RE: Establishing a new connection sometimes takes long (30s).

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Lars

Why would this be a DNS issue? The problem happens on the SERVER and HostnameLookups is Off!
Which name could Apache possibly want to look up? The server name is stored in the hosts. file for good measure.
Also the VirtualHosts are IP based so there is no name to be looked up.

The problem seems to occur BEFORE Apache even receives the message. 

Does Apache count (reverse) DNS lookups towards the execution time?

Thanks
Alex

-----Original Message-----
From: Lars [mailto:sunberg@xxxxxxxxx] 
Sent: 13 May 2008 09:22 AM
To: users@xxxxxxxxxxxxxxxx
Subject: Re:  Establishing a new connection sometimes takes long (30s).

Hi

Its most likely to be an DNS issue. If your not using vhosts, try
accessing it by its IP-adress. If that helps, check your DNS. Dont
remember your reverse dns settings.

--
  Lars

On Tue, May 13, 2008 at 9:10 AM, Alex Grässer <alexg@xxxxxxxxxxxxxxx> wrote:
> Hi
>
>  We are experiencing an intermittent but reproducible problem, where establishing a new connection to Apache httpd sometimes takes up to 30 seconds. We are running 350 threads with +-20 threads in keepalive state (according to /server-stats) and nothing else connecting or executing in Apache at the time the new connection comes in. There _should_ be a thread available for a new connection and the socket accept _should_ be listening. What we are seeing is that there is a pause between when the network card receives the message and Apache gets the message. In the test we were using a Java HttpConnection but we can reproduce the problem with IE and Firefox as well. There is no firewall on the machine.
>
>  Can anybody please explain why this could be happening or how we can go about finding the delay.
>
>  Thank you
>  Alexander Grässer
>
>  -TRACE------------------------
>  A case in point (delay of 17 seconds), running Packetyzer 5.0.0 on the network card:
>
>  13:02:25.249190000 client -> server : SYN (62 bytes)
>  13:02:25.249224000 server -> client : SYN ACK (62 bytes)
>  13:02:25.251134000 client -> server : ACK (60 bytes)
>  13:02:25.251864000 client -> server : HTTP GET (268 bytes)
>  13:02:25.442069000 server -> client : ACK (54 bytes)
>  13:02:42.960316000 server -> client : HTTP DATA (1514 bytes)
>  13:02:42.960327000 server -> client : HTTP continuation (155 bytes)
>  13:02:42.963080000 client -> server : ACK (60 bytes)
>
>  and then access.log (using LogFormat "%h %l %u %t \"%r\" %>s %b (%T/%D) \"%{Referer}i\" \"%{User-Agent}i\"" combined) indicates an execution time of 31,250 milliseconds.
>
>  [client-ip] - - [12/May/2008:13:02:42 +0200] "GET /xxxxx/xxxx HTTP/1.1" 200 1310 (0/31250) "-" "Java(tm) 2 SDK, Standard Edition v1.5.0_10 Java/1.5.0_10"
>
>  -CONFIG-------------------------
>  The config of the system is as follows: (Although we see this on differently configured Win2k machines as well)
>  System:
>   Microsoft Windows 2000
>   5.00.2195
>   Service Pack 4
>
>  Computer:
>   Intel(R) Xeon(TM)
>   CPU 3.20GHz
>   AT/AT Compatible
>   2,096,432 KB RAM
>
>  Disk:
>   Device: PERC LD 0 PERCRAID SCSI 6.34 GB (6,810,531,328 bytes) with 842 MB free.
>   Driver: Microsoft disk.sys, Version 5.0.2183.1 / 5.00.2195.6655 (11/14/1999)
>
>  Network:
>   Card: Intel(R) PRO/1000 MT
>   Driver: Intel e1000nt5.sys, version 7.2.19.0002 (8/2/2004)
>   WinSock: 3.10
>   WinSock32: 5.00.2195.6603
>
>  Apache
>   Server Version: Apache/2.2.8 (Win32) mod_jk/1.2.26
>   Server Built: Jan 18 2008 00:37:19
>  Httpd.conf:
>  <IfModule mpm_winnt_module>
>   ThreadsPerChild 350
>   ThreadLimit 350
>   ListenBacklog 511
>   MaxRequestsPerChild 0
>  </IfModule>
>  Timeout 300
>  KeepAlive On
>  MaxKeepAliveRequests 100
>  KeepAliveTimeout 120
>  HostnameLookups Off
>
>
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