Spring Framework Research & Evidence-Based Practice 5

Question 1

Which Spring Boot Actuator metric exposed via Micrometer provides evidence of HTTP request duration distribution including slow outliers?

Accepted Answer

http.server.requests with percentile histograms enabled

Answer

The http.server.requests metric with percentile histograms enabled (management.metrics.distribution.percentiles-histogram) records request duration distribution, exposing tail latency outliers.

Question 2

A team uses Spring's @Profile annotation to control bean registration. What is the evidence-based way to verify the correct profile is active in an integration test?

Accepted Answer

Use @ActiveProfiles in the test class and assert with Environment.getActiveProfiles()

Answer

@ActiveProfiles on the test class activates specific profiles, and asserting via Environment.getActiveProfiles() provides concrete evidence that the expected profile-conditional beans were loaded.

Question 3

Evidence-based capacity planning for a Spring Boot application on Kubernetes relies on which Actuator probe configuration?

Accepted Answer

Exposing /actuator/health/liveness and /actuator/health/readiness as separate probes

Answer

Spring Boot 2.3+ provides separate /actuator/health/liveness and /actuator/health/readiness probes, giving Kubernetes fine-grained evidence for restart vs. traffic-routing decisions.

Question 4

When researching Spring AOP proxy behavior, which empirical test reveals whether a self-invocation call bypasses the proxy?

Accepted Answer

Call the advised method externally and check the advice fires; then call it internally (this.method()) and confirm the advice does NOT fire

Answer

Externally calling the proxied method while observing advice execution, then repeating via self-invocation (this.method()), empirically demonstrates that proxy-based AOP does not intercept internal calls.

Question 5

Which Spring testing utility allows researchers to assert on the exact JSON structure and values returned by a REST controller without starting a full HTTP server?

Accepted Answer

MockMvc with jsonPath assertions

Answer

MockMvc with Hamcrest jsonPath matchers performs full Spring MVC request/response cycle including serialization in-process, allowing precise JSON structure assertions without a running HTTP server.

Spring Framework Practice Test

Spring Framework Practice Test

Spring Framework Research & Evidence-Based Practice 5