webseal problem after loadbalancer change

Hi ,

 

We have a setup for 4 webseal servers in our 1st datacenter , it's really very basic.

 

VIP --> with standard loadbalancing , tcp profile (standard , only disabled nagle) and pointing to a pool of 4 webseal servers (with source ip persistence enabled)

 

config :

 

virtual intra-test-web-http-vip {

 

pool intra-test-web-http

 

destination 10.10.0.10:http

 

ip protocol tcp

 

vlans vlan401 vlan402 vlan410 enable

 

profiles tcp-no-nagle

 

persist Persist10h }

 

we recently migrated to another loadbalancer (running in same version) , but instead of stanard loadbalancing we now used performance L4 loadbalacing. Everything seemed to work fine .But 1 application (website for logging problem tickets) started complaining.when they entered their url , in order to access via webseal , they now got an error "request was too large to store in session cache" from webseal.eventually they were able to solve this , by increasing the "request-body-max-read" parameter on webseal to 8192. I'm trying to find out why changing the loadbalancing type from "standard" to "perf l4" has triggered this error, but i'm blocked .Anyone has an idea what is causing this on loadbalancer & why increasing this parameters solves the issue? And also why only 1 website started complaining .We have lot's of other applications accessing web-sites via webseal & have no problem at all for these.