Recently I read about compute clusters and how they’re used. I just had to try it. I successfully installed (from source) OpenAIS and Pacemaker (guide here) on Slackware 12. The experience was, overall, extremely smooth. I had a few hiccups I can only attribute to my not being able to follow directions, but with a few Makefile tweaks and some very small code tweaks, I got everything to compile and run.

Keep in mind, this is all using VirtualBox VMs, so once the cluster stuff is installed on one machine, I can more or less copy and paste and have a 3-computer linux cluster running from the comfort of Windows 7 (it’s just for games, I swear!!). Aside from having to mess a bit with the networking in VirtualBox, everything was almost completely automatic.

The next step is to figure out DRBD and how it fits in with all this HA stuff. I’ve been trying to find a guide on using Pacemaker with MySQL, but no guide is written JUST for MySQL…it’s all MySQL with DRBD. I’d rather not complicate things too much until I can figure out how the hell this is all working.

Anyway, I’ll report back with my findings sometime soon.

Please note – at the time of installing (about 6 or 7 days ago), there was a bug in the Debian packaged distribution of OpenAIS/Pacemaker that makes the “expected votes” value of the quorum formula > 3 billion. Unless you have 3 billion machines laying around, you will NOT be able to start any resources unless you configure to ignore the quorum. I’ve confirmed this bug on the IRC channel, and to my knowledge, it still exists.

My advice is to compile from source (but that’s always my advice anyway :) )