Add ObservedTimestamp to LogRecordData by juliuskoval · Pull Request #6979 · open-telemetry/opentelemetry-dotnet

juliuskoval · 2026-03-18T17:41:15Z

Towards #4433

Changes

Adds ObservedTimestamp to LogRecordData and LogRecord.

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)

juliuskoval · 2026-03-18T17:53:48Z

On a somewhat related note, it seems to me that the spec suggests that LogRecordData.Timestamp should be nullable. LogRecord.Timestamp is always set in OpenTelemetryLogger so it shouldn't be a breaking change, but it would be changing the stable public API.

codecov · 2026-03-18T17:54:16Z

Codecov Report

❌ Patch coverage is 92.30769% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 89.73%. Comparing base (67a2e1f) to head (aec8a0a).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/OpenTelemetry/Logs/LogRecord.cs	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6979      +/-   ##
==========================================
- Coverage   89.73%   89.73%   -0.01%     
==========================================
  Files         276      276              
  Lines       14628    14635       +7     
==========================================
+ Hits        13127    13132       +5     
- Misses       1501     1503       +2

Flag	Coverage Δ
unittests-Project-Experimental	`89.53% <92.30%> (-0.20%)`	⬇️
unittests-Project-Stable	`89.63% <92.30%> (-0.06%)`	⬇️

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

Files with missing lines	Coverage Δ
src/OpenTelemetry.Api/Logs/LogRecordData.cs	`100.00% <100.00%> (ø)`
...metry.Exporter.Console/ConsoleLogRecordExporter.cs	`97.14% <100.00%> (+0.04%)`	⬆️
...ementation/Serializer/ProtobufOtlpLogSerializer.cs	`98.50% <100.00%> (-0.04%)`	⬇️
.../OpenTelemetry/Logs/ILogger/OpenTelemetryLogger.cs	`90.00% <100.00%> (+0.10%)`	⬆️
src/OpenTelemetry/Logs/LoggerSdk.cs	`100.00% <100.00%> (ø)`
src/OpenTelemetry/Logs/LogRecord.cs	`70.77% <66.66%> (-0.09%)`	⬇️

... and 1 file with indirect coverage changes

rajkumar-rangaraj

Left a suggestion to update OTLP Exporter changelog.

Kielek · 2026-03-20T08:13:47Z

On a somewhat related note, it seems to me that the spec suggests that LogRecordData.Timestamp and LogRecord.Timestamp should be nullable. LogRecord.Timestamp is always set in OpenTelemetryLogger so it shouldn't be a breaking change, but it would be changing the stable public API.

I think that we should document this spec deviation in the document (can be separate PR). What is more it will be great to create some issue to fix it. There is label required major bump.

juliuskoval · 2026-03-24T20:36:27Z

On a somewhat related note, it seems to me that the spec suggests that LogRecordData.Timestamp and LogRecord.Timestamp should be nullable. LogRecord.Timestamp is always set in OpenTelemetryLogger so it shouldn't be a breaking change, but it would be changing the stable public API.

I think that we should document this spec deviation in the document (can be separate PR). What is more it will be great to create some issue to fix it. There is label required major bump.

I created this issue to track all the deviations from the spec. #6992

Kielek

Sorry for delays with reviews. Finally, I was able to finish other OTel Auto task.

If we go with non-nullable approach, it should be fine with some small adjustments.

I have checked also other possibilities (the code is still dirty and probably needs to be split into at least 2 PRs, but it shows potential solution without breaking changes.
Description https://github.com/Kielek/opentelemetry-dotnet/blob/3ee221fe48f17ca399b3dd4d59d7cca9cf8b96de/docs/design/make-timestamp-nullable.md

and the PR itself: Kielek@3ee221f

juliuskoval · 2026-03-29T08:53:07Z

@Kielek Sorry about taking so long as well. Regarding your proposed solutions, couldn't we just leave LogRecord.Timestamp as it is right now given that all options would lead to deviations from the spec and document the difference somewhere?

juliuskoval · 2026-04-02T12:57:36Z

Hi @Kielek, do you have any thoughts on my previous comment?

Kielek · 2026-04-02T18:39:59Z

Yes, I have one more discussion about this last days. We could change a bit behavior in non-public class and treat DateTime.MinValue/default as not set (for both values) + check it during exporting.

As I know Go-lang is implemented in this way. Hidden null, to avoid extra memory footprint by Nullable version.

I will play a bit with thin Tuesday+ next week.

github-actions · 2026-04-10T04:13:40Z

This PR was marked stale due to lack of activity and will be closed in 7 days. Commenting or pushing will instruct the bot to automatically remove the label. This bot runs once per day.

