Solved! Go to Solution.
For the #1 issue, a potential problem could be global variables used. Please check your servlet code and make sure that variables are declared correctly with correct visibility.
For issue #1: Check global variables and debug what values you are getting on different user ids in your servlet code.
Issue #2:default Apache header size is 8 KB. You can increase limit to 16 or 32 KB. In httpd.conf file
Restart apache server. "service httpd restart"