Problem

Transfers hung up, no error message, no more WTO in the log

All is back working after a restart

Resolution

We faced this situation a couple of time and the analysis conducted to the fact that CFT code was not looping but was stuck on SVC 11 system calls.

The only way to go further was to analyze an SVC dump.

The next time the issue occurs, you can collect the information needed for analysis using the following steps:

• /f stcname,SGTRACE 209
• /f stcname, ? SCB
• /f stcname,? TASK
• wait 1 minute
• /f stcname,DEBUG
• Collect SVC dump
• /f stcname,SHUT FAST=YES

In the previous cases we face this problem, the root cause of the issue was due to the IBM HourGlass application (interacting with the SVC 11).

The solution was to get CFT excluded from IBM HourGlass, achievable from 'JOBCLASS or EXCLUDE' according to this document.