AWS Certified Developer Associate · Free Practice Question Medium
Question 22
You have a three-tier web application consisting of a web layer using AngularJS, an application layer using an AWS API Gateway and a data layer in an Amazon Relational Database Service (RDS) database. Your web application allows visitors to look up popular movies from the past. The company is looking at reducing the number of calls made to endpoint and improve latency to the API.
What can you do to improve performance?
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A
Use Stage Variables
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B
Use Mapping Templates
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C
Enable API Gateway Caching
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D
Use Amazon Kinesis Data Streams to stream incoming data and reduce the burden on Gateway APIs
Reveal correct answer
Correct answer: C
Explanation
Correct option:
Enable API Gateway Caching - You can enable API caching in Amazon API Gateway to cache your endpoint's responses. With caching, you can reduce the number of calls made to your endpoint and also improve the latency of requests to your API. When you enable caching for a stage, API Gateway caches responses from your endpoint for a specified time-to-live (TTL) period, in seconds. API Gateway then responds to the request by looking up the endpoint response from the cache instead of making a request to your endpoint. The default TTL value for API caching is 300 seconds. The maximum TTL value is 3600 seconds. TTL=0 means caching is disabled.
Incorrect options:
Use Mapping Templates - A mapping template is a script expressed in Velocity Template Language (VTL) and applied to the payload using JSONPath expressions. Mapping templates help format/structure the data in a way that it is easily readable, unlike a server response that might always be easy to ready. Mapping Templates do not help in latency issues of the APIs.
Use Stage Variables - Stage variables act like environment variables and can be used to change the behavior of your API Gateway methods for each deployment stage; for example, making it possible to reach a different back end depending on which stage the API is running on. Stage variables do not help in latency issues.
Use Amazon Kinesis Data Streams to stream incoming data and reduce the burden on Gateway APIs - Amazon Kinesis Data Streams (KDS) is a massively scalable and durable real-time data streaming service. KDS can continuously capture gigabytes of data per second from hundreds of thousands of sources such as website clickstreams, database event streams, financial transactions, social media feeds, IT logs, and location-tracking events.
Reference:
https://docs.aws.amazon.com/apigateway/latest/developerguide/api-gateway-caching.html
Discussion
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