[Spring Actuator] Example 3편 - Counter

이전글: https://bkjeon1614.tistory.com/782

 

• Counter (https://micrometer.io/docs/concepts#_counters)
  • 횟수를 세어 metric 으로 제공 단, 자연수만 가능하며 소수나 음수는 불가능하며 일반적으로는 cache hit 에 대한 누적 counter 및 http request 누적 횟수 등과 같이 지금까지 특정 이벤트가 몇 번 발생했는지 누적값을 제공할 때 Counter 를 사용한다. ()
  • 사용법
    • Counter.builder()
      [ApplicationRequestManager.java]

      package com.example.bkjeon.base.actuator.counter;
      
      import io.micrometer.core.instrument.Counter;
      import io.micrometer.core.instrument.MeterRegistry;
      import lombok.RequiredArgsConstructor;
      import org.springframework.stereotype.Service;
      
      import javax.annotation.PostConstruct;
      
      @Service
      @RequiredArgsConstructor
      public class ApplicationRequestManager {
      
          // MeterRegistry 는 기본적으로 Bean 으로 등록되기 때문에 바로 사용하면 된다.
          private final MeterRegistry meterRegistry;
      
          private Counter httpRequestCounter;
      
          @PostConstruct
          void init() {
              httpRequestCounter = Counter.builder("application.http.request").register(meterRegistry);
          }
      
          public void increase() {
              httpRequestCounter.increment();
          }
      
      }      
      

      [CounterController.java]

      package com.example.bkjeon.base.services.api.v1.actuator;
      
      import com.example.bkjeon.base.actuator.counter.ApplicationRequestManager;
      import lombok.RequiredArgsConstructor;
      import org.springframework.web.bind.annotation.GetMapping;
      import org.springframework.web.bind.annotation.RequestMapping;
      import org.springframework.web.bind.annotation.RestController;
      
      @RestController
      @RequestMapping("v1/counter")
      @RequiredArgsConstructor
      public class CounterController {
      
          private final ApplicationRequestManager applicationRequestManager;
      
          @GetMapping("req")
          public String req() {
              applicationRequestManager.increase();
              return "ok";
          }
      
      }      
      

    • /actuator/metrics/application.http.request 에서 확인이 가능하다.
  • Function Counter (https://micrometer.io/docs/concepts#_function_tracking_counters)
    • Counter 의 경우 기존에 만든 횟수 관리 클래스를 재활용하지 못하는 단점이 있어서 Function Counter 를 사용하자.
    • 사용법
      [ApplicationRequestWithoutMicrometer.java]

      package com.example.bkjeon.base.actuator.counter;
      
      import org.springframework.stereotype.Service;
      
      import java.util.concurrent.atomic.AtomicLong;
      
      @Service
      public class ApplicationRequestWithoutMicrometer {
      
          private AtomicLong count = new AtomicLong(0);
      
          public long getCount() {
              return count.get();
          }
      
          public void increase() {
              count.incrementAndGet();
          }
      
      }
      

      [ApplicationFunctionCounterConfig.java]

      package com.example.bkjeon.base.config.actuator;
      
      import com.example.bkjeon.base.actuator.counter.ApplicationRequestWithoutMicrometer;
      import io.micrometer.core.instrument.FunctionCounter;
      import io.micrometer.core.instrument.MeterRegistry;
      import lombok.RequiredArgsConstructor;
      import org.springframework.context.annotation.Configuration;
      
      import javax.annotation.PostConstruct;
      
      @Configuration
      @RequiredArgsConstructor
      public class ApplicationFunctionCounterConfig {
      
          private final ApplicationRequestWithoutMicrometer manager;
          private final MeterRegistry meterRegistry;
      
          @PostConstruct
          void init() {
              FunctionCounter.builder("application.function.counter", manager,
                      ApplicationRequestWithoutMicrometer::getCount).register(meterRegistry);
          }
      
      }
      

      [CounterController.java]

      package com.example.bkjeon.base.services.api.v1.actuator;
      
      import com.example.bkjeon.base.actuator.counter.ApplicationRequestManager;
      import com.example.bkjeon.base.actuator.counter.ApplicationRequestWithoutMicrometer;
      import lombok.RequiredArgsConstructor;
      import org.springframework.web.bind.annotation.GetMapping;
      import org.springframework.web.bind.annotation.RequestMapping;
      import org.springframework.web.bind.annotation.RestController;
      
      @RestController
      @RequestMapping("v1/counter")
      @RequiredArgsConstructor
      public class CounterController {
      
          private final ApplicationRequestManager applicationRequestManager;
          private final ApplicationRequestWithoutMicrometer applicationRequestWithoutMicrometer; // 추가
      
          @GetMapping("req")
          public String req() {
              applicationRequestManager.increase();
              applicationRequestWithoutMicrometer.increase();  // 추가
              return "ok";
          }
      
      }
      

  • MeterBinder 사용
    • FunctionCounter 를 meterRegistry 에 등록하는 방법으로 MeterBinder 를 이용할 수 있다.
      [CounterConfigWithMeterBinder.java]

      package com.example.bkjeon.base.config.actuator;
      
      import com.example.bkjeon.base.actuator.counter.ApplicationRequestWithoutMicrometer;
      import io.micrometer.core.instrument.FunctionCounter;
      import io.micrometer.core.instrument.binder.MeterBinder;
      import org.springframework.context.annotation.Bean;
      import org.springframework.context.annotation.Configuration;
      
      @Configuration
      public class CounterConfigWithMeterBinder {
      
          // MeterBinder 를 이용하면 @PostConstruct 없이 구현이 가능
          @Bean
          public MeterBinder applicationCounterWithMeterBinder(
                  ApplicationRequestWithoutMicrometer manager) {
              return registry -> FunctionCounter.builder("application.function.counter2", manager,
                      ApplicationRequestWithoutMicrometer::getCount).register(registry);
          }
      
      }
      

  • @Counted
    • Micrometer 에서 @Counted 라는 Annotation 을 통해서 AOP 를 제공하고 있다.
    • 예제
      • @Counted 를 사용하려면 AOP 를 사용해야 하므로 build.gradle 에 추가
        [build.gradle]

        dependencies {
            ...
        
            implementation 'org.springframework.boot:spring-boot-starter-aop'        
        }
        

      • 코드적용
        [CountConfig.java]

        package com.example.bkjeon.base.actuator.counter;
        
        import io.micrometer.core.aop.CountedAspect;
        import io.micrometer.core.instrument.MeterRegistry;
        import org.springframework.context.annotation.Bean;
        import org.springframework.context.annotation.Configuration;
        
        @Configuration
        public class CountConfig {
        
            // @Counted 를 사용하기위한 Aspect 등록
            @Bean
            public CountedAspect countedAspect(MeterRegistry meterRegistry) {
                return new CountedAspect(meterRegistry);
            }
        
        }        
        

        [CounterController.java]

        @RestController
        @RequestMapping("v1/counter")
        @RequiredArgsConstructor
        public class CounterController {        
         
            ...
        
            // @Counted 만 추가하면 된다.
            @Counted("my.counted.counter")
            @GetMapping("req2")
            public String req2() {
                return "OK";
            }            
        
        }
        

      • http://localhost:9090/api/v1/counter/req2 호출 후 http://localhost:9090/api/actuator/metrics/my.counted.counter 에서 확인

 

참고

- https://semtul79.tistory.com/

나는 학생이다

- https://docs.spring.io/

Spring | Home

- https://www.inflearn.com/course/spring-boot-actuator-%ED%8C%8C%ED%97%A4%EC%B9%98%EA%B8%B0/dashboard