Estimate the Java Stack Memory Worst case requirement

[benoit-schmid]

Hello,

On a SolMan 7.1, if I run a sappfpar check, I have the following results:

Shared memory resource requirements estimated

================================================================

Total Nr of shared segments required.....:         30

System-imposed number of shared memories.:        214

Shared memory segment size required min..:  532480000 ( 507.8 MB)

Currently available maximum segment size.: 103079215104 (98304.0 MB)

Swap space requirements estimated

================================================

Shared memory....................: 1453.0 MB

..in pool 10  133.4 MB,   97% used

..in pool 40  154.9 MB,   97% used

..not in pool: 1157.4 MB

Processes........................:  194.3 MB

Extended Memory .................: 4092.0 MB

------------------------------------------------

Total, minimum requirement.......: 5739.4 MB

Process local heaps, worst case..: 1907.3 MB

Total, worst case requirement....: 7646.7 MB

Is it correct to say that this only concern the ABAP stack?

How can I find the Total, worst case requirement for the Java stack?

Thanks in advance for your answers.

[Former Member · Accepted solution]

For java if you didn't change a memory parameter it is roughly:

[ PERM SIZE ] + [ HEAP SIZE ] + [ various local process memory ]

This gives you with default values:

1gb + 2gb + 1gb = 4gb (this is per java server node)

You can check the values for perm and heap size in the configtool. Various local process memory is memory for sapstartsrv, sapstart, igs, scs instance.

Also do not forget to account for about 10% of the total server memory for the operating system. Also the memory for the database if it is running on the same system.

Cheers Michael

[sujit_sharma]

Hi Benoît

Is it correct to say that this only concern the ABAP stack ?

Yes, SAPPFPAR check will give information on parameters related to ABAP stack only.

For JAVA VM settings, please go through the link below:

http://help.sap.com/saphelp_nwce71/helpdata/en/43/73949862c16fcbe10000000a1553f6/content.htm

Also you can check SAP NOTE: 723909, this aslo might help you.

Regards,

SUJIT

[benoit-schmid]

Hello,

I have checked the mx value that are used by the 3 jlaunch processes.

Java Dispatcher: JVM mx= 256M

Java server0: JVM mx=2048M

Java SDM: No value set

How much memory should be considered for the SDM server?

Thanks in advance for your answer.

[Reagan]

Hello

Please open the Config Tool and check the Max Heap value (Xmx) for Server node/nodes

Additionally check the Perm size as well.

You can also check the instance.properties file at the OS level for the memory assignment if for some reason you cant launch the Config Tool.

To estimate the Java stack memory consumption you may set up Wily Introscope for memory consumption.

Additionally you can use memory analysis using tools like MAT from Eclipse or IBM Support Agent to see the memory utilization trend across the server processes.

What you need to make sure is that the memory assigned for ABAP, Java and the Database should be configured based on the memory available on the machine.

Good Luck

RB