SUMMARY: More ESTABLISHED connection than Apache child process

From: Bousquet Francois <>
Date: Wed Jul 07 2004 - 16:18:53 EDT
I didn't fix my problem but this explanation of the ESTABLISHED connections
is from Russell Page:

"Established" means the operating system has accepted the connection
(Completed the three way SYN ACK SYN handshake). The connection is now in a
queue waiting for the application to process it. Every time apache closes a
connection there will be another one waiting to be processed. Obviously, if
the requests arrive more quickly than apache processes them, the
"Established" queue in the OS will fill up. Most likely users will
experience a timeout in their browsers when this happens.

Incidently, I have seen a Sun 450 running a Netscape server handling 50000
simultaneous requests!

-----Original Message-----
From: Bousquet Francois
Sent: July 6, 2004 3:03 PM
To: Mailing List - SunManagers (E-mail)
Subject: More ESTABLISHED connection than Apache child process


One of my server (E450 2 x UltraSPARC-II@400MHz, 1 Gb RAM Solaris 7 ) is
running Apache 1.3.31 to serve about 10 websites (http and https).  This
server is behind a firewall (CheckPoint) which allows only connections to
port 80 and 443.

Apache is configured with MaxClients 300 (compiled in consequence).

We were having test by a 3rd party vendor this afternoon and the number of
ESTABLISHED connection is netstat coming from the 3rd party IP was greater
than the number of max Apache child process.

netstat -an | grep ESTABLISHED | grep -c

How this is possible ?
Can ESTABLISHED connection be jammed in the IP stack and only cleared after
some time ?

Another question, this 3rd party is telling me that they are only doing 10
request at a time on my server but they were able to flood us in a way that
it was impossible to reach our website during that time.  Do you have cues
on what may be wrong with my webserver ?  Is the great number of ESTABLISHED
connection is the problem ?

- Frangois
sunmanagers mailing list
Received on Wed Jul 7 16:33:39 2004

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