4ed2e34a9e
This is a revamp of the attestation pool that cleans up several aspects of attestation processing as the network grows larger and block space becomes more precious. The aim is to better exploit the divide between attestation subnets and aggregations by keeping the two kinds separate until it's time to either produce a block or aggregate. This means we're no longer eagerly combining single-vote attestations, but rather wait until the last moment, and then try to add singles to all aggregates, including those coming from the network. Importantly, the branch improves on poor aggregate quality and poor attestation packing in cases where block space is running out. A basic greed scoring mechanism is used to select attestations for blocks - attestations are added based on how much many new votes they bring to the table. * Collect single-vote attestations separately and store these until it's time to make aggregates * Create aggregates based on single-vote attestations * Select _best_ aggregate rather than _first_ aggregate when on aggregation duty * Top up all aggregates with singles when it's time make the attestation cut, thus improving the chances of grabbing the best aggregates out there * Improve aggregation test coverage * Improve bitseq operations * Simplify aggregate signature creation * Make attestation cache temporary instead of storing it in attestation pool - most of the time, blocks are not being produced, no need to keep the data around * Remove redundant aggregate storage that was used only for RPC * Use tables to avoid some linear seeks when looking up attestation data * Fix long cleanup on large slot jumps * Avoid some pointers * Speed up iterating all attestations for a slot (fixes #2490) |
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| .. | ||
| README.md | ||
| attestation_pool.nim | ||
| block_clearance.nim | ||
| block_pools_types.nim | ||
| block_quarantine.nim | ||
| blockchain_dag.nim | ||
| exit_pool.nim | ||
| spec_cache.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/eth2.0-specs/blob/v1.0.1/specs/phase0/p2p-interface.md#beacon_block
- aggregate attestations: https://github.com/ethereum/eth2.0-specs/blob/v1.0.1/specs/phase0/p2p-interface.md#beacon_aggregate_and_proof
- unaggregate attestation: https://github.com/ethereum/eth2.0-specs/blob/v1.0.1/specs/phase0/p2p-interface.md#beacon_attestation_subnet_id
- voluntary exits https://github.com/ethereum/eth2.0-specs/blob/v1.0.1/specs/phase0/p2p-interface.md#voluntary_exit
- Attester slashings https://github.com/ethereum/eth2.0-specs/blob/v1.0.1/specs/phase0/p2p-interface.md#attester_slashing
- Proposer slashins https://github.com/ethereum/eth2.0-specs/blob/v1.0.1/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)