.NET Architecture & System Design Interview Question #142

What is admission control?

Resilience, Rate Limiting, Health Checks & Observability Senior Advanced

Quick Interview Answer

Admission control decides whether new work should enter a system based on current capacity, quotas, resource state, or policy.

Detailed Explanation

Admission control decides whether new work should enter a system based on current capacity, quotas, resource state, or policy.

Unlike allowing unlimited work to queue internally, admission control keeps overload outside protected resources. Rate limits, concurrency limits, quotas, and queue capacity are common admission-control mechanisms.

Code Example

Request
   |
Admission check
 /           Accept      Reject/Defer
  |
protected resource