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Plesk 11.5.30 with Watchdog 2.0.7 on Centos 6.4 – workaround for startup/shutdown problems

September 21st, 2013 Leave a comment Go to comments

I have a brand new machine with configuration stated above, moreover I’m using Nginx as proxy server to Apache. And it comes loaded with a lot of problems.

  • Machine cannot be shutdown – with last message in the console:

    init: psa-monit main process ended, respawning

  • After restart the machine reports following problems to console:

    Starting nginx: nginx: [emerg] bind() to [2001:8d8:8ae:e500::ae:4abd]:80 failed (99: Cannot assign requested address)[FAILED]

  • httpd process gets loaded with strange settins – it does not see VirtualHosts and serves all requests from default host, although it has opened all virtual host log files

Root Cause

Is unclear to me, but probably it is caused by incorrect change of starting scripts from Plesk. The scripts moved between Centos 5 and Centos 6 from /etc/inittab to /etc/init/psa-monit.conf and /etc/init/psa-wdcollect.conf . And I believe the scripts are not correct. They execute too early and respawn does not correctly handle situation when stopping machine.

Premature execution seems to cause that Apache gets started on port 80, Nginx refuses start consequently. Restarting Nginx seems to fix the port binding (strange) but Apache still does not serve proper pages. As if the started instance did not have NameVirtualHost setup properly and is serving default VirtualHost.


I’m not familiar with Centos init procedure good enough, and I believe the problem is inside Plesk code, not just in the init configuration. Changing the init script as shown below would solve all the problems. It will however disable automatic restart when the watchdog fails itself. But this seems acceptable for me – it is bettern than machine which cannot be restarted.

Yes I admit, the sleep is funny ūüėČ

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