Invalidating the cache
On that next request, the proxy will fetch a fresh copy from the application.
HTTP caching is a great solution for improving the performance of your web application.
Instead of finding some compromise, you can have both with cache invalidation.
When application data changes, the application takes care of invalidating its web representation as out-of-date.
The proxy can choose to either discard the content immediately, or do so when it is next requested.
If you want to invalidate selected objects but your users don't necessarily access every object on your origin, you can determine which objects viewers have requested from Cloud Front and invalidate only those objects.
To determine which objects viewers have requested, enable Cloud Front access logging.
Flush: Before the device read a portion of memory updated by CPU, CPU must flush (write back is also correct?
) the contents from cache to memory, so that device reads the contents from memory with updated contents.
If one function has updated variables that are cached, does it need to invalidate it or flush it?