CICS constraints
CICSĀ® constraints can also have an adverse effect on IBM MQ for z/OSĀ® performance. Use this topic for further information about CICS constraints.
Performance of IBM MQ tasks can be affected by CICS constraints. For example, your system might have reached MAXTASK, forcing transactions to wait, or the CICS system might be short on storage. For example, CICS might not be scheduling transactions because the number of concurrent tasks has been reached, or CICS has detected a resource problem. If you suspect that CICS is causing your performance problems (for example because batch and TSO jobs run successfully, but your CICS tasks time out, or have poor response times), see the CICS Problem Determination Guide and the CICS Performance Guide.
Note: CICS I/O to transient data extrapartition data sets uses the z/OS RESERVE command. This could affect I/O to other data sets on the same volume.