Re: [monit] Stuck processes?

[Stan Kaufman]

Ramon Miguel M. Tayag wrote:
> Hey everyone,
>
> Is there such a thing as a stuck process?  I'm new to administration
> so let me describe what happened:
>
> I had 3 processes runnign for about 4 days, then I uploaded new code
> via capistrano.  Capistrano tells monit to restart the 3 processes,
> but they all said execution failed.  So I logged into the server and
> saw the processes were still running.  That means they were never
> killed.
>
> So I kill them manually (using the same commands in the monit config
> file), and then get monit to run them, and it's able to start it.  I
> then tested monit, and restarted the processes one by one (all via
> monit).  They were able to restart fine.
>
> I also did a restart from Capistrano and it restarted fine.
>
> Would you guys know what the problem might be?
>
> Thank you,
> Ramon Tayag
>   


I've got no answer but can confirm some oddness here.

I've noticed that sometimes when monit restarts a group (of mongrels 
plus a separate ar_sendmail process) during a capistrano deploy of a 
Rails app, the ar_sendmail process gets restarted but the old one isn't 
terminated -- so that there are now two ar_sendmail processes. This 
happens only about 1/4 to 1/2 of the time. I usually just kill the 
obsolete process. The mongrels themselves restart fine.

This appears to be more of a nuisance than a real problem, but I do 
wonder why the inconsistent results. I've presumed it's due to something 
strange with ar_sendmail, which has to be modded to work with monit: 
http://www.lukeludwig.com/blog/articles/2007/12/05/running-ar_sendmail-with-monit

This is with monit 4.10.1. Does monit 5.x change something that might 
fix this?

Weird....