IBM announced a Red Alert for CICS TS 5.3 on June 19, 2017 (the first one in nearly 7 months).  This Red Alert is the result of a bug whereby two CICS transactions can be given the same Unit of Work ID (UOWID). The problem arises when the duplicate UOWIDs are passed to a subsystem that CICS is connected to.  The subsystems listed in the Red Alert are:

  • DB2
  • IBM (I assume this should be IMS)
  • WebSphere MQ
  • Coupling Facility Data Tables (CFDT)
  • Shared Temporary Storage Server
  • Named Counter Server
  • Vendors like Oracle

As you can imagine, duplicate UOWIDs can cause all sorts of problems in whatever subsystem is trying to deal with two transactions, both of which claim to have the same ID (is this the first documented case of identity fraud for a CICS transaction?).

The problem only appears to impact that one release of CICS (CICS TS 5.3), and it is fixed by APAR PI82188.

Hopefully you are already subscribed to the IBM Red Alerts Notification service.  If not, then go there right now and sign up before you get distracted with some other issue.