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Clustering !!

Nijeesh Balan
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Joined: Oct 09, 2000
Posts: 116
Hi All,
We have a java program which gets invoked through a servlet when the application starts up.
When we cluster the Websphere Appln., server do we have to make some code changes for this program to run on multiple JVM's.
Any help would be highly appreciated
Thanks & Regards,
Nijeesh.


Thanks & Regards,<br />Nijeesh.
Kyle Brown
author
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Joined: Aug 10, 2001
Posts: 3892
    
    5
How does your servlet invoke it? How does it communicate with it? Does it use RMI or some other mechanism like sockets? Is this an actual PROGRAM (running in its own JVM) or is it just a set of Java classes you use?
Kyle


Kyle Brown, Author of Persistence in the Enterprise and Enterprise Java Programming with IBM Websphere, 2nd Edition
See my homepage at http://www.kyle-brown.com/ for other WebSphere information.
Nijeesh Balan
Ranch Hand

Joined: Oct 09, 2000
Posts: 116
Hi Kyle,
It is actually a set of java classes which get invoked during server startup.
As of now, since the application is not clustered it runs on a single JVM.
[ January 08, 2003: Message edited by: Nijeesh BH ]
imran anwar
Greenhorn

Joined: May 06, 2002
Posts: 12

When we cluster the Websphere Appln., server do we have to make some code changes for this program to run on multiple JVM's.

are you saying that the set of java classes need to start on all instances in the cluster?
Rob Misek
Ranch Hand

Joined: Sep 24, 2002
Posts: 41
Hi Nijeesh,
There are a few considerations when moving to clustering:
- if you are using a DB as the baskend to your app you will have change the <db-is-shared> value to false since each node in your cluster will now be accessing the same DB.
- if you have a caching mechanism in your single JVM app then you will have modify your approach so that the data can be shared (cached) across the cluster. If this is a consideration that applies to you check out Tangosol's Coherence Clustered Caching Software.
Later.

Check out Tangosol


<a href="http://www.tangosol.com" target="_blank" rel="nofollow">www.tangosol.com</a><br /><a href="http://www.tangosol.com/coherence.jsp" target="_blank" rel="nofollow">Coherence:</a> Easily share live data across a cluster!
Nijeesh Balan
Ranch Hand

Joined: Oct 09, 2000
Posts: 116
Actually, the java classes are like scheduler programs which should not be started in all the cluster instances.
One of my developer over here recommends to write them as custom service. I'm not sure if that is the only way or the right way to do it.
Let me know if you have some suggestions.
[ January 10, 2003: Message edited by: Nijeesh BH ]
 
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