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Re: Multiple processes started when explicit start commands areused on d
Re: Multiple processes started when explicit start commands areused on dependant processes.
Tue, 7 Feb 2006 19:43:38 +0100
On Thursday 02 February 2006 15:05, Jan-Henrik Haukeland wrote:
> On 30. jan. 2006, at 20.14, P Holdaway wrote:
> > Conceptually, does the code make an effort to block other start/stop
> > process commands while the start/stop of a dependency tree is
> > executing?
> For start it does not wait, for stop it waits. You can examine
> control.c to see how this is handled.
What sense does it make to run several start scripts concurrently?
Especially if there are dependencies it is important to run the scripts one
after the other.
Note that checking for the process id is *NOT* enough, because the service may
have to initialize (spawn other processes, claim resources etc.).
Only after the start script has terminated you can be sure the service is
ready and may be used by dependant services.
Besides, even running non-dependant start-scripts in parallel probably just
complicates things, muddles logging and in most cases brings no noticable
performance gains. Most of today's init(8) systems don't do it.
I wouldn't want to trade determinism of startup order for a few ms unless I'm
perfectly sure it works and all scripts are designed for it.