CPSA Cross-cutting Concepts 3

Question 1

Which pattern provides a single, reusable implementation of a cross-cutting concern (e.g., retry logic) that is injected into multiple services without code duplication?

Accepted Answer

Sidecar / proxy pattern

Answer

The sidecar pattern deploys a co-located proxy that transparently handles cross-cutting concerns like retries, mTLS, and circuit breaking for the main service.

Question 2

In CPSA terms, which quality attribute is directly addressed by implementing a circuit breaker as a cross-cutting mechanism?

Accepted Answer

Resilience / fault tolerance

Answer

A circuit breaker prevents cascading failures by stopping calls to a failing dependency, directly improving fault tolerance and system resilience.

Question 3

Which approach best handles idempotency as a cross-cutting concern for HTTP POST endpoints?

Accepted Answer

Accepting a client-generated idempotency key and deduplicating on the server

Answer

An idempotency key lets the server detect and suppress duplicate requests, ensuring retried POSTs do not create duplicate effects.

Question 4

A CPSA candidate is reviewing an architecture where transaction boundaries span multiple services. Which cross-cutting pattern manages eventual consistency without distributed locking?

Accepted Answer

Saga pattern with compensating transactions

Answer

The Saga pattern decomposes a distributed transaction into a sequence of local transactions with compensating actions, achieving eventual consistency without 2PC overhead.

Question 5

Which cross-cutting technique allows teams to release new features to a subset of users without changing code between deployments?

Accepted Answer

Feature toggles (feature flags)

Answer

Feature toggles let you switch functionality on or off at runtime for specific user segments without deploying new code.

CPSA Exam Practice Test

CPSA Exam Practice Test

CPSA Cross-cutting Concepts 3