[HEADS-UP] systemd for F14 - the next steps

[Lennart Poettering]

On Thu, 22.07.10 11:29, Simo Sorce (ssorce at redhat.com) wrote:

> > they hence would have needed to be started one after the other, so
> > that every service using another services can be sure it can talk to
> > the one it needs. I mean, how awesome is that? We can completely
> > remove *any* kind of serialization from daemon startup.
> 
> how do you deal with circular dependencies in this case?
> I mean what will happen ? Will all services just deadlock?
> Malfunction ? Anything that guarantees correct initialization and
> behavior ?

If a service A uses functionality provided by a service B which in turn
uses functionality provided by A then things willbreak regardless
whether systemd is used or not.

Cyclic dependencies cause deadlocks. Introducing systemd has little
effect on that. It won't make the situation worse, and it won't make
itmuch better either.

Or in other words: If somebody writes a syslog implementation that
writes its logged data to mysql, ignoring that mysql actually itself
logs to syslog, then it is his own fault, and this simply doesn't work,
regardless if syslog or mysql is socket-activated or not, or whether
systemd is used at all. It cannot work, already on a theoretical level.

Or in even other words: this is a theoretical problem, not a practical
one, and orthogonal to the problem set systemd tries to solve.

Lennart

-- 
Lennart Poettering - Red Hat, Inc.