Chrome browser is not sending if-modified-since header to server

Question

I have these headers being sent to the client by the server:

Cache-Control:private
Connection:keep-alive
Content-Encoding:gzip
Content-Type:text/html
Date:Su         


        

Answer 1

After spending half a day on this yesterday, I tracked down what was causing the issue for me. So long as you have the Chrome object inspector/Client Debugger/Network monitor/Thing that pops up when you hit F12, Chrome will not send cache request headers. Period. (update: in newer versions of Chrome, there is a checkbox "Disable cache"). Even if you don't have the "network" tab open (ex: have the javascript console open), this checkbox still disables all cacheing.

Its sad, because debugging this from the client side obligates you to leave the network panel open to see what headers are being sent and received, and what codes are being returned. Without the network panel open, there is no way to know if your content is being cached from the client side.

If you dig into your server access logs, you will notice your server returning 304s(Cached Content) the minute you close the debug window on your Chrome client. Hope this helps.

Chrome 24.0.1312.57