thanks Subbu for prompt response!!
Does below one helps for configuring number of requests
Limiting HTTP Sessions
An administrator can limit the number of active HTTP sessions based on detection of a
low memory condition. This is useful in avoiding out of memory exceptions.
WebLogic Server refuses requests that create new HTTP sessions after the configured
threshold has been reached. In a WebLogic Server cluster, the proxy plug-in redirects a
refused request to another Managed Server in the cluster. A non-clustered server
instance can redirect requests to alternative server instance.
The Servlet container takes one of the following actions when maximum number of
sessions is reached:
■ If the server instance is in a cluster, the servlet container throws a
SessionCreationException. Your application code should handle this
run-time exception and send a relevant response.
To implement overload protection, you should handle this exception and send a
503 response explicitly. This response can then be handled by the proxy or load
You set a limit for the number of simultaneous HTTP sessions in the deployment
descriptor for the Web application. For example, the following element sets a limit of
Edited by: 835435 on Aug 21, 2012 10:47 AM
Edited by: 835435 on Aug 21, 2012 11:59 PM
"You can tune the number of connection requests that a WebLogic Server instance accepts before refusing additional requests. This tunable applies primarily for Web applications."
"You can tune the number of connection requests that a WebLogic Server instance will accept before refusing additional requests. The Accept Backlog parameter specifies how many Transmission Control Protocol (TCP) connections can be buffered in a wait queue. This fixed-size queue is populated with requests for connections that the TCP stack has received, but the application has not accepted yet. "
Some hints on operating system tuning can be found here: http://middlewaremagic.com/weblogic/?p=7932