[FFL-1720] Evaluation Logging: Integration by typotter · Pull Request #3147 · DataDog/dd-sdk-android

typotter · 2026-01-22T08:49:15Z

🥞 Evaluation Logging Stacked Pull Requests 🥞

👉 Integration & Configuration (this PR)
☑️ Storage & Network Infrastructure (PR #3146)
☑️ Aggregation Engine & Test Utilities (PR #3145)
☑️ FlagEvaluation Schema (PR #3166)
☑️ Event Schema & Data Models (PR #3144)
☑️ Evaluations Subfeature (PR #3159)
⎿ feature/flags-evaluations-logging (feature branch)

Datadog Internal
🎟️ Ticket: FFL-1720 - Implement Evaluation Logging for Android SDK

What does this PR do?

Wires the evaluation logging feature end-to-end by connecting the EvaluationsFeature to the flag evaluation flow. This is the final PR that enables evaluation logging in the Flags SDK.

Motivation

We need to implement Evaluation Logging to provide comprehensive visibility into all feature flag evaluations, including defaults, errors, and successful matches. This goes beyond exposure logging by capturing aggregated metrics about evaluation frequency, error rates, and runtime default usage across all flags.

Additional Notes

Review checklist (to be filled by reviewers)

Feature or bugfix MUST have appropriate tests (unit, integration, e2e)
Make sure you discussed the feature or bugfix with the maintaining team in an Issue
Make sure each commit and the PR mention the Issue number (cf the CONTRIBUTING doc)

typotter · 2026-01-22T09:27:34Z

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
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[FFL-1720] Evaluation Logging: Integration #3147 👈 (View in Graphite)
[FFL-1720] Evaluation Logging: Storage & Network Infrastructure #3146
[FFL-1720] Evaluation Logging: Aggregation Engine & Test Utilities #3145
[FFL-1720] Evaluation Logging: Event Schema & Data Models #3144
feature/flags-evaluations-logging

This stack of pull requests is managed by Graphite. Learn more about stacking.

...d-sdk-android-flags/src/main/kotlin/com/datadog/android/flags/internal/DatadogFlagsClient.kt

codecov-commenter · 2026-02-02T07:39:06Z

Codecov Report

❌ Patch coverage is 36.47059% with 54 lines in your changes missing coverage. Please review.
✅ Project coverage is 70.86%. Comparing base (3a685c2) to head (a0fea1d).

Files with missing lines	Patch %	Lines
...tadog/android/flags/internal/EvaluationsFeature.kt	2.33%	42 Missing ⚠️
...tadog/android/flags/internal/DatadogFlagsClient.kt	66.67%	7 Missing and 3 partials ⚠️
...in/kotlin/com/datadog/android/flags/FlagsClient.kt	0.00%	2 Missing ⚠️

Additional details and impacted files

@@                          Coverage Diff                          @@
##           typo/FFL-1720-pr3-storage-network    #3147      +/-   ##
=====================================================================
- Coverage                              70.92%   70.86%   -0.06%     
=====================================================================
  Files                                    906      906              
  Lines                                  33353    33430      +77     
  Branches                                5623     5643      +20     
=====================================================================
+ Hits                                   23654    23690      +36     
- Misses                                  8127     8166      +39     
- Partials                                1572     1574       +2

Files with missing lines	Coverage Δ
...src/main/kotlin/com/datadog/android/flags/Flags.kt	`92.86% <100.00%> (+1.95%)`	⬆️
...com/datadog/android/flags/internal/FlagsFeature.kt	`85.07% <100.00%> (+0.46%)`	⬆️
...in/kotlin/com/datadog/android/flags/FlagsClient.kt	`36.21% <0.00%> (-0.31%)`	⬇️
...tadog/android/flags/internal/DatadogFlagsClient.kt	`88.42% <66.67%> (-2.94%)`	⬇️
...tadog/android/flags/internal/EvaluationsFeature.kt	`18.18% <2.33%> (-56.82%)`	⬇️

... and 38 files with indirect coverage changes

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

Integrates the evaluation logging feature end-to-end, enabling it in the SDK. Configuration (FlagsConfiguration): - Add trackEvaluations(enabled: Boolean) - default true (EVALLOG.12) - Add useCustomEvaluationEndpoint(endpoint: String) - for testing/proxies - Add evaluationFlushInterval(intervalMs: Long) - configurable 1-60s, default 10s - Validation: interval coerced to valid range Lifecycle (FlagsFeature): - Initialize evaluation processor on onInitialize() when trackEvaluations enabled - Creates scheduled executor for periodic flushing - Creates evaluation writer (EvaluationEventRecordWriter) - Schedules periodic flush task - Clean up on onStop(): - Flush remaining evaluations via processor.stop() - Clean up processor and writer references - Renamed processor → exposureProcessor for clarity - Renamed dataWriter → exposureWriter for clarity Integration (DatadogFlagsClient): - Accept both exposureProcessor and evaluationProcessor (optional) - Add writeEvaluationEvent() method to log evaluations - Track ALL evaluations when trackEvaluations enabled: - Success evaluations in trackResolution() - Error evaluations via new trackErrorResolution() method - Error evaluations create synthetic PrecomputedFlag with ERROR reason Factory (FlagsClient): - Pass both processors to DatadogFlagsClient constructor Test Updates: - DatadogFlagsClientTest: Update all instantiations to pass both processors - FlagsFeatureTest: Update to test dual processor initialization - Add mock for createScheduledExecutorService() EVALLOG compliance: Enables evaluation logging (2, 3, 4, 5, 8, 10, 11, 12, 13) Zero user-facing breaking changes - all new options have defaults.

