JMH Benchmark with reactive Spring APIs

Question

Now I am trying to integrate JMH benchmark into my microservice which is written in reactive java. I am using a controller method with many other services integrated as maven dependencies. I can't find any resources on to use @Benchmark with asynchronous calls. Additionally, with many chained service classes within the controller, how does this work? My JUnit tests currently have a combination @MockBean and Mockito.

I have started with the framework outlinerd here https://github.com/stsypanov/spring-boot-benchmark but not sure how to expand to reactive java. An example of the code I want to benchmark:

@RestController
@Validated
@RequiredArgsConstructor
@RequestMapping(value = "/api/v1/projects", produces = HAL_UTF8)
public class ProjectController {

  private final ProjectService projectService; // interface with @Service annotation
  
  public Mono<ResponseEntity<Void>> deleteProject(
      @ApiParam(required = true, value = "Existing Project Directory URN") @PathVariable
          String id) {
    return projectService
        .deleteProject(finalId)
        .thenReturn(ResponseEntity.noContent().<Void>build());
  }
}

Answer 1

I think for measuring this you could use JLBH (Java Latency Benchmark Harness) instead of JMH. See it's repository for details: https://github.com/OpenHFT/JLBH .

The pros of JLBH as opposed to JMH are:

• code is running in context of you system with all of its dependencies
• variable throughput (for each throughput we can estimate max tail latency and provide SLA)
• various sampling points in the code

For quick start-up guide please have a look into https://www.javacodegeeks.com/2016/04/jlbh-introducing-java-latency-benchmarking-harness.html