The check whether an account's full rollup backfill is queued or
running answered false on any error, so a failed read let the dense
fold delete raw samples the backfill still had to read. A missing queue
table still answers false, since a web-only deployment has no backfill;
any other failure now counts as pending and is annotated. A backfill
that failed for good is still not pending, as the comment now says.
The full rollup backfill refills each day's figures from the raw
readings, and the dense fold deletes those readings once it has their
hourly means. On a large account the backfill can run longer than the
ten minutes the fold's boot job waits, and a year it reached after the
fold had taken it would compute its days from hourly means: the day
count, minimum and maximum of every folded day would change.
The consolidation walk now asks a per-account deferUser hook before it
reads an account, and both entries of the dense fold (the per-account
boot job and the nightly drain) pass isRollupFullBackfillPending, which
looks for a queued or running full fold of the account in pg-boss. The
account is folded on a later run, once its rollup tier is rebuilt.
On an account with tens of millions of readings the boot full backfill
never finished. It ran four aggregates over the whole five-year window,
each held to the connection's 60 s statement limit, so every attempt
was cancelled with 57014, the reading extremes added by 0417 stayed
NULL, and the readers that need them fell back to the raw table and
timed out as well (#1298).
The full backfill now folds the window one UTC calendar year per pass,
newest first, and every statement runs under its own five-minute limit,
the shape the pulse day-mean rebuild already uses. Calendar-year cuts
write exactly the buckets one pass writes: day, month and year buckets
fall inside one window and a week across New Year is folded whole by
both. Each window commits on its own, so a run that reaches its job
budget hands the remaining years to a follow-up job instead of failing
and starting over on the retry.
The boot discovery read every live reading in the window to find
uncovered days, the same scan that kept the fold from finishing. It
now walks the days per account and type off the live index, so its
cost follows the number of days with readings, and runs under the same
limit. The full backfill code moves to its own module.
Marc-André Bombeck