Re: [PATCH ipvs-next] ipvs: count pre-established TCP states as active

From: Simon Horman
Date: Mon Jun 13 2016 - 01:20:19 EST


On Sun, Jun 12, 2016 at 06:27:39PM +0300, Julian Anastasov wrote:
>
> Hello,
>
> On Fri, 3 Jun 2016, Michal Kubecek wrote:
>
> > Some users observed that "least connection" distribution algorithm doesn't
> > handle well bursts of TCP connections from reconnecting clients after
> > a node or network failure.
> >
> > This is because the algorithm counts active connection as worth 256
> > inactive ones where for TCP, "active" only means TCP connections in
> > ESTABLISHED state. In case of a connection burst, new connections are
> > handled before previous ones have finished the three way handshaking so
> > that all are still counted as "inactive", i.e. cheap ones. The become
> > "active" quickly but at that time, all of them are already assigned to one
> > real server (or few), resulting in highly unbalanced distribution.
> >
> > Address this by counting the "pre-established" states as "active".
> >
> > Signed-off-by: Michal Kubecek <mkubecek@xxxxxxx>
>
> Acked-by: Julian Anastasov <ja@xxxxxx>
>
> Simon, please apply!

Thanks, done.