HTTP 500 error when opening "App Server Control" (EM) in OAS 10.1.3.5.0

Question

Hi,
I have some (but not much) experience with OAS and am currently stuck. So hope to find someone who can help me further here.
When i open Oracle Application Server Control from the SOA Suite 10.1.3.5.0 home page i get most of the times an HTTP 500 error.
Initially i got this even when i opened the login page (/em) but worked around this by increasing the ThreadsPerChild from 100 > 250 in the httpd.conf and replacing the loopback adres 127.0.0.1 in the dms.conf for the virtual host configuration to the actual (fixed) ip-address.
The current situation is that when i restart the environment (opmn stopall & opmn startall) i can open the the EM login page.
After logging in om the Enterprise Manager, the page is partly loaded and a HTTP 500 error is shown when i refresh the page.
The apache log files now still shows the following errors;
[Tue Sep 07 15:46:19 2010] [error] [client 10.157.1.68] [ecid: 1283867060:10.150.50.110:10312:9568:5,0] mod_oc4j: Failed to find a failover oc4j process for session request for destination: application://ascontrol (no island or jgroup).
[Tue Sep 07 15:51:20 2010] [error] [client 10.157.1.68] [ecid: 1283867060:10.150.50.110:10312:9568:5,0] mod_oc4j: request to OC4J SOA-WTST:12501 failed: Connect failed
Any hints ?
Kind regards,
Peter

Answer 1

If finally found the cause of the problem, lack of PermGen space for the home instance;
When opening the EM Console most of the times i was able to open the login page, under stress opening this page failed most of the times.
The ascontrol-application.log pointed me in the right direction;
10/09/07 15:26:59.111 ascontrol: Servlet error
java.lang.OutOfMemoryError: PermGen space
When monitoring the PermGen of the home instance, is showed that the system was running out of PermGen space.
Increasing the PermGen size for the home instance in opmn.xml did the trick
<data id="java-options" value="-Xrs -server -XX:MaxPermSize=128M......"