How IMS maintains global information for sysplex serialized program management

Sysplex serialized program management allows users in a shared queues environment to prevent application programs that are defined as serial from being scheduled in parallel on another IMS system in an IMSplex.

Information about scheduled serial PSBs is maintained in the Resource Manager (RM) resource structure to ensure that the serial PSB is scheduled in only one IMS across an IMSplex at any point in time.

For an IMS in an IMSplex to schedule a serial PSB, that IMS must successfully create a unique instance for the PSB on the RM resource structure before it completes scheduling. If another IMS finds that the PSB instance is not unique, it discontinues the scheduling process for the PSB.

You can activate or deactivate the sysplex serial program management feature by using the GBL_SERIAL_PGM parameter in the DFSCGxxx member of the IMS PROCLIB data set. By default, sysplex serialized program management is active.