Click the only listing in the Available Servlets list. This will open the servlet and run
through your Memcache example, as shown in Figure 8-3.
Figure 8-3. Cache example on first run
Take a look at the code again. Notice that you are pulling the cache statistics after you
store your data and before you retrieve it from the cache. Because of this, the first
time you access the application the hit count to your cache should be zero, as shown
in Figure 8-3. Go ahead and reload the browser a few times and watch the hit count
increase, as shown in Figure 8-4.
Figure 8-4. Thirteen refreshes later
That's Memcache. It was a short example, but you've learned how to configure your cache
settings, store data, retrieve data, and query cache statistics in just 45 lines of code. Next
we'll take a look at another App Engine service used for HTTP requests and responses.
URL Fetch Service
App Engine applications can communicate with other systems using HTTP and HTTPS
callouts. This is a service that runs on the Google network infrastructure. It's fast and