Knowing when a node has joined the cluster without modcluster in jboss7

[ndipiazza]

When you use modcluster to cluster your jboss7 nodes... you will see the following message in the JBoss server.log file when another node has joined the cluster:

13:06:52,004 INFO  [org.jboss.modcluster.advertise.impl.AdvertiseListenerImpl] (MSC service thread 1-2) Listening to proxy advertisements on 224.0.1.105:23364 

However, when we are clustering JBoss AS7 with mod_jk or mod_proxy_ajp using standalone-ha.xml... we cannot seem to find anything in the log that shows another node has joined the cluster.

We are using the standalone-ha.xml file of which definitely has JGroups subsystem and JGroups is configured to use UDP. Therefore, I would expect that the multicast address is causing each node to listen for new cluster members.

How can you tell from the logs when a new node has joined the cluster when we aren't using modcluster?

Our company is considering fronting our JBoss AS7 using Websphere proxy server... so modcluster won't be an option in some cases. So we're simply looking for a way to know when JGroups is connecting with other servers successfully.

[rhusar]

However, when we are clustering JBoss AS7 with mod_jk or mod_proxy_ajp using standalone-ha.xml... we cannot seem to find anything in the log that shows another node has joined the cluster.

That doesnt seem right, mod_cluster has nothing to do with clustering itself.

At startup you clearly see:

10:45:07,207 INFO  [org.jboss.as.clustering.infinispan] (ServerService Thread Pool -- 73) JBAS010281: Started remote-connector-client-mappings cache from ejb container

10:45:07,208 INFO  [org.jboss.as.clustering] (MSC service thread 1-16) JBAS010238: Number of cluster members: 4

When a node leaves you see

10:48:31,940 INFO  [org.jboss.as.clustering] (Incoming-17,null) JBAS010226: New cluster view for partition ejb: 4 (org.jboss.as.clustering.impl.CoreGroupCommunicationService$GroupView@6bea46d6 delta: -1, merge: false)

10:48:31,943 INFO  [org.infinispan.remoting.transport.jgroups.JGroupsTransport] (Incoming-17,null) ISPN000094: Received new cluster view: [perf21/ejb|4] [perf21/ejb, perf20/ejb, perf19/ejb]

and when it joins you see

10:56:47,454 INFO  [org.jboss.as.clustering] (Incoming-11,null) JBAS010226: New cluster view for partition web: 9 (org.jboss.as.clustering.impl.CoreGroupCommunicationService$GroupView@ea7d85f delta: 1, merge: false)

10:56:47,455 INFO  [org.infinispan.remoting.transport.jgroups.JGroupsTransport] (Incoming-11,null) ISPN000094: Received new cluster view: [perf21/web|9] [perf21/web, perf18/web, perf19/web, perf20/web]

Check your logs again and that discovery is working for you.

HTH

Rado

[ndipiazza]

That's the explination I was looking for. Thanks.

[rhusar]

I have created https://issues.jboss.org/browse/AS7-5407 to see if we can make the logging more intuitive.

[ndipiazza]

That's cool, but bottom line we did not see the infinispan log messages in our logs.

We have two JBoss 7.1.1.Final nodes running in the same subnet, with identical JGroups attributes.

What kind of things are typical in preventing the JGroups broadcasting from working?

Note: This is not a cloud environment, and multi-cast should definitely be supported.

We verified multicast is working with ifconfig.

[kazaag]

If you don't see the infinispan log message aren't present can only mean the infinispan subsystem hasn't started as there is no application neededing clustering deployed.  As most of JBoss 7 subsystem, it only start when required.

So to trigger the start of infinispan (and then the cluster it self) you need to deployed an distributed applicaiton (the easest way, for cluster discovery testing, is a war with <distributable/> tag present in the web.xml file).  Without this there is no cluster.

Once the infinispan sub system start you should see the infinispan line even if the node don't discover each other.  Each server will have its own one node cluster.