Microservices Resilience and Fault Tolerance 3

Question 1

What problem does a cascading failure describe in a microservices system?

Accepted Answer

One service's failure propagating and overwhelming dependent services in a chain reaction

Answer

A single database query running slowly

Answer

A failed deployment rollback

Answer

A misconfigured DNS record

Question 2

Which technique limits the number of concurrent calls a service will accept to protect itself?

Accepted Answer

Rate limiting / concurrency limiting

Answer

Eager loading

Answer

Schema migration

Answer

Blue-green deployment

Question 3

What is the 'fail fast' principle in resilient design?

Accepted Answer

Detect failures quickly and return an error immediately rather than blocking

Answer

Always retry until success

Answer

Disable all error logging

Answer

Delay all responses to batch them

Question 4

When a circuit breaker is in the OPEN state, what happens to incoming requests?

Accepted Answer

They are short-circuited and fail immediately (or use a fallback) without calling the downstream

Answer

They are queued until the service recovers

Answer

They are retried five times each

Answer

They bypass the breaker entirely

Question 5

Why can aggressive retries make an outage worse?

Accepted Answer

They add extra load to an already struggling service, amplifying the problem

Answer

They reduce log volume

Answer

They always bypass the load balancer

Answer

They encrypt traffic twice

Question 6

What is a health check endpoint used for in resilient microservices?

Accepted Answer

Letting orchestrators and load balancers detect unhealthy instances and route around them

Answer

Generating API documentation

Answer

Encrypting database credentials

Answer

Compiling the application

Question 7

What distinguishes a liveness probe from a readiness probe in Kubernetes?

Accepted Answer

Liveness decides whether to restart a container; readiness decides whether to send it traffic

Answer

They are identical in function

Answer

Liveness checks the database; readiness checks the CPU

Answer

Readiness restarts pods; liveness load balances