Commit Graph

173 Commits

Author SHA1 Message Date
Diva M
1b9cfcc11b
Merge branch 'unstable' into eip4844 2023-03-24 13:32:50 -05:00
Paul Hauner
1f8c17b530 Fork choice modifications and cleanup (#3962)
## Issue Addressed

NA

## Proposed Changes

- Implements https://github.com/ethereum/consensus-specs/pull/3290/
- Bumps `ef-tests` to [v1.3.0-rc.4](https://github.com/ethereum/consensus-spec-tests/releases/tag/v1.3.0-rc.4).

The `CountRealizedFull` concept has been removed and the `--count-unrealized-full` and `--count-unrealized` BN flags now do nothing but log a `WARN` when used.

## Database Migration Debt

This PR removes the `best_justified_checkpoint` from fork choice. This field is persisted on-disk and the correct way to go about this would be to make a DB migration to remove the field. However, in this PR I've simply stubbed out the value with a junk value. I've taken this approach because if we're going to do a DB migration I'd love to remove the `Option`s around the justified and finalized checkpoints on `ProtoNode` whilst we're at it. Those options were added in #2822 which was included in Lighthouse v2.1.0. The options were only put there to handle the migration and they've been set to `Some` ever since v2.1.0. There's no reason to keep them as options anymore.

I started adding the DB migration to this branch but I started to feel like I was bloating this rather critical PR with nice-to-haves. I've kept the partially-complete migration [over in my repo](https://github.com/paulhauner/lighthouse/tree/fc-pr-18-migration) so we can pick it up after this PR is merged.
2023-03-21 07:34:41 +00:00
Diva M
d93753cc88
Merge branch 'unstable' into off-4844 2023-03-02 15:38:00 -05:00
Michael Sproul
0b6850221e
Fix Capella schema downgrades (#4004) 2023-02-20 17:50:42 +11:00
Emilia Hane
13efd47238
fixup! Disable use of system time in tests 2023-02-15 09:20:30 +01:00
Emilia Hane
73c7ad73b8
Disable use of system time in tests 2023-02-14 13:33:38 +01:00
realbigsean
ad9af6d8b1
complete match for has_context_bytes 2023-02-13 16:44:54 -05:00
realbigsean
28702c9d5d
merge upstream, add back get_blobs logic 2023-02-13 16:29:21 -05:00
Emilia Hane
2653f88b5f
Fix conflicts rebasing eip4844 2023-02-10 15:35:00 +01:00
Emilia Hane
4d3ff347a3
Fixes after rebasing eip4844 2023-02-10 15:34:58 +01:00
Emilia Hane
e9e198a2b6
Fix conflicts rebasing eip4844 2023-02-10 09:41:23 +01:00
Emilia Hane
d292a3a6a8
Fix conflicts rebasing eip4844 2023-02-10 09:41:23 +01:00
Emilia Hane
994990063a
Fix weak_subjectivity_sync test 2023-02-10 09:41:23 +01:00
Emilia Hane
16cb9cfca2
fixup! Debug tests 2023-02-10 09:39:22 +01:00
Emilia Hane
7220f35ff6
Debug tests 2023-02-10 09:39:21 +01:00
naviechan
9b5c2eefd5 Implement sync_committee_rewards API (per-validator reward) (#3903)
[#3661](https://github.com/sigp/lighthouse/issues/3661)

`/eth/v1/beacon/rewards/sync_committee/{block_id}`

```
{
  "execution_optimistic": false,
  "finalized": false,
  "data": [
    {
      "validator_index": "0",
      "reward": "2000"
    }
  ]
}
```

The issue contains the implementation of three per-validator reward APIs:
* `sync_committee_rewards`
* [`attestation_rewards`](https://github.com/sigp/lighthouse/pull/3822)
* `block_rewards`

This PR only implements the `sync_committe_rewards `.

