WAS8: updating web.xml from version="2.4" to version="3.0" causes OutOfMemoryException?

Question

Migrating a legacy web app from WAS6 to WAS8. Everything works fine with the original web.xml version="2.4" but after updating version attribute in web.xml to "3.0" the application crashes during install with OutOfMemoryError after hanging for a long time.

The application has 7000+ classes of its own plus it depends on 50M worth of jars. Can that be an issue when WAS8 scans for annotated classes? If so, what can be tweaked to make it either skip scanning or, better, scan quicker?

Answer 1

Fixpack 2 which upgrades WebSphere to version 8.0.0.2 fixed the OutOfMemoryError. But both new install and update are still unacceptably slower comparing to when the application was servlet-api version="2.4". So the conclusion is.. when migrating a big old app to a servlet "3.0" container, just relax and leave web.xml version="2.4". Alternatively change web-app version to "3.0" and add attribute metadata-complete="true".

Answer 2

Here's a technote - Slow deployment of Java EE 5 applications