Share the WebFlux parsed-route cache across requests by amarziali · Pull Request #12561 · DataDog/dd-trace-java

amarziali · 2026-09-18T09:16:43Z

What Does This Do

WebFlux functional-routing instrumentation created a new parsed-route cache for every routing callback, preventing reuse across requests.

Make the cache static and bounded to 64 entries. This avoids per-callback cache allocation and lets repeated route strings reuse their parsed paths, skipping regex replacements on cache hits. Route parsing and span-tag behavior remain unchanged.

Motivation

Additional Notes

Contributor Checklist

Format the title according to the contribution guidelines
Assign the type: and (comp: or inst:) labels in addition to any other useful labels
Avoid using close, fix, or any linking keywords when referencing an issue
Use solves instead, and assign the PR milestone to the issue
Update the CODEOWNERS file on source file addition, migration, or deletion
Update public documentation with any new configuration flags or behaviors
Once approved, use merge queue to merge the PR

Jira ticket: [PROJ-IDENT]

chatgpt-codex-connector · 2026-09-18T09:16:59Z

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-18T09:18:36.606507Z	`ac38f45`	PR opened
🔒 Security Review	✅ Completed 2026-09-18T09:19:53.451334Z	`ac38f45`	PR opened

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

Open a pull request for review
Mark a draft as ready
Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.

datadog-datadog-prod-us1-2

More details

The cache uses the full route string as its key. The bounded, thread-safe cache keeps the existing route result for each key.

Was this helpful? React 👍 or 👎

_{Open Bits AI session}

_{🤖 Datadog Autotest · Commit ac38f45 · What is Autotest? · @DataDog review to ask questions · Any feedback? Reach out in #autotest}

datadog-datadog-prod-us1-2 · 2026-09-18T09:29:55Z

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 58.69% (-0.41%)

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

🔗 Commit SHA: ac38f45 | Docs | Give us feedback!}

dd-octo-sts · 2026-09-18T09:39:44Z

🟢 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	14.00 s	14.00 s	[-0.7%; +0.7%] (no difference)
startup:insecure-bank:tracing:Agent	12.94 s	12.96 s	[-0.8%; +0.4%] (no difference)
startup:petclinic:appsec:Agent	17.06 s	16.82 s	[+0.6%; +2.3%] (maybe worse)
startup:petclinic:iast:Agent	16.95 s	17.11 s	[-1.8%; -0.1%] (maybe better)
startup:petclinic:profiling:Agent	16.69 s	16.83 s	[-2.0%; +0.3%] (no difference)
startup:petclinic:sca:Agent	17.05 s	16.67 s	[+1.3%; +3.3%] (significantly worse)
startup:petclinic:tracing:Agent	16.15 s	15.68 s	[-0.9%; +6.9%] (no difference)

Commit: ac38f45e · 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.

dougqh

Nice catch.

I created a couple follow-up tasks for us to create annotations, so the perf-review checker can catch this mistake in the future.

ygree

Nice catch!

amarziali · 2026-09-21T06:59:06Z

/merge

gh-worker-devflow-routing-ef8351 · 2026-09-21T06:59:11Z

View all feedbacks in Devflow UI.

2026-09-21 06:59:11 UTC ℹ️ Start processing command /merge

2026-09-21 06:59:17 UTC ℹ️ MergeQueue: pull request added to the queue

The expected merge time in master is approximately 1h (p90).

2026-09-21 07:23:06 UTC ❌ MergeQueue: The build pipeline contains failing jobs for this merge request

Build pipeline has failing jobs for 07423c6:

jetty-app.arm64.DOC: [public.ecr.aws/docker/library/oraclelinux:8.10, linux/arm64, 17.0.15-zulu]

⚠️ Do NOT retry failed jobs directly (why?).

What to do next?

Investigate the failures and when ready, re-add your pull request to the queue!
If your PR checks are green, try to rebase/merge. It might be because the CI run is a bit old.
Any question, go check the FAQ.

Details

Since those jobs are not marked as being allowed to fail, the pipeline will most likely fail.
Therefore, and to allow other builds to be processed, this merge request has been rejected and the pipeline got canceled.

amarziali · 2026-09-21T07:23:36Z

/merge

gh-worker-devflow-routing-ef8351 · 2026-09-21T07:23:40Z

View all feedbacks in Devflow UI.

