[juliusmarminge]

The managed tunnel reaper stopped shrinking the idle-tunnel backlog. Since Oct 22 the down count has swung between 5.5k and 8.5k every day, and its daily peak keeps creeping up. 93% of sweeps hit the 100-deletes-per-sweep cap. That caps the reaper at 1,200 deletes an hour, which is about the rate new idle tunnels arrive.

This change allows up to 250 deletes per sweep and runs 8 at a time instead of 4. I took the sizing from production traces:

• Time budget: a delete takes about 2.8s, so at 8 at a time a sweep fits about 230 into its 90s budget. The existing deadline stops a sweep cleanly if it runs long.
• Hyperdrive: about 1.85s of each delete is spent inside a row-locked transaction. Eight deletes at a time therefore hold about 5 of the 40 Hyperdrive origin connections, which request handlers also use. Request handlers average 12 queries in flight, and 17–20 in the busiest minutes. The code comment still said the limit was 20; it now says 40.
• Cloudflare API: the change adds at most about 300 calls per 5 minutes. Relay peaks at about 2,100 against the account's 20,000 limit, and there were no 429s in the last 3 days. The ops doc now records that limit.

The two rotation tests used 100 as the limit; they now read the constant.

Once this is deployed, the backlog should drain to about 1k within a day. What remains is legacy tunnels inside their 7-day grace period, plus each sweep's new arrivals.

🤖 Generated with Claude Code (Claude Opus 5.5)

[macroscopeapp]

Approvability

Verdict: Approved at bef2874

Macroscope's review found this PR approvable — Increases idle-tunnel cleanup throughput while retaining existing deletion eligibility, ownership checks, time limits, and rate-limit safeguards. Product behavior and retention thresholds remain unchanged.

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[coderabbitai]

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Recent review info

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• Source mode: Auto
• Repository: pingdotgg/t3code
• Branch: relay/reaper-throughput
• File: .coderabbit.config.ts
• Commit: bef2874
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• Run ID: 9a4d6367-f1f8-4873-a4bc-b8d5c52a1c17

Commits

Reviewing files that changed from the base of the PR and between 5808469 and bef2874.

Files selected for processing: 3

• docs/operations/relay-observability.md
• infra/relay/src/environments/ManagedEndpointReaper.test.ts
• infra/relay/src/environments/ManagedEndpointReaper.ts

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Walkthrough

The operations guidance now states Cloudflare’s October 2026 account rate limit and peak usage. The managed endpoint reaper increases its attempt limit and delete concurrency, and its tests use the configured attempt limit.

Changes: Cloudflare rate-limit guidance

Layer / File(s)	Summary
Update rate-limit figures docs/operations/relay-observability.md	The alert guidance states an account limit of 20,000 calls per 5 minutes and peak usage of about 2,100.

Managed endpoint reaper

Layer / File(s)	Summary
Update sweep limits and test thresholds infra/relay/src/environments/ManagedEndpointReaper.ts, infra/relay/src/environments/ManagedEndpointReaper.test.ts	The attempt limit increases from 100 to 250, and delete concurrency increases from 4 to 8. The deletion-order tests use the configured attempt limit for candidate counts and assertions.

Priority: Normal

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• pingdotgg/t3code#23683: Updates the same reaper cleanup path to pass recovery state and generation to ManagedEndpointProvider.release.

Suggested reviewers: maria-rcks, t3dotgg

Merge Risk: Minimal · up to bef28

No demonstrated issue prevents merging the sweep-limit and guidance updates after normal checks.

Pre-merge checks: 3 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Description check		The description explains the backlog problem and the concurrency and sweep-limit changes. It does not provide the required Scope and approval section, and it does not clearly document focused verifica…	Add explicit Problem, Change, Scope and approval, and Verification sections. Provide the linked issue or maintainer approval, or explain why this focused fix is exempt. List the focused tests or manual checks that were run and their observe…

Passed checks: 3 passed

Check name	Status	Explanation
Title check		The title clearly and concisely identifies the relay tunnel cleanup fix. It matches the main change in the pull request.
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

Full details: Description check

Explanation

The description explains the backlog problem and the concurrency and sweep-limit changes. It does not provide the required Scope and approval section, and it does not clearly document focused verification tests or their observed results.

Resolution

Add explicit Problem, Change, Scope and approval, and Verification sections. Provide the linked issue or maintainer approval, or explain why this focused fix is exempt. List the focused tests or manual checks that were run and their observed results, including anything not checked.

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