Session replication works..... at first

[jvandusen]

Our environment consists of two app servers running JBoss 3.2.6, which are behind two web servers running Apache/Tomcat with mod_jk doing load balancing, and those in turn are behind a content switch which handles load balancing between them. The mod_jk load balancing does not currently use sticky sessions. I am trying to set up session replication between the JBoss app servers.

The first issue is that session replication appears to be working at first, but within a half hour or so it just stops working. I don't know if it stops after a period of time or if it has to do with the number of testers on the system, or something else.

Replication itself appears to be properly configured (as I said, it does work for a while). I don't see any errors in the log between when it works and when it stops working. I tested the multicast send/receive and had no problems there. JMX-Console suggests it's configured properly.

The other issue, which may be part of the problem, is that I can't view information about my distributable app in the web-console. Someone else posted about the same problem, and their post describes my problem exactly, so I won't repeat it. Check here: http://staging.jboss.com/index.html?module=bb&op=viewtopic&t=59395&view=next

Any ideas on what could make session replication work for a while and then just stop? Any suggestions for tests I could perform to try to diagnose this?

[ben.wang]

Can you possibly try 4.0.3 to see if the problem persists there? That can rule out AS at the very least.

-Ben

[jvandusen]

Unfortunately, upgrading is not an option right now. This is our test environment, which is a replica of our production environment, and there are a number of issues preventing us from upgrading past 3.2.6 at this time, although there is a team working on that. Our development environment is just a single JBoss app server with no web server or load balancing, so the problems we're having only appear in test. We need to change our development environment, but that's an issue we'll deal with after we've solved this problem, as it is preventing us from deploying applications to production.

Anyway, I'm starting to think that the issue is actually caused by the existence of the two web servers, so it may be that JBoss is actually properly configured. I set up two JBoss instances on my workstation, and configured Apache with load balancing the same way our test environment is set up, and I'm having no problems getting session replication working in that environment.

So for now I'm thinking this is not a JBoss issue, it's a problem with our over-architected environment.

I will post more later if I discover further problems that are definitely JBoss-related.

[jvandusen]

I am still curious about why the distributed apps won't display information in the web console. If I get time I will try setting up an instance of JBoss 4 on my workstation to see if it's an issue specific to 3.2.6, but right now I don't have time to do that.

Has anyone else seen this problem?