DEBUG DD statement in the CICS JCL for the DBUG TDQUEUE

Products

• IDMS
• IDMS - Database

Issue/Introduction

There is  a DBUG TDQUEUE in the IDMS 19.0 CICS RDO group which maps to DDNAME DEBUG.

Is it necessary to define a DEBUG DD statement with SYSOUT=*  in the CICS JCL for this, or would this be dynamically allocated if/when needed? 

Is the new DEBUG DD required in CICS now?

Environment

Release: All supported releases.

Resolution

The DBUG transient data queue has been in the CICSCSD member in the CAGJSRC library since IDMS 18.0. It is used to write debug messages when DEBUG=YES or DEBUG=QTS is specified on the CICSOPT macro or when certain debugging functions are specified as SYSIDMS input in the CICS startup JCL. 

These functions are normally only used to diagnose a system problem at the direction of IDMS technical support. 

The default value for CICSOPT is DEBUG=NO. The destination queue is specified on the DBUGDCT parameter, the default is DBUG. 

So it does not need to be defined unless debugging is turned on. 

The queue is defined as deferred so the command CEMT INQUIRE/SET TDQUEUE must be used to open it. 

The queue has TYPEFILE(OUTPUT) and no DSNAME so it will be dynamically allocated to the default sysout class when it is opened, unless there is a DEBUG DD statement in the JCL in which case it will use that.