Tuning the Gateway to avoid out-of-memory conditions

The CICS® Transaction Gateway statistics provide information to help you avoid out-of-memory conditions.

You can use the statistics that are generated by CICS Transaction Gateway to establish whether the amount of available virtual storage being used by CICS Transaction Gateway might exceed the amount that is available to the CICS Transaction Gateway address space.

• CM_CCURR
• CM_SMAX
• SE_SELIM
• SE_CELOAL
• SE_C31MAX
• SE_SHEAPMAX
• WT_SMAX
• WT_CCURR

For more information, see Memory setting on IBM z/OS.

The total amount of native memory used by the Gateway daemon increases per thread. In 64-bit Java every thread running in AMODE64 requires at least 3 MB virtual storage above the bar for its stack storage and control blocks. Increase the MEMLIMIT and REGION size for CICS Transaction Gateway as per the configuration if OutOfMemory(OOM) error is seen.