Hi, mod_deflate seems to overwrite Vary headers set by applications (or mod_headers) when serving proxied content. Below my virtualhost configuration and the test data. _____________ # cat /usr/local/apache/conf/deflate.conf <Virtualhost *> ServerName direct.test.nl DocumentRoot /var/www/html AddOutputFilterByType DEFLATE text/html text/plain text/css </VirtualHost> <Virtualhost *> ServerName proxy.test.nl ProxyPass / http://backend.test.nl/ ProxyPassReverse / http://backend.test.nl/ AddOutputFilterByType DEFLATE text/html text/plain text/css </VirtualHost> <Virtualhost *> ServerName backend.test.nl DocumentRoot /var/www/html </VirtualHost> _________________ # cat test.cgi #!/bin/sh echo "Content-type: text/html" echo "Vary: Accept" echo "" echo "" echo " <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <title>Test</title> </head> </body> </html> " ______________ # wget --header="Accept-Encoding: compress, gzip" -SO backendhtml backend.test.nl/cgi-bin/test.cgi 2>&1 | grep Vary 4 Vary: Accept # wget --header="Accept-Encoding: compress, gzip" -SO directhtml direct.test.nl/cgi-bin/test.cgi 2>&1 | grep Vary 4 Vary: Accept,Accept-Encoding # wget --header="Accept-Encoding: compress, gzip" -SO proxyhtml proxy.test.nl/cgi-bin/test.cgi 2>&1 | grep Vary 4 Vary: Accept-Encoding ______________ The last request should generate the same Vary header as the second one.. Kind regards, Marc Guardiola
Forgot to mention that mod_proxy is not the cause, without mod_deflate it works fine (The Vary header is not deleted by mod_proxy): # cat /usr/local/apache/conf/deflate.conf <Virtualhost *> ServerName backend.test.nl DocumentRoot /var/www/html </VirtualHost> <Virtualhost *> ServerName proxynodeflate.test.nl ProxyPass / http://backend.test.nl/ ProxyPassReverse / http://backend.test.nl/ </VirtualHost> __________________ # wget --header="Accept-Encoding: compress, gzip" -SO proxynodeflate proxynodeflate.test.nl/cgi-bin/test.cgi 2>&1 | grep Vary 4 Vary: Accept Regards, Marc
Created attachment 16995 [details] Patch against 2.0.x (merge Vary instead of setting it) I think you hit the problem that has been fixed on the trunk in r161691 (http://svn.apache.org/viewcvs.cgi?rev=161691&view=rev). Please try if the attached patch fixes your problem.
It works! Vary headers set by applications and/or by mod_headers are merged now. Thanks! Marc
Proposed for backport to 2.0.x: (http://svn.apache.org/viewcvs.cgi?rev=347969&view=rev)