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Load Balancing and Maintain value between servlets.

Aruna Gopalakrishnan
Greenhorn

Joined: Feb 14, 2002
Posts: 8
Hi,
I have a Cisco local director and 2 websphere application servers. When application is launced,
cisco director directs the application to any one of server depends on the load of the other server.

Here is the question,
How to maintain values between servlets when each request goes to any one of the server. Right now i am lot serialized values thru sessions.
Thanks


Best Regards<br />Aruna G
Anonymous
Ranch Hand

Joined: Nov 22, 2008
Posts: 18944
I have the same problem but with iPlanet servers, the solution that I implemented was save the session data in database and pass the primary key across the pages as parameters. If you found a best solution please tell me.
Aruna Gopalakrishnan
Greenhorn

Joined: Feb 14, 2002
Posts: 8
This sounds like a Good solution, But for every page it has to go the DB.That's not is Good.
Surely, I will let you know when I get some other better solution than this.
Thank You
Regards
Aruna G
Al Green
Greenhorn

Joined: Feb 09, 2002
Posts: 10
The answer is definitely app server specific.
Iplanet has the idea of a "sticky session" which tells the load balancer to always come back to that instance on subsequent requests.
Kyle Brown
author
Ranch Hand

Joined: Aug 10, 2001
Posts: 3892
    
    5
Yes, this is certainly application server specific. However, this is something that is covered quite well in the redbooks and documentation on WebSphere.
WebSphere has a feature called "Session persistence" that will automatically store session values in the database. It also has a built-in feature called "Session affinity" that will notice which server a session is created on (based on the session id, which contains a hashed JVM id) and direct it there. However, this second feature is only used when you use the load-balancing features built into the WebSphere HTTP Server plugin.
Now, I have some questions for you -- how many users are you expecting to concurrently use this application? Why did you decide to use a Cisco local director instead of the built-in load balancing at the plugin? Are you open to rearranging your network topology a little?
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.
Aruna Gopalakrishnan
Greenhorn

Joined: Feb 14, 2002
Posts: 8
We are expectation about 100,000 - 200,000 hits possible per day after we get the application off the ground....
Sorry for the delay in reply.
jonnyk
Greenhorn

Joined: Feb 18, 2002
Posts: 2
Kyle,
To answer your questions, we expect to get over 100,000 hits per day to start once the application goes full scale. Using the Cisco Local Director was a company Network decision that we need to go along with. We want to implement something that will hopefully not slow performance.
Any further advice is much appreciated.


Regards,<br />Jon
jonnyk
Greenhorn

Joined: Feb 18, 2002
Posts: 2
Does anyone have any more ideas regarding this?
 
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