The endpoints can be viewed in the Ethereum Beacon nodes API browser: [https://ethereum.github.io/beacon-APIs/?urls.primaryName=dev#/Rewards](https://ethereum.github.io/beacon-APIs/?urls.primaryName=dev#/Rewards)

The implementation of [consensus client reward APIs](https://github.com/eth-protocol-fellows/cohort-three/blob/master/projects/project-ideas.md#consensus-client-reward-apis) is part of the [EPF](https://github.com/eth-protocol-fellows/cohort-three).

Co-authored-by: navie <naviechan@gmail.com>
Co-authored-by: kevinbogner <kevbogner@gmail.com>
2023-01-25 14:22:15 +01:00
ethDreamer
eb9da6c837 Use eth1_withdrawal_credentials in Test States (#3898)
* Use eth1_withdrawal_credential in Some Test States

* Update beacon_node/genesis/src/interop.rs

Co-authored-by: Michael Sproul <micsproul@gmail.com>

* Update beacon_node/genesis/src/interop.rs

Co-authored-by: Michael Sproul <micsproul@gmail.com>

* Increase validator sizes

* Pick next sync committee message

Co-authored-by: Michael Sproul <micsproul@gmail.com>
Co-authored-by: Paul Hauner <paul@paulhauner.com>
2023-01-25 14:21:54 +01:00
Michael Sproul
c76a1971cc
Merge remote-tracking branch 'origin/unstable' into capella 2023-01-25 14:20:16 +11:00
ethDreamer
3d4dd6af75
Use eth1_withdrawal_credentials in Test States (#3898)
* Use eth1_withdrawal_credential in Some Test States

* Update beacon_node/genesis/src/interop.rs

Co-authored-by: Michael Sproul <micsproul@gmail.com>

* Update beacon_node/genesis/src/interop.rs

Co-authored-by: Michael Sproul <micsproul@gmail.com>

* Increase validator sizes

* Pick next sync committee message

Co-authored-by: Michael Sproul <micsproul@gmail.com>
Co-authored-by: Paul Hauner <paul@paulhauner.com>
2023-01-24 16:22:51 +01:00
naviechan
2802bc9a9c Implement sync_committee_rewards API (per-validator reward) (#3903)
## Issue Addressed

[#3661](https://github.com/sigp/lighthouse/issues/3661)

## Proposed Changes

`/eth/v1/beacon/rewards/sync_committee/{block_id}`

```
{
  "execution_optimistic": false,
  "finalized": false,
  "data": [
    {
      "validator_index": "0",
      "reward": "2000"
    }
  ]
}
```

The issue contains the implementation of three per-validator reward APIs:
* `sync_committee_rewards`
* [`attestation_rewards`](https://github.com/sigp/lighthouse/pull/3822)
* `block_rewards`

This PR only implements the `sync_committe_rewards `.

The endpoints can be viewed in the Ethereum Beacon nodes API browser: [https://ethereum.github.io/beacon-APIs/?urls.primaryName=dev#/Rewards](https://ethereum.github.io/beacon-APIs/?urls.primaryName=dev#/Rewards)

## Additional Info

The implementation of [consensus client reward APIs](https://github.com/eth-protocol-fellows/cohort-three/blob/master/projects/project-ideas.md#consensus-client-reward-apis) is part of the [EPF](https://github.com/eth-protocol-fellows/cohort-three).

Co-authored-by: navie <naviechan@gmail.com>
Co-authored-by: kevinbogner <kevbogner@gmail.com>
2023-01-24 02:06:42 +00:00
realbigsean
8f8b7211d0
execution API related fixes 2023-01-19 09:32:08 -05:00
ethDreamer
26787412cd
Update engine_api to Latest spec (#3893)
* Update engine_api to Latest spec

