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From: Grant <emailgrant@gmail.com>
To: Gentoo mailing list <gentoo-user@lists.gentoo.org>
Subject: [gentoo-user] Re: TCP Queuing problem
Date: Mon, 19 Sep 2016 14:25:04 -0700	[thread overview]
Message-ID: <CAN0CFw1iVY=d5Yvy1PPxr+CkMBSQ0vOtR_1XgkxgEpMqm89HsA@mail.gmail.com> (raw)
In-Reply-To: <CAN0CFw1f+iybqsg=0k+somE9vANZt9byQgWmwtMZN=84DawyTA@mail.gmail.com>

>> My web server's response time for http requests skyrockets every
>> weekday between about 9am and 5pm.  I've gone over my munin graphs and
>> the only one that really correlates well with the slowdown is "TCP
>> Queuing".  It looks like I normally have about 400 packets per second
>> graphed as "direct copy from queue" in munin throughout the day, but 2
>> to 3.5 times that many are periodically graphed during work hours.  I
>> don't see the same pattern at all from the graph of all traffic on my
>> network interface which actually peaks over the weekend.  TCP Queuing
>> doesn't rise above 400 packets per second all weekend.  This is
>> consistent week after week.
>>
>> My two employees come into work during the hours in question, and they
>> certainly make frequent requests of the web server while at work, but
>> if their volume of requests were the cause of the problem then that
>> would be reflected in the graph of web server requests but it is not.
>> I do run a small MTU on the systems at work due to the config of the
>> modem/router we have there.
>>
>> Is this a recognizable problem to anyone?
>
>
> I'm in the midst of this.  Are there certain attacks I should check for?


It looks like the TCP Queuing spike itself was due to imapproxy which
I've now disabled.  I'll post more info as I gather it.

- Grant


  reply	other threads:[~2016-09-19 21:25 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-17 21:13 [gentoo-user] TCP Queuing problem Grant
2016-09-19 17:23 ` [gentoo-user] " Grant
2016-09-19 21:25   ` Grant [this message]
2016-09-20  0:38     ` Grant
2016-09-20 13:08       ` Grant
2016-09-21  4:01         ` Kai Krakow
2016-09-21 14:30           ` Grant
2016-09-21 19:29             ` Kai Krakow
2016-09-21 19:37               ` Grant
2016-09-21 20:06                 ` Kai Krakow
2016-09-21 20:28                   ` Kai Krakow
2016-09-21 19:41               ` Kai Krakow
2016-09-21 19:53                 ` Grant
2016-09-21 20:18                   ` Kai Krakow
2016-09-21 20:47                     ` Grant
2016-09-21 21:44                       ` Michael Mol
2016-09-22  0:30                         ` Grant
2016-09-22  7:06                       ` Kai Krakow
2016-09-25  0:25                         ` Grant
2016-10-01  9:57                           ` Grant
2016-09-20 13:50       ` J. Roeleveld
2016-09-20 14:53         ` Grant
2016-09-20 18:06           ` J. Roeleveld
2016-09-20 19:52             ` Grant
2016-09-20 20:19               ` Alarig Le Lay
2016-09-22 16:58               ` Volker Armin Hemmann

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