JSR-107 and a JSR on Data Grids

In response to Antonio Goncalves' blog post on his wish list for Java EE 7 and particularly on his comments around the inactive JSR-107 JCACHE spec, I'd like to spend a few moments jotting down my thoughts on the subject.

To start with, I am on the JSR-107 expert group, representing Red Hat.  I have also been in recent discussions with the JCP about the inactive JSR and what can be done about it.

My feel is JSR-107 needs to be axed.  It's been inactive for way too long, it is out of date, and the community is pretty jaded about it.  We do, however, need a JSR around distributed caches and in-memory data grids.  There is definitely a need in the Java EE 7 umbrella specification, particularly with increasing focus and alignment with cloud.  Apps designed to scale would almost certainly need a distributed, in-memory data grid.  If Java EE is to be the preferred platform to build Software-as-a-Service offerings, scalability is crucial.

So what should this data grid JSR look like?  Well, let's start with JSR-107.  After all, I didn't think there was anything wrong with JSR-107, just that it was too limiting/simplistic.

What's in JSR-107?
A quick summary:

• Primary interface - javax.cache.Cache - extending j.u.c.ConcurrentMap
• Adds ability to register, de-register and list event listeners
• Defines a CacheLoader interface for loading/storing cached data
• Defines an evict(K) method, as well as the support for different eviction algorithms
• Defines a ServiceLocator approach to loading the appropriate implementation at runtime
• Defines a CacheManager interface to construct and retrieve Cache instances

• JTA interoperability.  The ability to participate in transactions is necessary, both as an XA resource and as a simple cache to front a RDBMS, via JPA
  • Define behaviour at certain stages of a tx's lifecycle, particularly with regards to recovery
• Should play nice with JPA's second level cache SPI
• Define and mandate REPLICATION and DISTRIBUTION, as well as SYNCHRONOUS and ASYNCHRONOUS versions of network communications

• An asynchronous, Future-based API (See Infinispan's Async API)
• XML-based config file standardisation (including an XSD)
• Standardise programmatic config bean interfaces

• Distributed code execution API
• Map/Reduce API
• Querying/filtering API

From http://infinispan.blogspot.com/2011/02/jsr-107-and-jsr-on-data-grids.html