satoshi/KamadoPool
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

P1 reliability + block-broadcast fallback path

Browse Source 
P1 audits / fixes:

* Bitcoin Core RPC now retries up to 3 times with linear backoff on
  transport errors, 5xx responses, and warm-up/loading RPC errors
  (code -28). Hard "no" answers (block-not-found etc.) bubble up
  immediately so we don't mask real errors.

* WebSocket hub disconnects clients that miss 6 consecutive broadcasts
  (~30s with the default poll cadence). Stuck readers no longer hold
  stale snapshots indefinitely or freeze hub state.

* ZMQ subscriber freshness: aggregator records the last-event
  timestamp, surfaces zmq_enabled / has_last_zmq_event /
  last_zmq_event_age in the snapshot. /healthz flags zmq_stale when
  the gap exceeds 30 minutes.

* /healthz expanded with submit_attempts / submits_confirmed /
  submit_gap, fallback_submits_total + last_fallback_*, and the zmq
  staleness check. Now usable as a real-world ops dashboard signal.

Block-broadcast fallback (new feature):

  * ckpool patch 0004: hooks local_block_submit to write the raw block
    hex to <logdir>/pending-blocks/<height>-<hash16>.hex right before
    invoking generator_submitblock. Unlinks on success. ckpool's normal
    flow is otherwise untouched.

  * api/internal/blocksubmit: watcher polls the dir every 5s. Files
    sitting longer than the grace window (default 30s, configurable)
    are re-broadcast through operator-supplied backup RPC URLs in
    sequence. Treats both null and any "duplicate*" reject reason as
    success (the block landed). Pre-checks the primary chain first so
    a stale file from a successful-but-unlinked submit gets cleaned
    up without bothering fallbacks.

  * Aggregator records each successful fallback submission as a
    persistent counter and surfaces it in the snapshot so the UI can
    show a "primary bitcoind isn't accepting submits" alert.

  * Config: BACKUP_RPC_URLS (comma- or newline-separated, with
    optional inline credentials) plus PENDING_BLOCKS_DIR and
    PENDING_BLOCKS_GRACE. URLs are parsed via net/url so
    https://user:pass@host:port/ works cleanly.

The fallback is opt-in and disabled by default. Once enabled with at
least one URL, a primary bitcoind outage at the moment of solving no
longer means a lost block — kamado-api re-broadcasts via whichever
backup the operator trusts (a second self-hosted node, an
authenticated public RPC service, etc.).
This commit is contained in:
satoshi
2026-04-27 21:25:56 +03:00
parent df0dbf89e5
commit a4a894e196
10 changed files with 687 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files
ckpool/patches/README.md
+28 -4
View File
@@ -9,11 +9,15 @@ Patches are applied in alphabetical order by filename. Use a numeric prefix to e
## Current state
One Kamado patch is applied on top of the pinned upstream commit:
Four Kamado patches are applied on top of the pinned upstream commit, in
alphabetical order:
| Patch | What it does |
| --------------------------------------------- | -------------------------------------------------------------------------------------- |
| `0001-expose-bestever-in-runtime-json.patch` | Adds `bestever` field to the `users` / `workers` runtime socket JSON |
| Patch | What it does |
| -------------------------------------------------------- | --------------------------------------------------------------------------------------------- |
| `0001-expose-bestever-in-runtime-json.patch` | Adds `bestever` field to the `users` / `workers` runtime socket JSON |
| `0002-enable-socket-api-responses.patch` | Always reply on the listener socket so kamado-api gets responses even with `btcsolo: true` |
| `0003-share-error-as-stratum-array.patch` | Maps `share_err` to Stratum spec error codes; emits `[code, msg, null]` per Slush |
| `0004-dump-pending-block-for-fallback.patch` | Writes the raw block hex to `<logdir>/pending-blocks/` before submit; unlinks on success |
### Why 0001 matters
@@ -30,6 +34,26 @@ This patch adds `bestever` to the runtime JSON so the UI can show both
"this round" and "all-time" best share side by side. No behavioral change
to share validation or block handling. Candidate for upstreaming.
### Why 0004 matters
Block submission to bitcoind is the most revenue-critical RPC call ckpool
makes. If bitcoind is unreachable when a share meets network difficulty,
ckpool's `generator` thread retries indefinitely against the same single
endpoint — and the raw block data lives only in stratifier memory, so a
ckpool crash before bitcoind comes back permanently loses the block.
This patch hooks `local_block_submit` to write the raw block hex to
`<logdir>/pending-blocks/<height>-<rhash>.hex` *before* invoking
`generator_submitblock`, and unlinks the file on success. `kamado-api`
runs a watcher over that directory: if a file persists past a grace
period (default 30 s), it submits the block via fallback RPC URLs the
operator has configured. Multiple fallbacks are tried in sequence; the
file is unlinked when any fallback returns success or "duplicate"
(meaning the block already landed).
This is a Kamado-specific integration hook — almost certainly not
upstreamable, but minimal-impact on existing ckpool behavior.
Beyond this patch, the pinned upstream commit (`cfb0f83b`, tagged as
version 1.0) already includes every fix that Bassin issue #29 asked to
backport, plus several improvements: