Sp4 strange error: Browser goes for a spin

Question

We have an application developed in iAS SP1. We installed SP4 recently and ported the application to SP4. We are facing a strange problem, which I'm describing below,
We have a login page named "home.jsp" which submits uid/password to a "LoginServlet" and authenticates/ authorises a user against an LDAP directory. We construct a "UserProfile" object and place it in session. The Login servlt forwards to a page index.html.
"index.html" is a page containing four frames ( heading, bottom. navigation menu and content frame ). Each frame has a src tag, pointing to a relative link in the web application.
Now here, is the problem,
After a fresh restart of the application, when we access the application for the first time, we get the home page correctly. Login is successful (from the kjs logs). index.jsp is called. Now the browser sends fresh request to each frame's source and hangs eternally.
We have no other choice but kill the browser. When we open a new instance of the browser and try the same again, the application works fine. I get all my pages properly as required.
Why is this happening?
I have another such page in my application which has roughly the same pattern, (servlet calling first.jsp. and first.jsp having three frame tags.). In this case the page works correctly for the first time i access it. From the next time the browser hangs and CPU load goes to 100%.
I see some pattern here, but cannot zero in on the problem.
Looks to be something to do with URL rewriting. The same code works without such problems on SP1 server. So it cant be a browser issue.

Answer 1

I hear that there are some session concurrency problems in sp4. My first guess is that you are probably running into this bug. Because you have a frameset that is making several simultaneous requests to iAS (for each frame) you are probably getting into some sort of deadlock condition in the session manager.
Possible solutions (if this is the correct diagnosis):
* Contact tech support, who (I believe) has a patch for this concurrency problem.
* Enable sticky loadbalancing. This may relieve enough stress on the session manager to prevent the deadlock.
* Move to a different service pack or iAS 6.5
David
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