Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
1.3k views
in Technique[技术] by (71.8m points)

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

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:Sun, 27 Nov 2011 11:10:38 GMT
ETag:"12341234"
Set-Cookie:connect.sid=e1u...7o; path=/; expires=Sun, 27 Nov 2011 11:40:38 GMT; httpOnly
Transfer-Encoding:chunked
last-modified:Sat, 26 Nov 2011 21:42:45 GMT

I want the client to validate that the file hasn't changed on the server and send a "200" if it has otherwise a "304".

Firefox sends:

if-modified-since: Sat, 26 Nov 2011 21:42:45 GMT
if-none-match: "12341234"

Why isn't the chrome sending the same on a refresh of the page? I'm after the behavior that .Net has running:

context.Response.Cache.SetCacheability(HttpCacheability.ServerAndPrivate)
See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

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


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...