Resolving out of memory errors on WAS or WPS

Problem (Abstract):

Depending on your flow design and memory capacity, out-of-memory problems can be seen when you run WAS or WPS or WESB.

Resolving the problem:

Increase the heap size to its optimal size to prevent out of memory errors from occurring when you are working with large and complex applications.

Use the steps in the procedure to increase the heap size. However, note that if the heap size is too large, the system does not have enough physical memory, and uses virtual memory to hold the data that it is using. Virtual memory can be used up sooner than expected if you are running other memory intensive applications at the same time. Also, virtual memory is slower than physical memory.

Physical memory size (GB)	Optimal heap size (MB)
1.5	768
2	1024
4	2048

Note: Incase if you are using 64 Bit Operating System and 4 GB Physical Memory, we should keep 4096 MB Heap Size

Procedure

1. In the WebSphere® Application Server administrative console, select the name of your server.
   
2. In the configuration tab, under Server Infrastructure, click Java and Process Definition > Process Definition.
   
3. Click Java Virtual Machine.
   
4. In the Maximum Heap Size field, enter 2048 and in the Initial Heap Size field, enter 1024 then Click OK.
   
5. Click Save.
   
6. Log out, and then restart the server.