Commit Graph

668 Commits

Author SHA1 Message Date
Paul Hauner
fe52322088 Implement SSZ union type (#2579)
## 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.
2021-09-25 05:58:36 +00:00
Paul Hauner
be11437c27 Batch BLS verification for attestations (#2399)
## 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.
2021-09-22 08:49:41 +00:00
Michael Sproul
9667dc2f03 Implement checkpoint sync (#2244)
## Issue Addressed

Closes #1891
Closes #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>
2021-09-22 00:37:28 +00:00
Wink Saville
4755d4b236 Update sloggers to v2.0.2 (#2588)
fixes #2584
2021-09-14 06:48:26 +00:00
realbigsean
50321c6671 Updates to make crates publishable (#2472)
## 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>
2021-09-03 01:10:25 +00:00
Pawan Dhananjay
5a3bcd2904 Validator monitor support for sync committees (#2476)
## Issue Addressed

N/A

## Proposed Changes

Add functionality in the validator monitor to provide sync committee related metrics for monitored validators.


Co-authored-by: Michael Sproul <michael@sigmaprime.io>
2021-08-31 23:31:36 +00:00
Paul Hauner
44fa54004c Persist to DB after setting canonical head (#2547)
## Issue Addressed

NA

## Proposed Changes

Missed head votes on attestations is a well-known issue. The primary cause is a block getting set as the head *after* the attestation deadline.

This PR aims to shorten the overall time between "block received" and "block set as head" by:

1. Persisting the head and fork choice *after* setting the canonical head
    - Informal measurements show this takes ~200ms
 1. Pruning the op pool *after* setting the canonical head.
 1. No longer persisting the op pool to disk during `BeaconChain::fork_choice`
     - Informal measurements show this can take up to 1.2s.
     
I also add some metrics to help measure the effect of these changes.
     
Persistence changes like this run the risk of breaking assumptions downstream. However, I have considered these risks and I think we're fine here. I will describe my reasoning for each change.

## Reasoning

### Change 1:  Persisting the head and fork choice *after* setting the canonical head

For (1), although the function is called `persist_head_and_fork_choice`, it only persists:

- Fork choice
- Head tracker
- Genesis block root

Since `BeaconChain::fork_choice_internal` does not modify these values between the original time we were persisting it and the current time, I assert that the change I've made is non-substantial in terms of what ends up on-disk. There's the possibility that some *other* thread has modified fork choice in the extra time we've given it, but that's totally fine.

Since the only time we *read* those values from disk is during startup, I assert that this has no impact during runtime. 

### Change 2: Pruning the op pool after setting the canonical head

Similar to the argument above, we don't modify the op pool during `BeaconChain::fork_choice_internal` so it shouldn't matter when we prune. This change should be non-substantial.

### Change 3: No longer persisting the op pool to disk during `BeaconChain::fork_choice`

This change *is* substantial. With the proposed changes, we'll only be persisting the op pool to disk when we shut down cleanly (i.e., the `BeaconChain` gets dropped). This means we'll save disk IO and time during usual operation, but a `kill -9` or similar "crash" will probably result in an out-of-date op pool when we reboot. An out-of-date op pool can only have an impact when producing blocks or aggregate attestations/sync committees.

I think it's pretty reasonable that a crash might result in an out-of-date op pool, since:

- Crashes are fairly rare. Practically the only time I see LH suffer a full crash is when the OOM killer shows up, and that's a very serious event.
- It's generally quite rare to produce a block/aggregate immediately after a reboot. Just a few slots of runtime is probably enough to have a decent-enough op pool again.

## Additional Info

Credits to @macladson for the timings referenced here.
2021-08-31 04:48:21 +00:00
Michael Sproul
10945e0619 Revert bad blocks on missed fork (#2529)
## 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 🤞
2021-08-30 06:41:31 +00:00
Paul Hauner
f2a8c6229c Metrics and DEBG log for late gossip blocks (#2533)
## Issue Addressed

Which issue # does this PR address?

## Proposed Changes

- Add a counter metric to log when a block is received late from gossip.
- Also push a `DEBG` log for the above condition.
- Use Debug (`?`) instead of Display (`%`) for a bunch of logs in the beacon processor, so we don't have to deal with concatenated block roots.
- Add new ERRO and CRIT to HTTP API to alert users when they're publishing late blocks.

