread and it has to grab the locks… MySQL Replication goes in single thread it is enough for one statement to get stuck to have all replication stalled. Long Queries – MySQL Replication executes…
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 11 Comments
… trying to open or close tables can indicate LOCK_open contention. Replication is delayed or stopped. Our plugins are structured …. The pmp-check-mysql-replication-delay plugin checks for excessive delay, and pmp-check-mysql-replication-running checks that replication is functioning correctly. …
Post: Investigating MySQL Replication Latency in Percona XtraDB Cluster
March 3, 2013 By 13 Comments
… MySQL Replication Latency in Percona XtraDB Cluster[/caption] I was curious to check how Percona XtraDB Cluster behaves when it comes to MySQL replication… is an option you can enable to get fully synchronous replication behavior: mysql> set global wsrep_causal_reads=1; Query OK, 0… binlog_format=ROW default_storage_engine=InnoDB innodb_autoinc_lock_mode=2 innodb_locks_unsafe_for_binlog=1 wsrep_sst_auth=root:
Post: Percona XtraDB Cluster Feature 2: Multi-Master replication
January 19, 2012 By 22 Comments
… out-of-sync situation, as it regularly happens with regular MySQL replication if you imprudently write to the wrong server. This is… and master is the reason why this replication named “virtually synchronous replication“, not real “synchronous replication” The described behavior of COMMIT also has… InnoDB, that you may experience. In InnoDB usually DEADLOCK and LOCK TIMEOUT errors happen in response on particular query, but not…
Post: Fighting MySQL Replication Lag
September 22, 2008 By 7 Comments
… result in low hanging fruit troubleshooting MySQL Replication Lag First fact you absolutely need to remember is MySQL Replication is single threaded, which means… best to avoid INSERT … SELECT going through replication in 5.0 for many reasons (locking, long query time, waste of execution on…
Post: Making MySQL Replication Parallel
January 30, 2007 By 1 Comment
Kevin Burton writes about making MySQL Replication Parallel. Many of us have been beaten by the fact MySQL Replication is single threaded so in… threads inside the server to share same transactional/lock context. In this case replication could accumulate number of queries execute them in…
Post: MySQL Limitations Part 4: One thread per connection
October 27, 2010 By 14 Comments
… post is about the way MySQL handles connections, allocating one thread per connection to the server. MySQL is a single process with… MySQL 6.0, but is available now in MariaDB. Unfortunately it isn’t a full solution, because it can cause undesirable lock…, it wouldn’t be a great OLTP web database too. MySQL replication is one of the core, fundamental features — and it’s…
