[systemd-devel] Question about WATCHDOG

[Dave Reisner]

On Fri, Jan 11, 2019 at 08:03:45AM +0000, Sietse van Zanen wrote:
> Hi,
> 
>  
> 
> I am writing a daemon script which uses sd_notify watchdog. This works fine,
> system will kill the if the process doesn’t notify.
> 
>  
> 
> However, I have seen in 1 occasion where, due to a programming error, the
> script got stuck in a read and was not killed where it should have been.
> 
> So my question is, what does systemd actually do when the watchdog expires,
> which signal does it send?
> 

It's well documented in the manpages. From systemd.service(5) under the
description of WatchdogSec=:

  If the time between two such calls is larger than the configured time,
  then the service is placed in a failed state and it will be terminated
  with SIGABRT (or the signal specified by WatchdogSignal=)