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Re: Persistent connection synchronisation

To: "LinuxVirtualServer.org users mailing list." <lvs-users@xxxxxxxxxxxxxxxxxxxxxx>
Subject: Re: Persistent connection synchronisation
From: Paul Pech <paul.pech@xxxxxx>
Date: Sat, 29 Jul 2006 22:38:35 +0200
Hi Joe,

thanks for the swift answer.

> > So, am I right if I believe that:
> >
> > - Only connection states (ESTABLISHED, FIN_WAIT, NONE...) are
> > synchronized from lb1 to lb2
> 
> I thought only established connections were transferred.

Yes, you are right, FIN_WAIT is not being synchronised. But state 'NONE'
seems to get synchonised from lb1 to lb2, just without the same
expiration time as set on lb1.


> > I have tried to issue the command 'ipvsadm -A -t 10.0.0.222:80 -s lc -p
> > 3610 -M 255.255.255.0' on lb2 before starting the backup synchronisation
> > daemon on lb2, but this does not change the entries for expiration times
> > on lb2.
> 
> don't know what's supposed to happen there.

Well, this was a shot in the dark I tried to get the expiration times to
synchronise. As it does not work, the command should not be issued on
lb2.

> I take it that your setup is working and you just want to 
> make sure that you understand it?

Yes, my setup is working. I just wanted to make sure that there really
is no way to synchronise  expiration times of persistent connections
(state NONE) from lb1 to lb2. 

This is only important when lb1 fails and lb2 takes over. In this case,
almost all information about persistency is lost, as lb2 will only
recall persistent connections that occured in the last three minutes
(although the default setting for persistency is 300 seconds, so where
does it get the 180 seconds from?).

Yours, 

Paul


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