Add targeted recovery for rejected PTY source frames instead of
terminating the relay channel. Classify rejection reasons (malformed,
generation mismatch, range invalid) and attempt recovery based on the
rejection type. Implement admission control at publication time to ensure
frames aren't delivered after ownership changes. Bound recovery attempts
and retry with backoff to prevent exhaustion. Diagnose and log rejection
reasons to aid debugging.
An owner-capable `pty.openClient` had two failure modes that presented as something else.
If the relay still held an owner record but the request carried no matching resume proof, admission fell through to a SUBSCRIBER grant — a success-shaped response the client cannot use, which it then rejected as "did not grant an authenticated PTY session owner". And if the relay had forgotten the record the client named, admission threw a stale-recovery error, which the client answered by deleting its own recovery row — `clientInstanceId` included — and reopening. Two round trips, and the identity that lets it resume that target at all went with the deletion.
Now every owner grant carries a required `resumed` flag, a forgotten record mints a fresh claim in one round trip, a held claim returns one of three coded refusals, duplicate opens on one connection are rejected even when identical, and an attached-holder refusal becomes a typed error routed through the terminal-relay-error callback instead of feeding redeploy backoff a link that is working fine.
Independent review caught two regressions in the first attempt, both now fixed and both with tests that fail without them:
**A backpressure teardown could take a live owner's session.** The safety argument was that a record only becomes `disconnected` from an observed peer close — but two of the six paths there are capacity paths, where the relay destroys the client's socket itself because its lane queue filled. That is the signature of a client that is ALIVE but not draining fast enough. Demonstrated: the real owner is torn down for backpressure, a rival is granted ownership 270ms into a nominal 30s grace, and the owner's later reconnect with a valid resume proof is refused permanently, backoff cleared, no retry. Closes now carry a cause (`peer-closed` | `local`, defaulting to `local`, which only ever widens a grace), and the floor applies only to closes the transport actually observed on the peer's side. Capacity teardowns, decode faults and sink failures keep the default.
**A client's own zombie connection blocked it permanently.** Only `SshRelaySession` ever requests owner, and every endpoint-credential client shares one principal — so in a normal single-app deployment an `active` incumbent refusing you is almost always your own half-open connection the relay never saw close. That was refused as terminal, where main recovered on bounded backoff once keepalive noticed. The refusal already held both client identities; a match is now a distinct transient refusal that falls through to relay-lost backoff, restoring that recovery. A genuinely different client is still blocked.
Also: each retry deadline now starts when its own phase begins, instead of both being computed at entry where a slow first phase could leave the second with zero attempts.
Fixes STA-3365.
* fix(P1-A): persist SSH consumer recovery without a sync store flush
rememberPtyConsumerRecovery ran on the live establish/reconnect path and
called flushOrThrow -> writeToDiskSync, parking the Electron main thread on
the profile-directory write. On a stalled or slow profile mount that freezes
the whole app during SSH recovery and reconnect.
Add Store.flushAsync(): same debounce-cancel and write serialization as
flushOrThrow, but awaits writeToDiskAsync instead of blocking. The consumer
recovery upsert/remove pair is now async and awaits it, and the SSH callers
await through to establish()/reconnect() so ownership is still durable before
relay setup continues. In-memory state still mutates synchronously (before the
first await), so no caller can observe a torn record and dispose() stays
synchronous.
* fix(P1-A): detach the SSH session when a connect attempt fails
Both failure exits in doConnect dropped the session from activeSessions
without calling detach(). claimSshPtyConsumerRecovery only reuses an existing
in-memory entry when detached === true, so the next connect attempt fell
through to minting a fresh clientInstanceId, discarding the remembered owner
lease and its resume identity.
Route both exits through abandonFailedSshSession(), which detaches (keeping
PTY ownership, unlike dispose()) before removing the session, and tolerates a
teardown throw so it can't mask the connect error being rethrown.
* fix(P1-A): await async lease persistence in SSH relay teardown
Failed connect attempts now wait for 'detached' leases to persist before
throwing, preventing reconnects from claiming them before cleanup completes.
Detach and dispose operations are now async and await store durability.
* fix(ssh): make session detach lease writes retryable on failure
Separate in-memory detach (identity recovery, provider cleanup) from lease
write persistence so rejected writes can be re-issued without re-running
provider teardown or re-minting the session identity. Introduce
flushDurableStateOrThrowAsync to flush only SSH-recovery state on the
live establish/reconnect path, avoiding snapshot writes of sidecars that
belong to quit/startup. Use Promise.allSettled in test reset to prevent
one rejected disposal from leaking state into the next test.
* fix(ssh): dispose mux on failed establish and propagate sync errors
- Dispose mux when session is disposed during establish to prevent resource leak
- Propagate synchronous errors in teardown via the completion promise instead of leaving completion undefined
- Add test coverage for terminated PTYs that exit mid-reattach and must stay dead
Jinjing
Jinwoo Hong
Brennan Benson
Neil