Fix and tests for multiple metric readers #6458

hannahhaering · 2025-08-31T22:13:23Z

Fixes #2938

Changes

Added tests as suggested in the issue
Fix: the spec states "The SDK MUST NOT allow a MetricReader instance to be registered on more than one MeterProvider instance". Added a test for this and noticed that the test failed, so I added a verification in the MetricReader.

Merge requirement checklist

CONTRIBUTING guidelines followed (license requirements, nullable enabled, static analysis, etc.)
Unit tests added/updated
Appropriate CHANGELOG.md files updated for non-trivial changes
Changes in public API reviewed (if applicable)

…: The SDK MUST NOT allow a MetricReader instance to be registered on more than one MeterProvider instance.

martincostello · 2025-09-01T07:26:42Z

Can you also update the CHANGELOG please, as this changes behaviour for users.

src/OpenTelemetry/CHANGELOG.md

Co-authored-by: Martin Costello <[email protected]>

codecov · 2025-09-08T22:28:47Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.74%. Comparing base (5852193) to head (1330c5f).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6458      +/-   ##
==========================================
+ Coverage   86.57%   86.74%   +0.17%     
==========================================
  Files         258      258              
  Lines       11876    11878       +2     
==========================================
+ Hits        10282    10304      +22     
+ Misses       1594     1574      -20

Flag	Coverage Δ
unittests-Project-Experimental	`86.40% <100.00%> (+0.11%)`	⬆️
unittests-Project-Stable	`86.64% <100.00%> (+0.59%)`	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/OpenTelemetry/Metrics/Reader/MetricReader.cs	`88.03% <100.00%> (+0.20%)`	⬆️

