XCOM for z/OS started tasks stop unexpectedly and could not be restarted

Products

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

Issue/Introduction

Two XCOM for z/OS started tasks (STC) terminated unexpectedly and could not be restarted.
A weekly scheduled recycle was carried out. However, during the restart attempt, both components again terminated with errors.
Later the 2 STCs were successfully brought up manually.
From the provided STC logs from the failed restart attempts what could be the root cause?

Environment

XCOM™ Data Transport® for z/OS 12.0

Cause

• The STC job logs show that version "XCOM(tm) 12.0.01  (GEN LEVEL 2202)" is being used.
  There are no errors or XCOM*E error messages in the job logs.
  
  
• Just after the start of each job the STC reports messages for an orderly shutdown being initiated i.e.
  16.11.38 STC12345 XCOMM0013I STOP
16.11.38 STC12345 XCOMM0721I STOP COMMAND RECEIVED - XCOM ORDERLY SHUTDOWN INITIATED
  
  
• Eventually the shutdown ends with message:
  BPXP018I THREAD ... ENDED WITHOUT BEING UNDUBBED WITH COMPLETION CODE 0013E000
  
  
• In summary both XCOM STCs did not crash and both receive a STOP command and shut down. They receive the command right after starting, which is unusual. It therefore seems that the STOP commands are issued in error, perhaps by the automation software.

Resolution

1. Check the SYSLOG that corresponds to the problem timeframe for any messages relating to the source of the STOP command(s).
   
   
2. Verify automation software rules for XCOM STC recycling.
   
   
3. For the shutdown completion with message:
   BPXP018I THREAD ... ENDED WITHOUT BEING UNDUBBED WITH COMPLETION CODE 0013E000
   This is due to XCOM detaching some subtask that was still running, which the system terminates with S13E.
   XCOM has several fixes for this kind of abend.
   As level set 12.0.01 is being used it indicates the XCOM installations are behind on maintenance. Later level sets 12.0.02 (February 2025) and 12.0.03 (April 2025) are available so it is advised to apply the latest maintenance:
   Doc page XCOM™ Data Transport® for z/OS 12.0 > Release Notes > New Features
   XCOM for z/OS Solutions

Additional Information

For this scenario the user verified that they found no problems with XCOM and the incident appears to be operational in nature. Further monitoring to be undertaken.