## Issue Addressed
n/a Noticed this while working on something else
## Proposed Changes
- leverage the appropriate types to avoid a bunch of `unwrap` and errors
## Additional Info
n/a
## Issue Addressed
N/A
## Proposed Changes
Add lints for rust 1.71
[3789134](3789134ae2) is probably the one that needs most attention as it changes beacon state code. I changed the `is_in_inactivity_leak ` function to return a `ArithError` as not all consumers of that function work well with a `BeaconState::Error`.
## Issue Addressed
Fixes occasional compilation errors with mev-rs (see #4456).
## Proposed Changes
- Update `mev-rs` to the latest version, which allows us to remove hacky `[patch]` sections
- Update the `axum` version used in `watch` so LH only uses a single version
## Issue Addressed
Fix an issue observed by `@zlan` on Discord where Lighthouse would sometimes return this error when looking up states via the API:
> {"code":500,"message":"UNHANDLED_ERROR: ForkChoiceError(MissingProtoArrayBlock(0xc9cf1495421b6ef3215d82253b388d77321176a1dcef0db0e71a0cd0ffc8cdb7))","stacktraces":[]}
## Proposed Changes
The error stems from a faulty assumption in the HTTP API logic: that any state in the hot database must have its block in fork choice. This isn't true because the state's hot database may update much less frequently than the fork choice store, e.g. if reconstructing states (where freezer migration pauses), or if the freezer migration runs slowly. There could also be a race between loading the hot state and checking fork choice, e.g. even if the finalization migration of DB+fork choice were atomic, the update could happen between the 1st and 2nd calls.
To address this I've changed the HTTP API logic to use the finalized block's execution status as a fallback where it is safe to do so. In the case where a block is non-canonical and prior to finalization (permanently orphaned) we default `execution_optimistic` to `true`.
## Additional Info
I've also added a new CLI flag to reduce the frequency of the finalization migration as this is useful for several purposes:
- Spacing out database writes (less frequent, larger batches)
- Keeping a limited chain history with high availability, e.g. the last month in the hot database.
This new flag made it _substantially_ easier to test this change. It was extracted from `tree-states` (where it's called `--db-migration-period`), which is why this PR also carries the `tree-states` label.
## Issue Addressed
#4494
## Proposed Changes
- Remove explicit re-exports of various types to appease the new compiler lint
## Additional Info
It seems `warn(hidden_glob_reexports)` is the main culprit.
*Replaces #4434. It is identical, but this PR has a smaller diff due to a curated commit history.*
## Issue Addressed
NA
## Proposed Changes
This PR moves the scheduling logic for the `BeaconProcessor` into a new crate in `beacon_node/beacon_processor`. Previously it existed in the `beacon_node/network` crate.
This addresses a circular-dependency problem where it's not possible to use the `BeaconProcessor` from the `beacon_chain` crate. The `network` crate depends on the `beacon_chain` crate (`network -> beacon_chain`), but importing the `BeaconProcessor` into the `beacon_chain` crate would create a circular dependancy of `beacon_chain -> network`.
The `BeaconProcessor` was designed to provide queuing and prioritized scheduling for messages from the network. It has proven to be quite valuable and I believe we'd make Lighthouse more stable and effective by using it elsewhere. In particular, I think we should use the `BeaconProcessor` for:
1. HTTP API requests.
1. Scheduled tasks in the `BeaconChain` (e.g., state advance).
Using the `BeaconProcessor` for these tasks would help prevent the BN from becoming overwhelmed and would also help it to prioritize operations (e.g., choosing to process blocks from gossip before responding to low-priority HTTP API requests).
## Additional Info
This PR is intended to have zero impact on runtime behaviour. It aims to simply separate the *scheduling* code (i.e., the `BeaconProcessor`) from the *business logic* in the `network` crate (i.e., the `Worker` impls). Future PRs (see #4462) can build upon these works to actually use the `BeaconProcessor` for more operations.
