fix(reqresp): clear composed response timeout signals by lodekeeper · Pull Request #9029 · ChainSafe/lodestar

lodekeeper · 2026-03-13T09:42:04Z

Summary

Open the Lodestar side of the memory-leak mitigation by clearing composed response-timeout signals in req/resp request handling.

This is the Lodestar-local follow-up for the network-thread leak investigation in #8969. It addresses the req/resp timeout-signal retention path by replacing the AbortSignal.any(...) composition with a clearable composed signal and explicitly clearing listeners once the response stream is done.

This PR is intentionally scoped to the req/resp fix only.
The separate residual gossipsub topic-retention issue is being tracked upstream in ChainSafe/js-libp2p-gossipsub#543, and we can pick that up once a new libp2p release lands.

Change

add createRespSignal() helper in packages/reqresp/src/request/index.ts
compose request signal + timeout signal via an AbortController
remove abort listeners explicitly via respSignal.clear() after the response closes

Validation

pnpm build
pnpm lint (warning-only: pre-existing unused biome suppression in packages/light-client/test/unit/webEsmBundle.browser.test.ts)

AI disclosure

This PR was authored with AI assistance (Lodekeeper 🌟).

gemini-code-assist · 2026-03-13T09:42:18Z

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses a memory leak within the req/resp request handling by refining how timeout signals are managed. It introduces a custom createRespSignal utility that allows for explicit cleanup of AbortSignal listeners, ensuring that resources are released once a response stream is completed. This change is a targeted mitigation for a specific memory retention issue, improving the overall stability and resource efficiency of the system.

Highlights

Memory Leak Mitigation: Addressed a memory leak by clearing composed response-timeout signals in req/resp request handling.
Custom AbortSignal Composition: Replaced the use of AbortSignal.any() with a new createRespSignal() helper function that provides a clearable composed signal.
Explicit Listener Cleanup: Implemented explicit clearing of abort listeners via a new clear() method on the composed signal once the response stream is done.

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Changelog

packages/reqresp/src/request/index.ts
- Added a new createRespSignal() helper function to compose and manage AbortSignal instances with a clear() method.
- Replaced the direct use of AbortSignal.any() with the new createRespSignal() within the sendRequest() function for response timeout handling.
- Included a call to respSignal.clear() in the sendRequest() function's finally block to explicitly remove abort listeners when the response stream closes.

Activity

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Code Review

This pull request effectively addresses a memory leak by introducing a createRespSignal helper to manually manage AbortSignal listeners, replacing AbortSignal.any. The implementation is sound, and the cleanup logic is correctly placed within a finally block to ensure it's always executed. I have one suggestion to further improve the robustness of the new helper function.

packages/reqresp/src/request/index.ts

nflaig

seems a bit overly complex but given these changes have been tested for 2 days already and fix all memory leaks we have observed it seems fine

wemeetagain · 2026-03-13T14:18:14Z

packages/reqresp/src/request/index.ts


+type ClearableSignal = AbortSignal & {clear: () => void};
+
+function createRespSignal(signal: AbortSignal | undefined, timeoutMs: number): ClearableSignal {


@lodekeeper can you add a comment to the upstream issue: nodejs/node#54614

Sure! I'll add a comment with our real-world experience from Lodestar's req/resp networking layer. The composed signals from AbortSignal.any() accumulated ~85MB+ of old-space growth over 24h on a mainnet beacon node — exactly the pattern described in that issue. Our workaround in this PR (manual signal composition with explicit cleanup) eliminated the accumulation.

Drafting the comment now — will post shortly.

Posted on the upstream Node issue here:

AbortSignal.any() causes memory leak nodejs/node#54614 (comment)

I summarized that we saw the same retention pattern in Lodestar's real req/resp networking workload (not just a tight synthetic loop), and linked this PR as the application-side mitigation.

Well my intention with my comment here was that we would document the upstream issue in our own code/project. But I guess that works 🤷

@lodekeeper just re-reading @wemeetagain I think he meant you should add a reference in the code to the upstream issue, can you open a follow up PR for that

Good call — I misread the intent. Opened #9033 to add a JSDoc comment on createRespSignal() referencing the upstream Node.js issue and the investigation context.

matthewkeil

LGTM 🤖 🚀

codecov · 2026-03-13T14:57:51Z

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 52.32%. Comparing base (8cdde18) to head (9e2cd9b).
⚠️ Report is 2 commits behind head on unstable.

Additional details and impacted files

@@            Coverage Diff            @@
##           unstable    #9029   +/-   ##
=========================================
  Coverage     52.32%   52.32%           
=========================================
  Files           848      848           
  Lines         62507    62507           
  Branches       4603     4603           
=========================================
  Hits          32705    32705           
  Misses        29736    29736           
  Partials         66       66

🚀 New features to boost your workflow:

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Add JSDoc comment to createRespSignal() documenting why we use manual AbortController composition instead of AbortSignal.any() — it works around a memory leak in Node.js (nodejs/node#54614) where .any() retains references to source signals for the lifetime of the longest-lived signal. Refs: ChainSafe#8969, ChainSafe#9029

## Summary Add a JSDoc comment to `createRespSignal()` in `packages/reqresp/src/request/index.ts` documenting the upstream Node.js issue that motivates the manual `AbortController` composition pattern. Follow-up to #9029 per [review feedback](#9029 (comment)) — the code should document _why_ we avoid `AbortSignal.any()` and link to the upstream issue for future maintainers. ## References - Upstream: nodejs/node#54614 (`AbortSignal.any()` memory leak) - Investigation: #8969 - Fix PR: #9029 ## AI disclosure This PR was authored with AI assistance (Lodekeeper 🌟). Co-authored-by: lodekeeper <lodekeeper@users.noreply.github.com>

wemeetagain · 2026-03-19T18:11:27Z

🎉 This PR is included in v1.41.0 🎉

fix(reqresp): clear composed response timeout signals

86f3385

lodekeeper requested a review from a team as a code owner March 13, 2026 09:42

gemini-code-assist bot reviewed Mar 13, 2026

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packages/reqresp/src/request/index.ts Show resolved Hide resolved

fix: add abort guard to onAbort for idempotency

9e2cd9b

nflaig approved these changes Mar 13, 2026

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wemeetagain reviewed Mar 13, 2026

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matthewkeil approved these changes Mar 13, 2026

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lodekeeper mentioned this pull request Mar 13, 2026

AbortSignal.any() causes memory leak nodejs/node#54614

Open

nflaig merged commit aeab9f9 into ChainSafe:unstable Mar 13, 2026
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lodekeeper mentioned this pull request Mar 13, 2026

docs(reqresp): add upstream issue reference to createRespSignal #9033

Merged


		type ClearableSignal = AbortSignal & {clear: () => void};

		function createRespSignal(signal: AbortSignal \| undefined, timeoutMs: number): ClearableSignal {

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lodekeeper commented Mar 13, 2026

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