Sharpen your understanding of API Gateway performance optimization with a focus on load balancing strategies and caching mechanisms. This quiz helps you grasp core concepts, best practices, and essential configurations to ensure robust and high-performing API architectures.
Which primary benefit does load balancing provide to an API gateway managing multiple backend servers?
Explanation: Load balancing ensures that incoming requests are distributed evenly among available backend servers, helping prevent any single server from becoming overloaded. Increasing data encryption speed is unrelated to how requests are distributed. Reducing code size is not managed by the gateway. Creating database backups is a separate process from request distribution.
What is the main goal of enabling caching in an API gateway for frequently requested data?
Explanation: Caching stores frequently accessed data to quickly serve repeated requests, which improves response times and reduces the workload on backend servers. Increasing logging verbosity generates more logs but does not optimize performance. Automatic file format conversion is unrelated to API gateway caching. Blocking all duplicate requests is not a caching function; it might hinder valid client interactions.
Which load balancing method assigns each incoming request to the backend server with the fewest active connections?
Explanation: The 'least connections' algorithm sends requests to the server currently handling the fewest ongoing connections, promoting an even distribution during predictable and bursty traffic. Static round-robin cycles through servers in order, but does not account for current load. Random selection chooses servers unpredictably, risking uneven loads. DNS failover is used for redirecting when a server is down, not balancing connections based on load.
If you set a cache expiration time that is too long in your API gateway, what potential issue might arise?
Explanation: A cache expiration time that is too long means clients could be served stale data, as the cache may not refresh when the backend data changes. New cache entries can still be added after the old ones expire. If the cache is effective, backend servers handle fewer requests, not all. Authentication failures relate to different configuration issues, not cache expiration.
Why are health checks important when using load balancing with an API gateway?
Explanation: Health checks monitor backend servers, allowing the load balancer to stop sending requests to unhealthy servers, ensuring high availability. API request encryption is not enhanced by health checks. Increasing response payload size is not related to server health. Health checks do not block all HTTP requests; they selectively route traffic.
What could be a consequence of using only the URL path as the cache key in your API gateway?
Explanation: If cache keys are too broad, such as using just the URL path, personalized or sensitive responses may be incorrectly shared among users. Backend load might decrease due to cache hits, but data may be inaccurate. Cache entries will not expire immediately based on the key structure. Logging is independent of cache key settings.
In load balancing, what is the purpose of enabling sticky sessions (session persistence)?
Explanation: Sticky sessions ensure that all requests from a user during a session go to the same backend server, supporting session continuity. Cookie encryption is a security process, not directly related to sticky sessions. Separating HTTP from HTTPS is a different routing option. Random backend selection ignores session persistence, which sticky sessions specifically address.
Why is cache invalidation necessary for dynamic API data?
Explanation: Cache invalidation ensures that when backend data updates, obsolete cache entries are removed, so clients receive current information. Increasing file size does not improve cache validity. Encryption of cache content is handled separately. Directing all traffic to one server is unrelated and would harm load balancing effectiveness.
What often results if an API gateway does not use caching for expensive, repeatable queries?
Explanation: Without caching, backend servers must process every request, leading to increased resource use and slower response times for clients, especially with frequently repeated queries. Client requests are not universally denied, they are just slower. API gateways can remain stateless regardless of caching. Disabling load balancing algorithms is unrelated to caching.
How can performing SSL termination at the API gateway help improve overall API performance?
Explanation: SSL termination at the gateway decrypts incoming traffic before sending it to backend servers, decreasing their workload and improving API performance. Disabling load balancing for encrypted traffic is not the result; traffic can still be load balanced. Blocking authentication requests is not a direct result of SSL termination. Increasing time to first byte is opposite of the intended performance benefit.