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Date: Sun, 27 Apr 2008 17:37:17 -0400
Message-ID: <37275887801B1C46BEABB9FF44F0FF8D03FFBDDE@de01exm70.ds.mot.com>
Thread-Topic: Retransmissions seen for HTTP GETs and POSTS
Thread-Index: Aciort24VaP4VXYbRIWZuiVce9B82w==
From: "Nayman Felix-QA5535" <Felix.Nayman@motorola.com>
To: <users@httpd.apache.org>
Cc: "Brown Chris-CCB034" <Christopher.Brown@motorola.com>,
        "Kolodziej Cezary-QA5753" <Cezary.Kolodziej@motorola.com>
Subject: [users@httpd] Retransmissions seen for HTTP GETs and POSTS

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In some testing that I've done, anywhere from 1 to 10%  of HTTP GETs and
POSTs that apache receives are resulting in a TCP retransmission.  I've
captured a wireshark trace for these retransmissions and noticed that
the HTTP GET  or POST is being received, but no TCP ack is being sent
out resulting in a retransmission.  When the retransmission is received,
the ack for the initial GET or POST is finally sent back.  Has anyone
ever seen such a problem?  I don't see this issue with other TCP traffic
so it appears to be related to apache.   These tests were run with
Apache 2.2.4 and  on Linux 2.6.21.  If a wireshark trace would be
helpful I can provide one.  Thanks for any input.

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<DIV><FONT face=3DArial size=3D2><SPAN class=3D839003021-27042008>In =
some testing that=20
I've done, anywhere from 1 to 10% &nbsp;of HTTP GETs and POSTs that =
apache=20
receives are resulting in a TCP retransmission.&nbsp; I've captured a =
wireshark=20
trace for these retransmissions and noticed that&nbsp;the HTTP GET&nbsp; =
or POST=20
is being received, but no TCP ack is being sent out resulting in a=20
retransmission.&nbsp; When the retransmission&nbsp;is received,&nbsp;the =
ack for=20
the initial GET or POST is finally sent back.&nbsp; Has anyone ever seen =
such a=20
problem?&nbsp; I don't see this issue with other TCP traffic so it =
appears to be=20
related to apache.&nbsp;&nbsp; These tests were run with Apache 2.2.4 =
and&nbsp;=20
on Linux 2.6.21.&nbsp; If a wireshark trace would be helpful I can =
provide=20
one.&nbsp; Thanks for any input.</SPAN></FONT></DIV></BODY></HTML>

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