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.