EX378 Red Hat Certified Cloud-native Developer exam Practice Questions
Prepare for EX378 with more than an answer.
- Exam fee
- $500 USD
- Time limit
- 180 minutes
- Passing score
- 210 out of 300 (70%) (scale 0-300)
- Level
- Specialist
- Valid for
- 3 years
Domains covered on the exam 11
- Configuration and Dependency Injection10%
- Fault Tolerance10%
- Health Checks10%
- Metrics and Monitoring (Micrometer)10%
- JWT Security (RBAC)8%
- RESTful Services (Jakarta REST / Resteasy Reactive)14%
- Data Persistence with Panache10%
- Reactive Messaging8%
- OpenAPI Specification6%
- REST Client (REST Client Reactive)10%
- Distributed Tracing (OpenTelemetry)4%
- 1
You are applying the
@Bulkheadpattern to an asynchronous method returning aUni. You configured@Bulkhead(value = 5, waitingTaskQueue = 10). What happens when the bulkhead receives the 16th concurrent request?Show answer details
Correct answer: B
With
value=5, 5 requests execute concurrently.waitingTaskQueue=10allows 10 more to queue. Total capacity is 15. The 16th request exceeds the queue capacity and is immediately rejected with aBulkheadException. - 2
A method is annotated with both
@Retry(maxRetries = 3)and@Timeout(500). The method takes 600ms to complete and always succeeds if given enough time. What is the expected behavior when this method is invoked?Show answer details
Correct answer: B
The
Timeoutapplies to each execution. Since the method takes 600ms and the timeout is 500ms, the first attempt times out. TheRetrypolicy catches theTimeoutExceptionand retries 3 more times. Each retry also times out. After the last retry, theTimeoutExceptionis propagated. - 3
You are defining a fallback method for a service that retrieves user details. The original method signature is
public User getUser(String id). Which of the following is a valid signature for the fallback method referenced by@Fallback(fallbackMethod = "fallbackGetUser")?Show answer details
Correct answer: A
The fallback method must have the same parameter types and return type as the original method. It may optionally accept the exception as the last parameter, but matching the original signature exactly is the standard and valid approach.
- 4
Which annotation should you use to register a health check that is specifically designed to verify if the application has completed its initialization sequence and is ready to be considered 'started' by Kubernetes?
Show answer details
Correct answer: A
The
@Startupannotation (introduced in MicroProfile Health 3.0 / SmallRye Health) maps to the Kubernetes startup probe. It is used to indicate when a slow-starting application has finished initializing. Once the startup probe succeeds, the liveness and readiness probes take over. - 5
You are developing a Quarkus microservice that requires different database configurations for development, testing, and production environments. You want to define a property
db.urlthat changes automatically based on the active profile. Which of the following entries inapplication.propertiescorrectly sets the value for the 'production' profile specifically?Show answer details
Correct answer: B
In Quarkus, profile-specific properties are defined using the syntax
%profile.property-key=value. Therefore,%prod.db.urlis the correct syntax to target the 'prod' profile. The prefixprod.without the percent sign is interpreted as part of the property name, not a profile selector. - 6
A developer needs to map a complex configuration structure for an external payment provider into a Java object. The configuration includes a provider name, an API key, and a nested object for timeout settings. Which annotation should be applied to the interface to enable type-safe configuration mapping in Quarkus?
Show answer details
Correct answer: B
The
@ConfigMappingannotation (from SmallRye Config) is the recommended way to map configuration properties to an interface in Quarkus. It supports nested structures and validation.@ConfigPropertiesis deprecated in favor of@ConfigMapping.
