Re: Debian boot system
On Sat, 07 Oct 2000, Michael Moerz wrote:
> you will have to create an API with the functionality to add, modify and
> delete services including defining dependencies.
Yeap, basically, I could have a Makefile that included all the Makefiles in
the directory, and a software package would just add Makefiles to that
Makepool, with the virtual services and dependencies they have.
> Yeah, make will do the parallisation, but did you ever think about the
> output of the starting services? As stated in make's info there is NO
> guarantie that the output might get not mixed. How will you cope with that
> by simply using make? Did you ever think about that? You would have to
> seperate the output of the services and then to put it together again. But
> that would create a problem when debugging unknown dependencies. I mean
> when a failure happens in parallisation and two services are started
> concurrently and it happens that some struggling code pieces are executed
> together. Reproducing such events would be hardly possible due to
> race-conditions. Debugging for the error without knowing when and what was
> running is also impossible.
Just cancel out the parallilism for a boot, and you know right there if it is
the root of the problem. If it is, your dependencies are wrong. Race
conditions might be a nightmare when programming, but when running
shellscripts? The problems should be more trivial and less problematic,
especially as you add redundant dependencies.
About the log mixing: How about seperate logs for seperate daemons? Perhaps
putting it all together as a final step of the boot process?
> mmh, I don't want to think about the mixed output.
Yes, I have mixed output, the dots are everywhere :) All fixable.
> > I think the more graceful error recovery (remmember the
> > hostname-not-resolvable sendmail problem?), and the extra flexibility
> > (the ability to easily specify the SPECIFIC dependencies (Current
> > systems, for example, will sometimes not shutdown correctly, and try to
> > unmount NFS after shutting down the network, because the order is
> > specified manually, instead of being deduced from simpler[to humans]
> > dependency specifications)
> if your thing is sometime doing the output right, it really would help in
> such cases.
> I hope that you will make it.