IP->hostname is called reverse DNS lookup.
The slowdown consistently occurs when the client's hostname does not have an
"A" DNS record; having a "PTR" but no "A" record slows things down even further.
Now, rather than worry about why some clients are set up this way, I want to
make sure the application does not care nor try to resolve the IP back into a
host. Something in Cocoon does that today, either an InetAddress object or
Request.getRemoteHost type call.
A similar issue was captured a while ago here:
http://osdir.com/ml/text.xml.cocoon.user/2002-07/msg01283.html
But in our case, the servlet container (resin) does not make these requests in
a separate test web app. Only cocoon does.
-----Original Message-----
From: Joerg Heinicke [mailto:[EMAIL PROTECTED]
Sent: Mon 6/4/2007 11:28 PM
To: [email protected]
Cc:
Subject: Re: hostname lookup
On 05.06.2007 02:41, Leonid Geller wrote:
> hostname of the http requestor/client. we have the lookup disabled in
> apache (2.2.4), so requests handled by the web server or our j2ee
> container/default web app do not experience this problem. we can tell
> that because 1) they result in access log entries that have client
> ip, not hostname, and 2) they are very fast :)
>
> a request to a cocoon web app results in the client's hostname logged
> in access log, and if the client is behind a proxy/firewall that
> prevents IP->host resolution, this results in a 15-20 sec response
> delay. subsequent requests from the same client return
> instantaneously, as the dns entry is now cached.
I've never heard of such a "feature" and I'm not aware of a IP->host
resolution, only the other way around. Do you have a stacktrace when it
fails?
Joerg
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