How to create a multi-value tag metric gauge? - spring-boot

Question

Already read this but with no lucky.
All examples I've found just show how to create a single value tag like this:
{
"name" : "jvm.gc.memory.allocated",
"measurements" : [ {
"statistic" : "COUNT",
"value" : 1.98180864E8
} ],
"availableTags" : [ {
"tag" : "stack",
"values" : [ "prod" ]
}, {
"tag" : "region",
"values" : [ "us-east-1" ]
} ]
}
But I need to create a multi value tag like this:
availableTags: [
{
tag: "method",
values: [
"POST",
"GET"
]
},
My code so far:
List<Tag> tags = new ArrayList<Tag>();
tags.add( Tag.of("test", "John") );
tags.add( Tag.of("test", "Doo") );
tags.add( Tag.of("test", "Foo Bar") );
Metrics.gauge("my.metric", tags, new AtomicLong(3) );
As you can see I think I can just repeat the key but this is not the case and the second parameter of Tag.of is a String and not a String Array.

Answer 1

I don't think this was the real intent of authors of these metering libraries - to provide a multi-value tag for a metric.
The whole point of metrics tags is to provide a "discriminator" - something that can be used later to retrieve metrics whose tag has a specific, single, value.
Usually, this value is used in metrics storage systems, like Prometheus, DataDog, InfluxDB and so on. And above this Grafana can incorporate a single tag value in its queries.
The only possible use case of such a request that I see is that it will be possible to see the metrics value in an actuator in a kind of more convenient way, but again it's not the main point of the whole capability here, so, bottom line I doubt that its possible at all.