mod_cluster is not working properly with jboss

[bharat4212]

Hi All,

I have two servers, each having jboss 6.3 eap and both servers having one mod_cluster. I want to achieve HA, to resolve the single point of failure i configure mod_cluster on both the servers.

Server1(jboss+mod_cluster+apache+haproxy)                                                                                                         Server2(jboss+mod_cluster+apache+haproxy)

my issue is if i will stop the jboss of 1st server, my request will be redirected to second server's jboss. But if i will stop the jboss of second server after satrt of 1st jboss, it will not go back.

in logs i am getting below error:-

[error] ap_proxy_connect_backend disabling worker for (147.128.225.229)

[Wed Apr 29 13:05:03 2015] [error] proxy: ajp: disabled connection for (147.128.225.229)

[Wed Apr 29 13:05:08 2015] [error] proxy: ajp: disabled connection for (147.128.225.229)

mod cluster version is :- mod_cluster/1.2.6.Final

Please help me on this issue, suffering very much, have to deliver this week.

[lylewang]

Your error sounds like this ... https://velenux.wordpress.com/2012/10/11/solving-apache-503-service-temporarily-unavailable-error/

Are these 2 EAP nodes clustered ?

You didn't give details how you setup your mod_cluster and apache, but from what you said seems you didn't have EAP nodes clustered and just setup mod_cluster / apache to redirect requests ?

I'd suggest to cluster these 2 of your EAP nodes properly first , then setup single mod_cluster point for this EAP cluster

This article gives you an outline , followed by a step by step instruction showing how to setup domain mode JBoss7 cluster and then configure mod_cluster with it:

https://docs.jboss.org/author/display/AS72/AS7+Cluster+Howto

If you don't like domain mode and want to use standalone-ha profile (this can be easier) for your EAP instances, then you would want to try these 2 articles:

http://middlewaremagic.com/jboss/?p=1952

http://middlewaremagic.com/jboss/?p=2147

[bharat4212]

Hi Wang,

I have already configured the both jboss in clustered mode, they are in domain mode. And its working fine.

If you could help me on the same, i will be really thankful to you.

[lylewang]

I have already configured the both jboss in clustered mode, they are in domain mode. And its working fine.

Then you're going to follow the article exactly: https://docs.jboss.org/author/display/AS72/AS7+Cluster+Howto

There shouldn't be much to do on mod_cluster side, if ServerAdvertise is enabled you just need to follow the "Cluster Configuration" section in the article above.

If you disabled server advertise then make sure you add the mod_cluster's IP:port in the " proxy-list" attribute in "modcluster" subsystem inside domain.xml, as described in doc: https://access.redhat.com/documentation/en-US/JBoss_Enterprise_Application_Platform/6.3/html/Administration_and_Configuration_Guide/Configure_the_mod_cluster_Subsystem_to_Use_TCP.html

If you followed all these article and docs , mod_cluster should be able to detect the status of your eap nodes and add them back automatically when it's up again.

Did you check your mod_cluster-manager status when having the error ?

In addition, mod_cluster 1.2.11 is tested configuration see if you could upgrade to this version: https://access.redhat.com/articles/111663