## Issue Addressed
NA
## Proposed Changes
There are scenarios where the only viable head will have an invalid execution payload, in this scenario the `get_head` function on `proto_array` will return an error. We must recover from this scenario by importing blocks from the network.
This PR stops `BeaconChain::recompute_head` from returning an error so that we can't accidentally start down-scoring peers or aborting block import just because the current head has an invalid payload.
## Reviewer Notes
The following changes are included:
1. Allow `fork_choice.get_head` to fail gracefully in `BeaconChain::process_block` when trying to update the `early_attester_cache`; simply don't add the block to the cache rather than aborting the entire process.
1. Don't return an error from `BeaconChain::recompute_head_at_current_slot` and `BeaconChain::recompute_head` to defensively prevent calling functions from aborting any process just because the fork choice function failed to run.
- This should have practically no effect, since most callers were still continuing if recomputing the head failed.
- The outlier is that the API will return 200 rather than a 500 when fork choice fails.
1. Add the `ProtoArrayForkChoice::set_all_blocks_to_optimistic` function to recover from the scenario where we've rebooted and the persisted fork choice has an invalid head.
## Issue Addressed
Closes https://github.com/sigp/lighthouse/issues/3241
Closes https://github.com/sigp/lighthouse/issues/3242
## Proposed Changes
* [x] Implement logic to remove equivocating validators from fork choice per https://github.com/ethereum/consensus-specs/pull/2845
* [x] Update tests to v1.2.0-rc.1. The new test which exercises `equivocating_indices` is passing.
* [x] Pull in some SSZ abstractions from the `tree-states` branch that make implementing Vec-compatible encoding for types like `BTreeSet` and `BTreeMap`.
* [x] Implement schema upgrades and downgrades for the database (new schema version is V11).
* [x] Apply attester slashings from blocks to fork choice
## Additional Info
* This PR doesn't need the `BTreeMap` impl, but `tree-states` does, and I don't think there's any harm in keeping it. But I could also be convinced to drop it.
Blocked on #3322.
## Issue Addressed
Add a flag that optionally enables unrealized vote tracking. Would like to test out on testnets and benchmark differences in methods of vote tracking. This PR includes a DB schema upgrade to enable to new vote tracking style.
Co-authored-by: realbigsean <sean@sigmaprime.io>
Co-authored-by: Paul Hauner <paul@paulhauner.com>
Co-authored-by: sean <seananderson33@gmail.com>
Co-authored-by: Mac L <mjladson@pm.me>
## Issue Addressed
#3031
## Proposed Changes
Updates the following API endpoints to conform with https://github.com/ethereum/beacon-APIs/pull/190 and https://github.com/ethereum/beacon-APIs/pull/196
- [x] `beacon/states/{state_id}/root`
- [x] `beacon/states/{state_id}/fork`
- [x] `beacon/states/{state_id}/finality_checkpoints`
- [x] `beacon/states/{state_id}/validators`
- [x] `beacon/states/{state_id}/validators/{validator_id}`
- [x] `beacon/states/{state_id}/validator_balances`
- [x] `beacon/states/{state_id}/committees`
- [x] `beacon/states/{state_id}/sync_committees`
- [x] `beacon/headers`
- [x] `beacon/headers/{block_id}`
- [x] `beacon/blocks/{block_id}`
- [x] `beacon/blocks/{block_id}/root`
- [x] `beacon/blocks/{block_id}/attestations`
- [x] `debug/beacon/states/{state_id}`
- [x] `debug/beacon/heads`
- [x] `validator/duties/attester/{epoch}`
- [x] `validator/duties/proposer/{epoch}`
- [x] `validator/duties/sync/{epoch}`
Updates the following Server-Sent Events:
- [x] `events?topics=head`
- [x] `events?topics=block`
- [x] `events?topics=finalized_checkpoint`
- [x] `events?topics=chain_reorg`
## Backwards Incompatible
There is a very minor breaking change with the way the API now handles requests to `beacon/blocks/{block_id}/root` and `beacon/states/{state_id}/root` when `block_id` or `state_id` is the `Root` variant of `BlockId` and `StateId` respectively.
Previously a request to a non-existent root would simply echo the root back to the requester:
```
curl "http://localhost:5052/eth/v1/beacon/states/0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/root"
{"data":{"root":"0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"}}
```
Now it will return a `404`:
```
curl "http://localhost:5052/eth/v1/beacon/blocks/0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/root"
{"code":404,"message":"NOT_FOUND: beacon block with root 0xaaaa…aaaa","stacktraces":[]}
```
In addition to this is the block root `0x0000000000000000000000000000000000000000000000000000000000000000` previously would return the genesis block. It will now return a `404`:
```
curl "http://localhost:5052/eth/v1/beacon/blocks/0x0000000000000000000000000000000000000000000000000000000000000000"
{"code":404,"message":"NOT_FOUND: beacon block with root 0x0000…0000","stacktraces":[]}
```
## Additional Info
- `execution_optimistic` is always set, and will return `false` pre-Bellatrix. I am also open to the idea of doing something like `#[serde(skip_serializing_if = "Option::is_none")]`.
- The value of `execution_optimistic` is set to `false` where possible. Any computation that is reliant on the `head` will simply use the `ExecutionStatus` of the head (unless the head block is pre-Bellatrix).
Co-authored-by: Paul Hauner <paul@paulhauner.com>
## Issue Addressed
Closes https://github.com/sigp/lighthouse/issues/3189.
## Proposed Changes
- Always supply the justified block hash as the `safe_block_hash` when calling `forkchoiceUpdated` on the execution engine.
- Refactor the `get_payload` routine to use the new `ForkchoiceUpdateParameters` struct rather than just the `finalized_block_hash`. I think this is a nice simplification and that the old way of computing the `finalized_block_hash` was unnecessary, but if anyone sees reason to keep that approach LMK.
## Overview
This rather extensive PR achieves two primary goals:
1. Uses the finalized/justified checkpoints of fork choice (FC), rather than that of the head state.
2. Refactors fork choice, block production and block processing to `async` functions.
Additionally, it achieves:
- Concurrent forkchoice updates to the EL and cache pruning after a new head is selected.
- Concurrent "block packing" (attestations, etc) and execution payload retrieval during block production.
- Concurrent per-block-processing and execution payload verification during block processing.
- The `Arc`-ification of `SignedBeaconBlock` during block processing (it's never mutated, so why not?):
- I had to do this to deal with sending blocks into spawned tasks.
