netdev - Re: PROBLEM: Linux kernel 2.6.31 IPv4 TCP fails to open huge amount of outgoing connections (unable to bind ... )

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Date:	Wed, 21 Apr 2010 05:12:44 +0500
From:	Gaspar Chilingarov <gasparch@...il.com>
To:	Eric Dumazet <eric.dumazet@...il.com>
Cc:	Ben Greear <greearb@...delatech.com>,
	David Miller <davem@...emloft.net>,
	netdev <netdev@...r.kernel.org>
Subject: Re: PROBLEM: Linux kernel 2.6.31 IPv4 TCP fails to open huge amount 
	of outgoing connections (unable to bind ... )

2010/4/21 Eric Dumazet <eric.dumazet@...il.com>:
> Le mardi 20 avril 2010 à 16:49 -0700, Ben Greear a écrit :
>> On 04/20/2010 04:35 PM, Gaspar Chilingarov wrote:
>> > sysctl -a | grep local_port_range
>>
>> [root@...03-10G-09 ~]# sysctl -a | grep local_port_range
>> net.ipv4.ip_local_port_range = 10000  61000
>>
>> I'm explicitly binding to local ports as well as local IPs, btw.
>>
>
> I believe the bsockets 'optimization' is a bug, we should remove it.
>
> This is a stable candidate (2.6.30+)
>
> [PATCH net-next-2.6] tcp: remove bsockets count
>
> Counting number of bound sockets to avoid a loop is buggy, since we cant
> know how many IP addresses are in use. When threshold is reached, we try
> 5 random slots and can fail while there are plenty available ports.
>

Thank you a lot for the patch - I will try it.

In FreeBSD I was able to add about 32 C classes (8192 ips) on the
single interface (never tried to do that in Linux yet :) - so you
really never know how much IP's are there available. Tens and even up
to hundred IPs on the single machine are not that usual in hosting
environment at all.

/Gaspar
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