## Additional Info

NA
2021-08-23 00:59:14 +00:00
Michael Sproul
c0a2f501d9 Upgrade dependencies (#2513)
## Proposed Changes

* Consolidate Tokio versions: everything now uses the latest v1.10.0, no more `tokio-compat`.
* Many semver-compatible changes via `cargo update`. Notably this upgrades from the yanked v0.8.0 version of crossbeam-deque which is present in v1.5.0-rc.0
* Many semver incompatible upgrades via `cargo upgrades` and `cargo upgrade --workspace pkg_name`. Notable ommissions:
    - Prometheus, to be handled separately: https://github.com/sigp/lighthouse/issues/2485
    - `rand`, `rand_xorshift`: the libsecp256k1 package requires 0.7.x, so we'll stick with that for now
    - `ethereum-types` is pinned at 0.11.0 because that's what `web3` is using and it seems nice to have just a single version
    
## Additional Info

We still have two versions of `libp2p-core` due to `discv5` depending on the v0.29.0 release rather than `master`. AFAIK it should be OK to release in this state (cc @AgeManning )
2021-08-17 01:00:24 +00:00
Paul Hauner
ceda27371d Ensure doppelganger detects attestations in blocks (#2495)
## Issue Addressed

NA

## Proposed Changes

When testing our (not-yet-released) Doppelganger implementation, I noticed that we aren't detecting attestations included in blocks (only those on the gossip network).

This is because during [block processing](e8c0d1f19b/beacon_node/beacon_chain/src/beacon_chain.rs (L2168)) we only update the `observed_attestations` cache with each attestation, but not the `observed_attesters` cache. This is the correct behaviour when we consider the [p2p spec](https://github.com/ethereum/eth2.0-specs/blob/v1.0.1/specs/phase0/p2p-interface.md):

> [IGNORE] There has been no other valid attestation seen on an attestation subnet that has an identical attestation.data.target.epoch and participating validator index.

We're doing the right thing here and still allowing attestations on gossip that we've seen in a block. However, this doesn't work so nicely for Doppelganger.

To resolve this, I've taken the following steps:

- Add a `observed_block_attesters` cache.
- Rename `observed_attesters` to `observed_gossip_attesters`.

## TODO

- [x] Add a test to ensure a validator that's been seen in a block attestation (but not a gossip attestation) returns `true` for `BeaconChain::validator_seen_at_epoch`.
- [x] Add a test to ensure `observed_block_attesters` isn't polluted via gossip attestations and vice versa. 


Co-authored-by: realbigsean <seananderson33@gmail.com>
2021-08-09 02:43:03 +00:00
Michael Sproul
17a2c778e3 Altair validator client and HTTP API (#2404)
## Proposed Changes

* Implement the validator client and HTTP API changes necessary to support Altair


Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
2021-08-06 00:47:31 +00:00
Pawan Dhananjay
e8c0d1f19b Altair networking (#2300)
## Issue Addressed

Resolves #2278 

## Proposed Changes

Implements the networking components for the Altair hard fork https://github.com/ethereum/eth2.0-specs/blob/dev/specs/altair/p2p-interface.md

## Additional Info

This PR acts as the base branch for networking changes and tracks https://github.com/sigp/lighthouse/pull/2279 . Changes to gossip, rpc and discovery can be separate PRs to be merged here for ease of review.

Co-authored-by: realbigsean <seananderson33@gmail.com>
2021-08-04 01:44:57 +00:00
realbigsean
c5786a8821 Doppelganger detection (#2230)
## Issue Addressed

Resolves #2069 

## Proposed Changes

- Adds a `--doppelganger-detection` flag
- Adds a `lighthouse/seen_validators` endpoint, which will make it so the lighthouse VC is not interopable with other client beacon nodes if the `--doppelganger-detection` flag is used, but hopefully this will become standardized. Relevant Eth2 API repo issue: https://github.com/ethereum/eth2.0-APIs/issues/64
- If the `--doppelganger-detection` flag is used, the VC will wait until the beacon node is synced, and then wait an additional 2 epochs. The reason for this is to make sure the beacon node is able to subscribe to the subnets our validators should be attesting on. I think an alternative would be to have the beacon node subscribe to all subnets for 2+ epochs on startup by default.

## Additional Info

I'd like to add tests and would appreciate feedback. 

