Terracotta Open-Sources Clustering Technology

Summary
Terracotta today announced that it made its Java clustering technologyavailable under a Mozilla-style open-source license. Artima spoke withTerracotta co-founder Ari Zilka about his company‘s open-source move.
Terracottahas received a lot of attention since the company unveiled its Javaclustering product at JavaOne 2005. Part of the interest stems from thecompany‘s unique approach to clustering: Instead of aclustering-related API that developers would employ in their code,Terracotta clusters the Java VM‘s heap across multiple network nodes.The result is that in many cases, clustering an application withTerracotta requires few, if any, code changes, making clustering adeployment-time decision.
Anincreasing portion of the attention the company received has been fromopen-source projects, including companies supporting major open-sourceenterprise frameworks, according Terracotta co-founder Ari Zilka. Zilkaspoke to Artima about the role an enthusiastic open-source communityplayed in his decision to release Terracotta‘s flag-ship product undera Mozilla-style open-source license:
Thisis something we‘ve been monitoring very closely for a while, and allthe pieces came into alignment at this time. We‘ve been partnering witha lot of open-source projects and software: Spring, Tomcat, Geronimo,and so on. These have all discussed with us a tighter coupling...
Theylooked at us, and realized that Terracotta offered a really niceclustering solution their communities needed to know about. Theirsecond response was to try to see what they could do to make theirproducts better to leverage some of what Terracotta had to offer. Theanswer to that second question has been that they couldn‘t do muchbecause Terracotta was not open-source.
We‘vebeen tearing down that barrier for the last eighteen months. JavaOnethis year brought it to a head for us. A lot of the energy aroundTerracotta at JavaOne was about new potential partners. Glassfishshowed up, Geronimo showed up. We realized that momentum wasincreasing, but that momentum was mostly around open-source. Those guysare very forward-thinking, and we wanted to be part of that wave.
Simultaneously,we started asking our customers what they would have thought ifTerracotta was open-source. The answer was that most of them would havelooked at it sooner, faster.
So itcomes down to lower cost of sales for Terracotta, and easier access toclustering for the market. We‘re excited by what people are saying,what they‘re willing to do. Companies aroundopen-source-projects—Interface 21, Covalent, even IBM—are saying thatthey‘re willing to take Terracotta to the next level. It‘s definitely ahuge endorsement. I‘m personally quite honored to be a part of this, tobe part of the community and not being an outsider.
Zilkanoted that one of the most immediate benefits to Terracotta and itsuses will be tighter coupling with many popular open-source projects:
Thereare two types of tighter coupling. The first one is the business sortof thing. If you‘re running Spring, if you‘re running Tomcat, orrunning Terracotta in the application stack, we noticed that you‘regoing to have to pay Covalent for support of Tomcat, Interface 21 forsupport for Spring, and Terracotta for support for your clustering. Sowe will shortly announce a partnership between Terracotta and Covalent,where Covalent re-sells Terracotta support and puts Terracotta in thebox with their version of Tomcat and ship it to all their customers.
Onthe technical side, what will likely happen is that these projects willstart to do things slightly differently [to support clustering]. Wedon‘t know what those things will be just yet. Some of those projects,like Struts 2.0, will spend some time explaining to their users thatit‘s now time to think about stateful applications again. Another Webframework, Wicket, is doing the exact same thing. Their applicationframeworks or containers will now be easier to build as a result of[open-source] Terracotta...
Whatyou might start seeing is that these projects will favor Terracotta‘sclustering solution over other clustering approaches. For instance,they can make the decision to not make some of the internals of theirframeworks serializable, and they can stop thinking about portabilityacross VMs. As a result, also, you will see more and more state appearin applications.
Zilka also sees the community contributing to the Terracotta codebase in important ways:
Someof the things that Terracotta will do better as a result of communitycontributions are dynamic load balancing across Terracottaservers—distributing the workload to multiple Terracotta servers issomething the community is likely going to push. More JMX support isanother one.
Inaddition, what you‘ll be seeing from Terracotta the company, are somevalue-added things, for instance those that relate to managing aclustering environment inside the enterprise. From the businessperspective, we‘re starting out with the traditional support model, butreserve the right to add some of the value-adds that enterprises careabout.
The license under which Terracotta is available is a Mozilla-like license:
Thelicense is the Mozilla public license variant. We‘re working with OSIto make sure that it‘s approved and that we‘re working within theboundaries of the eight or so approved open-source licenses. You can‘tcall yourself Mozilla if you‘re not the Mozilla organization, so we‘recalling it a CDDL, or common distribution and development license.
What do you think of Terracotta‘s open-source move?