I have the following architecture on the web layer.
Varnish <-> Apache2 (mod_pagespeed <-> mod_jk) <-> Tomcat ^ ^ ^ | | |________: mod_jk | |_______________________________________________: port 8080 |__________________________________________________________: port 80
Where varnish and mod_pagespeed is installed with default config.
Now when i access the url http://example.org:8080 then i can see in the source code that mod_pagespeed was invoked and has rewritten the page (on the second refresh mind you as it wasn't cached the first time)
However when i access the url http://example.org:80 mod_pagespeed is not invoked and the html code is rendered unchanged.
The following shows the http headers recieved on each junction
PORT 80 < Server: Apache/2.2.14 (Ubuntu) < Set-Cookie: JSESSIONID=95ABA0EB57ACCBE15C9D7035C4397BD3; Path=/ < X-Mod-Pagespeed: 0.9.17.7-716 < Cache-Control: max-age=0, no-cache, no-store < Vary: Accept-Encoding < Content-Type: text/html;charset=UTF-8 < Content-Length: 13234 < Date: Wed, 01 Jun 2011 12:17:11 GMT < X-Varnish: 579414176 < Age: 0 < Via: 1.1 varnish < Connection: keep-alive PORT 8080 (mod_pagespeed working fine) < Date: Wed, 01 Jun 2011 12:19:26 GMT < Server: Apache/2.2.14 (Ubuntu) < Set-Cookie: JSESSIONID=DC3759CDE52D3B63A785F9C97B005EC0; Path=/ < X-Mod-Pagespeed: 0.9.17.7-716 < Cache-Control: max-age=0, no-cache, no-store < Vary: Accept-Encoding < Content-Length: 15990 < Content-Type: text/html;charset=UTF-8
Does anyone have any clues as of why this is happening? is it a bug in mod_pagespeed? is it caused by a config setting which is or isn't set in varnish or mod_pagespeed?
Any help to further drill down this issue is greatly appreciated.