TODO:  handle validators started via the API, potentially make this default behavior

Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
Co-authored-by: Paul Hauner <paul@paulhauner.com>
2021-07-31 03:50:52 +00:00
realbigsean
303deb9969 Rust 1.54.0 lints (#2483)
## Issue Addressed

N/A

## Proposed Changes

- Removing a bunch of unnecessary references
- Updated `Error::VariantError` to `Error::Variant`
- There were additional enum variant lints that I ignored, because I thought our variant names were fine
- removed `MonitoredValidator`'s `pubkey` field, because I couldn't find it used anywhere. It looks like we just use the string version of the pubkey (the `id` field) if there is no index

## Additional Info



Co-authored-by: realbigsean <seananderson33@gmail.com>
2021-07-30 01:11:47 +00:00
Paul Hauner
8efd9fc324 Add AttesterCache for attestation production (#2478)
## Issue Addressed

- Resolves #2169

## Proposed Changes

Adds the `AttesterCache` to allow validators to produce attestations for older slots. Presently, some arbitrary restrictions can force validators to receive an error when attesting to a slot earlier than the present one. This can cause attestation misses when there is excessive load on the validator client or time sync issues between the VC and BN.

## Additional Info

NA
2021-07-29 04:38:26 +00:00
Michael Sproul
923486f34c Use bulk verification for sync_aggregate signature (#2415)
## Proposed Changes

Add the `sync_aggregate` from `BeaconBlock` to the bulk signature verifier for blocks. This necessitates a new signature set constructor for the sync aggregate, which is different from the others due to the use of [`eth2_fast_aggregate_verify`](https://github.com/ethereum/eth2.0-specs/blob/v1.1.0-alpha.7/specs/altair/bls.md#eth2_fast_aggregate_verify) for sync aggregates, per [`process_sync_aggregate`](https://github.com/ethereum/eth2.0-specs/blob/v1.1.0-alpha.7/specs/altair/beacon-chain.md#sync-aggregate-processing). I made the choice to return an optional signature set, with `None` representing the case where the signature is valid on account of being the point at infinity (requires no further checking).

To "dogfood" the changes and prevent duplication, the consensus logic now uses the signature set approach as well whenever it is required to verify signatures (which should only be in testing AFAIK). The EF tests pass with the code as it exists currently, but failed before I adapted the `eth2_fast_aggregate_verify` changes (which is good).

As a result of this change Altair block processing should be a little faster, and importantly, we will no longer accidentally verify signatures when replaying blocks, e.g. when replaying blocks from the database.
2021-07-28 05:40:21 +00:00
Paul Hauner
6e3ca48cb9 Cache participating indices for Altair epoch processing (#2416)
## Issue Addressed

NA

## Proposed Changes

This PR addresses two things:

1. Allows the `ValidatorMonitor` to work with Altair states.
1. Optimizes `altair::process_epoch` (see [code](https://github.com/paulhauner/lighthouse/blob/participation-cache/consensus/state_processing/src/per_epoch_processing/altair/participation_cache.rs) for description)

## Breaking Changes

The breaking changes in this PR revolve around one premise:

*After the Altair fork, it's not longer possible (given only a `BeaconState`) to identify if a validator had *any* attestation included during some epoch. The best we can do is see if that validator made the "timely" source/target/head flags.*

Whilst this seems annoying, it's not actually too bad. Finalization is based upon "timely target" attestations, so that's really the most important thing. Although there's *some* value in knowing if a validator had *any* attestation included, it's far more important to know about "timely target" participation, since this is what affects finality and justification.

For simplicity and consistency, I've also removed the ability to determine if *any* attestation was included from metrics and API endpoints. Now, all Altair and non-Altair states will simply report on the head/target attestations.

The following section details where we've removed fields and provides replacement values.

### Breaking Changes: Prometheus Metrics

Some participation metrics have been removed and replaced. Some were removed since they are no longer relevant to Altair (e.g., total attesting balance) and others replaced with gwei values instead of pre-computed values. This provides more flexibility at display-time (e.g., Grafana).

The following metrics were added as replacements:

- `beacon_participation_prev_epoch_head_attesting_gwei_total`
- `beacon_participation_prev_epoch_target_attesting_gwei_total`
- `beacon_participation_prev_epoch_source_attesting_gwei_total`
- `beacon_participation_prev_epoch_active_gwei_total`

The following metrics were removed:

- `beacon_participation_prev_epoch_attester`
   - instead use `beacon_participation_prev_epoch_source_attesting_gwei_total / beacon_participation_prev_epoch_active_gwei_total`.
- `beacon_participation_prev_epoch_target_attester`
   - instead use `beacon_participation_prev_epoch_target_attesting_gwei_total / beacon_participation_prev_epoch_active_gwei_total`.
- `beacon_participation_prev_epoch_head_attester`
   - instead use `beacon_participation_prev_epoch_head_attesting_gwei_total / beacon_participation_prev_epoch_active_gwei_total`.

