From: Aleksandar Milivojevic <amilivojevic@pbl.ca>
To: netfilter@lists.netfilter.org
Subject: Re: connection tracking without iptables?
Date: Mon, 25 Oct 2004 15:48:44 -0500 [thread overview]
Message-ID: <417D66AC.1070600@pbl.ca> (raw)
In-Reply-To: <561dc326041014113163a6a9eb@mail.gmail.com>
Jiann-Ming Su wrote:
> On Thu, 30 Sep 2004 19:34:30 -0400, Jason Opperisano <opie@817west.com> wrote:
>
>> egrep 'ESTABLISHED|ASSURED' /proc/net/ip_conntrack | wc -l
>>
>
>
> We're finding that any read operation on /proc/net/ip_conntrack really
> locks the system until that operation is completed. That is, it's
> almost as if the read prevents any writes, so the firewall locks up
> momentarily until the read is done. Is there a less system intensive
> way to read ip_conntrack? Or, is my observation completely wrong?
From linux kernel 2.6.9 changelog:
[NETFILTER]: add sysctl to read out the number of current connections
Apparently a lot of scripts use a construct like
cat /proc/net/ip_conntrack | wc -l
which has a negative impact on system performance due to all the locking
required.
--
Aleksandar Milivojevic <amilivojevic@pbl.ca> Pollard Banknote Limited
Systems Administrator 1499 Buffalo Place
Tel: (204) 474-2323 ext 276 Winnipeg, MB R3T 1L7
next prev parent reply other threads:[~2004-10-25 20:48 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-09-30 18:19 connection tracking without iptables? Daniel Chemko
2004-09-30 18:26 ` Jason Opperisano
2004-09-30 23:04 ` Jiann-Ming Su
2004-09-30 23:34 ` Jason Opperisano
2004-10-14 18:31 ` Jiann-Ming Su
2004-10-14 18:57 ` Jason Opperisano
2004-10-15 5:16 ` Kiran Kumar Immidi
2004-10-16 12:30 ` Jose Maria Lopez
2004-10-25 20:48 ` Aleksandar Milivojevic [this message]
-- strict thread matches above, loose matches on Subject: below --
2004-09-30 23:20 Daniel Chemko
2004-09-29 21:22 Daniel Chemko
2004-09-30 2:24 ` Jiann-Ming Su
2004-09-29 20:50 Jiann-Ming Su
2004-09-29 20:57 ` Alexis
2004-09-29 21:01 ` Jason Opperisano
2004-09-29 21:37 ` Jose Maria Lopez
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