I've gone to some effort to use `git mv` to make the diff look more like "file was moved and modified" rather than "file was deleted and a new one added". This should reduce review burden and help maintain commit attribution.
## Issue Addressed
[Users on Twitter](https://twitter.com/ashekhirin/status/1676334843192397824) are getting checkpoint sync URL timeouts with the default of 60s, so this PR increases the default timeout to 3 minutes.
I've also added a short section to the book about adjusting the timeout with `--checkpoint-sync-url-timeout`.
## Issue Addressed
#4331
## Proposed Changes
- Use comparison rather than strict equality between the earliest epoch we know about and the backfill target (which will be the most recent WSP by default or genesis)
- Add helper function `BackFillSync<T>::would_complete` to achieve this in one location
## Additional Info
- There's an ad hoc test for this in #4461
Co-authored-by: Age Manning <Age@AgeManning.com>
## Issue Addressed
#4118
## Proposed Changes
This PR introduces a "progressive balances" cache on the `BeaconState`, which keeps track of the accumulated target attestation balance for the current & previous epochs. The cached values are utilised by fork choice to calculate unrealized justification and finalization (instead of converting epoch participation arrays to balances for each block we receive).
This optimization will be rolled out gradually to allow for more testing. A new `--progressive-balances disabled|checked|strict|fast` flag is introduced to support this:
- `checked`: enabled with checks against participation cache, and falls back to the existing epoch processing calculation if there is a total target attester balance mismatch. There is no performance gain from this as the participation cache still needs to be computed. **This is the default mode for now.**
- `strict`: enabled with checks against participation cache, returns error if there is a mismatch. **Used for testing only**.
- `fast`: enabled with no comparative checks and without computing the participation cache. This mode gives us the performance gains from the optimization. This is still experimental and not currently recommended for production usage, but will become the default mode in a future release.
- `disabled`: disable the usage of progressive cache, and use the existing method for FFG progression calculation. This mode may be useful if we find a bug and want to stop the frequent error logs.
### Tasks
- [x] Initial cache implementation in `BeaconState`
- [x] Perform checks in fork choice to compare the progressive balances cache against results from `ParticipationCache`
- [x] Add CLI flag, and disable the optimization by default
- [x] Testing on Goerli & Benchmarking
- [x] Move caching logic from state processing to the `ProgressiveBalancesCache` (see [this comment](https://github.com/sigp/lighthouse/pull/4362#discussion_r1230877001))
- [x] Add attesting balance metrics
Co-authored-by: Jimmy Chen <jimmy@sigmaprime.io>
## Issue Addressed
[#4292](https://github.com/sigp/lighthouse/issues/4292)
## Proposed Changes
Updated the node health endpoint
will return a 200 status code if `!syncing && !el_offline && !optimistic`
wil return a 206 if `(syncing || optimistic) && !el_offline`
will return a 503 if `el_offline`
## Additional Info
## Issue Addressed
[#4259](https://github.com/sigp/lighthouse/issues/4259)
## Proposed Changes
debounce spammy `Unable to send message to the beacon processor` log messages
## Additional Info
We could potentially debounce other logs that have the potential to be "spammy".
After some feedback we decided to additionally add the following change:
create a newtype wrapper around `mpsc::Sender<BeaconWorkEvent<T>>`. When there is an error on the try_send method on the wrapper, we increase a counter metric with one label per work type.
## Issue Addressed
- #4293
- #4264
## Proposed Changes
*Changes largely follow those suggested in the main issue*.
