Serious Cache issue - Cache Engine not working for Websphere

[Migrated From Jforum.net]

Hi,
We are facing serious cache issues. Our Enviroment details: webpshere(RAD).oracle 9i.jforum 2.1.6

Most of the users complained about Forums and categories getting invisible. They are able to see them only once we restart the server.

Issue here is : Cache Engines provided in Jforum (DefaultCacheEngine, JBossCacheEngine and EhCacheEngine(2.1.7)) do not clear cache on websphere.

and suggestions Please
[originally posted on jforum.net by rags]

[Migrated From Jforum.net]

Hhm.. DefaultCacheEngine is just a regular static map kept in memory.

Can you do the following test, please?

Configure a new JForum install on WS, pointing to a clean DB.. it works fine, or give the same problem?

Test now with Tomcat.. it works? The problem persists?

Rafael
[originally posted on jforum.net by Rafael Steil]

[Migrated From Jforum.net]

Hi Rafael,

Thanks for the immediate reply.

We already tried doing what you have suggested, but the problem persists(things work fine on tomcat as the cache cleaning is happng there)

Let me explain further what is happening..

When i go to Admin Control panel -->Cache--> Onclick of More info of topics, nothing happens.i.e we do not see any Topics - Cache Information.
Same thing works on tomcat.

Kindly let me know your inputs

Thanks,
rags


[originally posted on jforum.net by rags]

[Migrated From Jforum.net]

Hi Rafael,

I have 1 more query

what if i use - clearTemplateCache() as shown below,
I guess this would be a performance issue.right?

JForumExecutionContext.templateConfig().clearTemplateCache();// Added

return JForumExecutionContext.templateConfig().getTemplate(
				new StringBuffer(SystemGlobals.getValue(ConfigKeys.TEMPLATE_DIR)).
				append('/').append(this.templateName).toString());

this apart any suggestions for the server cache issue i am facing?

Users just complained they see old pages e.g. lastpost date as 31 Jan'07, although the lastpost date is 19th Feb'07 .Some users see it correctly.All in all it is not consistent
[originally posted on jforum.net by rags]

[Migrated From Jforum.net]

Hmm.. cached web pages? That's new for me.

I don't think that removing the template caching will hurt your performance - sure, it could be better with it, but for now we all agree that the most important thing is to get it working without any problem.

About the memory cache, I see any option but to attach a debugger and step into each part of some specifics actions to see how it is running...

Rafael
[originally posted on jforum.net by Rafael Steil]

[Migrated From Jforum.net]

You might try removing the install servlet definition from your web.xml as described in:

https://coderanch.com/t/576919 #14222

It could be that your caching engine is being re-initialized but not all the repository stuff.

Is this a clustered install of some sort? Jforum's caching mechanism is not cluster safe. It assumes that all repository classes are loaded in the same class loader domain.

With Jforum working fine in so many other application containers, I would start looking for Websphere config or bugs that deal with static properties not being updated across all sessions.
[originally posted on jforum.net by monroe]

[Migrated From Jforum.net]

Hi Monroe,

Thanks for the immdt reply and the suggestion.

Is this a clustered install of some sort? Jforum's caching mechanism is not cluster safe. It assumes that all repository classes are loaded in the same class loader domain.

We have jforum in clustered env.As a precaution, we can turnoff 1 server.. .
any further suggestions.

thanks
rags
[originally posted on jforum.net by rags]

[Migrated From Jforum.net]

Doing web application state synchronization in a clustered environment is pretty much up to the Application Container. I don't think there's a standard for this yet.

You might get lucky and find that WebSphere can be configured to synch application state across cluster nodes or you might have to write your own cache/respository replacement classes that use a Websphere's API.

I don't know WebSphere that well, sorry. (Last cluster caching stuff I did was with an early version of iPlanet's App Server (n.e. Netscape/Sun ). It was not fun or reliable.
[originally posted on jforum.net by monroe]