Re: Respawn limit for runsv?

[Charles Duffy <cduffy@spamcop.net>]

On Fri, 11 Feb 2005 22:13:43 -0500, Charlie Brady wrote:

> There is no general class of problem unless you can provide a single
> instance.

Let me jump in here.

I have a web server. It's running a big, complex servlet container (which
provides only one of the many services available) that eats a bunch of CPU
time and writes a bunch of logs trying to start up.

Should the servlet container be misconfigured in such a way as to die
immediately after startup (and some such misconfigurations could occur
based on issues on other systems ie. the DNS server), the automated
respawning would bring everything else on the web server to its knees.

> You say that respawning software is a reasonably common problem. Whenever
> I've seen it, it was a configuration problem. Or rather, there was a
> configuration problem, and the respawning was a symptom. I didn't see the
> respawning as a problem. The automated respawning is a feature.

Certainly, when it occurs, it's a symptom of a larger problem. That's not
to say that it wouldn't be useful to have more configurable respawning --
ranging from the simple "no more than N times in M minutes" to backoff
algorithms akin to those used for TCP.

Putting these more complex algorithms into runit, I agree, isn't
necessarily appropriate -- but that's why he mentioned having a second
process responsible for implementing them.