Relay worker micro-optimizations: socket-state caching, /prewarm, DO placement - #946
Merged
Conversation
Three additive, independently-deployable improvements to the tunnel relay
Worker. All are backward compatible with deployed desktop and iOS clients:
no auth, close-code, protocol, framing, or buffer-limit changes.
- Cache each socket's attachment and its paired partner in instance memory.
`normalizedAttachment()` deserialized on every frame and `partnerOf()`
rescanned the connection tag on every frame; both now read from a WeakMap.
Hibernation drops instance memory, so both caches fall back to the durable
attachment (or the tag scan) and repopulate themselves after a wake, and a
single write-through helper is now the only writer of an attachment so the
cache cannot drift. The partner entry is only ever a hint, re-checked
against the same predicate the scan uses.
- Add `GET /prewarm/:machineKey`, returning `{ok, control}`. Reaching the
object is the point: it un-hibernates it before a client needs the tunnel.
Inert by construction — no storage, no alarm, no attachment migration, no
signal to the host. Same auth stance as `/connect`. `/health` is answered
by the Worker and never reaches a DO, so it could not serve this.
- Derive a `locationHint` from `request.cf` on `claim` and `/host` only, so a
new machine's object is created near the machine rather than near whichever
request happened to arrive first. `/connect`, `/prewarm`, and `/pipe` never
carry a hint — a travelling phone must not place a machine's object.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Applied /quality dual-review findings. All behavior-preserving:
- partnerOf: the cache-hit path and the tag scan now share isPartnerOf, so
the "re-checked against the same predicate" invariant is structural rather
than coincidental. Drops two guards verified dead — a self-entry cannot be
inserted, and a stale reverse entry self-heals on its own next read.
- handlePrewarm: expressed as .some(), still reading the raw attachment so it
cannot trigger a migration write.
- RelayLocationHint aliases Cloudflare's DurableObjectLocationHint instead of
re-enumerating it, so the union cannot drift.
- parseLongitude: an empty longitude is missing data, not the prime meridian.
Number("") is 0, which read as a real coordinate and picked "me" for Asia.
- Renamed the caches cachedAttachments/cachedPartners: the socket's own
attachment stays authoritative, and the names now say so.
- Tests: establishEpochV2 delegates to openTunnel, so the {t:"open"} shape is
now asserted for every tunnel opened. Adds the empty-longitude case and one
test pinning the socket-identity premise the caches rest on.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
|
The latest updates on your projects. Learn more about Vercel for GitHub. |
|
No actionable comments were generated in the recent review. 🎉 ℹ️ Recent review info⚙️ Run configurationConfiguration used: Path: .coderabbit.yaml Review profile: CHILL Plan: Pro Plus Run ID: ⛔ Files ignored due to path filters (1)
📒 Files selected for processing (5)
📝 WalkthroughWalkthroughAdds a prewarm endpoint, geography-based Durable Object placement hints, centralized WebSocket attachment caching, safer partner lifecycle handling, and unit/integration coverage for routing, placement, hibernation, pairing, and prewarm behavior. ChangesTunnel relay behavior
Estimated code review effort: 4 (Complex) | ~45 minutes Possibly related PRs
Suggested labels: 🚥 Pre-merge checks | ✅ 5✅ Passed checks (5 passed)
✨ Finishing Touches📝 Generate docstrings
🧪 Generate unit tests (beta)
Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out. Comment |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary by CodeRabbit
New Features
Bug Fixes