- Previously we were cloning the beacon block at least 2 times during each block processing, these clones are either removed or turned into cheaper `Arc` clones.
- We were also `Box`-ing and un-`Box`-ing beacon blocks as they moved throughout the networking crate. This is not a big deal, but it's nice to avoid shifting things between the stack and heap.
- Avoids cloning *all the blocks* in *every chain segment* during sync.
- It also has the potential to clean up our code where we need to pass an *owned* block around so we can send it back in the case of an error (I didn't do much of this, my PR is already big enough 😅)
- The `BeaconChain::HeadSafetyStatus` struct was removed. It was an old relic from prior merge specs.
For motivation for this change, see https://github.com/sigp/lighthouse/pull/3244#issuecomment-1160963273
## Changes to `canonical_head` and `fork_choice`
Previously, the `BeaconChain` had two separate fields:
```
canonical_head: RwLock<Snapshot>,
fork_choice: RwLock<BeaconForkChoice>
```
Now, we have grouped these values under a single struct:
```
canonical_head: CanonicalHead {
cached_head: RwLock<Arc<Snapshot>>,
fork_choice: RwLock<BeaconForkChoice>
}
```
Apart from ergonomics, the only *actual* change here is wrapping the canonical head snapshot in an `Arc`. This means that we no longer need to hold the `cached_head` (`canonical_head`, in old terms) lock when we want to pull some values from it. This was done to avoid deadlock risks by preventing functions from acquiring (and holding) the `cached_head` and `fork_choice` locks simultaneously.
## Breaking Changes
### The `state` (root) field in the `finalized_checkpoint` SSE event
Consider the scenario where epoch `n` is just finalized, but `start_slot(n)` is skipped. There are two state roots we might in the `finalized_checkpoint` SSE event:
1. The state root of the finalized block, which is `get_block(finalized_checkpoint.root).state_root`.
4. The state root at slot of `start_slot(n)`, which would be the state from (1), but "skipped forward" through any skip slots.
Previously, Lighthouse would choose (2). However, we can see that when [Teku generates that event](de2b2801c8/data/beaconrestapi/src/main/java/tech/pegasys/teku/beaconrestapi/handlers/v1/events/EventSubscriptionManager.java (L171-L182)) it uses [`getStateRootFromBlockRoot`](de2b2801c8/data/provider/src/main/java/tech/pegasys/teku/api/ChainDataProvider.java (L336-L341)) which uses (1).
I have switched Lighthouse from (2) to (1). I think it's a somewhat arbitrary choice between the two, where (1) is easier to compute and is consistent with Teku.
## Notes for Reviewers
I've renamed `BeaconChain::fork_choice` to `BeaconChain::recompute_head`. Doing this helped ensure I broke all previous uses of fork choice and I also find it more descriptive. It describes an action and can't be confused with trying to get a reference to the `ForkChoice` struct.
I've changed the ordering of SSE events when a block is received. It used to be `[block, finalized, head]` and now it's `[block, head, finalized]`. It was easier this way and I don't think we were making any promises about SSE event ordering so it's not "breaking".
I've made it so fork choice will run when it's first constructed. I did this because I wanted to have a cached version of the last call to `get_head`. Ensuring `get_head` has been run *at least once* means that the cached values doesn't need to wrapped in an `Option`. This was fairly simple, it just involved passing a `slot` to the constructor so it knows *when* it's being run. When loading a fork choice from the store and a slot clock isn't handy I've just used the `slot` that was saved in the `fork_choice_store`. That seems like it would be a faithful representation of the slot when we saved it.
I added the `genesis_time: u64` to the `BeaconChain`. It's small, constant and nice to have around.
Since we're using FC for the fin/just checkpoints, we no longer get the `0x00..00` roots at genesis. You can see I had to remove a work-around in `ef-tests` here: b56be3bc2. I can't find any reason why this would be an issue, if anything I think it'll be better since the genesis-alias has caught us out a few times (0x00..00 isn't actually a real root). Edit: I did find a case where the `network` expected the 0x00..00 alias and patched it here: 3f26ac3e2.
You'll notice a lot of changes in tests. Generally, tests should be functionally equivalent. Here are the things creating the most diff-noise in tests:
- Changing tests to be `tokio::async` tests.
- Adding `.await` to fork choice, block processing and block production functions.
- Refactor of the `canonical_head` "API" provided by the `BeaconChain`. E.g., `chain.canonical_head.cached_head()` instead of `chain.canonical_head.read()`.
- Wrapping `SignedBeaconBlock` in an `Arc`.
- In the `beacon_chain/tests/block_verification`, we can't use the `lazy_static` `CHAIN_SEGMENT` variable anymore since it's generated with an async function. We just generate it in each test, not so efficient but hopefully insignificant.
I had to disable `rayon` concurrent tests in the `fork_choice` tests. This is because the use of `rayon` and `block_on` was causing a panic.
Co-authored-by: Mac L <mjladson@pm.me>
## Proposed Changes
Reduce post-merge disk usage by not storing finalized execution payloads in Lighthouse's database.
⚠️ **This is achieved in a backwards-incompatible way for networks that have already merged** ⚠️. Kiln users and shadow fork enjoyers will be unable to downgrade after running the code from this PR. The upgrade migration may take several minutes to run, and can't be aborted after it begins.
The main changes are:
- New column in the database called `ExecPayload`, keyed by beacon block root.
- The `BeaconBlock` column now stores blinded blocks only.
- Lots of places that previously used full blocks now use blinded blocks, e.g. analytics APIs, block replay in the DB, etc.
- On finalization:
- `prune_abanonded_forks` deletes non-canonical payloads whilst deleting non-canonical blocks.
- `migrate_db` deletes finalized canonical payloads whilst deleting finalized states.
- Conversions between blinded and full blocks are implemented in a compositional way, duplicating some work from Sean's PR #3134.
- The execution layer has a new `get_payload_by_block_hash` method that reconstructs a payload using the EE's `eth_getBlockByHash` call.
- I've tested manually that it works on Kiln, using Geth and Nethermind.
- This isn't necessarily the most efficient method, and new engine APIs are being discussed to improve this: https://github.com/ethereum/execution-apis/pull/146.
- We're depending on the `ethers` master branch, due to lots of recent changes. We're also using a workaround for https://github.com/gakonst/ethers-rs/issues/1134.
