[PROXY] Questions about fTP proxy (fwd)

[Rob Hartill <ro...@imdb.com>]

---------- Forwarded message ----------
Date: Mon, 28 Jul 1997 13:07:36 -0700 (PDT)
From: "Philip A. Prindeville" <ph...@enteka.com>
To: apache-bugs@mail.apache.org
Subject: Questions about fTP proxy

Hi,

I recently installed apache 1.2.0 to experiment with the proxy server,
and I noticed that with dialup clients going through the proxy to
get large files (like the NT 4.0 Service Pack 3, about 20MB), performance
was much worse than when accessing the file directly, even though the
proxy has a 1.5Mb/s connection to the internet.

My expectation was that the proxy would do a suck of the file at 1.5Mb/s
(hence less than two minutes to grab the whole file) and then farm it
out at a constant rate to the dialup clients, without the transient
outages that ones seems on the internet that cause long lasting
connections to break (ie. large files as slow speeds).

But instead of seeing 3KBytes/sec to the clients, I'm seeing much worse
performance, on the order of 0.9KB/sec instead...  Can you explain what
I'm seeing here?

I thought it might be related to the small send window size, so I did
a grep for SO_SNDBUF and found that the SendBufferSize directive
controls this in the main body of code, but since the proxy module
seems to create all of its own sockets, this directive is never used
for the proxy's sockets.  Is there a fix for this?

Also, relating to the way that the proxy code works:  does it retrieve
the data from the remote server and *then* send out the data to the
client, ie. first getting the data "flat out" from the remote server,
or does it throttle the remote connection to only send data out as
quickly as the client can accept it, ie. synchronizing the transfer
to match the rate to the proxy/client connection?

Thanks,

-Philip