Re: dependent processes starts simultaneously

[Martin Pala]

Stanisław Trytek wrote:
> On Tue, 23 May 2006 13:51:56 +0200, Martin Pala <address@hidden> 
> wrote:
>
> > Stanisław Trytek wrote:
> > >  Using monit I found some problems with starting dependent processes.
> > > Starting depandent processes is being done simultaneously (or 
> > > sequentialy but without waiting for the start script to finish).
> > > Searching through monit general list I have found out that it is 
> > > monit intended characteristic.
> > > I want to monitor some processes where both dependiecies and waiting 
> > > for process start are required.
> > > I have to start the next process only in case I know the previous one 
> > > is up (becouse it takes some time to initialize some processes).
> > > Starting/ restarting processes causes a big mess now. Sometimes not 
> > > knowing why I have even two instances of the same process.
> > >  My questions are:
> > > Have anybody ever tried to deal with that problem?
> > > Is it possible to force monit to wait for dependent processes to 
> > > start as it is during stoping sequence? Mayby some changes in source 
> > > code is enough?
> >
> > This problem was discussed in february:
> > http://lists.gnu.org/archive/html/monit-general/2006-02/msg00005.html
> >
> > The solution could probably be to use the service related testing 
> > rules definition for making sure that the parent is up and running => 
> > the procedure could look like:
> >
> >   1.) start the parent
> >   2.) check that the parent is running and there are no errors (using 
> > monit service check interface)
>
> If it was possible to check errors it would be great. It seems to be a 
> good solution.
> Sorry, it is not clear for me. "Monit service check interface" - I can 
> not imagine how to use it to check errors?

This is monit implementation of service testing (service->check method 
in validate.c).

> >   3.) if there are no errors, continue with the childs


... if developers will agree, we can add it to the TODO list.

Currently we cannot estimate when it will be implemented (so much work 
and so little time) ... any volunteers are welcomed ;)

Martin