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Malcolm Turnbull wrote:
> Question 1 :
>
> As HTTP is stateless is it safe to switch off a real server once weight
> has been set to zero ? (after waiting about 1 min for current page
> downloads to complete. I assume the users will get a stall otherwise.)
probably/maybe/but you can't be sure.
There is persistent connection in http 1.1, so the client may still be
connected. see
http://www.linuxvirtualserver.org/Joseph.Mack/HOWTO/LVS-HOWTO-6.html#ss6.1
The best thing is to wait till InActConn=0, but even that isn't perfect (see
next question).
> Question 2 :
>
> Whats the difference between an active connection and an inactive one ?
> Does it just depend on TCP timeouts ?
basically yes. In LVS-DR the director doesn't see the tcp packets from
the realserver to the client. When the realserver initiates breaking
the tcp connection, the director has to guess as to what may be going on,
and looks at reply packets from the client. The director uses it's own
table of tcp timeouts to declare a connection dropped. An InActConn is one
that the director knows existed a little while ago and which the client has
initiated the disconnect, but which hasn't timed out on the director yet.
Joe
--
Joseph Mack PhD, Senior Systems Engineer, SAIC contractor
to the National Environmental Supercomputer Center,
mailto:mack.joseph@xxxxxxx ph# 919-541-0007, RTP, NC, USA
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