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Paul Hauner b06559ae97 Disallow attestation production earlier than head (#2130)
## Issue Addressed

The non-finality period on Pyrmont between epochs [`9114`](https://pyrmont.beaconcha.in/epoch/9114) and [`9182`](https://pyrmont.beaconcha.in/epoch/9182) was contributed to by all the `lighthouse_team` validators going down. The nodes saw excessive CPU and RAM usage, resulting in the system to kill the `lighthouse bn` process. The `Restart=on-failure` directive for `systemd` caused the process to bounce in ~10-30m intervals.

Diagnosis with `heaptrack` showed that the `BeaconChain::produce_unaggregated_attestation` function was calling `store::beacon_state::get_full_state` and sometimes resulting in a tree hash cache allocation. These allocations were approximately the size of the hosts physical memory and still allocated when `lighthouse bn` was killed by the OS.

There was no CPU analysis (e.g., `perf`), but the `BeaconChain::produce_unaggregated_attestation` is very CPU-heavy so it is reasonable to assume it is the cause of the excessive CPU usage, too.

## Proposed Changes

`BeaconChain::produce_unaggregated_attestation` has two paths:

1. Fast path: attesting to the head slot or later.
2. Slow path: attesting to a slot earlier than the head block.

Path (2) is the only path that calls `store::beacon_state::get_full_state`, therefore it is the path causing this excessive CPU/RAM usage.

This PR removes the current functionality of path (2) and replaces it with a static error (`BeaconChainError::AttestingPriorToHead`).

This change reduces the generality of `BeaconChain::produce_unaggregated_attestation` (and therefore [`/eth/v1/validator/attestation_data`](https://ethereum.github.io/eth2.0-APIs/#/Validator/produceAttestationData)), but I argue that this functionality is an edge-case and arguably a violation of the [Honest Validator spec](https://github.com/ethereum/eth2.0-specs/blob/dev/specs/phase0/validator.md).

It's possible that a validator goes back to a prior slot to "catch up" and submit some missed attestations. This change would prevent such behaviour, returning an error. My concerns with this catch-up behaviour is that it is:

- Not specified as "honest validator" attesting behaviour.
- Is behaviour that is risky for slashing (although, all validator clients *should* have slashing protection and will eventually fail if they do not).
- It disguises clock-sync issues between a BN and VC.

## Additional Info

It's likely feasible to implement path (2) if we implement some sort of caching mechanism. This would be a multi-week task and this PR gets the issue patched in the short term. I haven't created an issue to add path (2), instead I think we should implement it if we get user-demand.
2021-01-20 06:52:37 +00:00
.github Automate docker version tag (#2150) 2021-01-19 03:50:10 +00:00
account_manager Represent slots in secs instead of millisecs (#2163) 2021-01-19 09:39:51 +00:00
beacon_node Disallow attestation production earlier than head (#2130) 2021-01-20 06:52:37 +00:00
book Update docs: Change --beacon-node to --beacon-nodes (#2145) 2021-01-19 03:50:08 +00:00
boot_node Version v1.0.6 (#2126) 2020-12-28 23:38:02 +00:00
common Represent slots in secs instead of millisecs (#2163) 2021-01-19 09:39:51 +00:00
consensus Represent slots in secs instead of millisecs (#2163) 2021-01-19 09:39:51 +00:00
crypto Clippy 1.49.0 updates and dht persistence test fix (#2156) 2021-01-19 00:34:28 +00:00
lcli Add lcli command to replace state pubkeys (#1999) 2021-01-19 08:42:30 +00:00
lighthouse Represent slots in secs instead of millisecs (#2163) 2021-01-19 09:39:51 +00:00
remote_signer replace tempdir by tempfile (#2143) 2021-01-06 06:36:11 +00:00
scripts Release v0.3.4 (#1894) 2020-11-13 06:06:35 +00:00
slasher Clippy 1.49.0 updates and dht persistence test fix (#2156) 2021-01-19 00:34:28 +00:00
testing Represent slots in secs instead of millisecs (#2163) 2021-01-19 09:39:51 +00:00
validator_client Represent slots in secs instead of millisecs (#2163) 2021-01-19 09:39:51 +00:00
.dockerignore Use OS file locks in validator client (#1958) 2020-11-26 11:25:46 +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 Remove macos tests (#1687) 2020-09-30 01:27:36 +00:00
Cargo.lock Represent slots in secs instead of millisecs (#2163) 2021-01-19 09:39:51 +00:00
Cargo.toml Add slasher broadcast (#2079) 2020-12-16 03:44:01 +00:00
CONTRIBUTING.md Update CONTRIBUTING.md (#751) 2020-01-03 10:45:53 +11:00
Cross.toml Ensure RUSTFLAGS is passed through on cross compile (#1529) 2020-08-17 10:06:06 +00:00
Dockerfile Improve compile time (#1989) 2020-12-09 01:34:58 +00:00
Dockerfile.cross Multiarch docker GitHub actions (#2065) 2020-12-09 06:06:37 +00:00
LICENSE Update License to Apache 2.0 2019-04-15 16:47:35 +10:00
Makefile Remove audit ignore ws server (#2051) 2020-12-06 23:35:51 +00:00
README.md Update PGP key in README (#1986) 2020-11-30 09:28:54 +00:00

Lighthouse: Ethereum 2.0

An open-source Ethereum 2.0 client, written in Rust and maintained by Sigma Prime.

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Overview

Lighthouse is:

  • Ready for use on Eth2 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 2.0 specification.

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