- Add new routes to HTTP API
- `post_beacon_blocks_v2`
- `post_blinded_beacon_blocks_v2`
- Add new routes to `BeaconNodeHttpClient`
- `post_beacon_blocks_v2`
- `post_blinded_beacon_blocks_v2`
- Define new Eth2 common types
- `BroadcastValidation`, enum representing the level of validation to apply to blocks prior to broadcast
- `BroadcastValidationQuery`, the corresponding HTTP query string type for the above type
- ~~Define `_checked` variants of both `publish_block` and `publish_blinded_block` that enforce a validation level at a type level~~
- Add interactive tests to the `bn_http_api_tests` test target covering each validation level (to their own test module, `broadcast_validation_tests`)
- `beacon/blocks`
- `broadcast_validation=gossip`
- Invalid (400)
- Full Pass (200)
- Partial Pass (202)
- `broadcast_validation=consensus`
- Invalid (400)
- Only gossip (400)
- Only consensus pass (i.e., equivocates) (200)
- Full pass (200)
- `broadcast_validation=consensus_and_equivocation`
- Invalid (400)
- Invalid due to early equivocation (400)
- Only gossip (400)
- Only consensus (400)
- Pass (200)
- `beacon/blinded_blocks`
- `broadcast_validation=gossip`
- Invalid (400)
- Full Pass (200)
- Partial Pass (202)
- `broadcast_validation=consensus`
- Invalid (400)
- Only gossip (400)
- ~~Only consensus pass (i.e., equivocates) (200)~~
- Full pass (200)
- `broadcast_validation=consensus_and_equivocation`
- Invalid (400)
- Invalid due to early equivocation (400)
- Only gossip (400)
- Only consensus (400)
- Pass (200)
- Add a new trait, `IntoGossipVerifiedBlock`, which allows type-level guarantees to be made as to gossip validity
- Modify the structure of the `ObservedBlockProducers` cache from a `(slot, validator_index)` mapping to a `((slot, validator_index), block_root)` mapping
- Modify `ObservedBlockProducers::proposer_has_been_observed` to return a `SeenBlock` rather than a boolean on success
- Punish gossip peer (low) for submitting equivocating blocks
- Rename `BlockError::SlashablePublish` to `BlockError::SlashableProposal`
## Additional Info
This PR contains changes that directly modify how blocks are verified within the client. For more context, consult [comments in-thread](https://github.com/sigp/lighthouse/pull/4316#discussion_r1234724202).
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
## Issue Addressed
NA
## Proposed Changes
Implements the `PrettyReqwestError` to wrap a `reqwest::Error` and give nicer `Debug` formatting. It also wraps the `Url` component in a `SensitiveUrl` to avoid leaking sensitive info in logs.
### Before
```
Reqwest(reqwest::Error { kind: Request, url: Url { scheme: "http", cannot_be_a_base: false, username: "", password: None, host: Some(Domain("localhost")), port: Some(9999), path: "/eth/v1/node/version", query: None, fragment: None }, source: hyper::Error(Connect, ConnectError("tcp connect error", Os { code: 61, kind: ConnectionRefused, message: "Connection refused" })) })
```
### After
```
HttpClient(url: http://localhost:9999/, kind: request, detail: error trying to connect: tcp connect error: Connection refused (os error 61))
```
## Additional Info
I've also renamed the `Reqwest` error enum variants to `HttpClient`, to give people a better chance at knowing what's going on. Reqwest is pretty odd and looks like a typo.
I've implemented it in the `eth2` and `execution_layer` crates. This should affect most logs in the VC and EE-related ones in the BN.
I think the last crate that could benefit from the is the `beacon_node/eth1` crate. I haven't updated it in this PR since its error type is not so amenable to it (everything goes into a `String`). I don't have a whole lot of time to jig around with that at the moment and I feel that this PR as it stands is a significant enough improvement to merge on its own. Leaving it as-is is fine for the time being and we can always come back for it later (or implement in-protocol deposits!).
## Issue Addressed
Resolves#3238
## Proposed Changes
Please list or describe the changes introduced by this PR.
## Additional Info
Please provide any additional information. For example, future considerations
or information useful for reviewers.
## Proposed Changes
Remove `max-skip-slots` checks when processing blocks.
