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Posted to apache-bugdb@apache.org by Jos� Mar�a Fern�ndez Gonz�lez <jm...@cnb.uam.es> on 1999/05/17 12:43:09 UTC
mod_proxy/4427: Apache reverse proxy and CGI's

>Number:         4427
>Category:       mod_proxy
>Synopsis:       Apache reverse proxy and CGI's
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    apache
>State:          open
>Class:          sw-bug
>Submitter-Id:   apache
>Arrival-Date:   Mon May 17 03:50:01 PDT 1999
>Last-Modified:
>Originator:     jmfernandez@cnb.uam.es
>Organization:
apache
>Release:        1.3.6
>Environment:
SunOS montblanc 5.7 Generic sun4u sparc SUNW,Ultra-60
gcc version 2.8.1
>Description:
        I have a Apache server (called A) configured as a reverse proxy, and it passes
some requests to a slave Apache server (called B) on another machine. My problem
is that I have a CGI program on B and when you run against B there is no
problem, but when you run the same CGI against A (the browser makes the request
to A, A makes the request to B, B processes the requests, B returns the answer
to A, and A returns the answer to the browser), it seems A is making some
caching, because only when the CGI has finished you get the answer. I don't want
this because the CGI program is using server push techniques to give the
answers. I have deactivated the proxy caching, so, where is the problem? Is
there a bug on Apache? I think the problem could be on the rewrite rule, when it
passes what it made to the proxy module, but I'm not an Apache hacker.
>How-To-Repeat:
You must configure server A with two lines like these (with mod_rewrite and
mod_proxy enabled, and proxy configuration enabled, too):

RewriteRule    ^/(jmfernandez.*)$  http://A.B.C/$1 [P,L]
ProxyPassReverse  /jmfernandez/ http://A.B.C/jmfernandez/

and the server B with this configuration line:

ScriptAliasMatch ^/(.*)/cgi-bin(.*)$	/usr/local/apache/htdocs/$1/cgi-bin$2

On server B, at /usr/local/apache/htdocs/jmfernandez/cgi-bin, put this simple
Perl program, and run calling through A or B, and you will be able to sense the
differences:

#!/usr/local/bin/perl -w

use strict;
&main;

sub main {
	my($dolar)=5;
	$|=1;
	print<<'EOF';
Content-type: multipart/x-mixed-replace;boundary=appboundary

--appboundary
EOF
	while($dolar--) {
		print<<'EOF';
Content-type: text/html

<HTML>
<META HTTP-EQUIV="Pragma" CONTENT="no-cache">
<BODY><CENTER><H1>H O L A</H1></CENTER>
</BODY></HTML>
--appboundary
EOF
	sleep 3;
	print<<'EOF';
Content-type: text/html

<HTML><BODY>
<CENTER><H1>A D I O S</H1></CENTER>
</BODY></HTML>
--appboundary
EOF
	sleep 3;
	}
}
>Fix:

>Audit-Trail:
>Unformatted:
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