- Payload reconstruction is used in the HTTP API via `BeaconChain::get_block`, which is now `async`. Due to the `async` fn, the `blocking_json` wrapper has been removed.
- Payload reconstruction is used in network RPC to serve blocks-by-{root,range} responses. Here the `async` adjustment is messier, although I think I've managed to come up with a reasonable compromise: the handlers take the `SendOnDrop` by value so that they can drop it on _task completion_ (after the `fn` returns). Still, this is introducing disk reads onto core executor threads, which may have a negative performance impact (thoughts appreciated).
## Additional Info
- [x] For performance it would be great to remove the cloning of full blocks when converting them to blinded blocks to write to disk. I'm going to experiment with a `put_block` API that takes the block by value, breaks it into a blinded block and a payload, stores the blinded block, and then re-assembles the full block for the caller.
- [x] We should measure the latency of blocks-by-root and blocks-by-range responses.
- [x] We should add integration tests that stress the payload reconstruction (basic tests done, issue for more extensive tests: https://github.com/sigp/lighthouse/issues/3159)
- [x] We should (manually) test the schema v9 migration from several prior versions, particularly as blocks have changed on disk and some migrations rely on being able to load blocks.
Co-authored-by: Paul Hauner <paul@paulhauner.com>
## Issue Addressed
NA
## Proposed Changes
Disallow the production of attestations and retrieval of unaggregated attestations when they reference an optimistic head. Add tests to this end.
I also moved `BeaconChain::produce_unaggregated_attestation_for_block` to the `BeaconChainHarness`. It was only being used during tests, so it's nice to stop pretending it's production code. I also needed something that could produce attestations to optimistic blocks in order to simulate scenarios where the justified checkpoint is determined invalid (if no one would attest to an optimistic block, we could never justify it and then flip it to invalid).
## Additional Info
- ~~Blocked on #3126~~
## Issue Addressed
NA
## Proposed Changes
Ensures that a `VALID` response from a `forkchoiceUpdate` call will update that block in `ProtoArray`.
I also had to modify the mock execution engine so it wouldn't return valid when all payloads were supposed to be some other static value.
## Additional Info
NA
## Issue Addressed
MEV boost compatibility
## Proposed Changes
See #2987
## Additional Info
This is blocked on the stabilization of a couple specs, [here](https://github.com/ethereum/beacon-APIs/pull/194) and [here](https://github.com/flashbots/mev-boost/pull/20).
Additional TODO's and outstanding questions
- [ ] MEV boost JWT Auth
- [ ] Will `builder_proposeBlindedBlock` return the revealed payload for the BN to propogate
- [ ] Should we remove `private-tx-proposals` flag and communicate BN <> VC with blinded blocks by default once these endpoints enter the beacon-API's repo? This simplifies merge transition logic.
Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: realbigsean <sean@sigmaprime.io>
## Issue Addressed
This address an issue which was preventing checkpoint-sync.
When the node starts from checkpoint sync, the head block and the finalized block are the same value. We did not respect this when sending a `forkchoiceUpdated` (fcU) call to the EL and were expecting fork choice to hold the *finalized ancestor of the head* and returning an error when it didn't.
This PR uses *only fork choice* for sending fcU updates. This is actually quite nice and avoids some atomicity issues between `chain.canonical_head` and `chain.fork_choice`. Now, whenever `chain.fork_choice.get_head` returns a value we also cache the values required for the next fcU call.
## TODO
- [x] ~~Blocked on #3043~~
- [x] Ensure there isn't a warn message at startup.
## Issue Addressed
As discussed on last-night's consensus call, the testnets next week will target the [Kiln Spec v2](https://hackmd.io/@n0ble/kiln-spec).
Presently, we support Kiln V1. V2 is backwards compatible, except for renaming `random` to `prev_randao` in:
- https://github.com/ethereum/execution-apis/pull/180
- https://github.com/ethereum/consensus-specs/pull/2835
With this PR we'll no longer be compatible with the existing Kintsugi and Kiln testnets, however we'll be ready for the testnets next week. I raised this breaking change in the call last night, we are all keen to move forward and break things.
We now target the [`merge-kiln-v2`](https://github.com/MariusVanDerWijden/go-ethereum/tree/merge-kiln-v2) branch for interop with Geth. This required adding the `--http.aauthport` to the tester to avoid a port conflict at startup.
### Changes to exec integration tests
There's some change in the `merge-kiln-v2` version of Geth that means it can't compile on a vanilla Github runner. Bumping the `go` version on the runner solved this issue.
Whilst addressing this, I refactored the `testing/execution_integration` crate to be a *binary* rather than a *library* with tests. This means that we don't need to run the `build.rs` and build Geth whenever someone runs `make lint` or `make test-release`. This is nice for everyday users, but it's also nice for CI so that we can have a specific runner for these tests and we don't need to ensure *all* runners support everything required to build all execution clients.
## More Info
- [x] ~~EF tests are failing since the rename has broken some tests that reference the old field name. I have been told there will be new tests released in the coming days (25/02/22 or 26/02/22).~~
## Description
This PR adds a single, trivial commit (f5d2b27d78349d5a675a2615eba42cc9ae708094) atop #2986 to resolve a tests compile error. The original author (@ethDreamer) is AFK so I'm getting this one merged ☺️
Please see #2986 for more information about the other, significant changes in this PR.
Co-authored-by: Mark Mackey <mark@sigmaprime.io>
Co-authored-by: ethDreamer <37123614+ethDreamer@users.noreply.github.com>
## Issue Addressed
NA
## Proposed Changes
Adds the functionality to allow blocks to be validated/invalidated after their import as per the [optimistic sync spec](https://github.com/ethereum/consensus-specs/blob/dev/sync/optimistic.md#how-to-optimistically-import-blocks). This means:
- Updating `ProtoArray` to allow flipping the `execution_status` of ancestors/descendants based on payload validity updates.
- Creating separation between `execution_layer` and the `beacon_chain` by creating a `PayloadStatus` struct.
- Refactoring how the `execution_layer` selects a `PayloadStatus` from the multiple statuses returned from multiple EEs.
- Adding testing framework for optimistic imports.
- Add `ExecutionBlockHash(Hash256)` new-type struct to avoid confusion between *beacon block roots* and *execution payload hashes*.
- Add `merge` to [`FORKS`](c3a793fd73/Makefile (L17)) in the `Makefile` to ensure we test the beacon chain with merge settings.
