FULL PRODUCT VERSION :


A DESCRIPTION OF THE PROBLEM :
Startup in 1.6.0_03-b05 server VM is much slower than 1.5 server VM. It mainly looks like classloading problem. I took the numbers for my sevrer application which needs to load huge number of classes (> 10K applications classes) at startup.

With nearly 10K classes, the times reuired to load these classes were
1.5 client VM : 64 sec
1.5 server VM : 27.5 sec
1.6 client VM : 66 sec
1.6 server VM : 53 sec

With 15K classes, the difference became even more
1.5 client VM : 236 sec
1.5 server VM : 128 sec
1.6 client VM : 274 sec
1.6 server VM : 267 sec

1.6 server VM performs nearly 50% slower than 1.5 server VM. In fact as you keep on increasing the number of classes to be loaded, the performance keeps on degrading.

Seems many people have observed this :
http://forums.java.net/jive/thread.jspa?messageID=204324
http://forum.java.sun.com/thread.jspa?threadID=5218663

In some cases we are seeing that complete initialization of application takes nearly 20 minutes on 1.6 server VM whereas it takes less than a minute on 1.5

Our customers can not move to 1.6 unless this is resolved.


REPRODUCIBILITY :
This bug can be reproduced always.

Release Regression From : 6
The above release value was the last known release where this
bug was not reproducible. Since then there has been a regression.