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On Fri, Jun 28, 2002 at 10:23:01PM +0800, Wensong Zhang wrote:
>
>
> Hi Horms,
>
> On Fri, 28 Jun 2002, Horms wrote:
>
> >
> > Interestingly I note that if a backup linux director takes over a
> > connection, its connection counters are not updated accordingly.
>
> Yes, the synchronized connections don't affect the server connection
> counters. After the backup takes over, new connections can be recorded in
> the server connection counters. And, in the most cases, the synchronized
> connections expires soon, so it doesn't affect the load balancing among
> the servers too much.
>
> > This is not a big problem, and doesn't cause any negative counts to
> > crop up, but may be worth fixing at some stage. What are your
> > thoughts?
> >
>
> There are several reasons that synchronized connections are not used in
> the server connection counters.
>
> 1) In many HA implementation, the backup load balancer doesn't have the
> ipvs scheduling table when it is in the standby mode. So, when the backup
> receives the synchronized connections, there is no server entry to update
> connection counters.
>
> 2) Even if the backup load balancer has the ipvs scheduling table, it is
> hard to lookup its server entry (through the address and port numbers).
> For example, you have to look up the virtual service first, if the
> connection belongs to the fwmark-based services, it is not possible to get
> the service entry through address and port. Then, you will have to
> synchronize the connections with its service info, it will transfer more
> data and bring more overhead.
>
> 3) Keep it simple :)
Hi Wensong,
That makes a lot of sense. I guess I was just supprised
that the connections didn't show up. I think that given
that this only effects connections that are active when a
fail-over takes palce it isn't really much of a problem
after all.
--
Horms
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