- Fix some tests here that were failing due to a missing execution layer.
## TODO
- [ ] Balance tests
Co-authored-by: Mark Mackey <mark@sigmaprime.io>
## Proposed Changes
Lots of lint updates related to `flat_map`, `unwrap_or_else` and string patterns. I did a little more creative refactoring in the op pool, but otherwise followed Clippy's suggestions.
## Additional Info
We need this PR to unblock CI.
## Proposed Changes
Update `superstruct` to bring in @realbigsean's fixes necessary for MEV-compatible private beacon block types (a la #2795).
The refactoring is due to another change in superstruct that allows partial getters to be auto-generated.
## Issue Addressed
Resolves: https://github.com/sigp/lighthouse/issues/2741
Includes: https://github.com/sigp/lighthouse/pull/2853 so that we can get ssz static tests passing here on v1.1.6. If we want to merge that first, we can make this diff slightly smaller
## Proposed Changes
- Changes the `justified_epoch` and `finalized_epoch` in the `ProtoArrayNode` each to an `Option<Checkpoint>`. The `Option` is necessary only for the migration, so not ideal. But does allow us to add a default logic to `None` on these fields during the database migration.
- Adds a database migration from a legacy fork choice struct to the new one, search for all necessary block roots in fork choice by iterating through blocks in the db.
- updates related to https://github.com/ethereum/consensus-specs/pull/2727
- We will have to update the persisted forkchoice to make sure the justified checkpoint stored is correct according to the updated fork choice logic. This boils down to setting the forkchoice store's justified checkpoint to the justified checkpoint of the block that advanced the finalized checkpoint to the current one.
- AFAICT there's no migration steps necessary for the update to allow applying attestations from prior blocks, but would appreciate confirmation on that
- I updated the consensus spec tests to v1.1.6 here, but they will fail until we also implement the proposer score boost updates. I confirmed that the previously failing scenario `new_finalized_slot_is_justified_checkpoint_ancestor` will now pass after the boost updates, but haven't confirmed _all_ tests will pass because I just quickly stubbed out the proposer boost test scenario formatting.
- This PR now also includes proposer boosting https://github.com/ethereum/consensus-specs/pull/2730
## Additional Info
I realized checking justified and finalized roots in fork choice makes it more likely that we trigger this bug: https://github.com/ethereum/consensus-specs/pull/2727
It's possible the combination of justified checkpoint and finalized checkpoint in the forkchoice store is different from in any block in fork choice. So when trying to startup our store's justified checkpoint seems invalid to the rest of fork choice (but it should be valid). When this happens we get an `InvalidBestNode` error and fail to start up. So I'm including that bugfix in this branch.
Todo:
- [x] Fix fork choice tests
- [x] Self review
- [x] Add fix for https://github.com/ethereum/consensus-specs/pull/2727
- [x] Rebase onto Kintusgi
- [x] Fix `num_active_validators` calculation as @michaelsproul pointed out
- [x] Clean up db migrations
Co-authored-by: realbigsean <seananderson33@gmail.com>
* Fix fork choice after rebase
* Remove paulhauner warp dep
* Fix fork choice test compile errors
* Assume fork choice payloads are valid
* Add comment
* Ignore new tests
* Fix error in test skipping
* Add payload verification status to fork choice
* Pass payload verification status to import_block
* Add valid back-propagation
* Add head safety status latch to API
* Remove ExecutionLayerStatus
* Add execution info to client notifier
* Update notifier logs
* Change use of "hash" to refer to beacon block
* Shutdown on invalid finalized block
* Tidy, add comments
* Fix failing FC tests
* Allow blocks with unsafe head
* Fix forkchoiceUpdate call on startup
* - Update the fork choice `ProtoNode` to include `is_merge_complete`
- Add database migration for the persisted fork choice
* update tests
* Small cleanup
* lints
* store execution block hash in fork choice rather than bool
Added Execution Payload from Rayonism Fork
Updated new Containers to match Merge Spec
Updated BeaconBlockBody for Merge Spec
Completed updating BeaconState and BeaconBlockBody
Modified ExecutionPayload<T> to use Transaction<T>
Mostly Finished Changes for beacon-chain.md
Added some things for fork-choice.md
Update to match new fork-choice.md/fork.md changes
ran cargo fmt
Added Missing Pieces in eth2_libp2p for Merge
fix ef test
Various Changes to Conform Closer to Merge Spec
## Issue Addressed
Resolves#2545
## Proposed Changes
Adds the long-overdue EF tests for fork choice. Although we had pretty good coverage via other implementations that closely followed our approach, it is nonetheless important for us to implement these tests too.
During testing I found that we were using a hard-coded `SAFE_SLOTS_TO_UPDATE_JUSTIFIED` value rather than one from the `ChainSpec`. This caused a failure during a minimal preset test. This doesn't represent a risk to mainnet or testnets, since the hard-coded value matched the mainnet preset.
## Failing Cases
There is one failing case which is presently marked as `SkippedKnownFailure`:
```
case 4 ("new_finalized_slot_is_justified_checkpoint_ancestor") from /home/paul/development/lighthouse/testing/ef_tests/consensus-spec-tests/tests/minimal/phase0/fork_choice/on_block/pyspec_tests/new_finalized_slot_is_justified_checkpoint_ancestor failed with NotEqual:
head check failed: Got Head { slot: Slot(40), root: 0x9183dbaed4191a862bd307d476e687277fc08469fc38618699863333487703e7 } | Expected Head { slot: Slot(24), root: 0x105b49b51bf7103c182aa58860b039550a89c05a4675992e2af703bd02c84570 }
```
This failure is due to #2741. It's not a particularly high priority issue at the moment, so we fix it after merging this PR.
## Issue Addressed
Continuation of #2728, fix the fork choice tests for Rust 1.56.0 so that `unstable` is free of warnings.
CI will be broken until this PR merges, because we strictly enforce the absence of warnings (even for tests)
## Issue Addressed
NA
## Proposed Changes
This PR is near-identical to https://github.com/sigp/lighthouse/pull/2652, however it is to be merged into `unstable` instead of `merge-f2f`. Please see that PR for reasoning.
I'm making this duplicate PR to merge to `unstable` in an effort to shrink the diff between `unstable` and `merge-f2f` by doing smaller, lead-up PRs.
