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Does J2EE Sever support 4G Heap memory ?

Former Member
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Hi.

I installed J2EE WAS 7.0 and I wondering how many size can I configure for Heap memory.

I installed 64 bit jvm and O/S.

Can I configure 4G Heap memory for J2EE WAS 7.0 ?

Regards, Arnold.

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Answers (3)

Answers (3)

Former Member
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Hello,

A small clarification. The note referred above 723909, does not restrict the size of heap you use for the JVM. It just suggests values which were tested at SAP and have proven to be enough for good performance.

The reason why big heaps (4g for example) are not recommended is that the bigger the heap the longer it takes for the garbage collector to run through it. So there is a trade off between less gc-s in the beginning when the JVM is started and much longer ones, when the heap is for example half full.

On the other hand if you add more server nodes you can scale more easily and serve a larger number of users, plus you can utilize better the cpu and other resources of the machine.

In short, if the JVM and the OS support such a big heap, then you can run the engine with it, but this is not recommended as you will not get the optimal performance.

Best Regards, Myriana

Former Member
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You can have only 2048 heap size

Former Member
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Thanks all.

Why do I have to configure 2048 memory for 64 bit JVM ?

Is there any restriction in SAP product or JVM ?

Regards, Arnold.

Former Member
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Hi Arlond

Yes there is a restriction by SAP itself.SAP has recommended it.It is mentioned in SAP note 723909.

Former Member
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Hi,

You can configure 2048 only maintain different server nodes.

please go through SAP Note: 723909

Regards

Ben