OTMA fast transaction pipe checkpoint cleanup (FASTTPCU) enhancement

In IMS 15.3, the OTMA fast transaction pipe (tpipe) checkpoint cleanup enhancement allows an IMS system to delete an idle OTMA tpipe more frequently.

This enhancement is added to IMS 15.3 by APAR PH52141/PTF UI93586.

By default, in IMS 15, an OTMA transaction pipe (tpipe) is deleted after it keeps being idle across three consecutive system checkpoints, even if other tpipes that are associated with the same transaction member are being used. The idle OTMA tpipe occupies unnecessary IMS storage space and cannot be reused for subsequent transaction requests. As a result, storage exhaustion or tpipe flooding could happen in the IMS system.

With the OTMA FASTTPCU enhancement, IMS introduces a new parameter: FASTTPCU, in the DFSOTMA descriptor. When the FASTTPCU function is activated, an idle OTMA tpipe will be cleaned up after two consecutive checkpoints.

When the FASTTPCU function is not activated, by default, an OTMA tpipe is still cleaned up after it is idle across three consecutive system checkpoints. This is a global OTMA attribute.

This new function can be activated by specifying FASTTPCU parameter in DFSOTMA descriptor in DFSYDTx PROCLIB member.

Changes to installing and defining IMS

The FASTTPCU parameter is added to the DFSOTMA descriptor in the DFSYDTx member of the IMS PROCLIB data set.

Changes to troubleshooting for IMS

Error texts for the FASTTPCU function are added to message DFS2385E.

For a list of the messages and codes that are new or changed for this enhancement, see the IMS messages and codes row in the table in Documentation changes.

For a complete list of all of the new, changed, and deleted messages, and abend codes in IMS 15.3, see Message and code changes in IMS 15.3.

Documentation changes

The following table lists the publications that contain new or changed topics for the New function name enhancement. Publications that are not impacted by this enhancement are not included in the table.

Table 1. Links to topics that have new or changed content for this enhancement
Publication	New or changed topics
Release planning	General planning information for IMS 15.3 Message and code changes in IMS 15.3 IMS 15.3 enhancements IMS 15.3 Transaction Manager continuous delivery functions OTMA fast transaction pipe checkpoint cleanup (FASTTPCU) enhancement (new) (this topic)
System definition	Members of the IMS PROCLIB data set DFSYDTx member of the IMS PROCLIB data set DFSOTMA descriptor syntax and parameters
Communications and connections	Open Transaction Manager Access (OTMA) Introduction to OTMA Using transaction pipes with OTMA OTMA fast transaction pipe checkpoint cleanup (FASTTPCU) (new) Enabling and using OTMA OTMA descriptors DFSOTMA descriptor Managing system resources and OTMA Monitoring tpipe usage Removing idle tpipes
IMS messages and codes	DFS messages DFS2385E