JBOSS Cluster isolation and multicasting

I configured two JBoss clusters in the same LAN: a production and a test environment.
I decided to configure every single cluster with a dedicate private LANs using a restricted netmask to isolate production and test connectivity, so I assigned to test and to production.
I configured Apache and mod_jk to loadbalance activities between cluster instances.

The page UsingMod_jk1.2WithJBoss (http://www.jboss.org/community/docs/DOC-12525) is a good tutorial to achieve this.

What problems should I expect?
JBoss uses UDP multicasting to replicate informations across cluster nodes: even if I isolate TCP traffic, JBoss will “ear” messages sent from other clusters and will log a lot of warnings like the following:

… WARN [NAKACK] […] discarded message from non-member ….

I had to change BOTH multicast ip address and port (attributes mcast_addr and mcast_port) in the following configuration files:

  • ./deploy/jboss-web-cluster.sar/META-INF/jboss-service.xml
  • ./deploy/jmx-console.war/WEB-INF/web.xml
  • ./deploy/cluster-service.xml
  • ./deploy/ejb3-clustered-sfsbcache-service.xml
  • ./deploy/ejb3-entity-cache-service.xml

Good luck!

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Principal Product Manager at Oracle
Ludovico is a member of the Oracle Database High Availability (HA), Scalability & Maximum Availability Architecture (MAA) Product Management team in Oracle. He focuses on Oracle Data Guard, Flashback technologies, and Cloud MAA.

2 thoughts on “JBOSS Cluster isolation and multicasting

  1. I think you should consider to use TCPPING as Discovery protocol to specify statically your initial IP addresses.
    Have a look at sections:
    7.4 Discovery Protocols
    7.7.11. JGroups Troubleshooting
    in jboss clustering guide.

    AFAIK, it’s not common to have cluster nodes across different LANs.
    It’s more common to have different clusters in the same LAN!
    Kind regards!


  2. Hi,

    I’m facing issues with multicasting while setting-up cluster;
    I have 2 node jboss cluster; each node is running separately in different LAN.
    The apache/mod_jk configuration is fine but, both the Jboss nodes are not discovered in the cluster i.e., both displays the message saying “only one is present in the cluster”

    I tried setting up the multicast Ip but, little conused!!!

    Could you please share me the changes you made!!


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