## Additional Info
NA
## Issue Addressed
NA
## Proposed Changes
Implements the "union" type from the SSZ spec for `ssz`, `ssz_derive`, `tree_hash` and `tree_hash_derive` so it may be derived for `enums`:
https://github.com/ethereum/consensus-specs/blob/v1.1.0-beta.3/ssz/simple-serialize.md#union
The union type is required for the merge, since the `Transaction` type is defined as a single-variant union `Union[OpaqueTransaction]`.
### Crate Updates
This PR will (hopefully) cause CI to publish new versions for the following crates:
- `eth2_ssz_derive`: `0.2.1` -> `0.3.0`
- `eth2_ssz`: `0.3.0` -> `0.4.0`
- `eth2_ssz_types`: `0.2.0` -> `0.2.1`
- `tree_hash`: `0.3.0` -> `0.4.0`
- `tree_hash_derive`: `0.3.0` -> `0.4.0`
These these crates depend on each other, I've had to add a workspace-level `[patch]` for these crates. A follow-up PR will need to remove this patch, ones the new versions are published.
### Union Behaviors
We already had SSZ `Encode` and `TreeHash` derive for enums, however it just did a "transparent" pass-through of the inner value. Since the "union" decoding from the spec is in conflict with the transparent method, I've required that all `enum` have exactly one of the following enum-level attributes:
#### SSZ
- `#[ssz(enum_behaviour = "union")]`
- matches the spec used for the merge
- `#[ssz(enum_behaviour = "transparent")]`
- maintains existing functionality
- not supported for `Decode` (never was)
#### TreeHash
- `#[tree_hash(enum_behaviour = "union")]`
- matches the spec used for the merge
- `#[tree_hash(enum_behaviour = "transparent")]`
- maintains existing functionality
This means that we can maintain the existing transparent behaviour, but all existing users will get a compile-time error until they explicitly opt-in to being transparent.
### Legacy Option Encoding
Before this PR, we already had a union-esque encoding for `Option<T>`. However, this was with the *old* SSZ spec where the union selector was 4 bytes. During merge specification, the spec was changed to use 1 byte for the selector.
Whilst the 4-byte `Option` encoding was never used in the spec, we used it in our database. Writing a migrate script for all occurrences of `Option` in the database would be painful, especially since it's used in the `CommitteeCache`. To avoid the migrate script, I added a serde-esque `#[ssz(with = "module")]` field-level attribute to `ssz_derive` so that we can opt into the 4-byte encoding on a field-by-field basis.
The `ssz::legacy::four_byte_impl!` macro allows a one-liner to define the module required for the `#[ssz(with = "module")]` for some `Option<T> where T: Encode + Decode`.
Notably, **I have removed `Encode` and `Decode` impls for `Option`**. I've done this to force a break on downstream users. Like I mentioned, `Option` isn't used in the spec so I don't think it'll be *that* annoying. I think it's nicer than quietly having two different union implementations or quietly breaking the existing `Option` impl.
### Crate Publish Ordering
I've modified the order in which CI publishes crates to ensure that we don't publish a crate without ensuring we already published a crate that it depends upon.
## TODO
- [ ] Queue a follow-up `[patch]`-removing PR.
## Issue Addressed
NA
## Proposed Changes
Adds the ability to verify batches of aggregated/unaggregated attestations from the network.
When the `BeaconProcessor` finds there are messages in the aggregated or unaggregated attestation queues, it will first check the length of the queue:
- `== 1` verify the attestation individually.
- `>= 2` take up to 64 of those attestations and verify them in a batch.
Notably, we only perform batch verification if the queue has a backlog. We don't apply any artificial delays to attestations to try and force them into batches.
### Batching Details
To assist with implementing batches we modify `beacon_chain::attestation_verification` to have two distinct categories for attestations:
- *Indexed* attestations: those which have passed initial validation and were valid enough for us to derive an `IndexedAttestation`.
- *Verified* attestations: those attestations which were indexed *and also* passed signature verification. These are well-formed, interesting messages which were signed by validators.
The batching functions accept `n` attestations and then return `n` attestation verification `Result`s, where those `Result`s can be any combination of `Ok` or `Err`. In other words, we attempt to verify as many attestations as possible and return specific per-attestation results so peer scores can be updated, if required.
When we batch verify attestations, we first try to map all those attestations to *indexed* attestations. If any of those attestations were able to be indexed, we then perform batch BLS verification on those indexed attestations. If the batch verification succeeds, we convert them into *verified* attestations, disabling individual signature checking. If the batch fails, we convert to verified attestations with individual signature checking enabled.
Ultimately, we optimistically try to do a batch verification of attestation signatures and fall-back to individual verification if it fails. This opens an attach vector for "poisoning" the attestations and causing us to waste a batch verification. I argue that peer scoring should do a good-enough job of defending against this and the typical-case gains massively outweigh the worst-case losses.
## Additional Info
Before this PR, attestation verification took the attestations by value (instead of by reference). It turns out that this was unnecessary and, in my opinion, resulted in some undesirable ergonomics (e.g., we had to pass the attestation back in the `Err` variant to avoid clones). In this PR I've modified attestation verification so that it now takes a reference.
I refactored the `beacon_chain/tests/attestation_verification.rs` tests so they use a builder-esque "tester" struct instead of a weird macro. It made it easier for me to test individual/batch with the same set of tests and I think it was a nice tidy-up. Notably, I did this last to try and make sure my new refactors to *actual* production code would pass under the existing test suite.
## Issue Addressed
Closes#1891Closes#1784
## Proposed Changes
Implement checkpoint sync for Lighthouse, enabling it to start from a weak subjectivity checkpoint.
## Additional Info
- [x] Return unavailable status for out-of-range blocks requested by peers (#2561)
- [x] Implement sync daemon for fetching historical blocks (#2561)
- [x] Verify chain hashes (either in `historical_blocks.rs` or the calling module)
- [x] Consistency check for initial block + state
- [x] Fetch the initial state and block from a beacon node HTTP endpoint
- [x] Don't crash fetching beacon states by slot from the API
- [x] Background service for state reconstruction, triggered by CLI flag or API call.
Considered out of scope for this PR:
- Drop the requirement to provide the `--checkpoint-block` (this would require some pretty heavy refactoring of block verification)
Co-authored-by: Diva M <divma@protonmail.com>
## Issue Addressed
Related to: #2259
Made an attempt at all the necessary updates here to publish the crates to crates.io. I incremented the minor versions on all the crates that have been previously published. We still might run into some issues as we try to publish because I'm not able to test this out but I think it's a good starting point.
