A production restart made this necessary: a service stopped with exit code 0,
having awaited close() on every pooled brain, and its next boot announced
"Overwriting stale writer lock ... appears dead" for every store it owned.
Nothing had crashed. "The recorded pid is gone" is equally true of an orderly
restart and of a crash, so the verdict could not tell an operator which one
they had — and when the OS recycles a pid it fails the other way, refusing to
open a store whose writer died days ago.
Three changes, all at the law:
- close() is two parts, and the second is unconditional. The durable steps
(flush, markers, component close, plugin deactivate, buffer drain) move to
closeDurableSteps(); the terminal releases — the flush-request watcher, the
WRITER LOCK, the VFS timers, the terminal `closed` flag — always run. The
original failure is narrated with what it costs the next open, then rethrown.
- releaseWriterLock() writes a CLEAN-CLOSE RECORD (`locks/_writer.close`)
naming the lock generation it released; the next claim consumes it, so a
record can never vouch for a later crash. An open reads the record instead
of guessing: recorded → nothing to recover; absent → say so, and name the
crash recovery this open will now run.
- The signal path stops failing in a batch. It was one try around a loop over
every open brain, so the first instance whose flush rejected stranded every
remaining brain's lock and markers — at exit code 0. Now: per-instance
isolation, the generation store's close (the clean-shutdown marker, without
which the next open folds the whole log) is part of shutdown, the lock is
given up in a finally, and the handler no longer calls process.exit() when
the host application has its own signal handler — that race truncated the
host's own close() mid-flight.
Pins: tests/integration/writer-lock-clean-close.test.ts — completed close
leaves no lock and a consumed-once record with a silent reopen; a failing
durable step still releases and still rethrows; SIGKILL leaves the lock with
no record and the reopen names the crash; a host SIGTERM handler runs to
completion.
Branch plan (10 lines):
1. writer lock: clean-close record + always-release close [this commit]
2. open narration: an always-on channel; production clamps prodLog to ERROR,
which is why a three-minute open printed nothing
3. open narration: per-phase lines as each phase ENDS, with progress cadence
4. measure both real-store fixtures on the box, before/after
5. move the generation-log fold out of the foreground where the serving law
allows; durable resumable progress marker
6. same for the VFS bootstrap
7. counts: a legacy container-rule ledger must not keep serving wrong
denominators; counts.json written atomically
8. counts pin with scar directories; two copies of one archive agree
9. docs/canonical-layout-ratification.md — 12 facts confirmed/corrected
10. report: MEASURED before/after, findings, and whether this is 10.4.4
David Snelling
e652162c1f