Monitoring running processes

For Developers
1

Hi,

I need a simple, yet effective solution to monitor two system services running on OpenWrt device. They are started as a init.d processes. I need to check whether the processes run, and if not, start them again. In case the process cannot start due to some persistent problem, I need to send notification - either e-mail or API request.

Please advise

Kal800

2

Hi,

I think this is the wrong thread. But basically monit does what you like to implement.

Best

3

For just one or two processes, I will often just do a custom script and set it up in cron to run periodically. If you navigate to System -> Scheduled Tasks in LuCI, that is an interface to cron.

Here is a simple example on one of my devices that checks if an sshfs filesystem has dropped out and resets it if it has.

Crontab:

# ---------------------- Minute (0 - 59)
# |   ------------------ Hour (0 - 23)
# |   |   -------------- Day (1 - 31)
# |   |   |   ---------- Month (1 - 12)
# |   |   |   |   ------ Day of week (0 - 6, Sunday = 0)
# |   |   |   |   |
# -   -   -   -   -
 */7  *   *   *   *     /root/bin/reSync

Script:

#!/bin/sh
if [ ! -f /root/Sync/syncthis ]; then
  /usr/bin/sshfs kfitzner@qsy.va1der.ca:Sync /root/Sync
fi

It's more handraulic, but it lets you do anything a shell script can do. Sending e-mail this way requires a package like mailsend to be configured. When you say an API, I assume you mean through a web server? Both curl and wget can likely do this.

EDIT: I haven't used monit, but it looks like it might be a simpler solution. I mention the above, though, in case you need more versatility than monit offers.