Exception when using @Timed annotation on a @Scheduled method with PrometheusMeterRegistry and TimedAspect

There is a TimedAspect bean defined:

@Bean
public TimedAspect timedAspect(MeterRegistry registry) {
	return new TimedAspect(registry);
}

And the method being timed looks like:

@Scheduled(cron = "0 0 0/1 * * *")
@Timed(value = "timer.doSomething", percentiles = { 0.5, 0.75, 0.95, 0,98, 0.99 })
public void doSomething() {
       // do something 
}

When the doSomething method finished execution, the exception is:

ERROR o.s.s.s.TaskUtils$LoggingErrorHandler - Unexpected error occurred in scheduled task.
java.lang.IllegalArgumentException: Prometheus requires that all meters with the same name have the same set of tag keys. There is already an existing meter containing tag keys [app]. The meter you are attempting to register has keys [app, class, method].
        at io.micrometer.prometheus.PrometheusMeterRegistry.lambda$collectorByName$9(PrometheusMeterRegistry.java:361)
        at java.util.concurrent.ConcurrentHashMap.compute(ConcurrentHashMap.java:1877)
        at io.micrometer.prometheus.PrometheusMeterRegistry.collectorByName(PrometheusMeterRegistry.java:348)
        at io.micrometer.prometheus.PrometheusMeterRegistry.newTimer(PrometheusMeterRegistry.java:160)
        at io.micrometer.core.instrument.MeterRegistry.lambda$timer$2(MeterRegistry.java:257)
        at io.micrometer.core.instrument.MeterRegistry.getOrCreateMeter(MeterRegistry.java:566)
        at io.micrometer.core.instrument.MeterRegistry.registerMeterIfNecessary(MeterRegistry.java:528)
        at io.micrometer.core.instrument.MeterRegistry.timer(MeterRegistry.java:255)
        at io.micrometer.core.instrument.Timer$Builder.register(Timer.java:447)
        at io.micrometer.core.aop.TimedAspect.timedMethod(TimedAspect.java:78)

app is the name of the default tag that is setup for all metrics. The exception seems to be because the ScheduledMethodMetrics aspect and TimedAspect are both trying to time the same method. ScheduledMethodMetrics creates timer timer.doSomething with only the app tag and then TimedAspect tries to create a timer with the same name but with additional class and method tags.

The timer created by ScheduledMethodMetrics was present in the /prometheus endpoint

timer_doSomething_seconds{app="sample-app",quantile="0.5",} 6.979321856
timer_doSomething_seconds{app="sample-app",quantile="0.75",} 6.979321856
timer_doSomething_seconds{app="sample-app",quantile="0.95",} 6.979321856
timer_doSomething_seconds{app="sample-app",quantile="0.98",} 6.979321856
timer_doSomething_seconds{app="sample-app",quantile="0.99",} 6.979321856
timer_doSomething_seconds_count{app="sample-app",} 2.0
timer_doSomething_seconds_sum{app="sample-app",} 15.689029194

Tested with versions 1.0.5 and 1.0.6 and spring boot version 1.5.15.RELEASE

[jkschneider]

@tooms4444 We can talk about this in more real time in Slack if you’d like, but I still think there is no problem in the Micrometer code itself. It appears that the method is being timed in two different ways with different sets of tags and Prometheus does not allow this. The second set of tags suggests that the method being timed is a rest endpoint (because status and uri are tags). This is instrumented by the framework. If you also add a @Timed annotation with different tags, Prometheus will fail.

[tooms4444]

Thank you @jkschneider and everyone : I didn’t get that the issue was coming from intricated timers, as the message seemed to be related to a particular duplicate timer name