Can QVDS task fail after queue and before running? Is this logged?

[rothtd]

After an upgrade to April 2019 SR3 I'm troubleshooting a random issue where about once a month a handful of my QVDS tasks don't run. I have hundreds of tasks that run daily and literally once every 3 weeks (or so) ~5 of them just don't run. No logs are created in QVDS, and they run fine the next day. My first thought is that the tasks in question are queued and waiting to run (no QVDS logs created at this point) and before they switch into the running status they error (perhaps a timeout). Does Qlik QVDS record tasks entering queue status so I can verify that there are, in fact, being queued? Would an error after queue but before run be logged anywhere (where?)? Is there a timeout setting for length of time a task is allowed to queue?

To clarify, I'm questioning if my QVDS is working as designed, but due to higher than normal system load tasks are sitting in queue longer - and some of them are reaching a timeout limit and terminated before entering the running status. 

Thanks in advance.

[rothtd · Accepted solution]

Quick update - this is looking like the QvbWaitTimeoutMinutes timeout setting (\Distribution Service\QVDistributionService.exe.config). You can see the task in question enters the queue status successfully but then fails with an error message. The third entry is QVDS setting the schedule for the next run time. Looks like my QVDS was pretty busy this morning...

Root.txt

20200807T070100.022-0500        Information        DistributeTask[def07327-2176-4ed1-bf81-ca0501d1652e] ("QVD_SRDP_IF"): TryQueue successful. Triggered by 'ScheduleTrigger'. Id:b60d0b94-a65c-4e6c-88cf-3e0d438f9cca. ExecID:10960174-0fd3-479a-bf06-1601f914f9d3

20200807T074602.946-0500        Information        TriggerState: Change State to Ignored. Task="QVD_SRDP_IF", ExecId=10960174-0fd3-479a-bf06-1601f914f9d3. Trigger ScheduleTrigger ignored. No QlikView Engine was available after waiting for 45 minutes.

20200807T074603.127-0500        Information        Triggers: Keep this trigger under observation: TriggerState[ChangedBy=1, Status=Unhandled, Planned=2020-08-08 07:01:00.000, ExecId=b52464b5-2879-4d2e-9921-26671dfc88af, Trigger="ScheduleTrigger" for task "QVD_SRDP_IF"]

[Brett_Bleess]

Just a clarification note, you can adjust that setting you mentioned to a max of 300 I believe, anything higher than that, and we will likely lose the exclusive lock on the QVW, such that the task would run, but it would be unable to save the file afterward.  It has been awhile since I tested the 300, so it is possible things may have changed again with changes in Microsoft side of things, just as an FYI to anyone that reads this, so you likely want to test to be sure of things.

Regards,
Brett