We are currently using Webcache 18.104.22.168 cluster in our production environment with Oracle 9iAS as the app server. Now there is some critical content which is served (for better performance) through the Web Cache. We have implemented the invalidation mechnism using the invalidation APIs. But the problem is if for some reason the invalidation mechanism fails then what is the alternate route to invalidate the cached contents as they will be otherwise serving wrong data. Let me give an example:
Case 1: Web cache is down
Solution: Well in this case we are safe as even the users of the system will not be able to get the Stale data from cache.Any Shout mechanism????
Case 2: The webcache is up but the link from n/w link from App Server to the webcache (via Load Balancers) is down. In this case our application will NOT be able to invalidate the cache if the underlying data changes. Moreover the users will continue to be served old content.
Solution: How can we invalidate or notify cache in this case? Use DMS APIs ???
Case 3: Both the Webcache & Network links are fine but in invalidation code (written in Java) throws an exception.
Solution: Possibly we can trap all the exceptions in the invalidation logic and do something..... what???
Any ideas will be highly appreciated