* Small Test Fix

* Fix Test Deserialization Issue
2023-01-19 22:42:17 +11:00
realbigsean
06f71e8cce
merge capella 2023-01-12 12:51:09 -05:00
Michael Sproul
aa896decc1 Fix some beacon_chain tests 2023-01-12 19:13:01 +11:00
Michael Sproul
2af8110529
Merge remote-tracking branch 'origin/unstable' into capella
Fixing the conflicts involved patching up some of the `block_hash` verification,
the rest will be done as part of https://github.com/sigp/lighthouse/issues/3870
2023-01-12 16:22:00 +11:00
realbigsean
438126f19a
merge upstream, fix compile errors 2023-01-11 13:52:58 -05:00
Paul Hauner
830efdb5c2 Improve validator monitor experience for high validator counts (#3728)
## Issue Addressed

NA

## Proposed Changes

Myself and others (#3678) have observed  that when running with lots of validators (e.g., 1000s) the cardinality is too much for Prometheus. I've seen Prometheus instances just grind to a halt when we turn the validator monitor on for our testnet validators (we have 10,000s of Goerli validators). Additionally, the debug log volume can get very high with one log per validator, per attestation.

To address this, the `bn --validator-monitor-individual-tracking-threshold <INTEGER>` flag has been added to *disable* per-validator (i.e., non-aggregated) metrics/logging once the validator monitor exceeds the threshold of validators. The default value is `64`, which is a finger-to-the-wind value. I don't actually know the value at which Prometheus starts to become overwhelmed, but I've seen it work with ~64 validators and I've seen it *not* work with 1000s of validators. A default of `64` seems like it will result in a breaking change to users who are running millions of dollars worth of validators whilst resulting in a no-op for low-validator-count users. I'm open to changing this number, though.

Additionally, this PR starts collecting aggregated Prometheus metrics (e.g., total count of head hits across all validators), so that high-validator-count validators still have some interesting metrics. We already had logging for aggregated values, so nothing has been added there.

I've opted to make this a breaking change since it can be rather damaging to your Prometheus instance to accidentally enable the validator monitor with large numbers of validators. I've crashed a Prometheus instance myself and had a report from another user who's done the same thing.

## Additional Info

NA

## Breaking Changes Note

A new label has been added to the validator monitor Prometheus metrics: `total`. This label tracks the aggregated metrics of all validators in the validator monitor (as opposed to each validator being tracking individually using its pubkey as the label).

Additionally, a new flag has been added to the Beacon Node: `--validator-monitor-individual-tracking-threshold`. The default value is `64`, which means that when the validator monitor is tracking more than 64 validators then it will stop tracking per-validator metrics and only track the `all_validators` metric. It will also stop logging per-validator logs and only emit aggregated logs (the exception being that exit and slashing logs are always emitted).

These changes were introduced in #3728 to address issues with untenable Prometheus cardinality and log volume when using the validator monitor with high validator counts (e.g., 1000s of validators). Users with less than 65 validators will see no change in behavior (apart from the added `all_validators` metric). Users with more than 65 validators who wish to maintain the previous behavior can set something like `--validator-monitor-individual-tracking-threshold 999999`.
2023-01-09 08:18:55 +00:00
Mark Mackey
be232c4587
Update Execution Layer Tests for Capella 2023-01-03 16:58:15 -06:00
realbigsean
d893706e0e
merge with capella 2022-12-15 09:33:18 -05:00
Michael Sproul
991e4094f8
Merge remote-tracking branch 'origin/unstable' into capella-update 2022-12-14 13:00:41 +11:00
Michael Sproul
775d222299 Enable proposer boost re-orging (#2860)
## 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>
2022-12-13 09:57:26 +00:00
realbigsean
8102a01085
merge with upstream 2022-12-01 11:13:07 -05:00
Mark Mackey
8a04c3428e Merged with unstable 2022-11-30 17:29:10 -06:00
Mark Mackey
f5e6a54f05 Refactored Execution Layer & Fixed Some Tests 2022-11-29 18:18:33 -06:00
Mark Mackey
36170ec428 Fixed some BeaconChain Tests 2022-11-29 18:18:18 -06:00
GeemoCandama
3534c85e30 Optimize finalized chain sync by skipping newPayload messages (#3738)
## 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.
2022-11-29 08:19:27 +00:00
realbigsean
48b2efce9f
merge with upstream 2022-11-22 18:38:30 -05:00
ethDreamer
24e5252a55
Massive Update to Engine API (#3740)
* Massive Update to Engine API

