Importing djb's public domain daemontools?

[Jos Backus]

2012/1/17 Dag-Erling Smørgrav <des at des.no>

> Jos Backus <jos at catnook.com> writes:
> > If FreeBSD had a solid solution out of the box, all this pidfile hackery
> in
> > the base system wouldn't be necessary. I always thought FreeBSD was about
> > good engineering. Perpetuating the pidfile mess in the base is not a sign
> > of good engineering.
>
> Software written by DJB hardly qualifies as "good engineering".  PID
> files are well-known and well-tested, we have a solid implementation
> with a simple API (pidfile(3)), and a lot of our infrastructure depends
> on them (/etc/rc, newsyslog etc.)
>

Just because lots of people have been doing something for a long time that
is widely supported, doesn't mean it's the right thing to do.

As I said before, pidfiles export partial information that is already
available in the process table, without requiring extra cached file system
copies that need to be created/removed, have their permissions managed
carefully and can get stale. daemontools is one implementation that solves
the same problem without using pidfiles. It also gives you the option of a
well-defined startup environment for each service (not tied to the
environment of the caller) and the ability to add fine-grained control over
a service (by manipulating the permissions on the control socket, so select
non-root users can start root services if desired). It also comes with
built-in logging (multilog). Additionally, using the finish script
functionality, policies around crashes can be instituted (e.g. down the
service and send an alert if it crashes more than N times within M
minutes). These are just some of the features that I have used in the past
to run services on hundreds of machines in multiple data centers.

daemontools is surprisingly flexible, and it doesn't require complex
configuration commands or configuration files - a boon when used in
combination with tools like Puppet. That said, I don't care what we pick as
long as we pick something that can do all the above.

Jos


> DES
> --
> Dag-Erling Smørgrav - des at des.no
>



-- 
Jos Backus
jos at catnook.com