On Tue, 19 Aug 2008, Nicholas Guarracino wrote:
> I have a cluster set up for load balancing a web based application
> that requires persistent connections. I'm using the ipvs sync daemon
> to keep the connection state information consistent between director
> and backup director. However, many times after a failover, the
> persistence does not work and clients end up connected to a different
> realserver. I'm running this on kernel 2.6.18 (RHEL 5, so not exactly
> bleeding edge.)
thanks for the nice description
> So after the failover, the clients' connections have been reversed:
> 18.104.22.168 is now connected to 10.204.54.166
> 22.214.171.124 is now connected to 10.204.54.167
> If I run ipvsadm -L on the backup director before the failover, I do
> see the proper connections so I know the multicast is getting through.
is there persistence on the backup director?
> Any thoughts on what I might be doing wrong?
Possibly nothing. It may be a bug. persistence has a lot of
problems. I personally suggest using the -SH scheduler for
your type of setup, but it hasn't been extensively tested
under the synch demon, so I don't know what will happen
there. There has been updates (not much) to the synch demon
since your kernel (and I don't know if they address your
problem). I can put the ball back in your court by asking
you to try a recent kernel. I remember something about
persistence and the synchd recently, but I looked back in my
list of open problems and didn't see it, so I don't know
what it might have been.
do you know any problems with the synchd not
transfering persistent state info to the backup director on
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