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, Flipper, Redhat Cluster Suite (RCS), MySQL Cluster, MySQL Master HA (MHA) and the Percona XtraDB Cluster (PXC).  Some of these are just very simple (Flipper) some are heavy (RCS) and some are promising but in Alpha (PXC) or still a little rough (MHA).  Yoshinori Matsunobu (author of MHA) describes some of the solutionsto the issues.

White papers and discussions abound. Shlomi Noach and Baron Schwartz have public discussed problems with MMM show just how hard this problem is. ( SH / BS ) Even Alexey Kovyrin said in a reply to Brian “…Every time I try to add HA to my clusters I remember MMM and want to stab myself because I simply could not trust my data to the tool…”.

Tungsten works. But size does matter. It is one of the heaver solutions requiring Java and many moving parts with version requirements and dependencies. As a result you can build a working system but its rock and hard to move forward to newer releases its parts.

Percona’s XtraDB Cluster gives me hope. It’s Alpha and only works on InnoDB tables (now) but it’s light, eazy to install and maintain.  (I think I can see the Holly Grail.)

I’m currently taking a second look at MySQL Master HA. My first run through was rough. MHA suffered from some dependency trouble and documentation holes. It seems to be currently under rapid development. That’s both good and bad. MHA may be your best choose if you’re looking from something free, simple to install and easy to maintain that keep your DBS alive. Unlike MMM, MHA does not move IP address.  You’ll still need something more like heartbeat.

How can you choose wisely?  Lets talk.