Hello,

I had the same problem as Jan Rekorajski with syslog-ng 3.0.1 and 2.0.10:

> Hi,
> Syslog-ng 3.0.1 dies on reload (kill -HUP pid) when config file contains
> log { destination { program() } } directive set. 100% repeatable.
>
> Here are the relevant config lines:
>
> destination d_sshguard { program("/usr/sbin/sshguard -a 6"); };
> # A desperate experiment
> #destination d_sshguard { program("read"); };
>
> log { source(s_sys); filter(f_authpriv); destination(d_sshguard); };

pstree revealed that the command /usr/sbin/sshguard was run by a shell (in my case pdksh). To make the shell go out of my way I've put exec before /usr/sbin/sshguard . See my syslog-ng.conf :

destination d_sshguard { program("exec /usr/sbin/sshguard" template("$DATE $FULLHOST $MESSAGE\n")); }

Since I've changed this and restarted syslog-ng, it survives killing it with HUP, now.

Furthermore, pstree revealed that killing syslog-ng with HUP makes it restart sshguard. Bazsi suggested that some pocess sends either SIGINT or SIGTERM to syslog-ng's process group. In my opinion it is the shell to do that. When syslog-ng reloads its configuration it destroys FIFO to sshguard. This action awakes the shell and triggers it to send some destructive signal to its process group.

Regards,

--
Bartosz Lis @ Institute of Comp. Science, Technical University of Lodz, Poland
bartoszl @ ics.p.lodz.pl