IDMS maintenance back-out considerations

Products

• IDMS

Issue/Introduction

When applying IDMS maintenance, it is important to be prepared for the eventuality that it may need to be backed out.

This article describes why, and provides guidance on how to do so.

Environment

Release: All supported releases.

Cause

Since IDMS r17.0, APARs have been provided as module replacements as opposed to zaps as they were before. This means that different APARs are much more likely to be dependent on each other. To be dependent, all they need is to replace a common module - they do not have to be changing the same part of the code as was the case in the past.

Should it become necessary to back-out (SMP/E RESTORE) an IDMS APAR, it is not uncommon to be forced to RESTORE a large chain of APARs and then re-APPLY them all except for the one being RESTOREd. In some cases, this becomes impractical. 

Resolution

When applying maintenance, be mindful of the potential need to back it out. Suggestions ...

1. Before the APPLY, take a back-up of the entire SMP/E CSI and the IDMS libraries under its control. If the maintenance needs to be backed out, simply restore that back-up.
   
   OR
   
   
2. Run an SMP/E ACCEPT prior to applying the maintenance. This will prevent any large APAR chains from needing to be RESTOREd.

These guidelines are relevant for any IDMS maintenance, but are particularly critical when applying test APARs (those with a "T" in the second character of the name).