Buffer pool usage for OTMA

If an IMS-OTMA environment has heavy OTMA traffic, a significant increase in LUMP and HIOP pool usage can occur.

Because LUMP and HIOP pools are allocated from private storage, you might need to increase the size of the IMS control region. Also, certain OTMA control blocks are allocated from extended common service area (ECSA), another limited resource.

Recommendation: Increase the ECSA size according to your workload. For example, if a client is sending more than 20 messages over 100 tpipes within a few seconds, try increasing the IMS control region size to 200 MB or more, and increase the ECSA size to 50 MB or more. If you cannot increase the IMS control region size or the ECSA size, try balancing your workload to allow IMS to reuse its buffers more effectively.