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From: Eric Dumazet <edumazet@google.com>
To: Ben Greear <greearb@candelatech.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
	Neal Cardwell <ncardwell@google.com>,
	netdev <netdev@vger.kernel.org>
Subject: Re: Debugging stuck tcp connection across localhost [snip]
Date: Wed, 12 Jan 2022 10:47:16 -0800	[thread overview]
Message-ID: <CANn89iK2iM=fM=EN3v3jfOfHRS4HKzbShLcnHt78U+OjnmeVjg@mail.gmail.com> (raw)
In-Reply-To: <a31557d8-13da-07e2-7a64-ce07e786f25c@candelatech.com>

On Wed, Jan 12, 2022 at 10:44 AM Ben Greear <greearb@candelatech.com> wrote:

> Well, I think maybe I found the problem.
>
> I looked in the right place at the right time and saw that the kernel was spewing about
> neigh entries being full.  The defaults are too small for the number of interfaces
> we are using.  Our script that was supposed to set the thresholds higher had a typo
> in it that caused it to not actually set the values.
>
> When the neigh entries are fully consumed, then even communication across 127.0.0.1
> fails in somewhat mysterious ways, and I guess this can break existing connections
> too, not just new connections.

Nice to hear this is not a TCP bug ;)

>
> We'll do some more testing with the thresh setting fix in...always a chance there is more than one
> problem in this area.
>
> Thanks,
> Ben

  reply	other threads:[~2022-01-12 18:47 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-06 14:59 Debugging stuck tcp connection across localhost Ben Greear
2022-01-06 15:20 ` Neal Cardwell
2022-01-06 15:39   ` Ben Greear
2022-01-06 16:16     ` Neal Cardwell
2022-01-06 19:05       ` Ben Greear
2022-01-06 20:04         ` Neal Cardwell
2022-01-06 20:20           ` Ben Greear
2022-01-06 22:26           ` Ben Greear
2022-01-10 18:10             ` Ben Greear
2022-01-10 22:16               ` David Laight
2022-01-11 10:46               ` Eric Dumazet
2022-01-11 21:35                 ` Ben Greear
2022-01-12  7:41                   ` Eric Dumazet
2022-01-12 14:52                     ` Ben Greear
2022-01-12 17:12                       ` Eric Dumazet
2022-01-12 18:01                         ` Debugging stuck tcp connection across localhost [snip] Ben Greear
2022-01-12 18:44                           ` Ben Greear
2022-01-12 18:47                             ` Eric Dumazet [this message]
2022-01-12 18:54                               ` Ben Greear

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