Installing MySQL on CentOS 6.2 with PaceMaker, MHA and more

When I work with High Availability software, I’m reminded of the maze in the original computer adventure game “You are Lost in a maze of twisty-turny passages all alike…”.

If you search the web for HA programs you will find many well maintained projects all related that refer each other. The goal of this document is to give you with a step by step guide to a production worthy MySQL system. It should provide at least 99.999% access to your data and be able to scale read requests as you grow.

I have chosen these programs and utilities because they are free (as in beer) and each has enterprise support available. (When you make the money to pay for it.) If you start with this MySQL platform you will avoid many common problems. Just write your application to read and write data from different servers.

Here is what we’ll be …

Searching for the Holly GrailFor months I have been writing and rewriting an blog post called “The Full Monty”. It’s a kind of how to build complete production system from scratch. I’m still not done. Maybe I’m fullish thinking I can build a one type fits all database server. But that’s not the problem. I’ve found myself chasing the Holly Grail of HA and replication.I’ve build many virtual clusters with all the HA / replication package I could find. I’ve tried DRBD, Heartbeat,  Multi Master Management (MMM), Tungsten, …

PART 1 – This will be a multi part post.

THIS DOCUMENT IS BEING UPDATED – PLEASE WATCH FOR CHANGES!

After years of supporting MySQL, for many different companies, I’ve seen this story played out again and again.
The company:

• chooses a Database Management System (MySQL)
• installs the DBMS on a computer with other processes
• writes many programs to access the data (Without concern on how the queries are written.)
• moves DBMS to a computer of its own and writes more programs
• buy bigger computer to run the DBMS and writes more programs
• tires of DBMS response times and outages caused by developers working on production systems and hires a Database Administrator to fix the mess

This is a step by step description of  how I build a highly available, production MySQL servers. Like most things it life, these problems …

This is one of a few MySQL High Availability strategies.  I have used this for years and found it work great.  If you don’t know about DRBD and MySQL you should read Peter’s comments.

These are step by step instructions for Redhat 5 or CentOS.

If you need more details please refer to:
http://www.drbd.org/users-guide/

Configuring MySQL for DRBD
http://dev.mysql.com/doc/refman/5.1/en/ha-drbd-install-mysql.html

Getting started:

The OS in this example is CentOS 5.5.  I added a new disk (/dev/sde) to the four disk RAID-5 and RAID-1 I was already using.   I’m only creating an 8 …