Re: [squid-users] Keep-Alive header not being displayed

From: Alex Rousskov <rousskov_at_measurement-factory.com>
Date: Fri, 12 Sep 2008 08:38:27 -0600

On Fri, 2008-09-12 at 03:47 -0700, JL wrote:
> On Thu, Sep 11, 2008 at 10:58 PM, Alex Rousskov
> <rousskov_at_measurement-factory.com> wrote:
> > On Thu, 2008-09-11 at 19:11 -0700, JL wrote:
> >
> >> I have configured my browser to use my Squid HTTP proxy and am going
> >> to the following URL to check the HTTP headers:
> >> http://www.proxyjudge.biz/az.php
> >>
> >> Unfortunately the HTTP_KEEP_ALIVE = 300 header is not displayed and I
> >> would like it to be.
> >
> > Squid does not forward the Keep-Alive header because Squid considers it
> > a hop-by-hop header. Per HTTP protocol, hop-by-hop headers are not
> > forwarded by proxies. When a client sends Keep-Alive to a proxy, the
> > header is for the proxy and not for the origin server; it only applies
> > to the connection that ends at the proxy.
> >
> > FWIW, the header itself is outdated and probably not supported by many
> > HTTP agents. Squid itself uses a Connection header to signal HTTP
> > connection persistence. The Connection is also a hop-by-hop header,
> > naturally.
> >
> > It may help if you explain why you want to see that header sent to the
> > script. What are you trying to accomplish or check?

> Alex, thank you for taking the time to help me. An individual that is
> using the proxy requires the HTTP_KEEP_ALIVE header as a script that
> worked with another proxy server is now not working. The only apparent
> difference is the lack of the HTTP_KEEP_ALIVE header. So, basically
> the individual is claiming the lack of the HTTP_KEEP_ALIVE header is
> preventing the script from working properly.

A script that requires a Keep-Alive header is broken because that header
is optional, hop-by-hop, and deprecated. If the individual can fix the
script, please advise them that the problem is on their side. At the
minimum, they can even wrap the script in a different one that sets the
HTTP_KEEP_ALIVE environment variable to zero, to meet script's unfounded
expectations.

If the individual does not have any control over the script
execution/code or does not want to change anything, you can [get
somebody to] hack Squid to send a Keep-Alive header. I did not find any
configuration options that would allow you to add a header to the
request, unfortunately.

Cheers,

Alex.
Received on Fri Sep 12 2008 - 14:39:40 MDT

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