CQS automatic structure checkpoint

In IMS 15, you can configure IMS to take checkpoints of a common queue server (CQS) structure automatically after a user-specified number of log records have been written by a CQS.

Coexistence considerations

An IMS 15 CQS that performs automatic structure checkpoints can coexist with IMS Version 13 and IMS 14 CQSs that are connected to the same shared queue structure. However, you can use the STRCHKPT= parameter in the CQSSLxxx member of the IMS PROCLIB data set to trigger the automatic structure checkpoint only for IMS 15 CQSs. Only the IMS 15 CQSs can become the master CQS that performs automatic structure checkpoints.

Fallback considerations

Before reverting an IMS 15 CQS that performs automatic structure checkpoint to a CQS of an earlier version of IMS, remove or comment out the STRCHKPT= parameter in the CQSSLxxx member of the IMS PROCLIB data set.

Documentation changes

The following table lists the publications that contain new or changed topics for the CQS automatic structure checkpoint 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 the CQS automatic structure checkpoint enhancement
Publication	Links to topics
Release planning	CQS automatic structure checkpoint fallback considerations Common Queue Server coexistence considerations CQS automatic structure checkpoint (new) (this topic)
System definition	CQSSLxxx member of the IMS PROCLIB data set
System administration	CQS recovery functions Using the Common Queue Server Using CQS structure checkpoint Common Queue Server overview
IMS messages and codes	CQS messages CQS0224E