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From Ben Ricker <>
Subject Re: [users@httpd] RE: Retransmissions seen for HTTP GETs and POSTS
Date Tue, 27 May 2008 21:49:03 GMT
TCP retransmissions are not related to Apache; it is an OS/network  
issue and you need to focus on the server interface configuration or  
the network(s) between the client and the server. There is a good,  
succinct troubleshooting guide here:

You might be looking at a network load issue or need to tweak the TCP  
retransmission timeout setting. But again, the issue is on the TCP/ 
networking layer and not an issue with Apache.

Good luck.


Ben Ricker


I use my cat's name for a password: he is called zo4W*!@n32G+ and I  
change his name every 60 days.

On May 27, 2008, at 4:23 PM, Nayman Felix-QA5535 wrote:

> I've posted this before, but since I haven't seen any response and  
> haven't had any success in debugging this, I'm wondering if anyone  
> can provide any insight.  My previous message is below:
> 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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