XAP Expires after half a Day?

Question

Im just wondering what would be causing my xap to expire every half day (approx). What i mean is that in the morning a user hits the website and it downloads a copy of the xap, by the afternoon if that user goes back to the website and the website downloads another copy of the xap for them.

I would hope that the only reason that a user should need to download a new copy of the xap would be when they have cleared their browser cache or ive put a new copy up on the server.

Any ideas on what would be the problem and fix?

I ran fiddler on the XAP download and got the following lines from the cache tab of the xap download entry in fiddler.

HTTP/200 responses are cacheable by default, unless Expires, Pragma, or Cache-Control headers are present and forbid caching.

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HTTP/1.1 ETAG Header is present: "2ad1d6bfdd43cb1:0" HTTP Last-Modified Header is present: Tue, 24 Aug 2010 22:43:19 GMT

No Explicit HTTP Expiration information was provided. Most browsers utilize heuristic expiration policies: 10% of the delta between Last-Modified and Date is '02:53:34' so this response will heuristically expire 26/08/2010 4:39:26 PM.

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Would this be what the problem is? Where do I set explicit HTTP expiration?

Answer 1

First thing to do is:-

• install a copy of Fiddler.
• Drop your temporary internet files.
• Run Fiddler.
• Visit your host web page.
• Find the HTTP session in fiddler that represents the Xap download
• Add the Raw response headers to your question above.

This will provide a very important set of clues to what the real problem is.

What happens when you refresh? Do you see the second XAP HTTP session return a status 304 response? If you get a 200 add the raw Request headers for this second attempt and its raw response headers to your question.

If you do get a 304, leave it for the appropriate amount of time then try again, is it still give a status 304? If not do the same as above.

This data will give us a lot of info to provide a diagnosis.