0xnm · 2026-02-03T22:52:39Z

...ures/dd-sdk-android-flags/src/main/kotlin/com/datadog/android/flags/internal/FlagsFeature.kt

+internal class FlagsFeature(
+    private val sdkCore: FeatureSdkCore,
+    internal val flagsConfiguration: FlagsConfiguration,
+    internal val evaluationsFeature: EvaluationsFeature? = null


Having it as a property just to be read in the FlagsClient setup without a real usage inside FlagsFeature may look a bit confusing. Maybe simply get it in the FlagsClient.Builder.build as it is done for the FlagsFeature?

0xnm · 2026-02-03T22:58:27Z

...d-sdk-android-flags/src/main/kotlin/com/datadog/android/flags/internal/DatadogFlagsClient.kt

+            doLog = false,
+            allocationKey = "",
+            variationKey = "",
+            extraLogging = org.json.JSONObject(),


Suggested change

extraLogging = org.json.JSONObject(),

extraLogging = JSONObject(),

We then need to have it as a static object instead of creating the same object all the time. But only if it is not supposed to be mutated during the downstream processing.

0xnm · 2026-02-04T00:36:01Z

...d-sdk-android-flags/src/main/kotlin/com/datadog/android/flags/internal/EvaluationsFeature.kt

+
+        // Get initial service from DatadogContext
+        val internalSdkCore = sdkCore as? InternalSdkCore
+        val initialService = internalSdkCore?.getDatadogContext()?.service


We should avoid doing this since it is a blocking call and may slow down SDK initialization.

What prevents from reading RUM context and SDK context during the event write stage? I believe it is evaluation aggregation where we write data to the disk only after some time.

Normally, service doesn't change during the SDK core lifetime, because there is no way to set if after SDK is initialized, so it can be read actually during the event write phase, not here.

typotter force-pushed the typo/FFL-1720-pr4-integration branch from 10e6149 to 5a11e3d Compare January 22, 2026 09:27

typotter force-pushed the typo/FFL-1720-pr3-storage-network branch from fa56eda to a83f2d5 Compare January 22, 2026 09:27

This was referenced Jan 22, 2026

[FFL-1720] Evaluation Logging: Event Schema & Data Models #3144

Merged

[FFL-1720] Evaluation Logging: Aggregation Engine & Test Utilities #3145

Open

[FFL-1720] Evaluation Logging: Storage & Network Infrastructure #3146

Open

typotter force-pushed the typo/FFL-1720-pr4-integration branch from 5a11e3d to 1c2b043 Compare January 22, 2026 16:29

typotter force-pushed the typo/FFL-1720-pr3-storage-network branch 2 times, most recently from 7ceef6b to 7c8d6b7 Compare January 22, 2026 21:27

typotter force-pushed the typo/FFL-1720-pr4-integration branch from 1c2b043 to cc350e3 Compare January 22, 2026 21:27

dd-oleksii approved these changes Jan 23, 2026

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...d-sdk-android-flags/src/main/kotlin/com/datadog/android/flags/internal/DatadogFlagsClient.kt Show resolved Hide resolved

sameerank mentioned this pull request Jan 26, 2026

FFL-1721 Emit flagevaluation EVP Track DataDog/dd-sdk-ios#2646

Open

5 tasks

typotter mentioned this pull request Jan 27, 2026

[Flags] Evaluations subfeature #3159

Merged

3 tasks

typotter force-pushed the typo/FFL-1720-pr3-storage-network branch 4 times, most recently from 3618528 to cce61c1 Compare January 28, 2026 23:04

typotter mentioned this pull request Jan 30, 2026

[Flags] FlagEvaluation schema #3166

Merged

3 tasks

typotter force-pushed the typo/FFL-1720-pr3-storage-network branch from 8813c89 to 56da165 Compare January 30, 2026 20:54

typotter force-pushed the typo/FFL-1720-pr4-integration branch from cc350e3 to 8c8b89d Compare January 30, 2026 20:54

typotter force-pushed the typo/FFL-1720-pr3-storage-network branch 4 times, most recently from e84dada to fb01eef Compare February 2, 2026 06:20

typotter force-pushed the typo/FFL-1720-pr4-integration branch from 8c8b89d to 14f24f6 Compare February 2, 2026 06:36

typotter changed the title ~~[FFL-1720] Evaluation Logging: Integration & Configuration~~ [FFL-1720] Evaluation Logging: Integration Feb 2, 2026

typotter marked this pull request as ready for review February 2, 2026 06:46

typotter requested a review from a team as a code owner February 2, 2026 06:46

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typotter added 8 commits February 2, 2026 11:45

fix: update to two-module arch

bc44c03

lint

d373761

wire up using cached dd context

8962b3d

move context check to evaluationsfeature

0e67e0e

fix cast

f96cec0

revert artifacts

a8a1285

drop unnecessary changes to FlagsClient

03a8d8d

typotter force-pushed the typo/FFL-1720-pr3-storage-network branch from fb01eef to 3a685c2 Compare February 2, 2026 18:47

typotter force-pushed the typo/FFL-1720-pr4-integration branch from cccb7f9 to 03a8d8d Compare February 2, 2026 18:47

update for aggregator lifecycle

a0fea1d

0xnm requested changes Feb 4, 2026

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[FFL-1720] Evaluation Logging: Integration#3147

[FFL-1720] Evaluation Logging: Integration#3147
typotter wants to merge 9 commits intotypo/FFL-1720-pr3-storage-networkfrom
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	extraLogging = org.json.JSONObject(),
	extraLogging = JSONObject(),

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🥞 Evaluation Logging Stacked Pull Requests 🥞

What does this PR do?

Motivation

Additional Notes

Review checklist (to be filled by reviewers)

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