Java VM Settings to avoid memory leaks

[Former Member]

hello gurus,

we have currently a few memory problems with our netweaver AS Java. Once a week our server dies because of "return code 666: out of memory". We are using a netweaver AS Java 640 on an Windows 2003 x64 Server. It is a dedicated machine with 16 GB Ram. The memory settings in the JVM are:

-Xms4096M

-Xmx4096M

-Xss2M

-XX:+DisableExplicitGC

-XX:+PrintGCDetails

-XX:+PrintGCTimeStamps

-XX:+UseParNewGC

-XX:+UseTLAB

-XX:CodeCacheMinimumFreeSpace 2M

-XX:CompilerThreadStackSize 4096

-XX:MaxNewSize 682m

-XX:MaxPermSize 2048m

-XX:NewSize 682m

-XX:PermSize 2048m

-XX:ReservedCodeCacheSize 64M

-XX:SoftRefLRUPolicyMSPerMB 1

-XX:SurvivorRatio 2

-XX:TargetSurvivorRatio 90

We are running our b2b Shop on this server. I don´t know if the 4 GB are enough Memory for Java since we have 16 GB available within our machine. But I´d like to know if i can just increase the Heap Size to 8GB or more.

I´m looking forward to hear your recommendations.

best regards

Tobias

[Former Member]

Hi,

As per your details, you have 4GB of RAM for this server and where as you have allocated 4GB to heap space which is not good. 4 GB of RAM is very less and you should increase the RAM.

As you have only 4GB of RAM available on the server, so you cannot allocate 8GB of RAM. Check SAP note 723909 for more information.

Thanks

Sunny