Lenin Jaganathan

Publish relative to PushMeterRegistry initialization time and align StepMeter boundaries to that

9

This PR tries to solve this issue (https://github.com/micrometer-metrics/micrometer/issues/2818). The start time is captured when the push meter registry is initialized. For Step based meters, this is passed to the Step...

Methods in coercing can throw RunTimeExceptions

3

**Describe the bug** The method contracts of Coercing allows for only Coercing*Exceptions to be thrown out of them. But, when the implementations only implement the deprecated versions of the methods...

Fixes https://github.com/micrometer-metrics/micrometer/issues/4856, This PR introduces the following changes, * No-op's adding meterfilters after the meters are registered to the registry. We can argue this could break people who add meter...

Improve the performance of meter interaction

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**Please describe the feature request.** To interact with a meter (recording values), the preferred pattern documented is to use the Builder to create a meter and interact with it. For...

Publishing partial step doesn't work for SignalFx registry

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**Describe the bug** https://github.com/micrometer-metrics/micrometer/pull/3681 fixed the issue of publishing partial values when the application is shut down. The issue was addressed by introducing a package-private StepMeter contract which defines _closingRollover()...

Avoid creating redundant NoopMeters

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**Please describe the feature request.** Currently, when the register method is called it invokes the `registerMeterIfNecessary` and then `getOrCreateMeter`. [getOrCreateMeter](https://github.com/micrometer-metrics/micrometer/blob/061dbf69e908ce530e11b6e34082b01197263df6/micrometer-core/src/main/java/io/micrometer/core/instrument/MeterRegistry.java#L611C19-L611C35) applies the meter-filters and if any of the filters reply...

Support for ExponentialHistogram in OTLP Registry

4

Resolves https://github.com/micrometer-metrics/micrometer/issues/3861. Adds support for https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/data-model.md#exponentialhistogram. Math used for index calculation is re-used from the OTEL specification which lays down the formula/techniques to be considered for index calculation also keeping...

Provide an option to supply common tags for registries.

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**Please describe the feature request.** This thought arrived during a discussion on https://github.com/micrometer-metrics/micrometer/issues/2818. The thought process is that MeterRegistries can take common tags static to a JVM (like app_name, host_name,...

Improve Class Loading metrics instrumentation

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**Describe the bug** Currently, the [JVM class unloading metric ](https://github.com/micrometer-metrics/micrometer/blob/main/micrometer-core/src/main/java/io/micrometer/core/instrument/binder/jvm/ClassLoaderMetrics.java#L47-L59) is being registered as a Function counter. The description says "The total number of classes unloaded since the Java virtual...

Adopt Stable OTEL Semantic Conventions for JVM metrics

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**Please describe the feature request.** In https://github.com/open-telemetry/semantic-conventions/pull/569, OpenTelemetry has made JVM metrics stable. It makes sense to adopt the stable semantic convention for OTLPMeterRegistry to keep in line with the...