Adds stopasgroup to the supervisor scripts (#4200)

* Adds stopasgroup to the supervisor scripts

* Add details on the stopasgroup parameter in supervisor configs

CONTRIBUTORS.txt

@@ -243,3 +243,4 @@ Samuel Dion-Girardeau, 2017/05/29
 Aydin Sen, 2017/06/14
 Preston Moore, 2017/06/18
 Nicolas Mota, 2017/08/10
+Martial Pageau, 2017/08/16

extra/supervisord/celerybeat.conf

@@ -17,6 +17,9 @@ autostart=true
 autorestart=true
 startsecs=10
 
+; Causes supervisor to send the termination signal (SIGTERM) to the whole process group.
+stopasgroup=true
+
 ; if rabbitmq is supervised, set its priority higher
 ; so it starts first
 priority=999

extra/supervisord/celeryd.conf

@@ -24,10 +24,8 @@ startsecs=10
 ; Increase this if you have very long running tasks.
 stopwaitsecs = 600
 
-; When resorting to send SIGKILL to the program to terminate it
-; send SIGKILL to its whole process group instead,
-; taking care of its children as well.
-killasgroup=true
+; Causes supervisor to send the termination signal (SIGTERM) to the whole process group.
+stopasgroup=true
 
 ; Set Celery priority higher than default (999)
 ; so, if rabbitmq is supervised, it will start first.