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Questions tagged [etag]

ETag is an HTTP Entity Tag. Use this tag if you have a question about HTTP requests using ETag, If-Match or If-None-Match headers, or the generation and comparison of ETag values.

An ETag is an opaque identifier assigned by a web server to a specific version of a resource found at a URL. If the resource content at that URL ever changes, a new and different ETag is assigned. Used in this manner ETags are similar to fingerprints, and they can be quickly compared to determine if two versions of a resource are the same or not.

http://en.wikipedia.org/wiki/HTTP_ETag

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Remove Etag Header in express

I have searched a lot and still couldn't find a solution, I am using nodejs with express which is setting etag to true by default, I tried all of the solutions i found online and it is still set, examples: res.set('etag',…
Labib Ismaiel
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In Nginx, "etag" directive doesn't work for proxy_pass?

I'm using Nginx 1.9.2 and following is my configuration upstream httpserver0{ server 127.0.0.1:35011 max_fails=3 fail_timeout=30s; #H_server0 …
Hanfei Sun
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Does if-no-match need to be set programmatically in ajax request, if server sends Etag

My question is pretty simple. Although while searching over, I have not found a simple satisfying answer. I am using Jquery ajax request to get the data from a server. Server hosts a rest API that sets the Etag and Cach-control headers to the GET…
Irshad
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Android WebView cache doesn't expire

in my Android App I use a WebView and got a problem with caching. After a file is cached the WebView just keeps it forever (or at least until I delete the cache manually). In the Apache Access-Log I see that the WebView doesn't send requests once…
Norkos
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HTML ETags and Github Pages

I am taking a course at Udacity and we are learning about the caching system that the ETags provide: https://developers.google.com/web/fundamentals/performance/optimizing-content-efficiency/http-caching I am using GitHub pages, and from an answer…
Flame_Phoenix
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Does If-None-Match header overrules Cache-Control: max-age?

I have a webapp that serves an image: I'm clearly setting the Cache-Control header properly, and the web server is setting the Etag. The problem is that the resources is being If-None-Matched every single time effectively ignoring the Cache-Control…
Pablo Fernandez
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HTTP ETags and HTTP Redirects

I have a webserver that issues the ETag header on responses and checks the If-None-Match header from the client, if present. The client in this case, is not a web browser but an extension of go's builtin net/http http.Client type. Here is my code…
Eric Urban
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Get scheduled extra updates from Doctrine UnitOfWork

I have a Doctrine Event Listener that listens to the onFlush event. I use it to update an eTag on an entity when saved. I need to get access to the entities scheduled for deletion, so I can access their associated object, however: I'm using a…
Adam
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IE does not return If-None-Match header over https

I have a problem with caching content using etags on IE over https. Chrome and Firefox allow me to successfully cache content using a combination of If-Modified-Since and If-None-Match The If-None-Match header is important because the same page…
niciliketo
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YSlow giving inconsistent results on ETags

When I run YSlow against my site, I get an "F" on the "Configure ETags" item; it claims that there are no etags for many (all?) of my images, stylesheets, etc. However, if I run the test on one of those images directly, I get an A on the etag test.…
Craig Walker
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Does the iOS Networking Framework (NSURLCache) transparently handle ETags?

We are wondering, whether NSURLCache transparently handles ETag based caching headers. Asked differently: If correctly setting up NSURLCache, will the iOS networking framework automatically "remember ETags per request URI" and add them to request…
Ralf
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spring's ETag filter is not effective when I use async servlet (spring 3.2)

Recently we use async feature in servlet 3.0 with spring 3.2, but then our ShallowEtagHeaderFilter was not effective at all, I think it must be the framework flush the response before my content was processed ... How to solve it? Anyone has…
lzj
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AFNetworking returns 200 when should receive 304 - ETag

I'm tring to use the etag to cache my images, the first time it downloads all the images like it should however the second time it does too when it should enter the failed block with 304. I've tried making the request externally and I get 304 like…
Mike Bryant
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GET request with "If-Match" and ETags

I'm working on implmenenting ETag functionality for a RESTful service, and I'd like to be as close to the HTTP spec as possible. The spec however is not as clear as it probably should be. Specifically: The If-Match header - what are it's semantics…
Eugen
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Android Image loader library with support for ETags, If-Modified-Since

I've been using for some time Android Http Image Manager, and recently I switched over to Android Universal Image Loader I'm afraid neither of them have support for verifying if local cache is up-to-date. What I'm currently looking for is an Image…
Marek Sebera
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