Retry and failure handling in Rest API - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is retry handling in REST APIs?

Retry handling means trying a failed request again automatically to recover from temporary problems like network issues or server overload.

beginner

Why is failure handling important in REST APIs?

Failure handling helps your app respond gracefully when something goes wrong, like showing a message or trying again, so users have a better experience.

intermediate

What is exponential backoff in retry strategies?

Exponential backoff means waiting longer and longer between retries, like 1 second, then 2, then 4, to avoid overwhelming the server.

intermediate

Name two common HTTP status codes that should trigger a retry.

Common retry codes are 429 (Too Many Requests) and 503 (Service Unavailable), which mean the server is busy or overloaded.

advanced

What is a circuit breaker in failure handling?

A circuit breaker stops retrying after many failures to prevent wasting resources and lets the system recover before trying again.

Which HTTP status code usually means you should retry the request?

A 503 Service Unavailable

B 404 Not Found

C 200 OK

D 400 Bad Request

503 means the server is temporarily unavailable, so retrying later might succeed.

What does exponential backoff do in retry handling?

A Retries immediately without delay

B Retries only once

C Stops retrying after the first failure

D Waits longer between each retry attempt

Exponential backoff increases wait time between retries to reduce server load.

What is the main goal of failure handling in REST APIs?

A To handle errors gracefully and improve user experience

B To ignore errors silently

C To crash the app on errors

D To always retry forever

Failure handling helps apps respond well to errors, keeping users informed and safe.

Which of these is NOT a good reason to retry a REST API request?

A Network timeout

B Server overload (503)

C Client sent bad data (400)

D Too many requests (429)

400 means the client made a bad request, so retrying won't help without fixing the data.

What does a circuit breaker do in failure handling?

A Keeps retrying endlessly

B Stops retries after many failures to protect the system

C Ignores all errors

D Sends error logs only

Circuit breakers prevent wasting resources by stopping retries after repeated failures.

Explain how retry and failure handling improve REST API reliability.

Think about what happens when a request fails and how retry helps.

Describe what exponential backoff is and why it is used in retry strategies.

Imagine waiting longer each time you try again.