Memory upgrade 4gb -> 8gb: change mem settings in netweaver?

[Former Member]

Hi all,

We currently have our development portal & production portal on 1 Windows 2003 Standard Edition 64Bit server with 4gb of RAM with database system Oracle 10 64bit install.

Our server runs with both portals but we notice that our memory is running rather low. That's why we want to add another 4gb of RAM on our server.

Do we have to modify any memory setttings in NetWeaver or in Oracle?

If so does anybody know what parameters, and where?

Thank you for your feedback.

Best regards,

Tom.

PS Helpfull answers will be rewarded!

[Former Member]

Ok thank you all for responding to my questions.

[Former Member]

Hi

Are the two instances under MCOD configuration or seperate instances ? each has its own advantages & disadvantages and recommendations for such settings..

You need to be extremely careful with your landscape setup, as even if dev system is loaded your production system will be affected..

w.r.t your problem, obviously development java server does not need much resources.. you can assign the additional memory to prod java engine..

Regards

Madhu

[Former Member]

Although you have to have Oracle on board, do you have any additional apps that use a separate DB in Oracle? I would look at the possibility of off loading that DB to another server then.

As for making sure that you java garbage collection is running ok, I will pimp my blog here.

/people/david.rutt/blog/2006/08/23/trouble-shooting-java-memory-dumpster-diving

Proper garbage collection in tight situations is key.

I agree with Walter in that you have to get Development off that server. It is impossible to do some testing without risking both portals. Case in point, if you have to upgrade you java from 1.4.2_09 to 1.4.2_13 to keep up with daylight savings time. Windows can not run two versions of java at the same time.

Another memory saver may be if you size you dev heap to 1024 and prod heap to 3072. You still have your same size foot print but, your setting will have to be adjusted.

On the 3 gig heap:

-Xss2m

-Xms3072M

-Xmx3072M

-XX:MaxNewSize=512M

-XX:NewSize=512M

-XX:+DisableExplicitGC

-XX:MaxPermSize=256M

-XX:PermSize=256M

-XX:SurvivorRatio=2

-XX:TargetSurvivorRatio=90

I have found that these are a good combo to keep young and perm generations in check.

As for the 1 gig heap:

-Xss2m

-Xms1024m

-Xmx1024m

-XX:NewSize=256m

-XX:MaxNewSize=256m

-XX:+DisableExplicitGC

-XX:PermSize=256m

-XX:MaxPermSize=256m

-XX:SurvivorRatio=2

-XX:TargetSurvivorRatio=90

Try it out, but agian, Dev should not be on Prod.

[Former Member]

Hi Walter, David,

Thank you guys for your feedback.

If somebody else has any additional info please don't hesitate to spit it out

Best regards,

Tom.

[Former Member]

Hello Tom,

First of all; you probably don't want to run the development and production

portals on one single box. Also SAP recommends having the production instance

on it's own dedicated hardware.

With regards to your question; the most important thing to remember about

Java memory is that you want to keep the heap in RAM, therefor you need

enough memory to cater for the total memory required for all java processes.

Following the standard requirements (for 64bit systems), the Java dispatcher

requires ~170M and each Java server requires 2048M. This means you require

about 4,5 Gb for your Java heaps alone, not taking into account the database

and OS.

For recommendation on the Java heap sizes, have a look at SAP note 709140

and for Windows SAP notes 716604 and 723909. You can have a look at SAP

note 710146 for a description of how to change the JVM settings by using the

configtool.

Hope this helps...

Kind regards,

Walter