<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta content="text/html;charset=iso-8859-1" http-equiv="Content-Type">
</head>
<body dir="ltr" bgcolor="#ffffff" text="#000000">
Amos Shapira wrote:
<blockquote
cite="mid:9c2cca270906090421l71d467eap2b15339fba5105b0@mail.gmail.com"
type="cite">
<pre wrap="">2009/6/9 shimi <a class="moz-txt-link-rfc2396E" href="mailto:linux-il@shimi.net"><linux-il@shimi.net></a>:
</pre>
<blockquote type="cite">
<pre wrap="">At what layer do you define "dropping a request" ? Not accepting a TCP
connection (4) ? Failure to complete the request from the reverse proxy to
the backend servers (HTTP error) (assuming you have backend servers - the
network structure is not obvious from your original message)?
</pre>
</blockquote>
<pre wrap=""><!---->
We use Linux Virtual Server (LVS) in DR mode (i.e. packets come in to
a virtual IP through the LVS, outgoing replies are sent directly from
the Real Servers) in load-balancing (i.e. multiple servers accept and
handle requests in parallel).
Some of the Real Servers are configured as "persistent", i.e. all
requests from same client within a two-minute period will be handled
by the same Real Server, due to functional requirements, others don't
have this requirement.
</pre>
<blockquote type="cite">
<pre wrap="">What answers the TCP requests to port 80?
</pre>
</blockquote>
<pre wrap=""><!---->
All requests are handled by Apache 2.2 modules written in C++.
</pre>
<blockquote type="cite">
<pre wrap="">Do you use efficient HTTP handlers already, e.g. Lighttpd or even better,
nginx? :)
</pre>
</blockquote>
<pre wrap=""><!---->
We looked at it (lighttpd) and back then didn't see a justification to
make the switch (already had in-house knowledge to write Apache
modules vs. another learning period to take with lighttpd, plus
Apache's flexibility back when we didn't know what we'll need was a
factor, e.g. we also had php, perl and CGI code running around at the
beginning).
As far as we can tell the bulk of the load is inside our own
home-grown module, not inside Apache.
What I'd like to know is how many failed connections clients receive,
be it "connection refused" or time outs.
</pre>
</blockquote>
If it's at the TCP level you want to know this, a sniffer is probably
your best approach. I'm not aware of any ready made one, but writing a
dedicated one (even without libpcap) that is capable of living up to
the load you describe should not be too big a project.<br>
<br>
Contact me if you want a quote :-)<br>
<br>
Shachar<br>
<br>
<pre class="moz-signature" cols="72">--
Shachar Shemesh
Lingnu Open Source Consulting Ltd.
<a class="moz-txt-link-freetext" href="http://www.lingnu.com">http://www.lingnu.com</a>
</pre>
</body>
</html>