MicroMeter: remove/disable a certain tag

Question

I'm using the default MicroMeter binders, one of them creating the Gauage jvm.memory.used. The issue is that it comes with 2 availableTags: "area" and "id". This is practically generating 6 Gauges which I'm not interested in.

I was able to do this:

@Bean
public MeterRegistryCustomizer<MeterRegistry> metricsCustomizer() {

    return  registry -> {
        registry.config().meterFilter(MeterFilter.ignoreTags("id"));
    };
}

but this will ignore all meters with this tag.

How can I deny() only jvm.memory.used with an id tag?

Thanks!

EDIT:
Looking at the globalRegistry:

Metrics.globalRegistry.getRegistries().iterator().next().meterMap

Every Meter of jvm.memory.used is of the following structure:

"MeterId{name='jvm.memory.used', tags=[tag(area=nonheap),tag(id=Metaspace)]}"

So we can't just filter by getName().equals("jvm.memory.used") && getTag("id") != null

Answer 1

I think you maybe conflating concepts. The tags just "decorate" the metrics/gauges with additional information, they don't actually result in more gauges being sent. For example, the line Metrics.gauge("name", Tags.of("id","a", "area","b"), 1) is just a single gauge object. Denying jvm.memory.used with an id tag will probably deny all jvm.memory.used. If you still want to filter jvm.memory.used with the id tag you can use

@Bean
public MeterFilter meterFilter() {
    return MeterFilter.deny(
        id -> "jvm.memory.used".equals(id.getName()) &&
              id.getTags().stream().anyMatch(t -> "id".equals(t.getKey()))
         );
    }

If on the other hand you just wanted to remove just the id tag, you will need to use the replaceTags method.

@Bean
public MeterFilter meterFilter() {
    return new MeterFilter() {
        @Override
        public Meter.Id map(Meter.Id id) {
            if("jvm.memory.used".equals(id.getName())) {
                List<Tag> tags = id.getTags().stream().filter(t -> !"id".equals(t.getKey())).collect(Collectors.toList());
                return id.replaceTags(tags);
            }
           return id;
        }
    };
}

You can also completely customize the Meter.Id returned by calling new Meter.Id(name, tags, baseUnit, description, type) as below, and chaning whichever values you want to:

@Bean
public MeterFilter meterFilter() {
    return new MeterFilter() {
        @Override
        public Meter.Id map(Meter.Id id) {
            if("jvm.memory.used".equals(id.getName())) {
                return new Meter.Id(id.getName(), <put tags here>, id.getBaseUnit(), id.getDescription(), id.getType()
            }
           return id;
        }
    };
}