May 24, 2013

Finding your MySQL High-Availability solution – Replication

In the last 2 blog posts about High Availability for MySQL we have introduced definitions and provided a list of ( questions that you need to ask yourself before choosing a HA solution. In this new post, we will cover what is the most popular HA solution for MySQL, replication.

State of the art: Galera – synchronous replication for InnoDB

First time I heard about Galera on Percona Performance Conference 2009, Seppo Jaakola was presenting “Galera: Multi-Master Synchronous MySQL Replication Clusters”. It was impressed as I personally always wanted it for InnoDB, but we had it in plans at the bottom of the list, as this is very hard to implement properly. The idea by [...]

Finding your MySQL High-Availability solution – The questions

After having reviewed the definition my the previous post (The definitions), the next step is to respond to some questions. Do you need MySQL High-Availability? That question is quite obvious but some times, it is skipped. It can also be formulated “What is the downtime cost of the service?”. In the cost, you need to [...]

Pretending to fix broken group commit

The problem with broken group commit was discusses many times, bug report was reported 3.5 years ago and still not fixed in MySQL 5.0/5.1 (and most likely will not be in MySQL 5.1). Although the rough truth is this bug is very hard (if possible) to fix properly. In short words if you enable replication (log-bin) on server [...]

Recovery beyond data restore

Quite frequently I see customers looking at recovery as on ability to restore data from backup which can be far from being enough to restore the whole system to operating state, especially for complex systems. Instead of looking just at data restore process you better look at the whole process which is required to bring [...]

Troubleshooting Relay Log Corruption in MySQL

Have you ever seen the replication stopped with message like this: Last_Error: Could not parse relay log event entry. The possible reasons are: the master’s binary log is corrupted (you can check this by running ‘mysqlbinlog’ on the binary log), the slave’s relay log is corrupted (you can check this by running ‘mysqlbinlog’ on the [...]

MySQL Master-Master replication manager released

The MySQL Master-Master replication (often in active-passive mode) is popular pattern used by many companies using MySQL for scale out. Most of the companies would have some internal scripts to handle things as automatic fallback and slave cloning but no Open Source solution was made available. Few months ago we were asked to implement such [...]

Getting use of Slave in MySQL Replication

MySQL Replication is asynchronous which causes problems if you would like to use MySQL Slave as it can contain stale data. It is true delay is often insignificant but in times of heavy load or in case you was running some heavy queries on the master which not take time to replicate to the slave [...]

Using LVM for MySQL Backup and Replication Setup

If someone asks me about MySQL Backup advice my first question would be if they have LVM installed or have some systems with similar features set for other operation systems. Veritas File System can do it for Solaris. Most SAN systems would work as well. What is really needed is ability to create atomic snapshot [...]

MySQL Crash Recovery

MySQL is known for its stability but as any other application it has bugs so it may crash sometime. Also operation system may be flawed, hardware has problems or simply power can go down which all mean similar things – MySQL Shutdown is unexpected and there could be various inconsistences. And this is not only [...]