Howdy all. I am looking for a MySQL solution that allows us to horizontally scale a number of MySQL nodes as peers without separating reads and writes, or slaves and masters. This may not be ideal, but the application we are using is an unchangeable aspect of the project.
I ran into this post by Giuseppe Maxia (http://onlamp.com/pub/a/onlamp/2006/04/20/advanced-mysql-replication.html) that details our concern exactly: MySQL Cluster... is a complex architecture to achieve high availability and performance. One of the advantages of MySQL Cluster is that each node is a peer to the others, whereas in a normal replicating system you have a master and many slaves, and applications must be careful to write only to the master... There are some cases where the MySQL Cluster is the perfect solution, but for the vast majority, replication is still the best choice. Replication, too, has its problems, though: * There is a fastidious distinction between master and slaves. Your applications must be replication-aware, so that they will write on the master and read from the slaves. It would be so nice to have a replication array where you could use all the nodes in the same way, and every node could be at the same time master and slave. * There is the fail-over problem. When the master fails, it's true that you have the slaves ready to replace it, but the process of detecting the failure and acting upon it requires the administrator's intervention. Fixing these two misfeatures is exactly the purpose of this article. Using features introduced in MySQL 5.0 and 5.1, it is possible to build a replication system where all nodes act as master and slave at the same time, with a built-in fail-over mechanism. The article goes on to talk about setting up a Multimaster Replication System. At one point, I was lured into using the Multi-Master Replication Manager for MySQL (MMM) since it was said to be a set of scripts that made this process easier, but found that like standard replication made a distinction between masters and slaves, so I'm back to the original Giuseppe article. Anyone have experience setting up MySQL Multi-Master Replication? Or is there a better list to ask this question on? Wes -- Wes Modes Systems Designer, Developer, and Administrator University Library ITS University of California, Santa Cruz