This was legacy code which was previously used in the Medalla testnet to sync to the correct fork.
With the addition of checkpoint sync which allows us to sync to any arbitrary fork, this is no longer a necessary feature, so it has been removed for simplicity.
## Additional Notes
The CLI flag and checks for attestation processing have been retained as it still may have uses in DoS protection.
Currently, the ENR of the node may not be correctly updated when specifying ipv6 fields through the CLI if an ENR exists on disk.
This remedies a bug where we were not checking for ipv6 fields when comparing whether to use an on-disk ENR or updating based on CLI configuration parameters.
## Issue Addressed
Closes#4332
## Proposed Changes
Remove the `CountUnrealized` type, defaulting unrealized justification to _on_. This fixes the #4332 issue by ensuring that importing the same block to fork choice always results in the same outcome.
Finalized sync speed may be slightly impacted by this change, but that is deemed an acceptable trade-off until the optimisation from #4118 is implemented.
TODO:
- [x] Also check that the block isn't a duplicate before importing
## Issue Addressed
Resolves#3980. Builds on work by @GeemoCandama in #4084
## Proposed Changes
Extends the `SupportedProtocol` abstraction added in Geemo's PR and attempts to fix internal versioning of requests that are mentioned in this comment https://github.com/sigp/lighthouse/pull/4084#issuecomment-1496380033
Co-authored-by: geemo <geemo@tutanota.com>
Done in different PRs so that they can reviewed independently, as it's likely this won't be merged before I leave
Includes resolution for #4080
- [ ] #4299
- [ ] #4318
- [ ] #4320
Co-authored-by: Diva M <divma@protonmail.com>
Co-authored-by: Age Manning <Age@AgeManning.com>
## Issue Addressed
This PR addresses issue https://github.com/sigp/lighthouse/issues/4350
## Proposed Changes
This change will enable slasher broadcast in the following cases:
No flag is passed,
`--slasher-broadcast` is passed and,
`--slasher-broadcast=true` is passed.
Only when an explicit false value is passed the slasher does not broadcast.(`--slasher-broadcast=false`).
## Additional Info
TODO
- [x] Modify CLI parsing logic
- [x] Write test
Refer to #4353
Co-authored-by: Rahul Dogra <rahulcooldogra@gmail.com>
Co-authored-by: Gua00va <105484243+Gua00va@users.noreply.github.com>
## Issue Addressed
Closes#4354Closes#3987
Replaces #4305, #4283
## Proposed Changes
This switches the default slasher backend _back_ to LMDB.
If an MDBX database exists and the MDBX backend is enabled then MDBX will continue to be used. Our release binaries and Docker images will continue to include MDBX for as long as it is practical, so users of these should not notice any difference.
The main benefit is to users compiling from source and devs running tests. These users no longer have to struggle to compile MDBX and deal with the compatibility issues that arises. Similarly, devs don't need to worry about toggling feature flags in tests or risk forgetting to run the slasher tests due to backend issues.
## Issue Addressed
N/A
## Proposed Changes
This change will log the value of the relay block and the local block when the relay block is more profitable.
## Additional Info
This change will help validators understand the block selection (as it looks like the execution reward sometimes is higher that the MEV-reward).
The rationale for this change is to aid operators to better understand why a relay-block was chosen over a local block.
Looking at produced blocks (at beaconcha.in for example) it sometimes looks like the builder is making a profit just from the execution reward vs the MEV-reward, and creates the nagging question: "Could i have built this block and made that extra profit?"... The answer is probably "No, not without the extra transactions included by the relay", but by logging the value of the local block-candidate, this will no longer be an issue..
