/metrics endpoint reports NaN values for micrometer histogram

[manderson23]

I'm using Spring Boot 2.0 M7 with the default Micrometer registry and actuator endpoint.

I've created a Timer to measure latency as follows

Timer.builder(name)
     .publishPercentiles(0.5, 0.75, 0.95, 0.99)
     .tags(Arrays.asList(tags))
     .register(registry);

When this time is reported via the /actuator/metrics endpoint I only see NaN values.

For example, calling localhost:8000/actuator/metrics/latency is see

{
    "availableTags": [
        {
            "tag": "percentile",
            "values": [
                "0.99",
                "0.95",
                "0.5",
                "0.75"
            ]
        }
    ],
    "measurements": [
        {
            "statistic": "Value",
            "value": "NaN"
        },
        {
            "statistic": "Count",
            "value": 301.0
        },
        {
            "statistic": "TotalTime",
            "value": 3027000000.0
        },
        {
            "statistic": "Max",
            "value": 3027000000.0
        }
    ],
    "name": "latency"
}

And calling localhost:8000/actuator/metrics/latency?tag=percentile:0.5 I see

{
    "availableTags": [],
    "measurements": [
        {
            "statistic": "Value",
            "value": "NaN"
        }
    ],
    "name": "latency"
}

If I call the Timer within my code I see that the values and percentiles are correctly recorded.

[snicoll]

paging @jkschneider

[manderson23]

Looks like this is resolved in RC1.

localhost:8000/actuator/metrics/latency?tag=percentile:75percentile returns a value.

[wilkinsona]

Thanks for following up, @manderson23.