… critical activities are overloading the system causing user experience to degrade. The first thing you need to know it is not MySQL problem, might be even not problem with your MySQL configuration, queries and hardware, even though… be a good idea. It also often helps with monopolizing replication thread. For example if I need to delete old data…
Post: Testing Percona Replication Manager (prm) with Vagrant
April 17, 2012 By 2 Comments
… about Percona Replication Manager (PRM), a new high availability tool for MySQL. Percona Live DC 2012 Percona Live MySQL Conference & Expo …replication. Corosync allows any number of servers to be part of the cluster using any number of fault-tolerant configurations (active/passive, active/active…
Post: InnoDB's gap locks
March 27, 2012 By 14 Comments
… avoid phantom reads and to get a consistent Statement based replication. To accomplish that, row level locking databases also acquire gap… that table. This makes reads consistent and therefore makes the replication between servers consistent. If you execute SELECT * FROM id > 1000… 72C, ACTIVE 755 sec 4 lock struct(s), heap size 1248, 3 row lock(s), undo log entries 1 MySQL thread id…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
… on the table. mysql> show processlist; +——-+——+———–+———-+————+——+——————————+——————————+———–+—————+———–+ | Id | User | Host | db | …and you’re not actively changing users, stored procedures…replication…
Comment: Is DRBD the right choice for me?
March 14, 2012 By 17 Comments
… we’ve experienced with MySQL replication is resyncing a master and slave on a database with high write activity. Locking the master and… database of reasonable size — thus limiting or halting all write activity on the master. This essentially places the master ‘out of…
Post: Actively monitoring replication connectivity with MySQL's heartbeat
December 29, 2011 By 1 Comment
… detected at all. We needed an active master/slave connection check. And here is where replication‘s heartbeat can help us. This… actively checking the communication. How can I configure replication‘s heartbeat? Is very easy to setup with negligible overhead: mysql_slave > STOP SLAVE; mysql…
Post: Estimating Replication Capacity
July 20, 2010 By 4 Comments
… query: mysql> select * from information_schema.user_statistics where user=”#mysql_system#” \G *************************** 1. row *************************** USER: #mysql_system…activity anyway. Using this way you can also measure “cold” vs “hot” replication capacity as well as how long replication…
Post: Statement based replication with Stored Functions, Triggers and Events
December 16, 2011 By 3 Comments
… have and how to avoid them. TRIGGERS When a statement activates a Trigger only the original query is logged not the…. So all used variables are replicated on the slave. Example: mysql> SELECT YEAR(CURDATE()) INTO @this_year; mysql> insert into t VALUES(@this… are working with statement based replication. Knowing in advances how MySQL works internally can help us to improve our replication availability and data.
Post: MySQL - to use or not to use
May 28, 2007 By 10 Comments
… too dynamic in development (nothing stops you from starting to actively break old code though). Indeed there are some problems which… as Semi-synchronous replication, advanced Monitoring and scaling features some users need other features than MySQL adding in newer MySQL releases. In other…
Post: Infinite Replication Loop
October 10, 2011 By 2 Comments
… replication master position on the active master to a newer position from the passive master (get position from show master status\G on mysql… replication on the active master (server 1): mysql> stop slave; Step 2: there are writes on the active master, the loop statements are also replicated…