## Proposed Changes
- Add description and license to `ssz_types` and `serde_util`
- rename `serde_util` to `eth2_serde_util`
- increment minor versions
- remove path dependencies
- remove patch dependencies
## Additional Info
Crates published:
- [x] `tree_hash` -- need to publish `tree_hash_derive` and `eth2_hashing` first
- [x] `eth2_ssz_types` -- need to publish `eth2_serde_util` first
- [x] `tree_hash_derive`
- [x] `eth2_ssz`
- [x] `eth2_ssz_derive`
- [x] `eth2_serde_util`
- [x] `eth2_hashing`
Co-authored-by: realbigsean <seananderson33@gmail.com>
## Issue Addressed
Closes#2526
## Proposed Changes
If the head block fails to decode on start up, do two things:
1. Revert all blocks between the head and the most recent hard fork (to `fork_slot - 1`).
2. Reset fork choice so that it contains the new head, and all blocks back to the new head's finalized checkpoint.
## Additional Info
I tweaked some of the beacon chain test harness stuff in order to make it generic enough to test with a non-zero slot clock on start-up. In the process I consolidated all the various `new_` methods into a single generic one which will hopefully serve all future uses 🤞
## Proposed Changes
Implement the consensus changes necessary for the upcoming Altair hard fork.
## Additional Info
This is quite a heavy refactor, with pivotal types like the `BeaconState` and `BeaconBlock` changing from structs to enums. This ripples through the whole codebase with field accesses changing to methods, e.g. `state.slot` => `state.slot()`.
Co-authored-by: realbigsean <seananderson33@gmail.com>
## Issue Addressed
NA
## Primary Change
When investigating memory usage, I noticed that retrieving a block from an early slot (e.g., slot 900) would cause a sharp increase in the memory footprint (from 400mb to 800mb+) which seemed to be ever-lasting.
After some investigation, I found that the reverse iteration from the head back to that slot was the likely culprit. To counter this, I've switched the `BeaconChain::block_root_at_slot` to use the forwards iterator, instead of the reverse one.
I also noticed that the networking stack is using `BeaconChain::root_at_slot` to check if a peer is relevant (`check_peer_relevance`). Perhaps the steep, seemingly-random-but-consistent increases in memory usage are caused by the use of this function.
Using the forwards iterator with the HTTP API alleviated the sharp increases in memory usage. It also made the response much faster (before it felt like to took 1-2s, now it feels instant).
## Additional Changes
In the process I also noticed that we have two functions for getting block roots:
- `BeaconChain::block_root_at_slot`: returns `None` for a skip slot.
- `BeaconChain::root_at_slot`: returns the previous root for a skip slot.
I unified these two functions into `block_root_at_slot` and added the `WhenSlotSkipped` enum. Now, the caller must be explicit about the skip-slot behaviour when requesting a root.
Additionally, I replaced `vec![]` with `Vec::with_capacity` in `store::chunked_vector::range_query`. I stumbled across this whilst debugging and made this modification to see what effect it would have (not much). It seems like a decent change to keep around, but I'm not concerned either way.
Also, `BeaconChain::get_ancestor_block_root` is unused, so I got rid of it 🗑️.
## Additional Info
I haven't also done the same for state roots here. Whilst it's possible and a good idea, it's more work since the fwds iterators are presently block-roots-specific.
Whilst there's a few places a reverse iteration of state roots could be triggered (e.g., attestation production, HTTP API), they're no where near as common as the `check_peer_relevance` call. As such, I think we should get this PR merged first, then come back for the state root iters. I made an issue here https://github.com/sigp/lighthouse/issues/2377.
## Issue Addressed
Closes#2052
## Proposed Changes
- Refactor the attester/proposer duties endpoints in the BN
- Performance improvements
- Fixes some potential inconsistencies with the dependent root fields.
- Removes `http_api::beacon_proposer_cache` and just uses the one on the `BeaconChain` instead.
- Move the code for the proposer/attester duties endpoints into separate files, for readability.
- Refactor the `DutiesService` in the VC
- Required to reduce the delay on broadcasting new blocks.
- Gets rid of the `ValidatorDuty` shim struct that came about when we adopted the standard API.
- Separate block/attestation duty tasks so that they don't block each other when one is slow.
- In the VC, use `PublicKeyBytes` to represent validators instead of `PublicKey`. `PublicKey` is a legit crypto object whilst `PublicKeyBytes` is just a byte-array, it's much faster to clone/hash `PublicKeyBytes` and this change has had a significant impact on runtimes.
- Unfortunately this has created lots of dust changes.
- In the BN, store `PublicKeyBytes` in the `beacon_proposer_cache` and allow access to them. The HTTP API always sends `PublicKeyBytes` over the wire and the conversion from `PublicKey` -> `PublickeyBytes` is non-trivial, especially when queries have 100s/1000s of validators (like Pyrmont).
- Add the `state_processing::state_advance` mod which dedups a lot of the "apply `n` skip slots to the state" code.
- This also fixes a bug with some functions which were failing to include a state root as per [this comment](072695284f/consensus/state_processing/src/state_advance.rs (L69-L74)). I couldn't find any instance of this bug that resulted in anything more severe than keying a shuffling cache by the wrong block root.
- Swap the VC block service to use `mpsc` from `tokio` instead of `futures`. This is consistent with the rest of the code base.
~~This PR *reduces* the size of the codebase 🎉~~ It *used* to reduce the size of the code base before I added more comments.
## Observations on Prymont
- Proposer duties times down from peaks of 450ms to consistent <1ms.
- Current epoch attester duties times down from >1s peaks to a consistent 20-30ms.
- Block production down from +600ms to 100-200ms.
## Additional Info
- ~~Blocked on #2241~~
- ~~Blocked on #2234~~
## TODO
- [x] ~~Refactor this into some smaller PRs?~~ Leaving this as-is for now.
- [x] Address `per_slot_processing` roots.
- [x] Investigate slow next epoch times. Not getting added to cache on block processing?
- [x] Consider [this](072695284f/beacon_node/store/src/hot_cold_store.rs (L811-L812)) in the scenario of replacing the state roots
Co-authored-by: pawan <pawandhananjay@gmail.com>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
## Issue Addressed
NA
## Proposed Changes
Add an optimization to perform `per_slot_processing` from the *leading-edge* of block processing to the *trailing-edge*. Ultimately, this allows us to import the block at slot `n` faster because we used the tail-end of slot `n - 1` to perform `per_slot_processing`.
