A failed wallet unlock was always treated as a wrong guess: the lockout
counter was bumped and the back-off curve armed no matter why the RPC
failed. A busy or warming-up node, a transport timeout, or a wallet that
is not actually encrypted would all eat an attempt and could push a user
into a lockout without a single mistyped passphrase.
The failed call is now classified before it is acted on:
- Only the daemon's "passphrase incorrect" error counts as a wrong
guess and advances the lockout.
- A warming-up or unreachable node, a reply timeout, or a full queue is
reported as a transient busy-node condition with no attempt charged.
- A "wallet is not encrypted" reply refreshes the local encryption state
instead of penalising the user.
- Any unknown error surfaces its message without touching the counter.
The PIN path got the same treatment: when the vault decrypts correctly
but the unlock RPC then fails for a non-credential reason, the attempt
is no longer counted.
Tests cover the classification of each failure kind.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
dragonxd serves RPC with 8 workers and a 16-deep queue. While a witness
rebuild holds cs_main, every request needing it waits, and a request the
client gave up on keeps its slot. The GUI kept polling and re-probing
until all 24 slots were its own abandoned requests (even stop was then
refused), treated the busy node as lost (tearing down the wallet state),
and retried connect at frame rate on some pages.
Busy gate (src/rpc/rpc_busy_gate.h), enforced in RPCClient::performCall
for the shared rpc_ / fast_rpc_:
- the first reply timeout or queue-full refusal marks the node busy;
from then on nothing needing cs_main is sent (calls fail at once with
the new RpcFailureKind::Deferred). stop, help and getrescaninfo are
lock-free in dragonxd and always go through
- one canary getinfo with no client timeout waits on its own client and
thread; its answer clears the gate and triggers an immediate refresh
(queue-full: retried after 2..30 s; no answer: back to normal handling)
- the timer dispatch skips Core/Tx/Addresses/Peers/chat/mining/opid and
connect attempts while busy
- the 3-strike teardown counts only failures that put the connection in
doubt, never busy ones; no balance scans follow a busy chain-info call
Reconnect storm: retries were armed with setTimer(Core, kCoreDefault - 1),
i.e. "4 s elapsed", which against Overview's 2 s interval meant every
frame. RefreshScheduler::deferFor() is an absolute hold, and
ConnectRetryBackoff picks the delay by failure kind (not listening
1/2/5 s, queue full 2..30 s, busy 30 s, else 4 s).
Measured against the fake daemon: abandoned requests during a rebuild
went from ~24 (every slot) to at most 2, with no teardown and recovery
when the rebuild ends; a saturated queue sees about one canary per
back-off step instead of ~190 requests/s.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Every caller guessed what went wrong from what(): "Timeout" meant busy,
"401" meant auth, and warmup was code -28 or one of six substrings. A
non-JSON HTTP 500 lost its body, so "Work queue depth exceeded" read as a
bare "HTTP 500", and libcurl reports connect- and reply-phase timeouts
with the same code.
New header-only src/rpc/rpc_failure.h:
- RpcFailureKind (NotListening, ConnectTimeout, ReplyTimeout, QueueFull,
ShuttingDown, Unhandled, Auth, Warmup, AppError, Aborted, Other) and a
pure classifyRpcFailure(curl code, request-sent, HTTP status, JSON-RPC
code, plain-text body)
- formatHttpError keeps a short, printable plain-text body
- RpcError (moved here) stays "the daemon answered with a JSON-RPC
error". The new RpcTransportError means "no JSON-RPC answer": curl
failures and HTTP-layer refusals (401, 503, queue full, unhandled).
Keeping them separate matters: callers catch RpcError to mean "the
daemon said no" (chat identity's no-mnemonic fallback, seed export),
so a timeout must not be one. They now treat a queue-full 500 as
transient rather than as "no".
RPCClient:
- performCall tells the two timeouts apart with CURLINFO_REQUEST_SIZE
(0 = never reached the daemon; reset on every transfer, checked on
libcurl 7.81), and callRaw now shares performCall and the HTTP-failure
path.
- connect() decides warmup by the -28 code only, so a plain-text body
saying "Loading" can't pass for warmup, and records
getLastConnectFailureKind().
- "Connection failed" names the kind and is logged once, then every
100th repeat (one incident logged it 60k times).
- secret-bearing calls never echo a response body.
tryConnect's "401"/"Timeout" checks now use the kind, and
CoreRefreshResult carries blockchainErrKind/balanceErrKind for the busy
handling to come.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
DanSandClaude Opus 4.8