### Example (Mainnet)
https://beaconcha.in/block/17370329
MEV Block Reward: 0.17122 Ether to 0xE35bBaFa0266089f95d745d348b468622805D82B
Execution Reward: 0.17528 Ether to 0x1f9090aaE28b8a3dCeaDf281B0F12828e676c326
Difference: 0.00406 Ether
### Examples (Goerli)
https://goerli.beaconcha.in/block/9040065
MEV Block Reward: 0.56423 Ether to 0xF5794543CF6055Ae710E9c8E99E31343Cea004a8
Execution Reward: 0.56488 Ether to 0xfC0157aA4F5DB7177830ACddB3D5a9BB5BE9cc5e
Difference: 0.00065 Ether
https://goerli.beaconcha.in/block/9019921
MEV Block Reward: 1.39440 Ether to 0xF5794543CF6055Ae710E9c8E99E31343Cea004a8
Execution Reward: 1.39469 Ether to 0xfC0157aA4F5DB7177830ACddB3D5a9BB5BE9cc5e
Difference: 0.00029 Ether
https://goerli.beaconcha.in/block/9015583
MEV Block Reward: 1.04356 Ether to 0xF5794543CF6055Ae710E9c8E99E31343Cea004a8
Execution Reward: 1.04896 Ether to 0xfC0157aA4F5DB7177830ACddB3D5a9BB5BE9cc5e
Difference: 0.0054 Ether
## Issue Addressed
On deneb devnetv5, lighthouse keeps rate limiting peers which makes it harder to bootstrap new nodes as there are very few peers in the network. This PR adds an option to disable the inbound rate limiter for testnets.
Added an option to configure inbound rate limits as well.
Co-authored-by: Diva M <divma@protonmail.com>
## Proposed Changes
This is a light refactor of the execution layer's block hash calculation logic making it easier to use externally. e.g. in `eleel` (https://github.com/sigp/eleel/pull/18).
A static method is preferable to a method because the calculation doesn't actually need any data from `self`, and callers may want to compute block hashes without constructing an `ExecutionLayer` (`eleel` only constructs a simpler `Engine` struct).
This PR address the following spec change: https://github.com/ethereum/consensus-specs/pull/3312
Instead of subscribing to a long-lived subnet for every attached validator to a beacon node, all beacon nodes will subscribe to `SUBNETS_PER_NODE` long-lived subnets. This is currently set to 2 for mainnet.
This PR does not include any scoring or advanced discovery mechanisms. A future PR will improve discovery and we can implement scoring after the next hard fork when we expect all client teams and all implementations to respect this spec change.
This will be a significant change in the subnet network structure for consensus clients and we will likely have to monitor and tweak our peer management logic.
This PR adds the ability to read the Lighthouse logs from the HTTP API for both the BN and the VC.
This is done in such a way to as minimize any kind of performance hit by adding this feature.
The current design creates a tokio broadcast channel and mixes is into a form of slog drain that combines with our main global logger drain, only if the http api is enabled.
The drain gets the logs, checks the log level and drops them if they are below INFO. If they are INFO or higher, it sends them via a broadcast channel only if there are users subscribed to the HTTP API channel. If not, it drops the logs.
If there are more than one subscriber, the channel clones the log records and converts them to json in their independent HTTP API tasks.
Co-authored-by: Michael Sproul <micsproul@gmail.com>
## Issue Addressed
NA
## Proposed Changes
Adds metrics to track validators that are submitting equivocating (but not slashable) sync messages. This follows on from some research we've been doing in a separate fork of LH.
## Additional Info
@jimmygchen and @michaelsproul have already run their eyes over this so it should be easy to get into v4.2.0, IMO.
## Issue Addressed
#4281
## Proposed Changes
- Change `ShufflingCache` implementation from using `LruCache` to a custom cache that removes entry with lowest epoch instead of oldest insertion time.
- Protect the "enshrined" head shufflings when inserting new committee cache entries. The shuffling ids matching the head's previous, current, and future epochs will never be ejected from the cache during `Self::insert_cache_item`.
