[systemd-devel] Unexplainable unit restart ("Start request repeated too quickly")

[Michael Chapman]

On Mon, 3 Jun 2019, Ulrich Windl wrote:
> Hi!
> 
> When installing a test package, I noticed that one unit
> (iotwatch-generator.service) triggered a restart for an unknown reason. The
> status is (note: no reason for restart shown):
> 
> # systemctl status iotwatch-generator.service -l
> ● iotwatch-generator.service - I/O performance monitor instance generator
>    Loaded: loaded (/usr/lib/systemd/system/iotwatch-generator.service;
> enabled; vendor preset: disabled)
>    Active: failed (Result: start-limit) since Mon 2019-06-03 09:41:18 CEST;
> 5min ago
>      Docs: man:iotwatch-generator(8)
>            man:iotwatch at .service(8)
>   Process: 29133 ExecStart=/usr/lib/iotwatch/iotwatch-generator
> /run/systemd/system (code=exited, status=0/SUCCESS)
>  Main PID: 29133 (code=exited, status=0/SUCCESS)
> 
> Jun 03 09:41:18 v04 systemd[1]: Starting I/O performance monitor instance
> generator...
> Jun 03 09:41:18 v04 systemd[1]: Started I/O performance monitor instance
> generator.
> Jun 03 09:41:22 v04 systemd[1]: iotwatch-generator.service: Start request
> repeated too quickly.
> Jun 03 09:41:22 v04 systemd[1]: Failed to start I/O performance monitor
> instance generator.
> Jun 03 09:41:22 v04 systemd[1]: iotwatch-generator.service: Unit entered
> failed state.
> Jun 03 09:41:22 v04 systemd[1]: iotwatch-generator.service: Failed with result
> 'start-limit'.
> 
> So there was a successful start, but then some spurious restart. Why?

It'd probably be easier if you supplied us with these units' 
configurations. My distribution does not ship iotwatch at .service or 
iotwatch-generator.service units.

It might also be good to know the RequiredBy, WantedBy, TriggeredBy, 
RequisiteOf and PartOf properties of this iotwatch-generator.service (see 
`systemctl show iotwatch-generator.service`), since they're possible ways 
in which the service may be implicitly started or restarted.