2026-09-21 07:23:40 UTC ℹ️ Start processing command /merge

2026-09-21 07:23:45 UTC ℹ️ MergeQueue: pull request added to the queue

The expected merge time in master is approximately 1h (p90).

2026-09-21 08:35:38 UTC ℹ️ MergeQueue: This merge request was merged

@Staticlifetime

Spot-checks the annotation against the real defect it was modeled on: PR #12561 (commit e6b8756) made this exact DDCache field static after it lived per-instance, unshared, for ~4 years. Serves as the first real call site for @Staticlifetime. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

@Staticlifetime

#12646) Add @Staticlifetime and @singleton marker annotations @Staticlifetime marks a field that must live for the whole program rather than for its enclosing instance's lifetime (e.g. a cache allocated per-request instead of once). @singleton is its escape valve, declaring a class has exactly one process-wide instance, so an instance field on it can satisfy @Staticlifetime without being static. Wires a matching check into the perf-review checks doc, mirroring the existing @NoEscape field-storage check. APMLP-1846, APMLP-1847 Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Add Checker contract section to @singleton javadoc Splits narrative vs. machine-checkable rule, matching the convention established by @NoEscape and @Staticlifetime. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Annotate WebFlux route cache with @Staticlifetime Spot-checks the annotation against the real defect it was modeled on: PR #12561 (commit e6b8756) made this exact DDCache field static after it lived per-instance, unshared, for ~4 years. Serves as the first real call site for @Staticlifetime. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Annotate UTF8 tag/value caches with @Staticlifetime TAG_CACHE/VALUE_CACHE in TraceMapperV0_4 and KEY_CACHE/VALUE_CACHE in OtlpCommonProto are already static final -- marking them adds compliant-example coverage alongside RouteOnSuccessOrError's violation-turned-compliant case. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Revert "Annotate WebFlux route cache with @Staticlifetime" Holding off on applying @Staticlifetime to real cache fields until @SuppressPerfContract (dougqh/perf-contract-suppress, PR #12647) lands -- want the exemption mechanism in place before widening the annotated surface. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Revert "Annotate UTF8 tag/value caches with @Staticlifetime" Same reason as the WebFlux route-cache revert: hold off until @SuppressPerfContract lands. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Close StaticLifetime checker-contract gaps: require final, static+non-final Per Bits AI review: the contract accepted "static" fields and singleton-scoped instance fields without requiring final, so a mutable field of either shape could pass while still being reassignable to a fresh, cold instance at runtime -- defeating the amortization guarantee the annotation exists to protect, just via a write instead of via scope. Add an explicit mutability trigger and require final in the Accepted description for both shapes. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Fix StaticLifetime's ClassValue paragraph to match its own checker contract Per review: the intro implied a ClassValue-backed holder need not be static itself, contradicting the Accepted list below it, which requires "static final ClassValue<T>". Clarify that it's the per-Class values ClassValue computes that get a free process-wide lifetime, not the holder field referencing the ClassValue instance -- that still has to be static final. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Merge remote-tracking branch 'origin/master' into dougqh/static-lifetime-singleton # Conflicts: # .agents/skills/perf-review/references/checks.md Move StaticLifetime/Singleton into datadog.perfcontract and meta-annotate with @PerfContract Relocates both annotations out of the legacy datadog.trace.api.function package into the new datadog.perfcontract package (introduced by #12647), alongside PerfContract/SuppressPerfContract, and adds @PerfContract so tooling can discover them as perf-contract markers the same way it already discovers Strategy/StrategyConsumer/NoEscape. No other code references either annotation, so no import-site updates are needed. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Tighten the @singleton Javadoc Applies a review suggestion: a static holder or DI registration does not by itself guarantee a single instance, and only final instance fields satisfy @Staticlifetime. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Restructure the @Staticlifetime Javadoc around one field rule Applies a review suggestion: a single accepted/violation/out-of-scope rule, an accurate ClassValue note, and block examples. Keeps the note on the name echoing Rust's 'static lifetime. Examples use <pre> with escaped @ and generics so javadoc does not read a leading @ as a block tag. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Require final for @Singleton-held fields in the perf-review StaticLifetime check Matches the @Staticlifetime and @singleton Javadoc: only a final instance field on a @singleton class is accepted, and ClassValue holders follow the plain static final rule. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Co-authored-by: devflow.devflow-routing-intake <devflow.devflow-routing-intake@kubernetes.us1.ddbuild.io>