* Update beacon_node/execution_layer/src/engine_api/json_structures.rs

Co-authored-by: Michael Sproul <micsproul@gmail.com>

* Update beacon_node/execution_layer/src/engine_api/json_structures.rs

Co-authored-by: Michael Sproul <micsproul@gmail.com>

* Update beacon_node/beacon_chain/src/execution_payload.rs

Co-authored-by: realbigsean <seananderson33@GMAIL.com>

* Update beacon_node/execution_layer/src/engine_api.rs

Co-authored-by: realbigsean <seananderson33@GMAIL.com>

Co-authored-by: Michael Sproul <micsproul@gmail.com>
Co-authored-by: realbigsean <seananderson33@GMAIL.com>
2022-11-22 13:27:48 -05:00
realbigsean
dc87156641
block and blob handling progress 2022-11-19 16:53:34 -05:00
Michael Sproul
edf23bb40e Fix attestation shuffling filter (#3629)
## Issue Addressed

Fix a bug in block production that results in blocks with 0 attestations during the first slot of an epoch.

The bug is marked by debug logs of the form:

> DEBG Discarding attestation because of missing ancestor, block_root: 0x3cc00d9c9e0883b2d0db8606278f2b8423d4902f9a1ee619258b5b60590e64f8, pivot_slot: 4042591

It occurs when trying to look up the shuffling decision root for an attestation from a slot which is prior to fork choice's finalized block. This happens frequently when proposing in the first slot of the epoch where we have:

- `current_epoch == n`
- `attestation.data.target.epoch == n - 1`
- attestation shuffling epoch `== n - 3` (decision block being the last block of `n - 3`)
- `state.finalized_checkpoint.epoch == n - 2` (first block of `n - 2` is finalized)

Hence the shuffling decision slot is out of range of the fork choice backwards iterator _by a single slot_.

Unfortunately this bug was hidden when we weren't pruning fork choice, and then reintroduced in v2.5.1 when we fixed the pruning (https://github.com/sigp/lighthouse/releases/tag/v2.5.1). There's no way to turn that off or disable the filtering in our current release, so we need a new release to fix this issue.

Fortunately, it also does not occur on every epoch boundary because of the gradual pruning of fork choice every 256 blocks (~8 epochs):

01e84b71f5/consensus/proto_array/src/proto_array_fork_choice.rs (L16)

01e84b71f5/consensus/proto_array/src/proto_array.rs (L713-L716)

So the probability of proposing a 0-attestation block given a proposal assignment is approximately `1/32 * 1/8 = 0.39%`.

## Proposed Changes

- Load the block's shuffling ID from fork choice and verify it against the expected shuffling ID of the head state. This code was initially written before we had settled on a representation of shuffling IDs, so I think it's a nice simplification to make use of them here rather than more ad-hoc logic that fundamentally does the same thing.

## Additional Info

Thanks to @moshe-blox for noticing this issue and bringing it to our attention.
2022-10-18 04:02:06 +00:00
Michael Sproul
59ec6b71b8 Consensus context with proposer index caching (#3604)
## Issue Addressed

Closes https://github.com/sigp/lighthouse/issues/2371

## Proposed Changes

Backport some changes from `tree-states` that remove duplicated calculations of the `proposer_index`.

With this change the proposer index should be calculated only once for each block, and then plumbed through to every place it is required.

## Additional Info

In future I hope to add more data to the consensus context that is cached on a per-epoch basis, like the effective balances of validators and the base rewards.

