304: Condition specified using conditional HTTP header (s) not satisfied

Question

I am currently storing files in Azure Blob and when I request files I get a message in firebug from 304 "Condition specified using conditional HTTP headers not fulfilled"

I looked at Azure Blob: “The condition specified using conditional HTTP headers is not met” and its a similar question, but I'm not reading the contents when using blob.openread, etc. I'm just trying to view the contents in a browser.

If I update the control (ctrl and f5) in firefox, I get a 200 response - so its maintenance is working correctly. I installed the cache control (max-age = 3600, public) in the file that I am returning, but still getting this error / notification.

My question is, should I worry that when I ask for the content to come back with this answer?

Any advice / thoughts that you have will be greatly accepted.

Thanks Steve

Answer 1

If the content in the Blob repository has not changed since the last time you accessed the contents of your browser, this is the correct behavior.

An HTTP 304 status code is defined as "Not Modified" (see http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html ). I would suggest that your browser sent the ETag that it last received with the content in the Blob repository in the If-None-Match HTTP header, and since this ETag still matches the ETag associated with the content in the repository, there is no need to submit a new version to the wire.

Read more about ETags here: http://en.wikipedia.org/wiki/HTTP_ETag . You can see this behavior in action through Fiddler.

FireFox Ctrl-F5 explicitly forcibly updates, which means that the If-None-Match header is not sent. Therefore, Blob Storage sends a fresh copy of the image via cable.