## Proposed Changes
With proposer boosting implemented (#2822) we have an opportunity to re-org out late blocks.
This PR adds three flags to the BN to control this behaviour:
* `--disable-proposer-reorgs`: turn aggressive re-orging off (it's on by default).
* `--proposer-reorg-threshold N`: attempt to orphan blocks with less than N% of the committee vote. If this parameter isn't set then N defaults to 20% when the feature is enabled.
* `--proposer-reorg-epochs-since-finalization N`: only attempt to re-org late blocks when the number of epochs since finalization is less than or equal to N. The default is 2 epochs, meaning re-orgs will only be attempted when the chain is finalizing optimally.
For safety Lighthouse will only attempt a re-org under very specific conditions:
1. The block being proposed is 1 slot after the canonical head, and the canonical head is 1 slot after its parent. i.e. at slot `n + 1` rather than building on the block from slot `n` we build on the block from slot `n - 1`.
2. The current canonical head received less than N% of the committee vote. N should be set depending on the proposer boost fraction itself, the fraction of the network that is believed to be applying it, and the size of the largest entity that could be hoarding votes.
3. The current canonical head arrived after the attestation deadline from our perspective. This condition was only added to support suppression of forkchoiceUpdated messages, but makes intuitive sense.
4. The block is being proposed in the first 2 seconds of the slot. This gives it time to propagate and receive the proposer boost.
## Additional Info
For the initial idea and background, see: https://github.com/ethereum/consensus-specs/pull/2353#issuecomment-950238004
There is also a specification for this feature here: https://github.com/ethereum/consensus-specs/pull/3034
Co-authored-by: Michael Sproul <micsproul@gmail.com>
Co-authored-by: pawan <pawandhananjay@gmail.com>
## Issue Addressed
Implementing the light_client_gossip topics but I'm not there yet.
Which issue # does this PR address?
Partially #3651
## Proposed Changes
Add light client gossip topics.
Please list or describe the changes introduced by this PR.
I'm going to Implement light_client_finality_update and light_client_optimistic_update gossip topics. Currently I've attempted the former and I'm seeking feedback.
## Additional Info
I've only implemented the light_client_finality_update topic because I wanted to make sure I was on the correct path. Also checking that the gossiped LightClientFinalityUpdate is the same as the locally constructed one is not implemented because caching the updates will make this much easier. Could someone give me some feedback on this please?
Please provide any additional information. For example, future considerations
or information useful for reviewers.
Co-authored-by: GeemoCandama <104614073+GeemoCandama@users.noreply.github.com>
* Add API endpoint to count statuses of all validators (#3756)
* Delete DB schema migrations for v11 and earlier (#3761)
Co-authored-by: Mac L <mjladson@pm.me>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
## Proposed Changes
Now that the Gnosis merge is scheduled, all users should have upgraded beyond Lighthouse v3.0.0. Accordingly we can delete schema migrations for versions prior to v3.0.0.
## Additional Info
I also deleted the state cache stuff I added in #3714 as it turned out to be useless for the light client proofs due to the one-slot offset.
## Issue Addressed
Closes https://github.com/sigp/lighthouse/issues/2327
## Proposed Changes
This is an extension of some ideas I implemented while working on `tree-states`:
- Cache the indexed attestations from blocks in the `ConsensusContext`. Previously we were re-computing them 3-4 times over.
- Clean up `import_block` by splitting each part into `import_block_XXX`.
- Move some stuff off hot paths, specifically:
- Relocate non-essential tasks that were running between receiving the payload verification status and priming the early attester cache. These tasks are moved after the cache priming:
- Attestation observation
- Validator monitor updates
- Slasher updates
- Updating the shuffling cache
- Fork choice attestation observation now happens at the end of block verification in parallel with payload verification (this seems to save 5-10ms).
