In this lab, we'll implement response caching to improve the performance of one of our API resources.
Return to the Apigee Edge Management UI open. Navigate to the Develop Tab of your API Proxy within the Proxy Editor view.
Click on the + button next to the Policies list in the left hand navigation pane. This will launch a dialog box where you can configure a new policy. In this case, we'll create a Response Cache policy:
In the Navigator pane on the left side of the Proxy Editor, you'll see a list of conditional flows underneath the default Proxy Endpoint. Select the flow called getReservationById.
Once you have selected the getReservationById flow, drag the Response Cache policy from the policy list into the Request Pipeline:
With this configuration, your API proxy will check the cache each time a reservation lookup API call is made. Next, we need to configure your API proxy to populate the cache when you get a response from the backend service. To do this, drag the same Response Cache policy to the response pipeline:
Once you have added the cache policy to the reponse pipeline, click on the blue Save button in the top left to save your changes:
Just as in the previous lab. Navigate to the Trace tab and click on the green Start Trace Session button to begin a new trace session:
You should have made several test API calls to the POST /reservations resource from API Studio in previous labs. Inspect the response from your last API call and copy the reservationId value into your clipboard:
With your reservationId copied, scroll down in the documentation to find the GET /reservations/{reservationId} resource. Click on the Try this operation button to reveal the parameters you can set on your sample API call.
As mentioned above, you should have copied the reservationId from the calls you made in the last lab onto your clipboard. Paste the reservationId into the reservationId field in the API form. Make a request to the API. The first request will be slow and take about 10 seconds to return. Subsequent requests should return much faster.
Once you have made several requests to retrieve your reservation you should have noticed a significant improvement in response time after the initial request. Navigate back to your trace session and observe the improvement in response time.
In this lab, you configured a response cache policy to reduce the response time of a poor performing API from 10 seconds down to a few milliseconds. Apigee Edge also provides fine grained cache policies that can be used for partial response caching or to cache arbitrary data.
When you're ready, you can get started on Lab 5 - Complete reservation check in using the API