long daemon outages on upgrade
My apologies if this has been raised an settled before.
Today I upgraded my firewall (62MBs worth - it's still serving as a backup
box ATM). All went well except that for about 10mins I lost most of my
internet access.
Why? Well both bind and squid where stopped as part of the upgrade, then
the upgrade continued on it's merry way for a while, finally restarting the
daemons 10 mins later. Is there any need for this? Can't we just issue a
"restart" once everything is done to minimize the service outage to a few
seconds?
I suspect that part of the issue is that this is how debhelper does things
by default (that's explains bind9 at least). dh_installinit can take a -r
flag to say "don't restart on an upgrade (just start if it's a new install).
Would it be worthwhile changing the default to "restart on an upgrade" and
maybe adding a "stop in prerm, start in postinst" option which does the
current behaviour? The only problem I can forsee is daemons which watch
their configuration files all the time rather than when they are sigHUPd or
started.
Whilst it'd be nice to have a minimum outage for most daemons, we should do
it for the most useful ones - bind, squid, email, gpm. Note that gpm
already follows this idea (no long outage on upgrades).
Adrian
Email: adrian.bridgett@iname.com
Windows NT - Unix in beta-testing. GPG/PGP keys available on public key servers
Debian GNU/Linux -*- By professionals for professionals -*- www.debian.org
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