The balance, address scan, history and probe were throttled one by one at
10% each, which added up to 30-40% of dragonxd's cs_main with all of them
due. services::WalletScanGovernor runs one wallet scan at a time across
both RPC lanes and keeps one shared quiet clock at 15% of wall-clock (cut
when the node is behind). Waiters are served first in, first out, with a
head start for what the page shows and a starvation floor of max(30 s
visible / 900 s hidden, 15x the stream's cost). Explicit work (a dirty
set, the user's send, a first load) is never refused but is charged.
Routine scans run only when the tip, the mempool size (getmempoolinfo:
no cs_main) or a wallet-mutation epoch changed since their last good scan,
or a safety sweep is due. Pages that don't show the balance poll it at
most every max(10 min, 50x its cost) (2 min with client-side auto-shield);
coming back into view with an old value fetches it at once. The staleness
badge counts from the last poll that confirmed nothing changed, and hides
while the budget holds the balance within its guarantee.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Every block re-ran z_listreceivedbyaddress for every z-address (O(wallet)
each, under cs_main) and a whole-wallet z_listsentbyaddress. On a 40-address
wallet that was ~80% of wall-clock. The history now advances in passes:
- an address is rescanned when it is stale by a number of blocks scaled to
its measured cost (8 to 500), never-scanned and hinted addresses first
(a hint: z_listunspent shows a note the history doesn't);
- z_listsentbyaddress covers only the blocks since the last good sweep
(+100 reorg margin); the whole-wallet sweep runs once per connect, with
a 10 min / 1 h / 6 h backoff after real failures;
- listtransactions pages are sized from last time, and an unchanged tip
reuses the transparent rows;
- found-but-unenriched txids carry over as a backlog; only -5 is a
definitive "not ours" for z_viewtransaction;
- between blocks, a cheap recent poll plus a one-address probe.
Duty model for a 40-address wallet at 10 s per scan: ~9% instead of ~80%.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
DanSandClaude Opus 5.5