Merger Madness & One Sample App To Rule Them All

VMware ---	SpringSource ---	/---G2One
		\---CloudFoundry
Terracotta ---	Ehcache
Oracle ---	Sun

With all the mergers and acquisitions happening in the Java world, I thought I'd suggest a sample app someone could build to bring them all together.

Here it is: a Grails app using an Oracle DB with distributed caching provided by Terracotta and Ehcache, all running in a VMware cloud, with deployment and management handled by CloudFoundry.  I think that covers all the bases.  I have no idea what it will do yet, but let me know if I've missed anything. :)

Note: I actually have a lot of respect for all the technologies and people involved, I'm just feeling a bit overwhelmed with all of the recent consolidation!

Terracotta Acquires Ehcache

Exciting news!  This morning I received a note from Greg Luck via the Ehcache Open Discussion mailing list announcing that the Ehcache project was joining forces with Terracotta and that Greg would be joining the team at Terracotta, Inc.  Since there's been a Terracotta Integration Module for Ehcache for a while, I don't foresee any instant improvements with regard to integration between the two technologies, but I was quite excited to see the following in Greg's blog post announcing the news:

I am full-time on Ehcache. I have not had the time I would have liked to devote to Ehcache (I have been doing a miserly 10-15 hours per week for the past 6 years) but now I do. Look out!

Given what he's done so far with limited time, I'm looking forward to seeing what Greg can do when Ehcache becomes his full-time job!

For more information, see Terracotta's announcement, CTO of Terracotta Ari Zilka's blog post, or Alex Miller's blog post.

p.s. I submitted a patch that Greg ended up incorporating into Ehcache 1.6, so I feel a tiny bit of ownership toward the project – similar to the way I feel toward Tomcat.

Update: Terracotta and Ehcache are holding a webcast on August 20th at 4PM ET to further discuss the acquisition.  Also, I just submitted my second patch to Ehcache. :)

ConcurrentLinkedHashMap and Possible Alternatives

I mentioned in an earlier post that a project I'm working on needed a thread-safe class with behavior similar to LinkedHashMap, which maintains the order of entries while allowing sub-classes to set a (rather primitive) eviction policy.  I came upon and started using Ben Manes's ConcurrentLinkedHashMap, with only minor modifications to allow for easier sub-classing.  I've been pretty happy with it so far and have been meaning to take a look at recent changes that he and "zellster" have made since I last downloaded the code.

The same project is also using ehcache for caching.  I was looking forward to the release of version 1.6 and inquired about the expected release date on the developer's forum.  That kicked off an exchange between me and Greg Luck, the lead for ehcache, that eventually led to him mentioning some problems he'd encountered with ConcurrentLinkedHashMap.  I'm going to check in with Ben and let him respond to what Greg said, along with giving him a chance to provide a guess for when his new version of CLHM is likely to be usable.  I also need to look into what Greg was referring to in the changelog for ehcache 1.6 beta5 when he said, "Make MemoryStore eviction policies injectable."  Interesting…

Just to confuse matters, I was also recently looking over some materials discussing Infinispan, which will essentially be the 4.0 release of JBoss Cache, and saw this interesting blog entry on "Implementing a performant, thread-safe ordered data container".  In it, Manik Surtani mentions their newly implemented classes FIFODataContainer and LRUDataContainer, which sound like another plausible way to approach my problem.  I'll make sure to ask more about them in the comments for that post.