OS: AIX 7.1, WAS + IHS 220.127.116.11
#1. IHS (IBM HTTP Server) slows to a crawl during high load
Observation: Slow response times (up to minutes), errors in http_plugin.log suggests an issue with SSL & GSKit.
Fix: IBM had a fix for the GSKit component a month ago, but no, they didn't feel the need to inform other customers running the same version of their product.
#2 WAS (WebSphere Application Server) memory leak
Observation: OutOfMemoryError (duh!), due to usage of JMS Queue Connection Factories over a long period of time (more than 12 hours).
Fix: IBM came out with a spanking new fix.
Lession Learnt: Endurance stress test should span across a few days.