Have some strange behaviour regarding output caching in an ASP.NET 4 application on IIS 7.5. I’ve been able to repeat the problem simply on other empty setups, I’m certain this is a bug, but unsure how to report it to Microsoft.
A site in IIS responds to more than 1 domain, the .NET application examins the hostname, and produces content accordingly. For example, it may print the name of the request URL in a blank page. Eg, http://www.first-domain.com, and http://www.second-domain.com
The web.config has the appropriate caching, urlCompression, and httpCompression all turned OFF under the system.webServer node.
The aspx page sets the cache-control header for public, with either a future date for expires, or a max-age value.
Visiting http://www.first-domain.com outputs the page that successfully writes ‘www.first-domain.com’.
However, visiting http://www.second-domain.com outputs a page that writes ‘www.first-domain.com’.
Examining the failed-request-traces, System.Web.Caching.OutputCacheModule has found the cached output (even though the .config files have turned the function off), the cache has matched even though the request URL hostname are different, and thus the second request will output the results of the first request to the different domain for as long as the max-age/expiry was set for, before the correct page for the second-domain will appear.
Either setting cache-control to private, or removing the ‘OutputCache’ module in the web.config solves the problem, while maintaining the correct cache-control headers sent to the browser, but obviously, I can’t take advantage of kernel caching when I need it.
I can’t find any MSDN documentation on how the OutputCacheModule is configured.
Has anyone else experienced this issue, how can I go about enabling kernel caching and let it take into account URL Hostname (without separating the application to different sites in IIS).
Thanks.
Update:
Adding SetSlidingExpiration has no effect, as the kernal cache still caches the output regardless of the request hostname. The only scenario now is to either disable output caching, or run a duplicate instance of the app on each domain it will run – considering the drop in server performance this would result in vs. the increase of performance gained in using output caching, we decided to disable output caching for this app.
No answer has been provided after 9 months, and no solution has been found, only a workaround, perhaps this will be fixed in the next version of IIS greater than 7.5…
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Adding SetSlidingExpiration has no effect, as the kernal cache still caches the output regardless of the request hostname. The only scenario now is to either disable output caching, or run a duplicate instance of the app on each domain it will run – considering the drop in server performance this would result in vs. the increase of performance gained in using output caching, we decided to disable output caching for this app.