... and 6 files with indirect coverage changes

src/OpenTelemetry/CHANGELOG.md

…3.1 (#65) Updated [OpenTelemetry.Extensions.Hosting](https://github.com/open-telemetry/opentelemetry-dotnet) from 1.12.0 to 1.13.1. <details> <summary>Release notes</summary> _Sourced from [OpenTelemetry.Extensions.Hosting's releases](https://github.com/open-telemetry/opentelemetry-dotnet/releases)._ ## 1.13.1 For highlights and announcements pertaining to this release see: [Release Notes > 1.13.1](https://github.com/open-telemetry/opentelemetry-dotnet/blob/main/RELEASENOTES.md#1131). The following changes are from the previous release [1.13.0](https://github.com/open-telemetry/opentelemetry-dotnet/releases/tag/core-1.13.0). * NuGet: [OpenTelemetry v1.13.1](https://www.nuget.org/packages/OpenTelemetry/1.13.1) * Fixed an issue where the Base2 Exponential Bucket Histogram did not reset its scale to 20 after each collection cycle when using delta aggregation temporality. ([#6557](open-telemetry/opentelemetry-dotnet#6557)) See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.13.1/src/OpenTelemetry/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Api v1.13.1](https://www.nuget.org/packages/OpenTelemetry.Api/1.13.1) No notable changes. See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.13.1/src/OpenTelemetry.Api/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Api.ProviderBuilderExtensions v1.13.1](https://www.nuget.org/packages/OpenTelemetry.Api.ProviderBuilderExtensions/1.13.1) No notable changes. See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.13.1/src/OpenTelemetry.Api.ProviderBuilderExtensions/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Exporter.Console v1.13.1](https://www.nuget.org/packages/OpenTelemetry.Exporter.Console/1.13.1) No notable changes. See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.13.1/src/OpenTelemetry.Exporter.Console/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Exporter.InMemory v1.13.1](https://www.nuget.org/packages/OpenTelemetry.Exporter.InMemory/1.13.1) No notable changes. See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.13.1/src/OpenTelemetry.Exporter.InMemory/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Exporter.OpenTelemetryProtocol v1.13.1](https://www.nuget.org/packages/OpenTelemetry.Exporter.OpenTelemetryProtocol/1.13.1) No notable changes. See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.13.1/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Exporter.Zipkin v1.13.1](https://www.nuget.org/packages/OpenTelemetry.Exporter.Zipkin/1.13.1) No notable changes. See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.13.1/src/OpenTelemetry.Exporter.Zipkin/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Extensions.Hosting v1.13.1](https://www.nuget.org/packages/OpenTelemetry.Extensions.Hosting/1.13.1) ... (truncated) ## 1.13.1-beta.1 The following changes are from the previous release [1.13.0-beta.1](https://github.com/open-telemetry/opentelemetry-dotnet/releases/tag/coreunstable-1.13.0-beta.1). * NuGet: [OpenTelemetry.Exporter.Prometheus.AspNetCore v1.13.1-beta.1](https://www.nuget.org/packages/OpenTelemetry.Exporter.Prometheus.AspNetCore/1.13.1-beta.1) * Updated OpenTelemetry core component version(s) to `1.13.1`. ([#6598](open-telemetry/opentelemetry-dotnet#6598)) See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/coreunstable-1.13.1-beta.1/src/OpenTelemetry.Exporter.Prometheus.AspNetCore/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Exporter.Prometheus.HttpListener v1.13.1-beta.1](https://www.nuget.org/packages/OpenTelemetry.Exporter.Prometheus.HttpListener/1.13.1-beta.1) * Updated OpenTelemetry core component version(s) to `1.13.1`. ([#6598](open-telemetry/opentelemetry-dotnet#6598)) See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/coreunstable-1.13.1-beta.1/src/OpenTelemetry.Exporter.Prometheus.HttpListener/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Shims.OpenTracing v1.13.1-beta.1](https://www.nuget.org/packages/OpenTelemetry.Shims.OpenTracing/1.13.1-beta.1) * Updated OpenTelemetry core component version(s) to `1.13.1`. ([#6598](open-telemetry/opentelemetry-dotnet#6598)) See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/coreunstable-1.13.1-beta.1/src/OpenTelemetry.Shims.OpenTracing/CHANGELOG.md) for details. ## 1.13.0 For highlights and announcements pertaining to this release see: [Release Notes > 1.13.0](https://github.com/open-telemetry/opentelemetry-dotnet/blob/main/RELEASENOTES.md#1130). The following changes are from the previous release [1.12.0](https://github.com/open-telemetry/opentelemetry-dotnet/releases/tag/core-1.12.0). * NuGet: [OpenTelemetry v1.13.0](https://www.nuget.org/packages/OpenTelemetry/1.13.0) * Added a verification to ensure that a `MetricReader` can only be registered to a single `MeterProvider`, as required by the OpenTelemetry specification. ([#6458](open-telemetry/opentelemetry-dotnet#6458)) * Added `FormatMessage` configuration option to self-diagnostics feature. When set to `true` (default is false), log messages will be formatted by replacing placeholders with actual parameter values for improved readability. Example `OTEL_DIAGNOSTICS.json`: ```json { "LogDirectory": ".", "FileSize": 32768, "LogLevel": "Warning", "FormatMessage": true } ``` * Fixed parsing of `OTEL_TRACES_SAMPLER_ARG` decimal values to always use `.` as the delimiter when using the `traceidratio` sampler, preventing locale-specific parsing issues. ([#6444](open-telemetry/opentelemetry-dotnet#6444)) See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.13.0/src/OpenTelemetry/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Api v1.13.0](https://www.nuget.org/packages/OpenTelemetry.Api/1.13.0) * Added `AddLink(SpanContext, SpanAttributes?)` to `TelemetrySpan` to support linking spans and associating optional attributes for advanced trace relationships. ([#6305](open-telemetry/opentelemetry-dotnet#6305)) * Experimental (only in pre-release versions): Added the `EventName` property to `LogRecordData` ([#6306](open-telemetry/opentelemetry-dotnet#6306)) See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.13.0/src/OpenTelemetry.Api/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Api.ProviderBuilderExtensions v1.13.0](https://www.nuget.org/packages/OpenTelemetry.Api.ProviderBuilderExtensions/1.13.0) No notable changes. See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.13.0/src/OpenTelemetry.Api.ProviderBuilderExtensions/CHANGELOG.md) for details. ... (truncated) ## 1.13.0-beta.1 The following changes are from the previous release [1.12.0-beta.1](https://github.com/open-telemetry/opentelemetry-dotnet/releases/tag/coreunstable-1.12.0-beta.1). * NuGet: [OpenTelemetry.Exporter.Prometheus.AspNetCore v1.13.0-beta.1](https://www.nuget.org/packages/OpenTelemetry.Exporter.Prometheus.AspNetCore/1.13.0-beta.1) * Updated OpenTelemetry core component version(s) to `1.13.0`. ([#6552](open-telemetry/opentelemetry-dotnet#6552)) See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/coreunstable-1.13.0-beta.1/src/OpenTelemetry.Exporter.Prometheus.AspNetCore/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Exporter.Prometheus.HttpListener v1.13.0-beta.1](https://www.nuget.org/packages/OpenTelemetry.Exporter.Prometheus.HttpListener/1.13.0-beta.1) * Updated OpenTelemetry core component version(s) to `1.13.0`. ([#6552](open-telemetry/opentelemetry-dotnet#6552)) See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/coreunstable-1.13.0-beta.1/src/OpenTelemetry.Exporter.Prometheus.HttpListener/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Shims.OpenTracing v1.13.0-beta.1](https://www.nuget.org/packages/OpenTelemetry.Shims.OpenTracing/1.13.0-beta.1) * Updated OpenTelemetry core component version(s) to `1.13.0`. ([#6552](open-telemetry/opentelemetry-dotnet#6552)) See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/coreunstable-1.13.0-beta.1/src/OpenTelemetry.Shims.OpenTracing/CHANGELOG.md) for details. Commits viewable in [compare view](open-telemetry/opentelemetry-dotnet@core-1.12.0...core-1.13.1). </details> [![Dependabot compatibility score](https://dependabot-badges.githubapp.com/badges/compatibility_score?dependency-name=OpenTelemetry.Extensions.Hosting&package-manager=nuget&previous-version=1.12.0&new-version=1.13.1)](https://docs.github.com/en/github/managing-security-vulnerabilities/about-dependabot-security-updates#about-compatibility-scores) Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@dependabot rebase`. [//]: # (dependabot-automerge-start) [//]: # (dependabot-automerge-end) --- <details> <summary>Dependabot commands and options</summary> <br /> You can trigger Dependabot actions by commenting on this PR: - `@dependabot rebase` will rebase this PR - `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it - `@dependabot merge` will merge this PR after your CI passes on it - `@dependabot squash and merge` will squash and merge this PR after your CI passes on it - `@dependabot cancel merge` will cancel a previously requested merge and block automerging - `@dependabot reopen` will reopen this PR if it is closed - `@dependabot close` will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually - `@dependabot show <dependency name> ignore conditions` will show all of the ignore conditions of the specified dependency - `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself) </details> Signed-off-by: dependabot[bot] <[email protected]> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com> Co-authored-by: Rene Bentes Pinto <[email protected]>

