While syncing the finalized portion of the chain, the execution client
cannot efficiently sync and most of the time returns `SYNCING` - in this
PR, we use CL-verified optmistic sync as long as the block is claimed to
be finalized, only occasionally updating the EL with progress.
Although a peer might lie about what is finalized and what isn't,
eventually we'll call the execution client - thus, all a dishonest
client can do is delay execution verification slightly. Gossip blocks in
particular are never assumed to be finalized.
* debug log upon sidecar validation failure
* Fill in signature catch upon SignedBeaconBlockAndBlobsSidecar deser
* Always fill blobssidecar slot and root
* Skip lastFCU when eth1monitor is nil
* fix
* Use cached root
* exit/validatorchange pool includes BLS to execution messages; REST
support for new pool
* catch failed individual futures
* increase BLS changes bound and keep BLS seen consistent with subpool
* deque capacities should be powers of 2
With https://github.com/status-im/nimbus-eth2/pull/4420 implemented, the
checks that we perform are equivalent to those of a `SYNCING` EL - as
such, we can treat missing EL the same as SYNCING and proceed with an
optimistic sync.
This mode of operation significantly speeds up recovery after an offline
EL event because the CL is already synced and can immediately inform the
EL of the latest head.
It also allows using a beacon node for consensus archival queries
without an execution client.
* deprecate `--optimistic` flag
* log block details on EL error, soften log level because we can now
continue to operate
* `UnviableFork` -> `Invalid` when block hash verification fails -
failed hash verification is not a fork-related block issue
When backfilling, we only need to download blocks that are newer than
MIN_EPOCHS_FOR_BLOCK_REQUESTS - the rest cannot reliably be fetched from
the network and does not have to be provided to others.
This change affects only trusted-node-synced clients - genesis sync
continues to work as before (because it needs to construct a state by
building it from genesis).
Those wishing to complete a backfill should do so with era files
instead.
We currently use `BlockError` for both beacon blocks and LC objects.
In light of EIP4844, we will likely also use it for blob sidecars.
To avoid confusion, renaming it to a more generic `VerifierError`,
and update its documentation to be more generic.
To avoid long lines as a followup, also renaming the `block_processor`'s
`BlockProcessingCompleted.completed`->`ProcessingStatus.completed` and
`BlockProcessingCompleted.notCompleted`->`ProcessingStatus.notCompleted`
In optimistic mode, Nimbus will sync optimistically even when the
execution client is offline / not available.
An optimistic node is less secure because it has not validated block
transactions via the execution client and can thus not be used for
validation duties.
* avoid database race-condition inconsistency after fcU `INVALID` then crash
* ensure head doesn't fall behind finalized; add more tests for head movement/reloading DAG
* more efficient forkchoiceUpdated usage
* await rather than asyncSpawn; ensure head update before dag.updateHead
* use action tracker rather than attached validators to check for next slot proposal; use wall slot + 1 rather than state slot + 1 to correctly check when missing blocks
* re-add two-fcU case for when newPayload not VALID
* check dynamicFeeRecipientsStore for potential proposal
* remove duplicate checks for whether next proposer
When the BN-embedded LC makes sync progress, pass the corresponding
execution block hash to the EL via `engine_forkchoiceUpdatedV1`.
This allows the EL to sync to wall slot while the chain DAG is behind.
Renamed `--light-client` to `--sync-light-client` for clarity, and
`--light-client-trusted-block-root` to `--trusted-block-root` for
consistency with `nimbus_light_client`.
Note that this does not work well in practice at this time:
- Geth sticks to the optimistic sync:
"Ignoring payload while snap syncing" (when passing the LC head)
"Forkchoice requested unknown head" (when updating to LC head)
- Nethermind syncs to LC head but does not report ancestors as VALID,
so the main forward sync is still stuck in optimistic mode:
"Pre-pivot block, ignored and returned Syncing"
To aid EL client teams in fixing those issues, having this available
as a hidden option is still useful.
When the EL fails to respond to `newPayload`, e.g., because connection
to the EL got interrupted, or due to misconfiguration, optimistic blocks
cannot be imported according to spec. This condition is treated the same
as if the peer returned a block with missing parent which gets the block
out of our processing queue, but can have nasty side effects.
For example, if sync manager asks for validation of a block known to be
in the finalized range, if it receives a `MissingParent` verdict, the
peer is immediately removed from the peer pool.
```
DBG 2022-08-24 11:45:26.874+02:00 newPayload: inserting block into execution engine parentHash=e4ca7424 blockHash=36cdc198 stateRoot=cf3902c1 receiptsRoot=56e81f17 prevRandao=0b49a172 blockNumber=1518089 gasLimit=30000000 gasUsed=0 timestamp=1657980396 extraDataLen=0 baseFeePerGas=7 numTransactions=0
ERR 2022-08-24 11:45:26.875+02:00 newPayload failed msg="Transport is not initialised (missing a call to connect?)"
DBG 2022-08-24 11:45:26.875+02:00 Block pool rejected peer's response topics="syncman" request=187232:32@1475 peer=16U*MsCJdx direction=forward blocks_map=xxxxxxxxxxxxxxxxxxxxxxxxxxxx.xxx blocks_count=31 ok=false unviable=false missing_parent=true sync_ident=main
ERR 2022-08-24 11:45:26.875+02:00 Unexpected missing parent at finalized epoch slot topics="syncman" request=187232:32@1475 peer=16U*MsCJdx direction=forward rewind_to_slot=187232 blocks_count=31 blocks_map=xxxxxxxxxxxxxxxxxxxxxxxxxxxx.xxx sync_ident=main
DBG 2022-08-24 11:45:26.875+02:00 Peer was removed from PeerPool due to low score topics="beacnde" peer=16U*MsCJdx peer_score=-1000 score_low_limit=0 score_high_limit=1000
DBG 2022-08-24 11:45:26.875+02:00 Lost connection to peer topics="networking" peer=16U*MsCJdx connections=0
```
By delaying issuing a verdict until the EL connection is restored and
`newPayload` successfully ran, the problem should be fixed. This also
induces back pressure to the sync manager by stopping download of new
blocks (or re-downloading the same block over and over again).
