Restart terminated services automatically

[SwedishWings]

I'm implementing a few service that will run on an embedded system. In other words, they must be restarted if they for any reason would terminate.

From what i figured so far, they'll be launched from /etc/init.d/* to follow the Linux standard.

What i do not know, is how to automatically restart any service if it would terminate. Is there a simple standard way to do this?

Thanks in advance,
Mike

[quux]

Unfortunately init.d does (at least AFAIK) not support automated restarts of terminated services. If you're not tied to init.d, then you might consider starting your service using daemontools (http://cr.yp.to/daemontools.html) which provides this particular feature.

The FAQ (http://cr.yp.to/daemontools/faq.html) should give you a quick overview how to use it. An Ubuntu package of the most recent version is available in the universe repository.

[SwedishWings]

Thanks for the pointer. Reading that makes me wonder why not all new services are using it. Very handy indeed.

Regards,
Mike

[Greyed]

There is also monit.



Package: monit
Description: A utility for monitoring and managing daemons or similar programs
monit is a utility for monitoring and managing daemons or similar
programs running on a Unix system. It will start specified programs
if they are not running and restart programs not responding.
.
monit supports:
* Daemon mode - poll programs at a specified interval
* Monitoring modes - active, passive or manual
* Start, stop and restart of programs
* Group and manage groups of programs
* Process dependency definition
* Logging to syslog or own logfile
* Configuration - comprehensive controlfile
* Runtime and TCP/IP port checking (tcp and udp)
* SSL support for port checking
* Unix domain socket checking
* Process status and process timeout
* Process cpu usage
* Process memory usage
* Process zombie check
* Check the systems load average
* Check a file or directory timestamp
* Alert, stop or restart a process based on its characteristics
* MD5 checksum for programs started and stopped by monit
* Alert notification for program timeout, restart, checksum, stop
resource and timestamp error
* Flexible and customizable email alert messages
* Protocol verification. HTTP, FTP, SMTP, POP, IMAP, NNTP, SSH, DWP,
LDAPv2 and LDAPv3
* An http interface with optional SSL support to make monit
accessible from a webbrowser

[SwedishWings]

Thanks Greyed,

that was another very interesting option. In particular, I like the flexibility like being able to monitor log file sizes etc. Very handy, thanks!

After reading a bit more about "upstart" (the Sys V "init" replacement in Ubuntu) i realized that there is a simple way to do this by adding a file to /etc/event.d/ looking something like this:


# myservice
start on stopped rc2
start on stopped rc3
start on stopped rc4
start on stopped rc5

stop on runlevel 0
stop on runlevel 1
stop on runlevel 6

respawn
exec /usr/bin/myservice

Is this the correct way of adding a service, or is this considered "hacking"? I can't find much doc's on this subject, so if anyone can tell me what the "standard" expects from services run like this, it would be most welcome.

Regards,
Mike