Tunning Java Heap Space

Question

Hello;
I am getting this error when running some of the Oracle Diagnostics through OAM:
JSP Error:
Request URI:/OA_HTML/jtfqaadv.jsp
Exception:
java.lang.OutOfMemoryError: Java heap space
When I review my configurations on my two Windows 32bit servers I find these results:
On the APP/Web/Forms Server:
In the %IAS_ORACLE_HOME%/Apache/Jserv/etc/jserv.properties file is:
wrapper.bin.parameters=-verbose:gc -Xmx512M -Xms128M -XX:MaxPermSize=128M -XX:NewRatio=2 -XX:+PrintGCTimeStamps -XX:+UseTLAB
In the Context file is:
<forms_jvm_options oa_var="s_forms_jvm_options" osd="NT">-Xmx256M -Xms128M -XX:MaxPermSize=128M -XX:NewSize=60M -XX:MaxNewSize=120M -Xrs</forms_jvm_options>
<jvm_options oa_var="s_jvm_options" osd="NT">-verbose:gc -Xmx512M -Xms128M -XX:MaxPermSize=128M -XX:NewRatio=2 -XX:+PrintGCTimeStamps -XX:+UseTLAB</jvm_options>
On the DB/CCM/Admin Server:
In the %IAS_ORACLE_HOME%/Apache/Jserv/etc/jserv.properties file is:
wrapper.bin.parameters=-verbose:gc -Xmx512M -Xms128M -XX:MaxPermSize=128M -XX:NewRatio=2 -XX:+PrintGCTimeStamps -XX:+UseTLAB
In the Context file is:
<forms_jvm_options oa_var="s_forms_jvm_options" osd="NT">-Xmx256M -Xms128M -XX:MaxPermSize=128M -XX:NewSize=60M -XX:MaxNewSize=120M -Xrs</forms_jvm_options>
<jvm_options oa_var="s_jvm_options" osd="NT">-verbose:gc -Xmx512M -Xms128M -XX:MaxPermSize=128M -XX:NewRatio=2 -XX:+PrintGCTimeStamps -XX:+UseTLAB</jvm_options>
I am considering changing the value of jvm_options oa_var Xmx from 512M to 640M. My problem is that I have not worked with the JVM at this level and am wondering if this is the correct approach or any tips/hints on this.

Answer 1

Hi Hussein;
Thanks for the reply. I have been reviewing these documents and a few others. I this is how I came up with the idea to increase Xmx value. How ever I did read about a number of other options that sound good like:
hotspot - HotSpot is an "ergonomic" JVM. Based upon the platform configuration, it will select a compiler, Java heap configuration, and garbage collector that produce good to excellent performance for most applications. The Java HotSpot Virtual Machine is a core component of the Java SE platform. It implements the Java Virtual Machine Specification, and is delivered as a shared library in the Java Runtime Environment.
-XX:+AggressiveOpts Turn on point performance compiler optimizations that are expected to be default in upcoming releases. (Introduced in 5.0 update 6.)
-XX:+UseFastAccessorMethods Use optimized versions of Get<Primitive>Field.
So I am looking for some skilled guidance as to how to tune this thing.