#XCOMM0745E SYSDSN ENQUEUE UNAVAILABLE, DSN= in XCOM server

Products

• XCOM Data Transport
• XCOM Data Transport - z/OS

Issue/Introduction

Issue

A transfer scheduled through XCOMJOB can be delayed by the server due to an ENQUEUE conflict with the scheduling job, when the dataset is being used again after the scheduling step in the scheduling job.

When there’s an XCOMJOB TYPE=INQUIRE step between the scheduling step and the step that references the dataset, you’ll get a lockout between this job and the XCOM server. The scheduling job will ‘hang’ until the INQWAIT time of the INQUIRE step is reached.

Symptoms:

1. Message #XCOMM0745E SYSDSN   ENQUEUE  UNAVAILABLE, DSN=dataset.name issued by the XCOM server. The scheduling job seems to hang in the INQUIRE step
2. XCOM for z/OS, transfer scheduled with XCOMJOB, dataset allocated + referenced by two separate steps in the job

 

Environment

Release: XCOM for z/OS 12.1

xcmvs

Cause

This behavior has nothing to do with XCOM logic, nor can it be influenced by XCOM. This  z/OS logic, because the dataset is being created and referenced by different steps in the same job and so the EXCL ENQUEUE is held until the end of the last step referencing it.

Resolution

To avoid such a situation you can do one of the following:

1. Allocate the dataset.name in a prior job
2. Put step(s) referencing it after the INQUIRE step in a successor job
3. (if possible) Put all steps referencing it before the INQUIRE step
4. Put the INQUIRE step in a successor job