adding additional j2ee node

[Former Member]

Hello,

we are running BI 7 - abap+java stacks with 16 GB ram (recently added)

i would like to know what is the thumb rule for adding additional j2ee node?

when is it neccassary to add additional j2ee node?

Regards,

Moshe

[former_member197561 · Accepted solution]

Hi,

you should add additional Java server node to Java instance, if garbage collection activity of already installed java server nodes is getting more intensive than 1 small gc per second and more than 1 full GC per 10 minutes.

The total RAM on the machine allows for it, which means that the total heap of the newly configured java server should fit into tree RAM, without pushing other java server or other programs that are running on that server out of RAM. There should be no swapping due to added java server node.

if the RAM is not sufficient - hardware upgrade should be performed, or the java instance should be added on separate machine, which has sufficient memory/CPU capacity.

Best Regards,

Sylvia

[hemanth2]

Hi,

The JLaunch starts a Java program. It loads the JVM into its own address space and then represents the required cluster element. The program can receive notification from the JControl process via named pipes to stop the cluster element, and terminates, if the JControl stops running (fork emulation under Windows).

So Jlaunch consuming high CPU time means that server, dispatcher or bootstrap process consume it. If there are not enough system or application threads avaliable means that the engine must buffering requests for web application or system processes. Things to check in this case are:

SAP NOTE 1016241 - J2EE Engine hangs because of unsufficient system threads

SAP note: 716604 and upgrade JDK.

SAP note: 723909 -> set correct VM parameters

and if issue persists, then you will need to analyse the application causing teh leak...

SAP note: 1259465: Memory analyser.

Regards,

Hemanth

[Former Member]

It depends on how much memory is available in your system. Each java process can take upto 2GB of RAM. Based on this you can calculate how many nodes you want to add. I would add one at a time. I belive you can add upto maximum 16 nodes.

You may want to add the node to increase the performance.

Hope this helps.

Manoj

[Former Member]

Hi,

There is no thumb rule as such to increase the server node. This can be done initially or when you face a performance issue with the server.

Adding an additional server node increases the performance. The Heap size is totalled accross the system.

This is also particularly useful when you have issues with a server node. Still you can run the application on additional server node.

This also helps at the time of cluster installation.

Best Regards

Raghu.

[Former Member]

Hello,

Please refer SAP Note 883948 - NW 7.00(2004s): Inst.Add.Java Usage Types/Software Units

Best Regards

Imran

[Former Member]

Hello,

you are mistaken - i'm talking about adding additional j2ee server node to the one already exists - not adding java stack - this one already exists from the installation.

Regards,

Moshe