….0 (#1201) Updated [OpenTelemetry.Exporter.OpenTelemetryProtocol](https://github.com/open-telemetry/opentelemetry-dotnet) from 1.15.3 to 1.16.0. <details> <summary>Release notes</summary> _Sourced from [OpenTelemetry.Exporter.OpenTelemetryProtocol's releases](https://github.com/open-telemetry/opentelemetry-dotnet/releases)._ ## 1.16.0 For highlights and announcements pertaining to this release see: [Release Notes > 1.16.0](https://github.com/open-telemetry/opentelemetry-dotnet/blob/main/RELEASENOTES.md#1160). The following changes are from the previous release [1.16.0-rc.1](https://github.com/open-telemetry/opentelemetry-dotnet/releases/tag/core-1.16.0-rc.1). * NuGet: [OpenTelemetry v1.16.0](https://www.nuget.org/packages/OpenTelemetry/1.16.0) No notable changes. See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.16.0/src/OpenTelemetry/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Api v1.16.0](https://www.nuget.org/packages/OpenTelemetry.Api/1.16.0) No notable changes. See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.16.0/src/OpenTelemetry.Api/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Api.ProviderBuilderExtensions v1.16.0](https://www.nuget.org/packages/OpenTelemetry.Api.ProviderBuilderExtensions/1.16.0) No notable changes. See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.16.0/src/OpenTelemetry.Api.ProviderBuilderExtensions/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Exporter.Console v1.16.0](https://www.nuget.org/packages/OpenTelemetry.Exporter.Console/1.16.0) No notable changes. See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.16.0/src/OpenTelemetry.Exporter.Console/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Exporter.InMemory v1.16.0](https://www.nuget.org/packages/OpenTelemetry.Exporter.InMemory/1.16.0) No notable changes. See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.16.0/src/OpenTelemetry.Exporter.InMemory/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Exporter.OpenTelemetryProtocol v1.16.0](https://www.nuget.org/packages/OpenTelemetry.Exporter.OpenTelemetryProtocol/1.16.0) No notable changes. See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.16.0/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Exporter.Zipkin v1.16.0](https://www.nuget.org/packages/OpenTelemetry.Exporter.Zipkin/1.16.0) No notable changes. See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.16.0/src/OpenTelemetry.Exporter.Zipkin/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Extensions.Hosting v1.16.0](https://www.nuget.org/packages/OpenTelemetry.Extensions.Hosting/1.16.0) No notable changes. ... (truncated) ## 1.16.0-rc.1 The following changes are from the previous release [1.15.3](https://github.com/open-telemetry/opentelemetry-dotnet/releases/tag/core-1.15.3). * NuGet: [OpenTelemetry v1.16.0-rc.1](https://www.nuget.org/packages/OpenTelemetry/1.16.0-rc.1) * Stop validating View-provided metric stream `Name` against the instrument name syntax, per [spec clarification](open-telemetry/opentelemetry-specification#5094). ([#7300](open-telemetry/opentelemetry-dotnet#7300)) * Fix incorrect validation of `OTEL_BSP_*` and `OTEL_BLRP_*` environment variables. ([#7187](open-telemetry/opentelemetry-dotnet#7187)) * Fix observable instrument callbacks running once per reader instead of once per collection cycle. ([#7188](open-telemetry/opentelemetry-dotnet#7188)) * Added exception safety for user-supplied `ExemplarReservoir` implementations. Exceptions thrown from `Offer` are now caught and logged rather than propagating out of `Counter.Add`/`Histogram.Record`. ([#7277](open-telemetry/opentelemetry-dotnet#7277)) * Update `OpenTelemetrySdkEventSource` to support the W3C randomness flag. ([#7301](open-telemetry/opentelemetry-dotnet#7301)) * Added `ObservedTimestamp` property to `LogRecord`. ([#6979](open-telemetry/opentelemetry-dotnet#6979)) * **Breaking Change** Explicit histogram boundaries no longer allow more than 10 million values. ([#7165](open-telemetry/opentelemetry-dotnet#7165)) * Fixed a circular reference which could cause a `LoggerProvider` to fail to resolve when one of its dependencies depends on `ILogger` or `ILoggerFactory`. As part of this fix the `LoggerProvider` resolved from dependency injection is now created lazily when the first logger is created rather than when `ILoggerProvider` or `ILoggerFactory` is resolved. A consequence is that any invalid configuration now surfaces when the first log record is written instead of when the logging services are resolved. ([#7308](open-telemetry/opentelemetry-dotnet#7308)) See [CHANGELOG](https://github.com/open-telemetry/opentelemetry-dotnet/blob/core-1.16.0-rc.1/src/OpenTelemetry/CHANGELOG.md) for details. * NuGet: [OpenTelemetry.Api v1.16.0-rc.1](https://www.nuget.org/packages/OpenTelemetry.Api/1.16.0-rc.1) * **Experimental (pre-release builds only):** Add support for using environment variables as context propagation carriers. ([#7174](open-telemetry/opentelemetry-dotnet#7174)) * Fix `BaggagePropagator` to correctly follow Key and Value Encoding rules as per ... (truncated) ## 1.16.0-beta.1 The following changes are from the previous release [1.15.3-beta.1](https://github.com/open-telemetry/opentelemetry-dotnet/releases/tag/coreunstable-1.15.3-beta.1). * NuGet: [OpenTelemetry.Exporter.Prometheus.AspNetCore v1.16.0-beta.1](https://www.nuget.org/packages/OpenTelemetry.Exporter.Prometheus.AspNetCore/1.16.0-beta.1) * Fixed scrape response cache freshness using monotonic time so it is not affected by NTP system clock adjustments. ([#7253](open-telemetry/opentelemetry-dotnet#7253)) * **Breaking Change** Removed `DisableTimestamp` property from `PrometheusAspNetCoreOptions`. ([#7176](open-telemetry/opentelemetry-dotnet#7176)) * Fixed the serialization of `NaN`, `PositiveInfinity`, and `NegativeInfinity` values in Prometheus metrics to be compliant with the specification. ([#7179](open-telemetry/opentelemetry-dotnet#7179)) * Fixed loss of precision when serializing `double` and `float` values in Prometheus metrics to be compliant with the specification by using 17 significant digits to represent such values. ([#7179](open-telemetry/opentelemetry-dotnet#7179)) * Fix non-ASCII characters in metric names and unit strings not being sanitized correctly during Prometheus serialization. ([#7184](open-telemetry/opentelemetry-dotnet#7184)) * Fix case where reader tracking could be reset while readers were still active. ([#7190](open-telemetry/opentelemetry-dotnet#7190)) * Improve `Accept` header handling for format negotiation so OpenMetrics is selected correctly by considering whitespace and `q` weights. ([#7208](open-telemetry/opentelemetry-dotnet#7208)) * Emit OpenMetrics exemplars for counters and histogram buckets. ([#7222](open-telemetry/opentelemetry-dotnet#7222)) * Fix incorrect handling of untyped metrics when using OpenMetrics format. ([#7219](open-telemetry/opentelemetry-dotnet#7219)) * Fix Prometheus/OpenMetrics serialization to emit metric and label names containing `_` instead of dropping them and prefixing leading digits. Invalid characters are replaced with `_` instead of being dropped. ([#7209](open-telemetry/opentelemetry-dotnet#7209)) * Add `escaping=underscores` to the `Accept` header handling for content negotiation so OpenMetrics are handled correctly. ([#7209](open-telemetry/opentelemetry-dotnet#7209)) * Omit histogram `_sum` and `_count` in OpenMetrics when negative bucket thresholds are present. ([#7221](open-telemetry/opentelemetry-dotnet#7221)) ... (truncated) Commits viewable in [compare view](open-telemetry/opentelemetry-dotnet@core-1.15.3...core-1.16.0). </details> [![Dependabot compatibility score](https://dependabot-badges.githubapp.com/badges/compatibility_score?dependency-name=OpenTelemetry.Exporter.OpenTelemetryProtocol&package-manager=nuget&previous-version=1.15.3&new-version=1.16.0)](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 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] <support@github.com> Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

