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

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Date:	Mon, 13 Jun 2016 14:20:07 +0900
From:	Simon Horman <horms@...ge.net.au>
To:	Julian Anastasov <ja@....bg>
Cc:	Michal Kubecek <mkubecek@...e.cz>, lvs-devel@...r.kernel.org,
	Wensong Zhang <wensong@...ux-vs.org>,
	netfilter-devel@...r.kernel.org, coreteam@...filter.org,
	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	Pablo Neira Ayuso <pablo@...filter.org>,
	Patrick McHardy <kaber@...sh.net>,
	Jozsef Kadlecsik <kadlec@...ckhole.kfki.hu>,
	"David S. Miller" <davem@...emloft.net>
Subject: Re: [PATCH ipvs-next] ipvs: count pre-established TCP states as
 active

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@...e.cz>
> 
> Acked-by: Julian Anastasov <ja@....bg>
> 
> 	Simon, please apply!

Thanks, done.