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From "Bill Stoddard" <b...@wstoddard.com>
Subject Re: Suggested direction for fixing threaded mpm thread startup.
Date Mon, 23 Apr 2001 03:28:38 GMT

> On Sun, 22 Apr 2001, Greg Ames wrote:
>
> > Bill Stoddard wrote:
> > >
> > > >
> > > > AFAIK, Paul hit this problem because of idle_server_maintenance and/or
> > > > MaxRequestsPerChild - true?  If that's really the extent of it, I
> > > > believe there's a pretty easy solution.
> >
> > > >
> > > > If you buy that, then why doesn't that solution work for
> > > > MaxRequestsPerChild as well?
> >
> > >
> > > True (IMHO).
> > >
> > > > For the low end folks it's probably the default anyway, which we
> > > > developers just pulled out of the air.  So if we have our mixed workload
> > > > process basket case scenario going on, just hold off on killing any more
> > > > processes until the first one terminates completely.
> > >
> > > Show us some code :-)
> > >
> >
> > OK, it's committed...works swell for me.  Paul?
>
> Um...  This is an incredibly dangerous change.  This makes Apache shutdown
> one threaded process at a time.  I think we have all downloaded tarballs
> that are hundreds of megs, which can take a few hours to download.  What
> happens if while my server is serving one of those files, I need to do a
> graceful restart to re-config my server.  If the first process shutdown is
> the one with the thread serving a three hour request, then my server won't
> actually restart for 3 hours.
>
> Ryan
>

I agree with you Ryan.  Haven't thought about this much over the weekend, but my inclination
is that
a combination of strategies is required. First, split the scoreboard into two, one for process
management and one for status.  The process management scoreboard will be small enough to
enable us
to overcommit processes to compensate for multiple processes being restarted at once. Then
as Greg
suggests, put some bounds on the number of process that may be in restart.

Bill


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