added tests for multiple readers registered to the same provider; fix…

fa7a7a5

…: The SDK MUST NOT allow a MetricReader instance to be registered on more than one MeterProvider instance.

github-actions bot added the pkg:OpenTelemetry Issues related to OpenTelemetry NuGet package label Aug 31, 2025

hannahhaering marked this pull request as ready for review August 31, 2025 22:13

hannahhaering requested a review from a team as a code owner August 31, 2025 22:13

hannahhaering mentioned this pull request Aug 31, 2025

Multiple MetricReader test improvements #2938

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martincostello approved these changes Sep 1, 2025

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added changelog entry

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martincostello reviewed Sep 1, 2025

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src/OpenTelemetry/CHANGELOG.md Outdated Show resolved Hide resolved

Update src/OpenTelemetry/CHANGELOG.md

efe35df

Co-authored-by: Martin Costello <[email protected]>

Kielek approved these changes Sep 2, 2025

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Merge branch 'main' into multiple-metric-reader-tests

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rajkumar-rangaraj approved these changes Sep 8, 2025

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Kielek reviewed Sep 9, 2025

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src/OpenTelemetry/CHANGELOG.md Outdated Show resolved Hide resolved

lint changelog

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Kielek added the ready to merge label Sep 9, 2025

Merge branch 'main' into multiple-metric-reader-tests

1330c5f

rajkumar-rangaraj merged commit ea2cfdc into open-telemetry:main Sep 9, 2025
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Fix and tests for multiple metric readers #6458

Fix and tests for multiple metric readers #6458

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Fix and tests for multiple metric readers #6458

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hannahhaering commented Aug 31, 2025

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