There are some other changes to remove indexing in tests that were also useful for `tree-states` (the `tree-states` types don't implement `Index`).
2022-10-15 22:25:54 +00:00
Paul Hauner
9246a92d76 Make garbage collection test less failure prone (#3599)
## Issue Addressed

NA

## Proposed Changes

This PR attempts to fix the following spurious CI failure:

```
---- store_tests::garbage_collect_temp_states_from_failed_block stdout ----
thread 'store_tests::garbage_collect_temp_states_from_failed_block' panicked at 'disk store should initialize: DBError { message: "Error { message: \"IO error: lock /tmp/.tmp6DcBQ9/cold_db/LOCK: already held by process\" }" }', beacon_node/beacon_chain/tests/store_tests.rs:59:10
```

I believe that some async task is taking a clone of the store and holding it in some other thread for a short time. This creates a race-condition when we try to open a new instance of the store.

## Additional Info

NA
2022-09-23 03:52:44 +00:00
Paul Hauner
fa6ad1a11a Deduplicate block root computation (#3590)
## Issue Addressed

NA

## Proposed Changes

This PR removes duplicated block root computation.

Computing the `SignedBeaconBlock::canonical_root` has become more expensive since the merge as we need to compute the merke root of each transaction inside an `ExecutionPayload`.

Computing the root for [a mainnet block](https://beaconcha.in/slot/4704236) is taking ~10ms on my i7-8700K CPU @ 3.70GHz (no sha extensions). Given that our median seen-to-imported time for blocks is presently 300-400ms, removing a few duplicated block roots (~30ms) could represent an easy 10% improvement. When we consider that the seen-to-imported times include operations *after* the block has been placed in the early attester cache, we could expect the 30ms to be more significant WRT our seen-to-attestable times.

## Additional Info

NA
2022-09-23 03:52:42 +00:00
Michael Sproul
ca42ef2e5a Prune finalized execution payloads (#3565)
## Issue Addressed

Closes https://github.com/sigp/lighthouse/issues/3556

## Proposed Changes

Delete finalized execution payloads from the database in two places:

1. When running the finalization migration in `migrate_database`. We delete the finalized payloads between the last split point and the new updated split point. _If_ payloads are already pruned prior to this then this is sufficient to prune _all_ payloads as non-canonical payloads are already deleted by the head pruner, and all canonical payloads prior to the previous split will already have been pruned.
2. To address the fact that users will update to this code _after_ the merge on mainnet (and testnets), we need a one-off scan to delete the finalized payloads from the canonical chain. This is implemented in `try_prune_execution_payloads` which runs on startup and scans the chain back to the Bellatrix fork or the anchor slot (if checkpoint synced after Bellatrix). In the case where payloads are already pruned this check only imposes a single state load for the split state, which shouldn't be _too slow_. Even so, a flag `--prepare-payloads-on-startup=false` is provided to turn this off after it has run the first time, which provides faster start-up times.

There is also a new `lighthouse db prune_payloads` subcommand for users who prefer to run the pruning manually.

## Additional Info

The tests have been updated to not rely on finalized payloads in the database, instead using the `MockExecutionLayer` to reconstruct them. Additionally a check was added to `check_chain_dump` which asserts the non-existence or existence of payloads on disk depending on their slot.
2022-09-17 02:27:01 +00:00
Michael Sproul
66eca1a882 Refactor op pool for speed and correctness (#3312)
## Proposed Changes

This PR has two aims: to speed up attestation packing in the op pool, and to fix bugs in the verification of attester slashings, proposer slashings and voluntary exits. The changes are bundled into a single database schema upgrade (v12).

Attestation packing is sped up by removing several inefficiencies: 

- No more recalculation of `attesting_indices` during packing.
- No (unnecessary) examination of the `ParticipationFlags`: a bitfield suffices. See `RewardCache`.
- No re-checking of attestation validity during packing: the `AttestationMap` provides attestations which are "correct by construction" (I have checked this using Hydra).
- No SSZ re-serialization for the clunky `AttestationId` type (it can be removed in a future release).

