Re: question about 3sec timeouts with tcp

[Gabriel Barazer]

On 04/01/2008 7:01:07 PM +0200, Leo <neleo@xxxxxxx> wrote:
> Brett Paden wrote:
> > on Tuesday, Apr 01, 2008, H. Willstrand, wrote:
> >  
> > > On Tue, Apr 1, 2008 at 4:43 PM, Brett Paden <paden@xxxxxxxxxxxx> wrote:
> > >    
> > > > > If I'm right Brett's problem relays in the test client (provided in
> > > > >         
> > > >  > the first mail). This has probably to do with the number of ports
> > > >  > opened and closed during a short time period.
> > > >
> > > >  My test client is designed to simulate the sort of load our production
> > > >  databases and web servers see.  We're talking on the order of 100-400
> > > >  connections per second.  On an unloaded server the 3000ms occur right
> > > >  around 400 connections a second but we have seen them a lower 
> > > > connection
> > > >  rates.  Are you suggesting that we could do something simple (like 
> > > > reap
> > > >  TIME_WAIT connections) to allevaite the problem?
> > > >
> > > >
> > > >
> > > >       
> > > What I try to say is that I also got a 3000ms delay, at client-side...
> > > No problems at server-side at all. Do you expirience the same?
> > >     
> >
> > Yes; exactly the same
> >   
> And we did too ...

There is no doubt that Leo's problem, Brett/Marlon's one and mine are 
the same.

I'm going to reopen my capture files to take a more precise look at the 
sequence numbers. Note that when capturing in promiscuous mode on the 
client, I capture the SYN/ACK server packet, but the client doesn't 
seems to process it. Definitely not a network issue. I also tested 
with/without TOE/TSO engine and other fancy I/OAT stuff, this doesn't 
change a thing, except my CPU load.

Gabriel
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