Question

Is it possible to clear the output cache of one asp.net web application from inside another asp.net web application?

Reason being… We have several wep applications structured like…

• http://www.website.com/intranet/cms/
• http://www.website.com/area1/
• http://www.website.com/area2/

Pages in /area1/ and /area2/ are cached and are managed through /intranet/cms/. When a page is edited using /intranet/cms/ I want to clear it out of the cache in the appropriate /area#/ application.

I already tried using a VaryByCustom that looks up a guid stored in the HttpContext.Cache but that seems to be cached per web application, that doesn’t work.

Really if there were any way of passing data between web applications on a single server, that would solve my problem, since I can use that + VaryByCustom.

Thanks!

-Mike Thomas

Answer 1

The way I’ve done this in the past is to have a “hidden” page (in each of the /areaX sites) that does the flushing, reloading, etc. The page validates a shared secret query parameter before doing anything (to avoid DoS attacks). If valid the page would output an “OK” message once the operation is complete; generates a 404 error if the secret is invalid.

If you want the flush to be on a per-item or per-group basis then add a second parameter that identifies that item/group.

This method is also server technology independent, and can be triggered by other management tools if required.