Re: Suppress / delay SYN-ACK

Evgeniy Polyakov
2006-10-12T10:53:54Z

On Thu, Oct 12, 2006 at 12:39:30PM +0200, Eric Dumazet (dada1@cosmosbay.com) wrote:
> > You should break your decision into per state change transformations.
> > I think it is possible with either conntrack or netlink module Samir
> > Bellabes <sbellabes_mandriva.com> creates (Network Events Connector
> > subject) or even using syncookie algo changes.
>
> Hum.. they are some cases where conntrack is not an option (way too expensive
> if your server handle XXX.XXX concurrent tcp streams)

I think any netlink related work here can not be used for any kind of
high performance setup - it will be too slow to send/receive one or more
messages per state change for each new connection...

> > But it will drastically change your server performance...
>
> Sure, at least its capacity to answer to SYN packets (session establishment
> should be slower, unless the thread receiving/handling SYN packets has
> realtime scheduling)

Maybe it will be better to create some more complex protocol which will
collect data before sending netlink message, or just use a procfs file
or syscall/ioctl/socket option.

> Eric

--
Evgeniy Polyakov