Micrometer @Timed annotation on simple public and private (service) methods-CodePudding

I'm trying to apply Prometheus metrics using the micrometer @Timed annotations. I found out that they only work on controller endpoints and not "simple" public and private methods.

Given this example:

@RestController
public class TestController {

    @GetMapping("/test")
    @Timed("test-endpoint") //does create prometheus metrics
    public String test() {
        privateMethod();
        publicMethod();
        return "test";
    }

    @Timed("test-private") //does NOT create prometheus metrics
    private void privateMethod() {System.out.println("private stuff");}

    @Timed("test-public") //does NOT create prometheus metrics
    public void publicMethod() {System.out.println("public stuff");}
}

creates the following metrics:

...
# HELP test_endpoint_seconds  
# TYPE test_endpoint_seconds summary
test_endpoint_seconds_count{,exception="none",method="test",} 1.0
test_endpoint_seconds_sum{,exception="none",method="test",} 0.0076286
# HELP test_endpoint_seconds_max  
# TYPE test_endpoint_seconds_max gauge
test_endpoint_seconds_max{,exception="none",method="test",} 0.0076286
...

No metrics found for @Timed("test-private") and @Timed("test-public"), why is that?

Note: I've read on this github thread, that Spring Boot does not recognize @Timed annotations on arbitrary methods and that you need to manually configure a TimedAspect Bean in order for it to work. I've tried that but still it yields no results.

@Configuration
@EnableAspectJAutoProxy
public class MetricsConfig {
    @Bean
    public TimedAspect timedAspect(MeterRegistry registry) {
        return new TimedAspect(registry);
    }
}

To try this locally see necessary gist here

CodePudding user response：

@Timed works only on public methods called by another class.

Spring boot annotations like @timed / @transactional need the so called proxying that happens only between invocation of public methods.

A good explanation is this one https://stackoverflow.com/a/3429757/2468241