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From Rainer Jung <rainer.j...@kippdata.de>
Subject Re: Speeding up mod_proxy_balancer on Windows
Date Mon, 13 Oct 2008 13:54:52 GMT
Mladen Turk wrote:
> Ruediger Pluem wrote:
>>
>>
>> Not exactly. I would prefer to fix the basic issue with Windows. If we 
>> need to
>> support milliseconds for connection timeouts seems to be another story 
>> for me.
>> Can some of the Windows gurus come to the rescue to either confirm and 
>> explain
>> why it takes that long for connect to return after trying to connect 
>> to a closed
>> port (on the same machine !!!) or if this must be a local issue on a 
>> specific machine.
>>
> 
> According to the Microsoft
> (http://support.microsoft.com/default.aspx/kb/314053)
> 
> TcpMaxConnectRetransmissions
> Key: Tcpip\Parameters
> Value Type: REG_DWORD - Number
> Valid Range: 0 - 0xFFFFFFFF
> Default: 2
> Description: This parameter determines the number of times that TCP 
> retransmits a connect request (SYN) before aborting the attempt. The 
> retransmission timeout is doubled with each successive retransmission in 
> a particular connect attempt. The initial timeout value is three seconds.
> 
> 
> So, looks like with default of 2 retransmits there is at least 9
> second delay.

I thought the problem was with local connects to a port, to which no 
process listens to. In this case the OS should immediately sending a RST 
(reset) and the client should not resend the SYN. I expect this 
TcpMaxConnectRetransmissions to be used in the case, were the remote 
server doesn't send any answer (neither RST nor SYN/ACK) and the client 
needs to retry the connection establishment after some timeout. That 
shouldn't be the case here, because the local system should always be 
able to send a RST if nothing is listening on the port.

Except there's a local firewall with packet drop coming into the game 
(or name resolution timeouts, or ...).

Regards,

Rainer

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