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Posted to dev@httpd.apache.org by Randy Terbush <ra...@zyzzyva.com> on 1997/06/30 00:34:15 UTC
Re: [PATCH] http_main big patch
I can vouch for it's dependability on FreeBSD 2.2.x
> Oh yeah, I meant to beef up that comment. I personally totally trust
> graceful on all the architectures I've used it on (linux 2.x, irix 5.3 and
> 6.2, solaris 2.5.1, bsdi 2.x). They handle a while 1 { kill -USR1 } loop
> no problem for about 10 minutes while still surfing the site without
> broken links.
>
> On those architectures, this will either kill off one child (satisfying
> the definition of scoreboard maintenance) or that one child's status will
> have changed between counting and killing, which also satisfies the
> definition of scoreboard maintenance. Er, well close enough -- Two
> children might change state, one into idle and one out of idle... but
> given the randomness of request arrival time this sort of thing isn't
> likely to happen for a long enough time for it to be critical.
>
> But it might fail on boxes where delivering a USR1 to the child is somehow
> unreliable. I'm open for other suggestions ... one option is a "char
> parent_says_die_now[ HARD_SERVER_LIMIT ];" array in the scoreboard. But
> this should be a #define that we add only when we discover such
> unfortunate boxes.
>
> Dean
>
> On Sun, 29 Jun 1997, Jim Jagielski wrote:
>
> > Dean Gaudet wrote:
> > >
> > > + if (idle_count > daemons_max_free) {
> > > + /* kill off one child... we use SIGUSR1 because that'll cause it to
> > > + * shut down gracefully, in case it happened to pick up a request
> > > + * while we were counting
> > > + */
> > > + kill (SIGUSR1, scoreboard_image->servers[to_kill].pid);
> >
> > Do we trust graceful restarts enough for this?
> > --
> > ====================================================================
> > Jim Jagielski | jaguNET Access Services
> > jim@jaguNET.com | http://www.jaguNET.com/
> > "Look at me! I'm wearing a cardboard belt!"
> >