- Payload verification now happens _before_ advancing the pre-state and writing it to disk! States were previously being written eagerly and adding ~20-30ms in front of verifying the execution payload. State catchup also sometimes takes ~500ms if we get a cache miss and need to rebuild the tree hash cache.
The remaining task that's taking substantial time (~20ms) is importing the block to fork choice. I _think_ this is because of pull-tips, and we should be able to optimise it out with a clever total active balance cache in the state (which would be computed in parallel with payload verification). I've decided to leave that for future work though. For now it can be observed via the new `beacon_block_processing_post_exec_pre_attestable_seconds` metric.
Co-authored-by: Michael Sproul <micsproul@gmail.com>
## Issue Addressed
#3704
## Proposed Changes
Adds is_syncing_finalized: bool parameter for block verification functions. Sets the payload_verification_status to Optimistic if is_syncing_finalized is true. Uses SyncState in NetworkGlobals in BeaconProcessor to retrieve the syncing status.
## Additional Info
I could implement FinalizedSignatureVerifiedBlock if you think it would be nicer.
## Issue Addressed
Part of https://github.com/sigp/lighthouse/issues/3651.
## Proposed Changes
Add a flag for enabling the light client server, which should be checked before gossip/RPC traffic is processed (e.g. https://github.com/sigp/lighthouse/pull/3693, https://github.com/sigp/lighthouse/pull/3711). The flag is available at runtime from `beacon_chain.config.enable_light_client_server`.
Additionally, a new method `BeaconChain::with_mutable_state_for_block` is added which I envisage being used for computing light client updates. Unfortunately its performance will be quite poor on average because it will only run quickly with access to the tree hash cache. Each slot the tree hash cache is only available for a brief window of time between the head block being processed and the state advance at 9s in the slot. When the state advance happens the cache is moved and mutated to get ready for the next slot, which makes it no longer useful for merkle proofs related to the head block. Rather than spend more time trying to optimise this I think we should continue prototyping with this code, and I'll make sure `tree-states` is ready to ship before we enable the light client server in prod (cf. https://github.com/sigp/lighthouse/pull/3206).
## Additional Info
I also fixed a bug in the implementation of `BeaconState::compute_merkle_proof` whereby the tree hash cache was moved with `.take()` but never put back with `.restore()`.
## Summary
The deposit cache now has the ability to finalize deposits. This will cause it to drop unneeded deposit logs and hashes in the deposit Merkle tree that are no longer required to construct deposit proofs. The cache is finalized whenever the latest finalized checkpoint has a new `Eth1Data` with all deposits imported.
This has three benefits:
1. Improves the speed of constructing Merkle proofs for deposits as we can just replay deposits since the last finalized checkpoint instead of all historical deposits when re-constructing the Merkle tree.
2. Significantly faster weak subjectivity sync as the deposit cache can be transferred to the newly syncing node in compressed form. The Merkle tree that stores `N` finalized deposits requires a maximum of `log2(N)` hashes. The newly syncing node then only needs to download deposits since the last finalized checkpoint to have a full tree.
3. Future proofing in preparation for [EIP-4444](https://eips.ethereum.org/EIPS/eip-4444) as execution nodes will no longer be required to store logs permanently so we won't always have all historical logs available to us.
## More Details
Image to illustrate how the deposit contract merkle tree evolves and finalizes along with the resulting `DepositTreeSnapshot`
## Other Considerations
I've changed the structure of the `SszDepositCache` so once you load & save your database from this version of lighthouse, you will no longer be able to load it from older versions.
Co-authored-by: ethDreamer <37123614+ethDreamer@users.noreply.github.com>
* add capella gossip boiler plate
* get everything compiling
Co-authored-by: realbigsean <sean@sigmaprime.io
Co-authored-by: Mark Mackey <mark@sigmaprime.io>
* small cleanup
* small cleanup
* cargo fix + some test cleanup
* improve block production
* add fixme for potential panic
Co-authored-by: Mark Mackey <mark@sigmaprime.io>
