Dear All,

I wants to implements the Clustering/Load balancing technology in to my application for avoiding server failover and providing high availability. I am using Tomcat 5.0.28 and JKD1.5. I already gone through the Tomcat documentation. Still i am not able to complete this implementstions. Can any of you please tell me the steps to be implements those techniques.

Regards
Vink

Dear All,I wants to implements the Clustering/Load balancing technology in to my application for avoiding server failover and providing high availability. I am using Tomcat 5.0.28 and JKD1.5. I already gone through the Tomcat documentation. Still i am not able to complete this implementstions. Can any of you please tell me the steps to be implements those techniques.RegardsVink

I have been using load balancing technology for years with WebSphere; also, I know that you can use WebLogic in a cluster. On the other hand, I'm not sure that you can do load balancing with only tomcat.

You can use an external machine that redirects the request to different machines (with Tomcat or with any other app server) based on the IP of the PC that performs the request.


Jose Ramon Huerga
http://www.terra.es/personal/jrhuerga

Session replication in Tomcat clusters

http://www.onjava.com/pub/a/onjava/2004/11/24/replication1.html

There are more OnJava articles on clustering tomcat
These two are recent
http://www.onjava.com/pub/a/onjava/2004/03/31/clustering.html
http://www.onjava.com/pub/a/onjava/2004/04/14/clustering.html
This is an older one, but it may help
http://www.onjava.com/pub/a/onjava/2002/07/17/tomcluster.html

If you put Apache server in front of your Tomcat servers, you can use mod_jk's load-balancing capabilities. We have been using it for a while and it seems pretty decent. At least, we found it much more solid than IBM's Edge Server (that's what Webshpere uses, I believe) that we were using before and that proved to be quite buggy + heavy.

Tomcat allows session clustering I believe and for application data clustering you may consider a clustered cache. JBossCache and OSCache are solid open-source options. There's also a very good commercial one - Tangasol Coherence, in case you do not mind to pay.

Hi All,

Yes, Coherence includes our Coherence*Web HTTP session management module (latest news item). Our customers use Coherence*Web when planning for linear scale and fault tolerance. Take a look at this customer story that focuses on Betfair's use of Coherence*Web.

Later,
Rob Misek
Tangosol, Inc.
Coherence: It just works.

I've used this method and it works .
http://jakarta.apache.org/tomcat/tomcat-5.0-doc/balancer-howto.html

Activate mod_proxy, mod_proxy_connect, mod_proxy_http in htpd.conf

Connectors is such an important topic that JBoss has dedicated a special review for its customers. Here is what they say about mod_proxy:

"mod_proxy. A cheap way to proxy without the hassles of configuring mod_jk. This solution lacks sticky session load balancing. If you don't need some of the features of mod_jk or mod_jk2 - this is a very simple alternative. In Apache 2.2, there will be a much improved mod_proxy version which will be the only supported connector on this platform."

Right now, we are using mod_jk and are very happy with it. I do not know why it is hard to configure. I think, it's pretty easy. In any case, you can find a documentation of how to configure it with JBoss on our project site, if you need help:
http://jira.digijava.org:9023/display/DGO/Installations