Intermittent Login issue 11i - 500 Internal Server Error

Check Logs for Error Details:

[appltest@appnode jvm]$ pwd
/oraclesw/testora/iAS/Apache/Jserv/logs/jvm
[appltest@appnode jvm]$

[appltest@appnode jvm]$ tail -15f OACoreGroup.0.stderr
java.lang.OutOfMemoryError
java.lang.OutOfMemoryError
java.lang.OutOfMemoryError
java.lang.OutOfMemoryError
java.lang.OutOfMemoryError
java.lang.OutOfMemoryError
java.lang.OutOfMemoryError
java.lang.OutOfMemoryError
java.lang.OutOfMemoryError
java.lang.OutOfMemoryError
java.lang.OutOfMemoryError
ApacheJServ/1.1.2: An error occurred listening to the port: java.lang.OutOfMemoryError
-------------------------------
Thu Nov 12 13:50:09 PST 2015

Increase the JVM Memory:

To increase the memory for oacore JVM,
edit the file   $IAS_ORACLE_HOME/Apache/Jserv/etc/jserv.properties

From:

wrapper.bin.parameters=-verbose:gc -Xmx512M -Xms128M -XX:MaxPermSize=128M -XX:NewRatio=2 -XX:+PrintGCTimeStamps -XX:+UseTLAB

To:
wrapper.bin.parameters=-verbose:gc -Xmx1024M -Xms512M -XX:MaxPermSize=128M -XX:NewRatio=2 -XX:+PrintGCTimeStamps -XX:+UseTLAB

Bounce Apache Services:

./adapcctl.sh stop
./adapcctl.sh start

Verify in below log file to confirm JVM started with updated memory parameter:

[appltest@appnode jvm]$ pwd
/oraclesw/testora/iAS/Apache/Jserv/logs/jvm

[appltest@appnode jvm]$ tail -f OACoreGroup.0.stdout

-------------------------------
Mon Nov 23 00:44:25 PST 2015
-------------------------------
/usr/java/j2sdk1.4.2_15/jre/bin/java -DCLIENT_PROCESSID=11905 -Xmx1024M -Xms512M -XX:NewSize=60M -XX:MaxPermSize=128M -XX:MaxNewSize=120M -Xrs

Also Modify the JVM parameter in CONTEXT_FILE, so next time when we run the autoconfig this will make changes permanently:

Parameter : 
<jvm_options oa_var="s_jvm_options" osd="Linux">-Xmx1024M -Xms512M -XX:NewSize=60M -XX:MaxPermSize=128M -XX:MaxNewSize=120M -Xrs</jvm_options>