cache-control

问题 I've a CMS application code which calls Response.Cache.SetNoStore() on all request and if i'm correct, this will be prevents proxies/cdn to cache those pages/content. Therefore, i'm conditionally calling the below code: Response.Cache.SetCacheability(HttpCacheability.Public); Response.Cache.SetMaxAge(new TimeSpan(0, 30, 0)); Response.Cache.SetValidUntilExpires(true); But this doesn't take out the no-store param from the response header, this is the returned http header: Cache-Control:public,

问题 Expressjs automatically send etags. I would like to know how the etag is generated..is it based on the content that is generated dynamically by the get routine. or is there way I can mainpulate it, by not even going through the process of generating the content(dynamic content - from DB) and pass back etag as same. may be a middleware which start with just checking if it is valid session id and pass back the same etag that the client gives or may be based of the url + session id..that way it

问题 I have a handful of directories with content which will never change. Is it possible to create .htaccess file which tells the browser that anything in this directory and sub- directories can be cached for a very long time? I would like to copy the same .htaccess file in each directory if possible. If this is possible would you recommend max-age over expires or both? 回答1: So it does look possible.... the .htaccess file syntax is: Header unset Last-Modified FileETag none ExpiresActive On

问题 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

问题 I'm hosting an SPA on firebase where almost all paths get rewritten to index.html . I'm using webpack hash based cache busting, so I want to always prevent caching of my index.html but not any other files. I'm finding it surprisingly difficult to do so. Specifically, my file layout looks like this / ├── index.html ├── login.html ├── js │ ├── login.ba22ef2579d744b26c65.bundle.js │ └── main.6d0ef60e45ae7a11063c.bundle.js └── public └── favicon-16x16.ico I started naively with "sources": "index

问题 i'm issuing a request using MSXML's XmlHttpRequest object: IXMLHttpRequest http = new XmlHttpRequest(); http.open("GET", "http://www.bankofcanada.ca/stat/fx-xml.xml", False, "", ""); http.send(); And the send succeeds, and i get my xml data. Except that XmlHttpRequest didn't actually hit the network (i can see there no actual http request issued). And Process Monitor shows the file is actually being served from my cache: So i want to instruct the XmlHttpRequest user agent that any cached

问题 When I visit chesseng.herokuapp.com I get a response header that looks like Cache-Control:private Connection:keep-alive Content-Encoding:gzip Content-Type:text/css Date:Tue, 16 Oct 2012 06:37:53 GMT Last-Modified:Tue, 16 Oct 2012 03:13:38 GMT Status:200 OK transfer-encoding:chunked Vary:Accept-Encoding X-Rack-Cache:miss and then I refresh the page and get Cache-Control:private Connection:keep-alive Date:Tue, 16 Oct 2012 06:20:49 GMT Status:304 Not Modified X-Rack-Cache:miss so it seems like

问题 For the following image: https://upload.wikimedia.org/wikipedia/commons/7/79/2010-brown-bear.jpg There isn't any cache-control header. And based on here even if you don't send anything then it will use its default value which is private . That being doesn't the URLSession need to perform a conditional request to make sure its still valid? Is there anything in the headers that allows it to make such a conditional request? Because I don't see cache-control , max-age , Expires . The only things

问题 Definition of ETag header (https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/ETag): The ETag HTTP response header is an identifier for a specific version of a resource. It allows caches to be more efficient, and saves bandwidth, as a web server does not need to send a full response if the content has not changed. On the other side, if the content has changed, etags are useful to help prevent simultaneous updates of a resource from overwriting each other ("mid-air collisions").

问题 I am making a a request to an image and the response headers that I get back are: Accept-Ranges:bytes Content-Length:4499 Content-Type:image/png Date:Tue, 24 May 2011 20:09:39 GMT ETag:"0cfe867f5b8cb1:0" Last-Modified:Thu, 20 Jan 2011 22:57:26 GMT Server:Microsoft-IIS/7.5 X-Powered-By:ASP.NET Note the absence of the Cache-Control header. On subsequent requests on Chrome, Chrome knows to go to the cache to retrieve the image. How does it know to use the cache? I was under the impression that I