juliuskoval marked this pull request as ready for review March 18, 2026 17:53

juliuskoval requested a review from a team as a code owner March 18, 2026 17:53

martincostello approved these changes Mar 19, 2026

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Comment thread ...emetry.Exporter.OpenTelemetryProtocol/Implementation/Serializer/ProtobufOtlpLogSerializer.cs Outdated

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Kielek mentioned this pull request Mar 20, 2026

Update OTel SDK/API to 1.16.0 open-telemetry/opentelemetry-dotnet-instrumentation#4941

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juliuskoval mentioned this pull request Mar 24, 2026

Track differences between the OpenTelemetry spec and the .NET implementation of the logs bridge API #6992

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Kielek reviewed Mar 26, 2026

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Comment thread ...emetry.Exporter.OpenTelemetryProtocol/Implementation/Serializer/ProtobufOtlpLogSerializer.cs

Comment thread src/OpenTelemetry.Api/Logs/LogRecordData.cs

juliuskoval and others added 5 commits March 29, 2026 10:33

Add ObservedTimestamp to LogRecordData

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add changelog entries

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add unit test

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fixes

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md lint

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juliuskoval force-pushed the ObservedTimeStamp branch from dee66ac to 27cb08b Compare March 29, 2026 08:36

fix console exporter

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github-actions Bot added the pkg:OpenTelemetry.Exporter.Console Issues related to OpenTelemetry.Exporter.Console NuGet package label Mar 29, 2026

Kielek mentioned this pull request Apr 8, 2026

Logs API - initialize LogRecordData.Timestamp with MinValue #7045

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Add ObservedTimestamp to LogRecordData#6979

Add ObservedTimestamp to LogRecordData#6979
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