Shared memory issue on enterprise portal

Hello,

We are facing below issue on Enterprice portal (NW 7.31):

" 500 SAP Internal Server Error

ERROR : No memory available for 9680 bytes in the shared object memory. (termination : RABAX_STATE)

We have done restart sap also cleanipc to clean shared memory and its worked.

But we are frequently facing this issue.

Please let me know which parameter we have to increase in JAVA system or how to resolve this issue??

Thanks,

Siddhesh