# Cylc 7.9.3: suicided task \*occasionally\* not suiciding, causing suite hangs

**URL:** <https://cylc.discourse.group/t/cylc-7-9-3-suicided-task-occasionally-not-suiciding-causing-suite-hangs/600>\
**Category:** Cylc Support\
**Created:** [March 6, 2023, 8:01am UTC](https://cylc.discourse.group/t/cylc-7-9-3-suicided-task-occasionally-not-suiciding-causing-suite-hangs/600 "2023-03-06T08:01:08Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![funkapus](https://avatars.discourse-cdn.com/v4/letter/f/b19c9b/32.png) [@funkapus](https://cylc.discourse.group/u/funkapus)\
**Post date:** [March 6, 2023, 8:01am UTC](https://cylc.discourse.group/t/cylc-7-9-3-suicided-task-occasionally-not-suiciding-causing-suite-hangs/600/1 "2023-03-06T08:01:08Z")

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Hi. I hope it’s still possible to get support for 7.9.3 – my customer won’t be migrating to Cylc 8 for a while, so I can’t.

I have a workflow where a task compares the cycle point to the wall clock and sends a message based on the degree to which the suite is lagging the wall clock. On that basis, if the lag is too severe, a great many tasks are suicided, to speed up processing. I use an intermediate dummy task in the way the graph is written, e.g.:

check\_lag:too\_much\_lag =\> suicide\_tasks  
suicide\_tasks =\> !taskA  
suicide\_tasks =\> !taskB  
suicide\_tasks =\> !taskC  
suicide\_tasks =\> !taskD  
(etc.)

I am occasionally experiencing some weird behavior: one of tasks that should be suicided occasionally _isn’t_. For example, from the lines above, taskC is not suicided (the suite log shows no attempt to suicide taskC), but only _occasionally_. Most of the time it’s supposed to suicide, it does so just fine. But occasionally, it’s as if the suite server never tries to suicide the task.

This causes a problem because it leaves the task in a “waiting” state; but it’ll never be spawned because it’ll never be triggered, because all the tasks it’d trigger off of have been successfully suicided. Then, a few hours later, the suite runs into the “max active cycle points” limit and just stops. If I discover this has happened, and manually remove-without-spawning the task that should have been suicided, everything works OK.

Any advice on what to look at? I’ve been banging on this for a while, and folks are rattling my cage for a fix.

Thanks!

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**Author:** ![oliver.sanders](https://yyz2.discourse-cdn.com/free1/user_avatar/cylc.discourse.group/oliver.sanders/32/110_2.png) [@oliver.sanders](https://cylc.discourse.group/u/oliver.sanders)\
**Post date:** [March 6, 2023, 11:46am UTC](https://cylc.discourse.group/t/cylc-7-9-3-suicided-task-occasionally-not-suiciding-causing-suite-hangs/600/2 "2023-03-06T11:46:54Z")

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Hi, we’re not aware of any issue with suicide triggers at Cylc 7.

It’s worth checking that `taskC` was constrained by its dependencies at the time `suicide_tasks` is run. If it gets queued or marked as ready the suicide logic may be skipped.

Could you take a look at the logs to find the point where `suicide_tasks` yielded the `too_much_lag` output. After this you the workflow should list each of the tasks it attempted to suicide-trigger.

Cheers,  
Oliver