Intermittent S02A CV abends

Products

• IDMS
• IDMS - Database

Issue/Introduction

A CV is abending intermittently with S02A.

 

 

Environment

Release: All supported releases.

Cause

The S02A abend is related to improper serialization of the Internal Reader.

This abend typically happens when the WTOEXIT and a user defined SYSOUTL LINE name the same DD for the Internal Reader.

The sample WTOEXIT writes JCL to a DD called JESRDR. Most clients use this DD in their WTOEXIT and define this DD in their CV startup JCL as follows:

        //JESRDR   DD SYSOUT=(A,INTRDR),DCB=(RECFM=FB,LRECL=80,BLKSIZE=80)

Many CVs also define a SYSOUTL LINE in sysgen that is used by user applications to submit JCL to the Internal Reader.

Resolution

The DDNAME parameter specified in the SYSOUTL LINE definition must be something other than the DDNAME which the WTOEXIT uses to write JCL to the internal reader.

For example: 

Assuming there is this SYSOUTL LINE called SUBJCL (the LINE name can be anything, it does not have to be SUBJCL):

  ADD LINE SUBJCL                   
      ENABLED                       
      NOCOMPACT                     
      PROTOCOL IS DEFRESP           
      TYPE IS SYSOUTL               
      DDNAME IS JESRDR.    <---  This DDNAME needs to change because WTOEXIT uses JESRDR

  MOD LINE SUBJCL                   
      ENABLED                       
      NOCOMPACT                     
      PROTOCOL IS DEFRESP           
      TYPE IS SYSOUTL               
      DDNAME IS INTRDR.    <---  A DDNAME that is not used by WTOEXIT or any other SYSOUTL Line in the CV.

Then add the INTRDR DD to the startup JCL so there are now two DDs for the Internal Reader, one for WTOEXIT to use and one for user applications to use via the SYSOUTL LINE.

//JESRDR   DD SYSOUT=(A,INTRDR),DCB=(RECFM=FB,LRECL=80,BLKSIZE=80)
//INTRDR   DD SYSOUT=(A,INTRDR),DCB=(RECFM=FB,LRECL=80,BLKSIZE=80)   

This will prevent the S02A abends related to Internal Reader Serialization errors.