[Gluster-users] systemd kill mode

[Ward Poelmans]

Hi,

I've playing with glusterfs on a couple of VMs to get some feeling with
it. The setup is 2 bricks with replication with a thin arbiter. I've
noticed something 'odd' with the systemd unit file for glusterd. It has
KillMode=process
 which means that on a 'systemctl stop glusterd' it will only kill the
glusterd daemon and not any of the subprocesses started by glusterd
(like glusterfs and glusterfsd).

Does anyone know the reason for this? The git history of the file
doesn't help. It was added in 2013 but the commit doesn't mention
anything about it.

The reason I'm asking is because I noticed that a write was hanging when
I rebooted one of the brick VMs: a client was doing 'dd if=/dev/zero
of=/some/file' on gluster when I did a clean shut down of one of the
brick VMs. This caused the dd to hang for the duration of
network.ping-timeout (42 seconds by default). When I changed the kill
mode to 'control-group' (which kills all process started by glusterd
too), this didn't happen any more.

I was not expecting any 'hangs' on a proper shut down of one of the
bricks when replication is used. Is this a bug or is something wrong
with my setup?

Ward