Share the WebFlux parsed-route cache across requests

ac38f45

amarziali requested a review from a team as a code owner September 18, 2026 09:16

amarziali removed the request for review from a team September 18, 2026 09:16

amarziali added the type: feature Enhancements and improvements label Sep 18, 2026

amarziali requested a review from ygree September 18, 2026 09:16

amarziali added the inst: spring Spring instrumentation label Sep 18, 2026

datadog-datadog-prod-us1-2 Bot reviewed Sep 18, 2026

View reviewed changes

dougqh approved these changes Sep 18, 2026

View reviewed changes

ygree approved these changes Sep 18, 2026

View reviewed changes

gh-worker-dd-mergequeue-cf854d Bot merged commit b01dd8b into master Sep 21, 2026
608 of 611 checks passed

gh-worker-dd-mergequeue-cf854d Bot deleted the andrea.marziali/webflux-shared-route-cache branch September 21, 2026 08:35

github-actions Bot added this to the 1.67.0 milestone Sep 21, 2026

Navigation Menu

Repository navigation

Share the WebFlux parsed-route cache across requests - #12561

Share the WebFlux parsed-route cache across requests#12561
gh-worker-dd-mergequeue-cf854d[bot] merged 1 commit into
masterfrom
andrea.marziali/webflux-shared-route-cache

amarziali commented Sep 18, 2026

Uh oh!

chatgpt-codex-connector Bot commented Sep 18, 2026 •

edited

Loading

Uh oh!

datadog-datadog-prod-us1-2 Bot left a comment

Uh oh!

datadog-datadog-prod-us1-2 Bot commented Sep 18, 2026 •

edited by datadog-datadog-us1-prod Bot

Loading

Uh oh!

dd-octo-sts Bot commented Sep 18, 2026

Uh oh!

dougqh left a comment

Uh oh!

ygree left a comment

Uh oh!

amarziali commented Sep 21, 2026

Uh oh!

gh-worker-devflow-routing-ef8351 Bot commented Sep 21, 2026 •

edited

Loading

Uh oh!

amarziali commented Sep 21, 2026

Uh oh!

gh-worker-devflow-routing-ef8351 Bot commented Sep 21, 2026 •

edited

Loading

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Conversation

amarziali commented Sep 18, 2026

What Does This Do

Motivation

Additional Notes

Contributor Checklist

Uh oh!

chatgpt-codex-connector Bot commented Sep 18, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Codex Review Summary

Uh oh!

datadog-datadog-prod-us1-2 Bot left a comment

Choose a reason for hiding this comment

Uh oh!

datadog-datadog-prod-us1-2 Bot commented Sep 18, 2026 • edited by datadog-datadog-us1-prod Bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

dd-octo-sts Bot commented Sep 18, 2026

🟢 Java Benchmark SLOs — All performance SLOs passed

Uh oh!

dougqh left a comment

Choose a reason for hiding this comment

Uh oh!

ygree left a comment

Choose a reason for hiding this comment

Uh oh!

amarziali commented Sep 21, 2026

Uh oh!

gh-worker-devflow-routing-ef8351 Bot commented Sep 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

What to do next?

Uh oh!

amarziali commented Sep 21, 2026

Uh oh!

gh-worker-devflow-routing-ef8351 Bot commented Sep 21, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

chatgpt-codex-connector Bot commented Sep 18, 2026 •

edited

Loading

datadog-datadog-prod-us1-2 Bot commented Sep 18, 2026 •

edited by datadog-datadog-us1-prod Bot

Loading

gh-worker-devflow-routing-ef8351 Bot commented Sep 21, 2026 •

edited

Loading

gh-worker-devflow-routing-ef8351 Bot commented Sep 21, 2026 •

edited

Loading