Wednesday, October 17, 2007

Terracotta Clustering

A product I have been reading about is Terracotta. Currently at my company we use Tomcat's native clustering, which does session replication across all nodes - this is practical for many of our subsystems, but obviously it has to change your perspective on the way you use (abuse) the session for storage. A solution like Terracotta is great because you aren't replicating session across every JVM, and you don't have to deal with annoying things like making sure any object that is replicated implements I hope to test it as part of some R&D for my company as a potential configuration. The architecture is explained by this diagram:

The architecture diagram would make it appear that in a clustered environment, you have introduced a single point of failure, which would be pretty counterintuitive, but of course, you can cluster the Terracotta servers as well. Effectively, Terracotta with its granular session update writes, configured in a clustered setup, should theoretically scale in a near-linear fashion. I am curious to see if this is the case. Furthermore, I am interested to see if we can integrate it with our application without having to completely hack the installer!

Some interesting links for anyone who is interested:

Interview with Terracotta
Terracotta Confluence Site
Terracotta from theServerSide
Terracotta's Scalability Story

I will post an update with my experiences.


Orion Letizi said...


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