apt-get install monit 

1. Open the monitrc configuration file

sudo vi /etc/monit/monitrc

2. Add following lines at the end of file

check process trisul_flushd_context0 with pidfile /usr/local/var/lib/trisul-hub/domain0/hub0/context0/run/flushd.pid
  start program = "/usr/local/bin/trisulctl_hub start context context0"
  stop program = "/usr/local/bin/trisulctl_hub stop context context0"
check process trisul_probe_context0 with pidfile /usr/local/var/lib/trisul-probe/domain0/probe0/context0/run/trisul-probe.pid
  start program = "/usr/local/bin/trisulctl_probe start context context0@probe0"
  stop program = "/usr/local/bin/trisulctl_probe stop context context0@probe0"

3. Restart the monit

 systemctl restart monit 

4. Start monit on boot

 systemctl enable monit 

If you want to receive email for trisul process status please add following lines in monitrc file

set mail-format {
    from: xxx@abc.com
    reply-to: abc@xxx.com
    subject: Trisul Monit $SERVICE $EVENT at $DATE
    message: Monit $ACTION $SERVICE at $DATE on $HOST: $DESCRIPTION.
          Yours sincerely,
          Unleash Networks
  }

set mailserver smtp.gmail.com port 587
username "xxx@abc.com" password "xxxxxxxxxxxxx"
    using tlsv1

set alert abc@xxx.com on {nonexist, timeout,resource}