Switching roles

To get a taste of the power of Tungsten Replicator, we will show how to switch roles. This is a controlled operation (as opposed to fail-over), where we can decide when to switch and which nodes are involved.

In our topology, host1 is the master, and we have three slaves. We can either ask for a switch and let the script select the first available slave, or tell the script which slave should be promoted. The script will show us the steps needed to perform the operation.

IMPORTANT! Please note that this operation is not risk free. Tungsten replicator is a simple replication system, not a complete management tool like Continuent Tungsten. WIth the replicator, you must make sure that the applications have stopped writing to the master before starting the switch, and then you should address the application to the new master when the …

Intro

Tungsten Replicator is an open source tool that does high performance replication across database servers. It was designed to replace MySQL replication, although it also supports replication from and to Oracle and other systems. In this article, we will only cover MySQL replication, both simple and multi-master.

Preparing for installation

To follow the material in this article, you will need a recent build of Tungsten Replicator. You can get the latest ones from http://bit.ly/tr20_builds. In this article, we are using build 2.0.8-167.

Before starting any installation, you should make sure that you have satisfied all the prerequisites. Don't underestimate the list. Any missing …

If you haven't done that, thinking that you would spare your energies for more juicy matters, I have news for you. What I explained in the previous part is exactly what you need to do to set up parallel replication. With just a tiny additional detail.
For the sake of the diligent readers who have followed the instructions with the first lessons, I won't repeat them, but I'll invite you to set the environment as explained in the first part.
Once you have a cluster up and …