How to Fail or Crash Your MySQL Instances for Testing
You can take down a MySQL database in multiple ways. Some obvious ways are to shut down the host, pull out the power cable, or hard kill the mysqld process with SIGKILL to simulate an...
Manage and Automate Galera Cluster – Why ClusterControl
Galera Cluster by Codership is a synchronous multi-master replication technology which can be utilized to build highly available MySQL or MariaDB clusters. It has been downloaded over one million times since last year, establishing itself...
Automatic Failover of Postgres Replication
Streaming replication setups with Postgres are inevitably related to failovers. The sole writer in the setup would be the primary, it generates XLOG records and continuously ships them to one or more standby servers. If...
Full Restore of a MySQL or MariaDB Galera Cluster from Backup
Performing regular backups of your database cluster is imperative for high availability and disaster recovery. If for any reason you lost your entire cluster and had to do a full restore from backup, you would...
MySQL Replication and GTID-Based Failover – A Deep Dive Into Errant Transactions
For years, MySQL replication used to be based on binary log events - all a slave knew was the exact event and the exact position it just read from the master. Any single transaction from...
Automatic Failover of MySQL Replication – New in ClusterControl 1.4
MySQL replication setups are inevitably related to failovers. Unlike multi-master clusters like Galera, there is one single writer in a whole setup - the master. If the master fails, one of the slaves will have...
Recovering your MongoDB Data
In previous posts of our MongoDB DBA series, we have covered Deployment, Configuration, Monitoring (part 1), Monitoring (part 2) and backup. Now it is time to recover MongoDB using a backup we made in the...
MySQL Replication Failover – MaxScale vs MHA: Part Four
In the earlier blogs in this series, we concluded that MaxScale with MariaDB Replication Manager still has some way to go as a failover solution. The failover mechanism relied on MariaDB GTID, needed a wrapper...
MySQL Replication Failoverv – Maxscale vs MHA: Part Three
In our previous two posts we described in depth how MySQL Master-HA (MHA) and MaxScale + MariaDB Replication Manager (MRM) both perform their so called slave promotions (also known as master failover). MHA has been...
MySQL Replication Failover – Maxscale vs MHA: Part Two
In our previous post, we described how MySQL Master-HA (MHA) performs a so called slave promotion (also known as master failover) and ensures all remaining slaves in the topology get attached under the new master...
MySQL Replication Failover – Maxscale vs MHA: Part One
In our MySQL replication tutorial we have covered different aspects of replication including master failover by performing a slave promotion using ClusterControl. The slave promotion will turn a slave into the new master, and re-attach...
Architecting for Failure – Disaster Recovery of MySQL Galera Cluster
Failure is a fact of life, and cannot be avoided. No IT vendor in their right mind will claim 100% system availability, although some might claim several nines :-) We might have armies of ops...