Prometheus Exporters do not interact with Resource attributes

[yangtaoran]

https://github.com/open-telemetry/opentelemetry-java/blob/main/sdk/metrics/src/main/java/io/opentelemetry/sdk/metrics/SdkMeterProviderBuilder.java#L56
Here,I set setResource to all meter.I think all metrics will add attributes from the resource,but it not.
I init SdkMeterProvider by follow:

SdkMeterProvider.builder().setResource(Resource.create(Attributes.of(
                AttributeKey.stringKey("instance"), "xxxx")))
                .registerMetricReader(
                        PrometheusHttpServer.builder().setHost("127.0.0.1").setPort(9092).newMetricReaderFactory())
                .buildAndRegisterGlobal();
Meter meter = GlobalMeterProvider.get().get("test");
LongCounter testCounter = meter.counterBuilder("meter_test").setUnit("1").setDescription("test").build();
testCounter.add(1, Attributes.of(AttributeKey.stringKey("hello"), "world"));

I scrap the metrics like this:

meter_test_total{hello="world",} 1.0 1641357854770

I think it will be ”meter_test_total{hello="world",instance="xxxx"} 1.0 1641357854770”

[anuraaga]

Hi @yangtaoran - there is currently not any support for mapping resource properties into metric attributes for Prometheus exporter. Are you using the prometheus exporter in this repository or are you using the OpenTelemetry collector? Currently I believe the way to achieve what you want is to use resource_to_telemetry_conversion in the prometheus exporter in the collector

https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/exporter/prometheusexporter#getting-started

[yangtaoran]

Hi @yangtaoran - there is currently not any support for mapping resource properties into metric attributes for Prometheus exporter. Are you using the prometheus exporter in this repository or are you using the OpenTelemetry collector? Currently I believe the way to achieve what you want is to use resource_to_telemetry_conversion in the prometheus exporter in the collector

https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/exporter/prometheusexporter#getting-started

I am using the prometheus exporter in this repository. So what can do for the SdkMeterProviderBuilder setResource method？According to you, I can use OTLP to export metrics data to the collector, and the collector configure prometheus exporter with resource_to_telemetry_conversion. So the prometheus exporter will export the metrics data with the resource.Is my understanding right?

[anuraaga]

Yup I think using OTLP exporter from SDK to collector and using that setting is probably the best bet for now. We need to think of how to better support this in the SDK natively.

[yangtaoran]

I think It's necessary that the Prometheus exporter from SDK should export metrics data with resource.Although I can do like above,it's complicated.If it is possible,I can push a PR.

[jsuereth]

@yangtaoran The prometheus exporter is not fully specified in OTEL yet. I fully expect resource -> prometheus labels to part of that final specification, but we're still discussing the details of what would be done in SDKs.

You can see:

• How do I know which resource attributes are important enough to identify a Prometheus Metrics Stream? opentelemetry-specification#1782
• How to map the Meter name in non-OTLP exporters? opentelemetry-specification#1906
• Inconsistency between Spec and Prometheus Translation with regards to Resource. opentelemetry-specification#2251

@anuraaga's workaround should be good for now, but expect improvements in the SDK-exporter going forward.