00cdc4bb35
## Issue Addressed
Partly addresses #1547
## Proposed Changes
This fix addresses the missing attestations at slot 0 of an epoch (also sometimes slot 1 when slot 0 was skipped).
There are 2 cases:
1. BN receives the block for the attestation slot after 4 seconds (1/3rd of the slot).
2. No block is proposed for this slot.
In both cases, when we produce the attestation, we pass the head state to the
`produce_unaggregated_attestation_for_block` function here
9833eca024/beacon_node/beacon_chain/src/beacon_chain.rs (L845-L850)
Since we don't advance the state in this function, we set `attestation.data.source = state.current_justified_checkpoint` which is atleast 2 epochs lower than current_epoch(wall clock epoch).
This attestation is invalid and cannot be included in a block because of this assert from the spec:
```python
if data.target.epoch == get_current_epoch(state):
assert data.source == state.current_justified_checkpoint
state.current_epoch_attestations.append(pending_attestation)
```
https://github.com/ethereum/eth2.0-specs/blob/dev/specs/phase0/beacon-chain.md#attestations
This PR changes the `produce_unaggregated_attestation_for_block` function to ensure that it advances the state before producing the attestation at the new epoch.
Running this on my node, have missed 0 attestations across all 8 of my validators in a 100 epoch period 🎉
To compare, I was missing ~14 attestations across all 8 validators in the same 100 epoch period before the fix.
Will report missed attestations if any after running for another 100 epochs tomorrow.
Lighthouse: Ethereum 2.0
An open-source Ethereum 2.0 client, written in Rust and maintained by Sigma Prime.
Overview
Lighthouse is:
- Fully open-source, licensed under Apache 2.0.
- Security-focused. Fuzzing has begun and security reviews are underway.
- Built in Rust, a modern language providing unique safety guarantees and excellent performance (comparable to C++).
- Funded by various organisations, including Sigma Prime, the Ethereum Foundation, ConsenSys and private individuals.
- Actively involved in the specification and security analysis of the emerging Ethereum 2.0 specification.
Like all Ethereum 2.0 clients, Lighthouse is a work-in-progress.
Development Status
Current development overview:
- Specification
v0.12.1implemented, optimized and passing test vectors. - Rust-native libp2p with Gossipsub and Discv5.
- RESTful JSON API via HTTP server.
- Events via WebSocket.
- Metrics via Prometheus.
Roadmap
April 2019: Inital single-client testnets.September 2019: Inter-operability with other Ethereum 2.0 clients.Q1 2020:lighthouse-0.1.0release: All major phase 0 features implemented.Q2 2020: Public, multi-client testnet with user-facing functionality.Q2 2020: Third-party security review.- Q3 2020: Additional third-party security reviews.
- Q3 2020: Long-lived, multi-client Beacon Chain testnet
- Q4 2020: Production Beacon Chain (tentative).
Documentation
The Lighthouse Book contains information for testnet users and developers.
Code documentation is generated via cargo doc and hosted at
lighthouse-docs.sigmaprime.io.
If you'd like some background on Sigma Prime, please see the Lighthouse Update #00 blog post or sigmaprime.io.
Contributing
Lighthouse welcomes contributors.
If you are looking to contribute, please head to the Contributing section of the Lighthouse book.
Contact
The best place for discussion is the Lighthouse Discord server. Alternatively, you may use the sigp/lighthouse gitter.
Encrypt sensitive messages using our PGP key.
Donations
Lighthouse is an open-source project and a public good. Funding public goods is hard and we're grateful for the donations we receive from the community via:
- Gitcoin Grants.
- Ethereum address:
0x25c4a76E7d118705e7Ea2e9b7d8C59930d8aCD3b(donation.sigmaprime.eth).