[201803][monit] Restart rsyslog service if rsyslogd consumes > 800 MB memory (sonic-net#2963)

Author: jleveque

build_debian.sh

@@ -304,6 +304,10 @@ check system $HOST
   if memory usage > 50% for 5 times within 10 cycles then alert
   if cpu usage (user) > 90% for 5 times within 10 cycles then alert
   if cpu usage (system) > 90% for 5 times within 10 cycles then alert
+check process rsyslog with pidfile /var/run/rsyslogd.pid
+  start program = "/bin/systemctl start rsyslog.service"
+  stop program = "/bin/systemctl stop rsyslog.service"
+  if totalmem > 800 MB for 5 times within 10 cycles then restart
 EOF
 
 ## Config sysctl