Richards Blog

Thoughts on Terracotta

Recently I’ve been working on session clustering with terracotta, jetty and wicket, so I thought I’d write about my experience.

Good points:

• It works!  This may seem a bit silly to state, but other session clustering methods I tried didn’t work and cost me time trying to get them to work.  The time I put into terracotta actually paid off.
• Good support.  Even though the guys that develop terracotta sell consultation services for it they will still help people in the forums.  From finding and reporting a bug in terracotta it was about a week before it was fixed and integrated into the nightly builds.
• Its open source.
• Its versatile, you don’t just have to use it for http sessions.
• A useful admin console for connecting to your terracotta instances (you can even do cluster wide thread dumps in the 2.6 versions).
• It just worked with wicket due to a special wicket integration module (which was included)

Bad Points:

• Lots of config.  Even after you get your system working there is still lots of performance tuning to be done to get the best out of everything (although the admin console in the 2.6 release helps with this).
• Large download (ok this isnt really a bad point in todays world of broadband and terrabyte hard discs).  Does it really need to bundle tomcat?
• Eclipse plugin kept complaining that the config xml file was not valid - it created it for petes sake (ok this is another small point, running through eclipse was very easy with the plugin)