Buffer pool size

There is a buffer pool associated with each page set. We can specify the number of buffers in the buffer pool using the DEFINE BUFFPOOL command. See the WebSphere MQ for z/OS System Setup Guide manual for more information.

Incorrect specification of buffer pool size can adversely impact WebSphere MQ performance. The smaller the buffer pool, the more frequently physical I/O is required. RMF might show heavy I/O to volumes that hold page sets. For buffer pool with only short-lived messages the buffer manager statistics QPSTSLA, QPSTSOS, and QPSTRIO should usually be zero. For other buffer pools, QPSTSOS and QPSTSTLA should be zero.