Additionally, add a "block proposer cache" which allows us to cache the block proposer for some epoch. Since we're now doing trailing-edge `per_slot_processing`, we can prime this cache with the values for the next epoch before those blocks arrive (assuming those blocks don't have some weird forking).
There were several ancillary changes required to achieve this:
- Remove the `state_root` field of `BeaconSnapshot`, since there's no need to know it on a `pre_state` and in all other cases we can just read it from `block.state_root()`.
- This caused some "dust" changes of `snapshot.beacon_state_root` to `snapshot.beacon_state_root()`, where the `BeaconSnapshot::beacon_state_root()` func just reads the state root from the block.
- Rename `types::ShuffingId` to `AttestationShufflingId`. I originally did this because I added a `ProposerShufflingId` struct which turned out to be not so useful. I thought this new name was more descriptive so I kept it.
- Address https://github.com/ethereum/eth2.0-specs/pull/2196
- Add a debug log when we get a block with an unknown parent. There was previously no logging around this case.
- Add a function to `BeaconState` to compute all proposers for an epoch without re-computing the active indices for each slot.
## Additional Info
- ~~Blocked on #2173~~
- ~~Blocked on #2179~~ That PR was wrapped into this PR.
- There's potentially some places where we could avoid computing the proposer indices in `per_block_processing` but I haven't done this here. These would be an optimization beyond the issue at hand (improving block propagation times) and I think this PR is already doing enough. We can come back for that later.
## TODO
- [x] Tidy, improve comments.
- [x] ~~Try avoid computing proposer index in `per_block_processing`?~~
## Issue Addressed
resolves#2129resolves#2099
addresses some of #1712
unblocks #2076
unblocks #2153
## Proposed Changes
- Updates all the dependencies mentioned in #2129, except for web3. They haven't merged their tokio 1.0 update because they are waiting on some dependencies of their own. Since we only use web3 in tests, I think updating it in a separate issue is fine. If they are able to merge soon though, I can update in this PR.
- Updates `tokio_util` to 0.6.2 and `bytes` to 1.0.1.
- We haven't made a discv5 release since merging tokio 1.0 updates so I'm using a commit rather than release atm. **Edit:** I think we should merge an update of `tokio_util` to 0.6.2 into discv5 before this release because it has panic fixes in `DelayQueue` --> PR in discv5: https://github.com/sigp/discv5/pull/58
## Additional Info
tokio 1.0 changes that required some changes in lighthouse:
- `interval.next().await.is_some()` -> `interval.tick().await`
- `sleep` future is now `!Unpin` -> https://github.com/tokio-rs/tokio/issues/3028
- `try_recv` has been temporarily removed from `mpsc` -> https://github.com/tokio-rs/tokio/issues/3350
- stream features have moved to `tokio-stream` and `broadcast::Receiver::into_stream()` has been temporarily removed -> `https://github.com/tokio-rs/tokio/issues/2870
- I've copied over the `BroadcastStream` wrapper from this PR, but can update to use `tokio-stream` once it's merged https://github.com/tokio-rs/tokio/pull/3384
Co-authored-by: realbigsean <seananderson33@gmail.com>
## Issue Addressed
NA
## Proposed Changes
- Panic or return error if we overflow `usize` in SSZ decoding/encoding derive macros.
- I claim that the panics can only be triggered by a faulty type definition in lighthouse, they cannot be triggered externally on a validly defined struct.
- Use `Ordering` instead of some `if` statements, as demanded by clippy.
- Remove some old clippy `allow` that seem to no longer be required.
- Add comments to interesting clippy statements that we're going to continue to ignore.
- Create #1713
## Additional Info
NA
## Issue Addressed
Closes#1557
## Proposed Changes
Modify the pruning algorithm so that it mutates the head-tracker _before_ committing the database transaction to disk, and _only if_ all the heads to be removed are still present in the head-tracker (i.e. no concurrent mutations).
In the process of writing and testing this I also had to make a few other changes:
* Use internal mutability for all `BeaconChainHarness` functions (namely the RNG and the graffiti), in order to enable parallel calls (see testing section below).
* Disable logging in harness tests unless the `test_logger` feature is turned on
And chose to make some clean-ups:
* Delete the `NullMigrator`
* Remove type-based configuration for the migrator in favour of runtime config (simpler, less duplicated code)
* Use the non-blocking migrator unless the blocking migrator is required. In the store tests we need the blocking migrator because some tests make asserts about the state of the DB after the migration has run.
* Rename `validators_keypairs` -> `validator_keypairs` in the `BeaconChainHarness`
## Testing
To confirm that the fix worked, I wrote a test using [Hiatus](https://crates.io/crates/hiatus), which can be found here:
https://github.com/michaelsproul/lighthouse/tree/hiatus-issue-1557
That test can't be merged because it inserts random breakpoints everywhere, but if you check out that branch you can run the test with:
```
$ cd beacon_node/beacon_chain
$ cargo test --release --test parallel_tests --features test_logger
```
It should pass, and the log output should show:
```
WARN Pruning deferred because of a concurrent mutation, message: this is expected only very rarely!
```
## Additional Info
This is a backwards-compatible change with no impact on consensus.
## Issue Addressed
- Resolves#1706
## Proposed Changes
Updates dependencies across the workspace. Any crate that was not able to be brought to the latest version is listed in #1712.
## Additional Info
NA
This commit was edited by Paul H when rebasing from master to
v0.3.0-staging.
Solution 2 proposed here: https://github.com/sigp/lighthouse/issues/1435#issuecomment-692317639
- Adds an optional `--wss-checkpoint` flag that takes a string `root:epoch`
- Verify that the given checkpoint exists in the chain, or that the the chain syncs through this checkpoint. If not, shutdown and prompt the user to purge state before restarting.
Co-authored-by: Paul Hauner <paul@paulhauner.com>
- Resolves#1550
- Resolves#824
- Resolves#825
- Resolves#1131
- Resolves#1411
- Resolves#1256
- Resolve#1177
- Includes the `ShufflingId` struct initially defined in #1492. That PR is now closed and the changes are included here, with significant bug fixes.
- Implement the https://github.com/ethereum/eth2.0-APIs in a new `http_api` crate using `warp`. This replaces the `rest_api` crate.
