The clustering plugin (*1) allows more than one server to support client connections transparently providing scalability and high availability. Previous releases have included clustering based on Oracle Coherence (*2), but this is a proprietary, closed source service. The monitary cost of the licensing fees for running the service is expensive (*3). Jive software has released their part of the plugin as open source (*4). Several community members have begun a project to transition to a newly designed plugin based on JGroups / JBossCache (*5 & 6). Students interested in assisting this effort can by collaborating with developers in coding, testing existing code functionality, and or providing documentation.
Refs:
1 http://www.igniterealtime.org/community/blogs/pocasts/2007/08/16/openfire-cluste ring-technologies-with-gato
2 http://www.oracle.com/technology/products/coherence/index.html
3 http://www.igniterealtime.org/community/thread/40739
4 http://www.igniterealtime.org/community/blogs/ignite/2009/11/10/clustering-plugi n-for-openfire-is-now-open-source
5 http://www.igniterealtime.org/community/message/201513
6 http://wiki.github.com/tomstrummer/openfire-jboss-clustering