There’s an interesting discussion about IIS and OC4J on OTN- OC4J discussion
I think there’s a lot of confusion as to what is a difference between web server and web application server (apparently web server just serves static HTML (it can also server PHP/ASP pages), however, doesn’t run applications — on the other side – it’s tough to distinguish between dynamic web applications written in script languages and Java container OC4J). If you
I think that it’s clear from the discussion that OBIEE requires IIS (in Windows server) and OC4J is an quasi-optional module for BI Publisher and Scheduler.
Another thing -check your connection pool settings. According to Oracle, BI Server might crash if there’re “Several Connection Pools in the custom RPD had ‘Execute Queries Asynchronously’ enabled. This is no longer recommended in OBI 10g as it can cause the OBI EE (NQServer) Server to crash.”
This is addressed in Bug No.BUG 7634602 – ‘OBI SERVER CRASH – 3-818156441′