Ethereum consensus client in Rust
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Michael Sproul 8fa032c8ae Run fork choice before block proposal (#3168)
## Issue Addressed

Upcoming spec change https://github.com/ethereum/consensus-specs/pull/2878

## Proposed Changes

1. Run fork choice at the start of every slot, and wait for this run to complete before proposing a block.
2. As an optimisation, also run fork choice 3/4 of the way through the slot (at 9s), _dequeueing attestations for the next slot_.
3. Remove the fork choice run from the state advance timer that occurred before advancing the state.

## Additional Info

### Block Proposal Accuracy

This change makes us more likely to propose on top of the correct head in the presence of re-orgs with proposer boost in play. The main scenario that this change is designed to address is described in the linked spec issue.

### Attestation Accuracy

This change _also_ makes us more likely to attest to the correct head. Currently in the case of a skipped slot at `slot` we only run fork choice 9s into `slot - 1`. This means the attestations from `slot - 1` aren't taken into consideration, and any boost applied to the block from `slot - 1` is not removed (it should be). In the language of the linked spec issue, this means we are liable to attest to C, even when the majority voting weight has already caused a re-org to B.

### Why remove the call before the state advance?

If we've run fork choice at the start of the slot then it has already dequeued all the attestations from the previous slot, which are the only ones eligible to influence the head in the current slot. Running fork choice again is unnecessary (unless we run it for the next slot and try to pre-empt a re-org, but I don't currently think this is a great idea).

### Performance

Based on Prater testing this adds about 5-25ms of runtime to block proposal times, which are 500-1000ms on average (and spike to 5s+ sometimes due to state handling issues 😢 ). I believe this is a small enough penalty to enable it by default, with the option to disable it via the new flag `--fork-choice-before-proposal-timeout 0`. Upcoming work on block packing and state representation will also reduce block production times in general, while removing the spikes.

### Implementation

Fork choice gets invoked at the start of the slot via the `per_slot_task` function called from the slot timer. It then uses a condition variable to signal to block production that fork choice has been updated. This is a bit funky, but it seems to work. One downside of the timer-based approach is that it doesn't happen automatically in most of the tests. The test added by this PR has to trigger the run manually.
2022-05-20 05:02:11 +00:00
.github Update mdbook runner to Ubuntu 20.04 (#3138) 2022-04-04 06:08:26 +00:00
account_manager Improve slashing import log (#3122) 2022-03-28 07:14:16 +00:00
beacon_node Run fork choice before block proposal (#3168) 2022-05-20 05:02:11 +00:00
book Add client authentication to Web3Signer validators (#3170) 2022-05-18 23:14:37 +00:00
boot_node v2.2.1 (#3149) 2022-04-12 02:52:12 +00:00
common Add client authentication to Web3Signer validators (#3170) 2022-05-18 23:14:37 +00:00
consensus Separate execution payloads in the DB (#3157) 2022-05-12 00:42:17 +00:00
crypto Update and consolidate dependencies (#3136) 2022-04-04 00:26:16 +00:00
database_manager Conserve disk space by raising default SPRP (#3137) 2022-04-01 07:16:25 +00:00
lcli Remove lcli block packing analysis (#3179) 2022-05-16 01:59:46 +00:00
lighthouse Run fork choice before block proposal (#3168) 2022-05-20 05:02:11 +00:00
scripts Updates to tests and local testnet for Ganache 7 (#3056) 2022-03-20 22:48:14 +00:00
slasher Update and consolidate dependencies (#3136) 2022-04-04 00:26:16 +00:00
testing Add client authentication to Web3Signer validators (#3170) 2022-05-18 23:14:37 +00:00
validator_client Add client authentication to Web3Signer validators (#3170) 2022-05-18 23:14:37 +00:00
.dockerignore Exclude EE build dirs from Docker context (#3174) 2022-05-09 23:43:31 +00:00
.editorconfig Add editorconfig template 2019-03-11 15:09:57 +11:00
.gitignore Delete uncompressed genesis states (#2092) 2020-12-16 03:44:05 +00:00
.gitmodules Replace EF tests submodule with a makefile 2019-09-08 04:19:54 +10:00
bors.toml Add minimum supported Rust version (#3082) 2022-03-17 03:33:29 +00:00
Cargo.lock Run fork choice before block proposal (#3168) 2022-05-20 05:02:11 +00:00
Cargo.toml Update and consolidate dependencies (#3136) 2022-04-04 00:26:16 +00:00
CONTRIBUTING.md Update CONTRIBUTING.md (#751) 2020-01-03 10:45:53 +11:00
Cross.toml Optimise slasher DB layout and switch to MDBX (#2776) 2021-12-21 08:23:17 +00:00
Dockerfile Optimized Docker images (#2966) 2022-01-31 22:55:03 +00:00
Dockerfile.cross Update docker images to Ubuntu latest (#2862) 2021-12-15 07:44:44 +00:00
LICENSE Update License to Apache 2.0 2019-04-15 16:47:35 +10:00
Makefile cargo audit updates (#3063) 2022-03-08 19:48:12 +00:00
README.md Change the url of the blog post (#3161) 2022-04-21 14:59:08 +00:00
SECURITY.md Add how users should report security vulnerabilities for this repository (#2562) 2021-09-07 01:54:05 +00:00

Lighthouse: Ethereum consensus client

An open-source Ethereum consensus client, written in Rust and maintained by Sigma Prime.

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Overview

Lighthouse is:

  • Ready for use on Ethereum consensus mainnet.
  • Fully open-source, licensed under Apache 2.0.
  • Security-focused. Fuzzing techniques have been continuously applied and several external security reviews have been performed.
  • 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, the Decentralization Foundation and private individuals.
  • Actively involved in the specification and security analysis of the Ethereum proof-of-stake consensus specification.

Staking Deposit Contract

The Lighthouse team acknowledges 0x00000000219ab540356cBB839Cbe05303d7705Fa as the canonical staking deposit contract address.

Documentation

The Lighthouse Book contains information for users and developers.

The Lighthouse team maintains a blog at lighthouse-blog.sigmaprime.io which contains periodical progress updates, roadmap insights and interesting findings.

Branches

Lighthouse maintains two permanent branches:

  • stable: Always points to the latest stable release.
    • This is ideal for most users.
  • unstable: Used for development, contains the latest PRs.
    • Developers should base their PRs on this branch.

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Lighthouse welcomes contributors.

If you are looking to contribute, please head to the Contributing section of the Lighthouse book.

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The best place for discussion is the Lighthouse Discord server.

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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:

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  • Ethereum address: 0x25c4a76E7d118705e7Ea2e9b7d8C59930d8aCD3b (donation.sigmaprime.eth).