So far the speed-up seems to be roughly 2-10x, from 500ms down to 50-100ms.

Verification of attester slashings, proposer slashings and voluntary exits is fixed by:

- Tracking the `ForkVersion`s that were used to verify each message inside the `SigVerifiedOp`. This allows us to quickly re-verify that they match the head state's opinion of what the `ForkVersion` should be at the epoch(s) relevant to the message.
- Storing the `SigVerifiedOp` on disk rather than the raw operation. This allows us to continue track the fork versions after a reboot.

This is mostly contained in this commit 52bb1840ae5c4356a8fc3a51e5df23ed65ed2c7f.

## Additional Info

The schema upgrade uses the justified state to re-verify attestations and compute `attesting_indices` for them. It will drop any attestations that fail to verify, by the logic that attestations are most valuable in the few slots after they're observed, and are probably stale and useless by the time a node restarts. Exits and proposer slashings and similarly re-verified to obtain `SigVerifiedOp`s.

This PR contains a runtime killswitch `--paranoid-block-proposal` which opts out of all the optimisations in favour of closely verifying every included message. Although I'm quite sure that the optimisations are correct this flag could be useful in the event of an unforeseen emergency.

Finally, you might notice that the `RewardCache` appears quite useless in its current form because it is only updated on the hot-path immediately before proposal. My hope is that in future we can shift calls to `RewardCache::update` into the background, e.g. while performing the state advance. It is also forward-looking to `tree-states` compatibility, where iterating and indexing `state.{previous,current}_epoch_participation` is expensive and needs to be minimised.
2022-08-29 09:10:26 +00:00
Pawan Dhananjay
c25934956b Remove INVALID_TERMINAL_BLOCK (#3385)
## Issue Addressed

Resolves #3379 

## Proposed Changes

Remove instances of `InvalidTerminalBlock` in lighthouse and use 
`Invalid {latest_valid_hash: "0x0000000000000000000000000000000000000000000000000000000000000000"}` 
to represent that status.
2022-08-10 07:52:58 +00:00
Michael Sproul
6bc4a2cc91 Update invalid head tests (#3400)
## Proposed Changes

Update the invalid head tests so that they work with the current default fork choice configuration.

Thanks @realbigsean for fixing the persistence test and the EF tests.

Co-authored-by: realbigsean <sean@sigmaprime.io>
2022-08-05 23:41:09 +00:00
Paul Hauner
bcfde6e7df Indicate that invalid blocks are optimistic (#3383)
## Issue Addressed

NA

## Proposed Changes

This PR will make Lighthouse return blocks with invalid payloads via the API with `execution_optimistic = true`. This seems a bit awkward, however I think it's better than returning a 404 or some other error.

Let's consider the case where the only possible head is invalid (#3370 deals with this). In such a scenario all of the duties endpoints will start failing because the head is invalid. I think it would be better if the duties endpoints continue to work, because it's likely that even though the head is invalid the duties are still based upon valid blocks and we want the VC to have them cached. There's no risk to the VC here because we won't actually produce an attestation pointing to an invalid head.

Ultimately, I don't think it's particularly important for us to distinguish between optimistic and invalid blocks on the API. Neither should be trusted and the only *real* reason that we track this is so we can try and fork around the invalid blocks.


## Additional Info

- ~~Blocked on #3370~~
2022-07-30 05:08:57 +00:00
ethDreamer
034260bd99 Initial Commit of Retrospective OTB Verification (#3372)
## Issue Addressed

* #2983 

## Proposed Changes

Basically followed the [instructions laid out here](https://github.com/sigp/lighthouse/issues/2983#issuecomment-1062494947)


Co-authored-by: Paul Hauner <paul@paulhauner.com>
Co-authored-by: ethDreamer <37123614+ethDreamer@users.noreply.github.com>
2022-07-30 00:22:38 +00:00
Paul Hauner
25f0e261cb Don't return errors when fork choice fails (#3370)
## 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.
2022-07-28 13:57:09 +00:00