Handle a rush without hammering your API — API Gateway and Throttling

Your goal

Plan how an API responds when traffic arrives faster than it can handle.

Why this matters

A busy client sends a sudden burst of requests. You will set traffic targets, handle a throttled response, and understand which protections still need separate limits.

Words you will use

A rate is requests over time. A burst is a short rush. Throttling rejects some requests when targets are exceeded. Backoff means waiting longer between retries.

How to proceed

Read each situation and choose an answer. The lesson explains the result. Try again if needed, then continue through all three decisions and finish the tour.

1. Match targets to capacity

Your backend handles steady traffic well but slows under large bursts. Choose a reason for API rate and burst settings.

What should these settings protect?

The backend’s ability to handle useful work.

Choose targets using load tests and downstream capacity. Rate and burst settings manage incoming pressure, but API Gateway throttles are best-effort targets rather than exact ceilings for every instant.

Traffic targets reflect measured backend behavior.

Measured capacity → rate and burst targets

2. Respond politely to throttling

A client receives a 429 Too Many Requests response. Retrying immediately many times can make the overload worse. Choose the client behavior.

How should the client retry?

Use bounded backoff with jitter and safe request handling.

Backoff spaces attempts out, and jitter varies the wait so clients do not all return together. Limit the number of retries and use repeat-safe operations so recovery does not create duplicate work.

The client reduces pressure while handling a temporary limit.

429 → bounded wait + jitter → safe retry

3. Avoid a false billing promise

Someone calls the throttle an exact monthly spending cap. That claim would confuse traffic management with financial control. Choose the correct explanation.

What can you promise?

It helps manage traffic; costs need separate monitoring and controls.

Throttling is neither an exact cost cap nor an access policy. Use authentication, authorization, usage monitoring, and suitable budget controls alongside it. Set expectations around what each protection actually does.

The design separates traffic, access, and cost controls.

Throttling + access checks + cost monitoring → layered controls

Practice, then check your understanding

In the interactive tour, make each decision before seeing the outcome. Wrong answers receive coaching, and replay gives you a fresh attempt without duplicating earned XP.

Read the official AWS documentation for service behavior and production details.