## Additional Info
There is a bonus point on shuffling preferences in the issue description that hasn't been implemented yet, as I haven't figured out a good way to do this:
> However I'm not convinced since there are some complexities around tie-breaking when two entries have the same epoch. Perhaps preferring entries in the canonical chain is best?
We should be able to check if a block is on the canonical chain by:
```rust
canonical_head
.fork_choice_read_lock()
.contains_block(root)
```
However we need to interleave the shuffling and fork choice locks, which may cause deadlocks if we're not careful (mentioned by @paulhauner). Alternatively, we could use the `state.block_roots` field of the `chain.canonical_head.snapshot.beacon_state`, which avoids deadlock but requires more work.
I'd like to get some feedback on review & testing before I dig deeper into the preferences stuff, as having the canonical head preference may already be quite useful in preventing the issue raised.
Co-authored-by: Jimmy Chen <jimmy@sigmaprime.io>
## Issue Addressed
Closes https://github.com/sigp/lighthouse/issues/4291, part of #3613.
## Proposed Changes
- Implement the `el_offline` field on `/eth/v1/node/syncing`. We set `el_offline=true` if:
- The EL's internal status is `Offline` or `AuthFailed`, _or_
- The most recent call to `newPayload` resulted in an error (more on this in a moment).
- Use the `el_offline` field in the VC to mark nodes with offline ELs as _unsynced_. These nodes will still be used, but only after synced nodes.
- Overhaul the usage of `RequireSynced` so that `::No` is used almost everywhere. The `--allow-unsynced` flag was broken and had the opposite effect to intended, so it has been deprecated.
- Add tests for the EL being offline on the upcheck call, and being offline due to the newPayload check.
## Why track `newPayload` errors?
Tracking the EL's online/offline status is too coarse-grained to be useful in practice, because:
- If the EL is timing out to some calls, it's unlikely to timeout on the `upcheck` call, which is _just_ `eth_syncing`. Every failed call is followed by an upcheck [here](693886b941/beacon_node/execution_layer/src/engines.rs (L372-L380)), which would have the effect of masking the failure and keeping the status _online_.
- The `newPayload` call is the most likely to time out. It's the call in which ELs tend to do most of their work (often 1-2 seconds), with `forkchoiceUpdated` usually returning much faster (<50ms).
- If `newPayload` is failing consistently (e.g. timing out) then this is a good indication that either the node's EL is in trouble, or the network as a whole is. In the first case validator clients _should_ prefer other BNs if they have one available. In the second case, all of their BNs will likely report `el_offline` and they'll just have to proceed with trying to use them.
## Additional Changes
- Add utility method `ForkName::latest` which is quite convenient for test writing, but probably other things too.
- Delete some stale comments from when we used to support multiple execution nodes.
## Issue Addressed
#2335
## Proposed Changes
- Remove the `lighthouse-network::tests::gossipsub_tests` module
- Remove dead code from the `lighthouse-network::tests::common` helper module (`build_full_mesh`)
## Additional Info
After discussion with both @divagant-martian and @AgeManning, these tests seem to have two main issues in that they are:
- Redundant, in that they don't test anything meaningful (due to our handling of duplicate messages)
- Out-of-place, in that it doesn't really test Lighthouse-specific functionality (rather libp2p functionality)
As such, this PR supersedes #4286.
## Issue Addressed
NA
## Proposed Changes
Adds an additional check to a feature introduced in #4179 to prevent us from re-queuing already-known blocks that could be rejected immediately.
## Additional Info
Ideally this would have been included in v4.1.0, however we came across it too late to release it safely. We decided that the safest path forward is to release *without* this check and then patch it in the next version. The lack of this check should only result in a very minor performance impact (the impact is totally negligible in my assessment).
## Issue Addressed
NA
## Proposed Changes
Adds a flag to store invalid blocks on disk for teh debugz. Only *some* invalid blocks are stored, those which:
- Were received via gossip (rather than RPC, for instance)
- This keeps things simple to start with and should capture most blocks.
