Purging undeliverable commit-then-send output

When configured, if the OTMA client requests the purge function, OTMA dequeues and discards the undeliverable commit mode 0 (CM0) IOPCB output from the IMS output queue. The purge function is requested on a message-by-message basis.

When the purge function is not specified, IMS stores undeliverable commit-then-send IOPCB output on the asynchronous hold queue of the OTMA tpipe associated with the client application that submitted the original input message. The output message remains on the hold queue for later retrieval by using a RESUME TPIPE call.

You can specify the purge function on either CM0 or commit mode 1 (CM1) input messages. However, when specified on CM1 input messages, IMS purges only CM0 IOPCB output, such as might be generated by a program-to-program switch. For example, if you specify the purge function on a CM1 transaction input that does a program switch to a second transaction and the first transaction does an insert to the IOPCB, the purge function applies only to the subsequent transactions that insert to the IOPCB.

Both user-written applications and IMS TM Resource Adapter applications on either persistent sockets or transaction sockets can request the purge function.