Overview of Clustering roadmaps (JGroups, JBossCache, POJOCache, JBoss Clustering)


We always try to plan 2 versions ahead for all projects under Clustering.

The release overview below summarizes the main features of each release



JGroups (lead: Bela Ban)



  • Released in Feb 2008



  • Last version released, EOL'ed



Target date: Feb 2008

  • Stable branch for JBoss 5 (hopefully we get 2.6.3 into JBoss 5, target date: march 15 2008)

  • Shared transport

  • FLUSH simplification and improvements

  • Multiplexer and MuxChannel bug fixes



Target date: n/a

  • We'll leave this branch open and backport all bugs to the 2.6 branch



JBoss Cache (lead: Manik Surtani)


Please refer to

this page.

for detailed JIRA tasks (more up to date).


JBoss Cache 2.2.0

  • Core architectural change introducing a visitor/command pattern for each cache command

  • Improved unit tests


JBoss Cache 3.0.0

  • MVCC


JBoss Cache 3.1.0

  • New state transfer algorithm


JBoss Cache 3.2.0

  • Partitioning


POJO Cache (lead: Jason Greene)

See roadmap for latest information.

POJO Cache Cache 2.1 release

  • AS5 compliance

  • Context API with the ability to selectively enable/disable gravitation

  • Support for final fields

  • JBoss AOP 2.0

  • Support for Java Security Manager

  • Support for objects that are missing a no-arg constructor

  • FQN versions of POJO Cache methods

  • exist() method for improving performance with JDBCCacheLoader

  • Bug Fixes


POJO Cache 2.2 release

  • Array interception

  • Static fields

  • Ability to release objects (object is removed, but data remains in cache)


POJO Cache 3.0 release

  • Adjust to MVCC locking

  • Collection performance refactor


JBoss Clustering (lead: Brian Stansberry)


See AS Clustering by release in JIRA for more details.


JBoss AS 4.2.0.CR1 Release (March 5, 2007)


  • Upgraded JGroups from the 2.2.7 used in 4.0.x to 2.4.1.

  • Proper handling of clustered EJB3 SFSBs

  • Resolved classloading issues with clustered EJB3 entities

  • Configurable policies for determining HASingleton master


JBoss AS 4.2.0.GA Release (April 17, 2007)


  • Move to JBoss Cache 1.4.1.SP3 and JGroups 2.4.1.SP1


JBoss AS 5.0.0.Beta3 Release


  • Streaming state transfer for ClusterPartition

  • Performance and stability testing of shared JGroups channel used by multiple services (ClusterPartition, HttpSession, EJB3, JBM)

  • Passivation of distributed sessions


JBoss AS 5.0.0.GA Release


  • Clustered deployments using the Profile Service

  • Sharable http sessions

  • Unified client side failover/load-balancing on top of Remoting


JBoss AS 5.0.1.GA Release


  • Pluggable policies (a la "useJK") to integrate with load balancers

  • Properly handle merging state following a JGroups merge

  • EJB3 fine-grained SFSB replication using PojoCache



Rules for API and binary compatibility

  • Major: 1, minor: 1.1, micro: 1.1.1

  • API compatibility: breaking is allowed only between major versions. Note that additional methods in an API doesn't constitute breaking, so this is okay

  • Binary compatibility: breaking is allowed between minor versions

  • Configuration compatibility: breaking is allowed between minor versions

  • Changes between micro versions: only implementation changes


We're currently looking into how to provide backwards and forward binary compatibility for JGroups and JBoss Cache


Compatibility Matrix -- JBoss AS / JBoss Cache / JGroups


This page documents what versions of JGroups and JBoss Cache ship with and work with each other and with JBoss AS.  This includes information on which combinations have been officially certified by QA.