- Aggregation backfill walks build into a STAGING map and swap in atomically
on completion. A mid-walk failure drops the staging map — the previous live
state keeps serving, the aggregate stays flagged pending, and the storage
error surfaces to the failing query. Previously the walk wiped live state
before a scan that could throw, never cleared the pending flag on failure,
and re-ran a full walk on every subsequent query: a silent wipe/walk/throw
loop at the caller's retry rate.
- Failed walks are latched: retries within a 30s cooldown rethrow the recorded
error instantly instead of re-walking, so a tight caller-side retry loop
costs one loud error per query, never a full store walk per query.
- Persisted aggregation state is stamped with the store's committed generation
at flush; reopen adoption requires stamp equality. Stale state (unclean
shutdown) or over-counting state (a log truncation on a copied store pulled
the watermark back) triggers exactly one loud rescan, never a silent adopt.
- The backfill/adoption path narrates: adoption decisions, walk start/finish
with counts and duration, and failures all log by default.
- getNouns/getVerbs refuse a supplied-but-undecodable pagination cursor with a
loud error instead of silently restarting the walk at offset 0 (which
re-served page 1 forever to any while(hasMore) caller).
- The graph cold-load verb walk aborts loudly on a missing or non-advancing
cursor with hasMore=true.
- A versioned index provider whose generation is AHEAD of the committed
watermark (torn copy / crash-recovery truncation) is now named loudly at
open, alongside the existing behind-direction message.
David Snelling
a77b064bd7