- Passed gossip verification
- This reduces the ability for random people to fill up our disk. A proposer signature is required to write something to disk.
## Additional Info
It's possible that we'll store blocks that aren't necessarily invalid, but we had an internal error during verification. Those blocks seem like they might be useful sometimes.
## Issue Addressed
N/A
## Proposed Changes
Replace ganache-cli with anvil https://github.com/foundry-rs/foundry/blob/master/anvil/README.md
We can lose all js dependencies in CI as a consequence.
## Additional info
Also changes the ethers-rs version used in the execution layer (for the transaction reconstruction) to a newer one. This was necessary to get use the ethers utils for anvil. The fixed execution engine integration tests should catch any potential issues with the payload reconstruction after #3592
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
## Issue Addressed
#4233
## Proposed Changes
Remove the `best_justified_checkpoint` from the `PersistedForkChoiceStore` type as it is now unused.
Additionally, remove the `Option`'s wrapping the `justified_checkpoint` and `finalized_checkpoint` fields on `ProtoNode` which were only present to facilitate a previous migration.
Include the necessary code to facilitate the migration to a new DB schema.
## Issue Addressed
Addresses #4238
## Proposed Changes
- [x] Add tests for the scenarios
- [x] Use the fork of the attestation slot for signature verification.
## Issue Addressed
Addresses #4234
## Proposed Changes
- Skip withdrawals processing in an inconsistent state replay.
- Repurpose `StateRootStrategy`: rename to `StateProcessingStrategy` and always skip withdrawals if using `StateProcessingStrategy::Inconsistent`
- Add a test to reproduce the scenario
Co-authored-by: Jimmy Chen <jimmy@sigmaprime.io>
## Issue Addressed
#4266
## Proposed Changes
- Log `Using external block builder` instead of `Connected to external block builder` on its initialization to resolve the confusion (there's no actual connection there)
## Additional Info
The log is mentioned in builders docs, so it's changed there too.
This commit adds a check to the networking service when handling core gossipsub topic subscription requests. If the BN is already subscribed to the core topics, we won't attempt to resubscribe.
## Issue Addressed
#4258
## Proposed Changes
- In the networking service, check if we're already subscribed to all of the core gossipsub topics and, if so, do nothing
## Additional Info
N/A
## Limit Backfill Sync
This PR transitions Lighthouse from syncing all the way back to genesis to only syncing back to the weak subjectivity point (~ 5 months) when syncing via a checkpoint sync.
There are a number of important points to note with this PR:
- Firstly and most importantly, this PR fundamentally shifts the default security guarantees of checkpoint syncing in Lighthouse. Prior to this PR, Lighthouse could verify the checkpoint of any given chain by ensuring the chain eventually terminates at the corresponding genesis. This guarantee can still be employed via the new CLI flag --genesis-backfill which will prompt lighthouse to the old behaviour of downloading all blocks back to genesis. The new behaviour only checks the proposer signatures for the last 5 months of blocks but cannot guarantee the chain matches the genesis chain.
- I have not modified any of the peer scoring or RPC responses. Clients syncing from gensis, will downscore new Lighthouse peers that do not possess blocks prior to the WSP. This is by design, as Lighthouse nodes of this form, need a mechanism to sort through peers in order to find useful peers in order to complete their genesis sync. We therefore do not discriminate between empty/error responses for blocks prior or post the local WSP. If we request a block that a peer does not posses, then fundamentally that peer is less useful to us than other peers.
- This will make a radical shift in that the majority of nodes will no longer store the full history of the chain. In the future we could add a pruning mechanism to remove old blocks from the db also.
Co-authored-by: Paul Hauner <paul@paulhauner.com>
## Issue Addressed
#3873
## Proposed Changes
add a cache to optimise historical state lookup.
## Additional Info
N/A
Co-authored-by: Michael Sproul <micsproul@gmail.com>
