d839b9d07e
Currently, we require genesis and a checkpoint block and state to start from an arbitrary slot - this PR relaxes this requirement so that we can start with a state alone. The current trusted-node-sync algorithm works by first downloading blocks until we find an epoch aligned non-empty slot, then downloads the state via slot. However, current [proposals](https://github.com/ethereum/beacon-APIs/pull/226) for checkpointing prefer finalized state as the main reference - this allows more simple access control and caching on the server side - in particular, this should help checkpoint-syncing from sources that have a fast `finalized` state download (like infura and teku) but are slow when accessing state via slot. Earlier versions of Nimbus will not be able to read databases created without a checkpoint block and genesis. In most cases, backfilling makes the database compatible except where genesis is also missing (custom networks). * backfill checkpoint block from libp2p instead of checkpoint source, when doing trusted node sync * allow starting the client without genesis / checkpoint block * perform epoch start slot lookahead when loading tail state, so as to deal with the case where the epoch start slot does not have a block * replace `--blockId` with `--state-id` in TNS command line * when replaying, also look at the parent of the last-known-block (even if we don't have the parent block data, we can still replay from a "parent" state) - in particular, this clears the way for implementing state pruning * deprecate `--finalized-checkpoint-block` option (no longer needed) |
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| .. | ||
| vanity_logs | ||
| README.md | ||
| attestation_pool.nim | ||
| block_clearance.nim | ||
| block_dag.nim | ||
| block_pools_types.nim | ||
| block_pools_types_light_client.nim | ||
| block_quarantine.nim | ||
| blockchain_dag.nim | ||
| blockchain_dag_light_client.nim | ||
| consensus_manager.nim | ||
| exit_pool.nim | ||
| light_client_pool.nim | ||
| spec_cache.nim | ||
| sync_committee_msg_pool.nim | ||
README.md
Consensus object pools
This folder holds the various consensus object pools needed for a blockchain client.
Object in those pools have passed the "gossip validation" filter according to specs:
- blocks: https://github.com/ethereum/consensus-specs/blob/v1.1.10/specs/phase0/p2p-interface.md#beacon_block
- aggregate attestations: https://github.com/ethereum/consensus-specs/blob/v1.1.10/specs/phase0/p2p-interface.md#beacon_aggregate_and_proof
- unaggregated attestation: https://github.com/ethereum/consensus-specs/blob/v1.2.0-rc.2/specs/phase0/p2p-interface.md#beacon_attestation_subnet_id
- voluntary exits: https://github.com/ethereum/consensus-specs/blob/v1.2.0/specs/phase0/p2p-interface.md#voluntary_exit
- Attester slashings: https://github.com/ethereum/consensus-specs/blob/v1.2.0/specs/phase0/p2p-interface.md#attester_slashing
- Proposer slashings: https://github.com/ethereum/consensus-specs/blob/v1.2.0/specs/phase0/p2p-interface.md#proposer_slashing
After "gossip validation" the consensus objects can be rebroadcasted as they are optimistically good, however for internal processing further verification is needed. For blocks, this means verifying state transition and all contained cryptographic signatures (instead of just the proposer signature). For other consensus objects, it is possible that gossip validation is a superset of consensus verification (TODO).
The pools presenet in this folder are:
- block_pools:
- block_quarantine: for seemingly valid blocks that are on a fork unknown to us.
- block_clearance: to verify (state_transition + cryptography) candidate blocks.
- blockchain_dag: an in-memory direct-acyclic graph of fully validated and verified blockchain candidates with the tail being the last finalized epoch. A block in the DAG MUST be in the fork choice and a block in the fork choice MUST be in the DAG (except for orphans following finalization). On finalization non-empty epoch blocks are stored in the beacon_chain_db.
- attestation_pool: Handles the attestation received from gossip and collect them for fork choice.
- exit_pool: Handle voluntary exits and forced exits (attester slashings and proposer slashings)