Define OTLP Trace Metrics Histogram and Writers by mhlidd · Pull Request #11656 · DataDog/dd-trace-java

mhlidd · 2026-06-16T19:27:03Z

What Does This Do

This PR introduces a OTLP Trace Metrics Histogram class and OTLP Trace Metrics Writers. Aggregate metrics are encoded into protobuf and sent out in OTel semantics. Additional Datadog specific attributes are added under a config DD_TRACE_OTEL_SEMANTICS_ENABLED.

Note that OTLP Trace Metrics force temporality delta in order to properly use an OTLP histogram in Datadog.

Motivation

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Jira ticket: [PROJ-IDENT]

datadog-datadog-prod-us1-2 · 2026-06-16T19:28:51Z

🎯 Code Coverage (details)
• Patch Coverage: 85.25%
• Overall Coverage: 57.01% (+0.55%)

_{This comment will be updated automatically if new data arrives.

🔗 Commit SHA: 7b264b9 | Docs | Datadog PR Page | Give us feedback!}

dd-octo-sts · 2026-06-16T19:51:22Z

🟢 Java Benchmark SLOs — All performance SLOs passed

Suite	Status
Startup	🟢 pass

SLO thresholds are defined here based on automatically generated metrics. A warning is raised when results are within 5% of the threshold.

PR vs. master results

Scenario	Candidate	master	Δ (95% CI of mean)
startup:insecure-bank:iast:Agent	13.93 s	13.97 s	[-1.2%; +0.6%] (no difference)
startup:insecure-bank:tracing:Agent	12.87 s	13.03 s	[-2.1%; -0.4%] (maybe better)
startup:petclinic:appsec:Agent	16.68 s	17.21 s	[-7.2%; +1.1%] (no difference)
startup:petclinic:iast:Agent	17.37 s	17.51 s	[-1.8%; +0.3%] (no difference)
startup:petclinic:profiling:Agent	17.44 s	16.67 s	[+0.1%; +9.2%] (maybe worse)
startup:petclinic:sca:Agent	17.51 s	17.45 s	[-0.4%; +1.1%] (no difference)
startup:petclinic:tracing:Agent	16.50 s	16.66 s	[-1.9%; -0.0%] (maybe better)

Commit: 7b264b95 · CI Pipeline · Benchmarking Platform UI

Load and DaCapo benchmarks can be triggered manually in the GitLab pipeline. Results will appear in the Benchmarking Platform UI after completion.

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mhlidd · 2026-06-27T13:36:57Z

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mhlidd · 2026-06-30T18:41:32Z

+    this.startNanos = start;
+    this.endNanos = start + duration;


It seems like the report function that calls this startBucket function is sending the clock time when report is called. I followed the precedence set in SerializingMetricWriter that uses the clock time passed in as the start time.

This seems odd, because when report is called, I would imagine that's the "end" time. Is this difference something that we've accepted, or is it a bug? cc: @mcculls

mhlidd · 2026-06-30T18:42:16Z

@@ -0,0 +1,70 @@
+package datadog.trace.common.metrics;


Note that I don't like how these classes are in the common package, but that is the only way the Writer can access AggregateEntry.

remove irrelevant test following rebase

mhlidd · 2026-07-02T20:15:40Z

+    writeStringAttribute(SPAN_NAME, entry.getResource());
+    writeStringAttribute(SPAN_KIND, entry.getSpanKind());


Maybe these need to be gated w/ a not empty check.

mhlidd · 2026-07-02T20:15:57Z

+      writeStringAttribute(DATADOG_OPERATION_NAME, entry.getOperationName());
+      writeStringAttribute(DATADOG_SPAN_TYPE, entry.getType());


Maybe these need to be gated w/ a not empty check.

mhlidd changed the base branch from master to mhlidd/otlp_trace_metrics_config June 17, 2026 17:50

mhlidd changed the base branch from mhlidd/otlp_trace_metrics_config to mhlidd/otlp_trace_metrics_aggregate_entry June 23, 2026 20:32

mhlidd force-pushed the mhlidd/otlp_trace_metrics_setup branch from e11a634 to d202d88 Compare June 23, 2026 20:37

mhlidd changed the title ~~Mhlidd/otlp trace metrics setup~~ Define OTLP Trace Metrics Histogram and Writers Jun 26, 2026

mhlidd added comp: metrics Metrics type: enhancement Enhancements and improvements labels Jun 26, 2026

mhlidd marked this pull request as ready for review June 26, 2026 03:31

mhlidd requested a review from a team as a code owner June 26, 2026 03:31

mhlidd requested a review from ygree June 26, 2026 03:31

chatgpt-codex-connector Bot reviewed Jun 26, 2026

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Comment thread dd-trace-core/src/main/java/datadog/trace/common/metrics/OtlpStatsMetricWriter.java Outdated

Comment thread dd-trace-core/src/main/java/datadog/trace/common/metrics/OtlpStatsMetricWriter.java Outdated

mhlidd requested review from PerfectSlayer and mcculls June 27, 2026 13:32

chatgpt-codex-connector Bot reviewed Jun 27, 2026

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Comment thread dd-trace-core/src/main/java/datadog/trace/common/metrics/OtlpStatsMetricWriter.java

Comment thread dd-trace-core/src/main/java/datadog/trace/common/metrics/OtlpStatsMetricWriter.java

mhlidd commented Jun 30, 2026

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mhlidd mentioned this pull request Jul 1, 2026

Wire OTLP Trace Metrics Writers into Metrics Aggregators #11680

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mhlidd force-pushed the mhlidd/otlp_trace_metrics_aggregate_entry branch from fb6b228 to 2d8a515 Compare July 2, 2026 18:23

mhlidd added 10 commits July 2, 2026 13:31

init

5942fe0

adding exact sums for ok/error

095eec3

remove host.name changes

4c92994

init tests

da4d67d

adding datadog-specific datapoint attribtues

5ef4652

more specific logging

a1a428c

refactor origin usage in test helpers and add origin specific testS

72c12bb

remove irrelevant test following rebase

rename histogram class and refactor tests

9662967

force temporality delta on tracemetrics histogram

aa351f0

gating error latencies on empty as well

9cf8a25

mhlidd added 2 commits July 2, 2026 14:46

update metricintegrationtest

f04268a

cleanup

7b264b9

mhlidd force-pushed the mhlidd/otlp_trace_metrics_setup branch from 94fbcc0 to 7b264b9 Compare July 2, 2026 19:57

mhlidd commented Jul 2, 2026

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Define OTLP Trace Metrics Histogram and Writers#11656

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		writeStringAttribute(SPAN_NAME, entry.getResource());
		writeStringAttribute(SPAN_KIND, entry.getSpanKind());

		writeStringAttribute(DATADOG_OPERATION_NAME, entry.getOperationName());
		writeStringAttribute(DATADOG_SPAN_TYPE, entry.getType());

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What Does This Do

Motivation

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