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
* 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
Since these files may have been created in a previous run or manually,
we want to keep loading them even on nodes that don't enable the
keystore API (for example static setups)
Other changes:
* log keystore loading progressively (#3699)
* print initial fee recipient when loading validators
* log dynamic fee recipient updates
* 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.
Adds the `--web3-url` launch argument to `nimbus_light_client` to enable
driving the EL with the optimistic head obtained from LC sync protocol.
This will keep issuing `newPayload` / `forkChoiceUpdated` requests for
new blocks, marking them as optimistic. `ZERO_HASH` is reported as the
finalized block for now.