- Add a new `common/eth2` crate which provides a wrapper around `reqwest`, providing the HTTP client that is used by the validator client and for testing. This replaces the `common/remote_beacon_node` crate.
- Create a `http_metrics` crate which is a dedicated server for Prometheus metrics (they are no longer served on the same port as the REST API). We now have flags for `--metrics`, `--metrics-address`, etc.
- Allow the `subnet_id` to be an optional parameter for `VerifiedUnaggregatedAttestation::verify`. This means it does not need to be provided unnecessarily by the validator client.
- Move `fn map_attestation_committee` in `mod beacon_chain::attestation_verification` to a new `fn with_committee_cache` on the `BeaconChain` so the same cache can be used for obtaining validator duties.
- Add some other helpers to `BeaconChain` to assist with common API duties (e.g., `block_root_at_slot`, `head_beacon_block_root`).
- Change the `NaiveAggregationPool` so it can index attestations by `hash_tree_root(attestation.data)`. This is a requirement of the API.
- Add functions to `BeaconChainHarness` to allow it to create slashings and exits.
- Allow for `eth1::Eth1NetworkId` to go to/from a `String`.
- Add functions to the `OperationPool` to allow getting all objects in the pool.
- Add function to `BeaconState` to check if a committee cache is initialized.
- Fix bug where `seconds_per_eth1_block` was not transferring over from `YamlConfig` to `ChainSpec`.
- Add the `deposit_contract_address` to `YamlConfig` and `ChainSpec`. We needed to be able to return it in an API response.
- Change some uses of serde `serialize_with` and `deserialize_with` to a single use of `with` (code quality).
- Impl `Display` and `FromStr` for several BLS fields.
- Check for clock discrepancy when VC polls BN for sync state (with +/- 1 slot tolerance). This is not intended to be comprehensive, it was just easy to do.
- See #1434 for a per-endpoint overview.
- Seeking clarity here: https://github.com/ethereum/eth2.0-APIs/issues/75
- [x] Add docs for prom port to close#1256
- [x] Follow up on this #1177
- [x] ~~Follow up with #1424~~ Will fix in future PR.
- [x] Follow up with #1411
- [x] ~~Follow up with #1260~~ Will fix in future PR.
- [x] Add quotes to all integers.
- [x] Remove `rest_types`
- [x] Address missing beacon block error. (#1629)
- [x] ~~Add tests for lighthouse/peers endpoints~~ Wontfix
- [x] ~~Follow up with validator status proposal~~ Tracked in #1434
- [x] Unify graffiti structs
- [x] ~~Start server when waiting for genesis?~~ Will fix in future PR.
- [x] TODO in http_api tests
- [x] Move lighthouse endpoints off /eth/v1
- [x] Update docs to link to standard
- ~~Blocked on #1586~~
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
## Issue Addressed
- Resolves#1616
## Proposed Changes
If we look at the function which persists fork choice and the canonical head to disk:
1db8daae0c/beacon_node/beacon_chain/src/beacon_chain.rs (L234-L280)
There is a race-condition which might cause the canonical head and fork choice values to be out-of-sync.
I believe this is the cause of #1616. I managed to recreate the issue and produce a database that was unable to sync under the `master` branch but able to sync with this branch.
These new changes solve the issue by ignoring the persisted `canonical_head_block_root` value and instead getting fork choice to generate it. This ensures that the canonical head is in-sync with fork choice.
## Additional Info
This is hotfix method that leaves some crusty code hanging around. Once this PR is merged (to satisfy the v0.2.x users) we should later update and merge #1638 so we can have a clean fix for the v0.3.x versions.
## Issue Addressed
- Resolves#1616
## Proposed Changes
Fixes a bug where we are unable to read the finalized block from fork choice.
## Detail
I had made an assumption that the finalized block always has a parent root of `None`:
e5fc6bab48/consensus/fork_choice/src/fork_choice.rs (L749-L752)
This was a faulty assumption, we don't set parent *roots* to `None`. Instead we *sometimes* set parent *indices* to `None`, depending if this pruning condition is satisfied:
e5fc6bab48/consensus/proto_array/src/proto_array.rs (L229-L232)
The bug manifested itself like this:
1. We attempt to get the finalized block from fork choice
1. We try to check that the block is descendant of the finalized block (note: they're the same block).
1. We expect the parent root to be `None`, but it's actually the parent root of the finalized root.
1. We therefore end up checking if the parent of the finalized root is a descendant of itself. (note: it's an *ancestor* not a *descendant*).
1. We therefore declare that the finalized block is not a descendant of (or eq to) the finalized block. Bad.
## Additional Info
In reflection, I made a poor assumption in the quest to obtain a probably negligible performance gain. The performance gain wasn't worth the risk and we got burnt.
The PR:
* Adds the ability to generate a crucial test scenario that isn't possible with `BeaconChainHarness` (i.e. two blocks occupying the same slot; previously forks necessitated skipping slots):
* New testing API: Instead of repeatedly calling add_block(), you generate a sorted `Vec<Slot>` and leave it up to the framework to generate blocks at those slots.
* Jumping backwards to an earlier epoch is a hard error, so that tests necessarily generate blocks in a epoch-by-epoch manner.
* Configures the test logger so that output is printed on the console in case a test fails. The logger also plays well with `--nocapture`, contrary to the existing testing framework
* Rewrites existing fork pruning tests to use the new API
* Adds a tests that triggers finalization at a non epoch boundary slot
* Renamed `BeaconChainYoke` to `BeaconChainTestingRig` because the former has been too confusing
* Fixed multiple tests (e.g. `block_production_different_shuffling_long`, `delete_blocks_and_states`, `shuffling_compatible_simple_fork`) that relied on a weird (and accidental) feature of the old `BeaconChainHarness` that attestations aren't produced for epochs earlier than the current one, thus masking potential bugs in test cases.
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
## Issue Addressed
- Resolves#1451
## Proposed Changes
- Restricts the `contains_block` and `contains_block` so they only indicate a block is present if it descends from the finalized root. This helps to ensure that fork choice never points to a block that has been pruned from the database.
- Resolves#1451
- Before importing a block, double-check that its parent is known and a descendant of the finalized root.
- Split a big, monolithic block verification test into smaller tests.
## Additional Notes
I suspect there would be a craftier way to do the `is_descendant_of_finalized` check, but we're a bit tight on time now and we can optimize later if it starts showing in benches.
## TODO
- [x] Tests
