>From: David Lu <[EMAIL PROTECTED]>
>you're talking about a clustered environment.  such capabilities
>are already available in commercial app servers like weblogic.

I've often wondered why somebody would actually want to put out several 
thousand US$ for a BEA or ATG when Tomcat is available. Are such features in 
the Tomcat roadmap ? I presume that they were not in the J2EE 
specifications.

>here are some things you want to do now if you think you'll ever
>go clustered:
>
>- make sure everything you put into the session implements  Serializable. 
>this way the app server can share session data.

Nice tip. How does a clustered environment share these objects ? I'm 
surprised that they (and Tomcat) don't provide the option of usinga central 
relational database for storing session objects between multiple servers.

>- don't put large data objects (like a Collection) into the session.
>- don't rely on static data held in singleton objects, because you may
>   end up with multiple singleton objects, one in every app server 
>instance.
>- code to standards and avoid app-server-specific "features" as much
>   as you can, for you may have to change app servers for clustering.

Super. Thank you for sharing this experience and wisdom, David.

Soefara.


_________________________________________________________________
Join the world�s largest e-mail service with MSN Hotmail. 
http://www.hotmail.com


--
To unsubscribe:   <mailto:[EMAIL PROTECTED]>
For additional commands: <mailto:[EMAIL PROTECTED]>
Troubles with the list: <mailto:[EMAIL PROTECTED]>

Reply via email to