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Date: Mon, 18 Jul 2011 10:48:03 +0400
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From: Vladimir Budnev <vladimir.budnev@gmail.com>
To: Andre Oppermann <andre@freebsd.org>
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Subject: Re: (TCP/IP) Server side sends RST after 3-way handshake.Syn flood
 defense or queue overflow?
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> When you enable "net.inet.tcp.log_debug=1" it will tell you at LOG_DEBUG
> level what went wrong and why it sent the RST.
>


Thank you Andre. Now its clear what causes the problem, here is what i got
in logs:
Jul 18 10:33:55  kernel: TCP: [127.0.0.1]:52971 to [127.0.0.1]:10002
tcpflags 0x10<ACK>; tcp_input: Listen socket: Socket allocation failed due
to limits or memory shortage, sending RST

I'v decided not to tune system parametrs cause it looks like a "crutch".
I'll rewrite data sending mechanism to "one connection and stream
transmission fro all chunks" instead of "one connection for each data
chunk". That way there will be no more huge connections amount per second to
the server side.