Comments on: Revenge of Hello Terracotta

By: Kablooie! » Blog Archive » 10 Eye-Catching DZone Titles With Words Like ‘Naughty’

Fri, 23 May 2008 17:22:52 +0000

[...] Revenge of Hello Terracotta – Aha! Someone wrote a post which was a sequel to another post, and in naming it cleverly referenced old monster movie sequels like Revenge of the Creature or Revenge of the Son of Blacula’s Return. What a funny guy that author must be! [...]

By: Scott

Scott — Mon, 31 Mar 2008 14:59:29 +0000

Thanks for the comments. One of my goals to was to demystify Terracotta a little bit. It’s fortunate that Terracotta is open source because we’ve found that many just can’t believe we can do what we do until they take a peek under the hood.

By: Peter Veentjer

Peter Veentjer — Mon, 31 Mar 2008 13:25:43 +0000

Nice blogpost, removes some of the magic from Terracotta. Nice to see how the bytecode actually is transformed.

By: Alex Miller

Alex Miller — Mon, 31 Mar 2008 05:23:24 +0000

Nice writeup.

On the lock config chunk, this is actually a relatively recent addition (2.5.0) to allow us to do tracing of lock stats in the admin console. If you use the lock stats view, you can see which locks are currently being used and a bunch of statistics. You can also see find out what part of the config caused that lock to exist (if for example, it’s wrong or needs to be changed). This lets you find a problem and go directly to where it can be fixed. I suspect there are probably better ways to factor the code to add a layer of abstraction for that locking config but that’s still a to-do. Ideally we’d be tied to the internal object form of the config instead.

In case anyone is wondering “test.HelloTerracotta.root” is the cluster root object name as per the config file. And the lock level 2 is a write lock (this is a constant value compiled into the class).

By: Eugene Kuleshov

Eugene Kuleshov — Mon, 31 Mar 2008 05:21:53 +0000

Jonas Boner and I wrote paper for AOSD’07 conference that illustrated core Terracotta internals using AspectJ. We didn’t exactly followed what you see in that decompiled code, but it is quite close. It would be interesting to try to wire those aspects to the real Terracotta backend using ManagerUtil API.

[1] http://www.aosd.net/2007/program/industry/I1-ClusteringJVMUsingAOP.pdf