The `beacon_participation_prev_epoch_attester` endpoint has been removed. Users should instead use the pre-existing `beacon_participation_prev_epoch_target_attester`. 

### Breaking Changes: HTTP API

The `/lighthouse/validator_inclusion/{epoch}/{validator_id}` endpoint loses the following fields:

- `current_epoch_attesting_gwei` (use `current_epoch_target_attesting_gwei` instead)
- `previous_epoch_attesting_gwei` (use `previous_epoch_target_attesting_gwei` instead)

The `/lighthouse/validator_inclusion/{epoch}/{validator_id}` endpoint lose the following fields:

- `is_current_epoch_attester` (use `is_current_epoch_target_attester` instead)
- `is_previous_epoch_attester` (use `is_previous_epoch_target_attester` instead)
- `is_active_in_current_epoch` becomes `is_active_unslashed_in_current_epoch`.
- `is_active_in_previous_epoch` becomes `is_active_unslashed_in_previous_epoch`.

## Additional Info

NA

## TODO

- [x] Deal with total balances
- [x] Update validator_inclusion API
- [ ] Ensure `beacon_participation_prev_epoch_target_attester` and `beacon_participation_prev_epoch_head_attester` work before Altair

Co-authored-by: realbigsean <seananderson33@gmail.com>
2021-07-27 07:01:01 +00:00
Michael Sproul
f5bdca09ff Update to spec v1.1.0-beta.1 (#2460)
## Proposed Changes

Update to the latest version of the Altair spec, which includes new tests and a tweak to the target sync aggregators.

## Additional Info

This change is _not_ required for the imminent Altair devnet, and is waiting on the merge of #2321 to unstable.


Co-authored-by: Paul Hauner <paul@paulhauner.com>
2021-07-27 05:43:35 +00:00
Michael Sproul
84e6d71950 Tree hash caching and optimisations for Altair (#2459)
## Proposed Changes

Remove the remaining Altair `FIXME`s from consensus land.

1. Implement tree hash caching for the participation lists. This required some light type manipulation, including removing the `TreeHash` bound from `CachedTreeHash` which was purely descriptive.
2. Plumb the proposer index through Altair attestation processing, to avoid calculating it for _every_ attestation (potentially 128ms on large networks). This duplicates some work from #2431, but with the aim of getting it in sooner, particularly for the Altair devnets.
3. Removes two FIXMEs related to `superstruct` and cloning, which are unlikely to be particularly detrimental and will be tracked here instead: https://github.com/sigp/superstruct/issues/5
2021-07-23 00:23:53 +00:00
Age Manning
c1d2e35c9e
Bleeding edge discovery (#2435)
* Update discovery banning logic and tokio

* Update to latest discovery

* Shift to latest discovery

* Fmt
2021-07-15 16:43:17 +10:00
realbigsean
a3a7f39b0d [Altair] Sync committee pools (#2321)
Add pools supporting sync committees:
- naive sync aggregation pool
- observed sync contributions pool
- observed sync contributors pool
- observed sync aggregators pool

Add SSZ types and tests related to sync committee signatures.

Co-authored-by: Michael Sproul <michael@sigmaprime.io>
Co-authored-by: realbigsean <seananderson33@gmail.com>
2021-07-15 00:52:02 +00:00
divma
304fb05e44 Maintain attestations that reference unknown blocks (#2319)
## Issue Addressed

#635 

## Proposed Changes
- Keep attestations that reference a block we have not seen for 30secs before being re processed
- If we do import the block before that time elapses, it is reprocessed in that moment
- The first time it fails, do nothing wrt to gossipsub propagation or peer downscoring. If after being re processed it fails, downscore with a `LowToleranceError` and ignore the message.
2021-07-14 05:24:08 +00:00
Paul Hauner
9656ffee7c Metrics for sync aggregate fullness (#2439)
## Issue Addressed

NA

## Proposed Changes

Adds a metric to see how many set bits are in the sync aggregate for each beacon block being imported.

## Additional Info

NA
2021-07-13 02:22:55 +00:00
Paul Hauner
a7b7134abb Return more detail when invalid data is found in the DB during startup (#2445)
## Issue Addressed

- Resolves #2444

## Proposed Changes

Adds some more detail to the error message returned when the `BeaconChainBuilder` is unable to access or decode block/state objects during startup.

## Additional Info

NA
2021-07-12 07:31:27 +00:00
Michael Sproul
b4689e20c6 Altair consensus changes and refactors (#2279)
## 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>
2021-07-09 06:15:32 +00:00
Mac L
406e3921d9 Use forwards iterator for state root lookups (#2422)
## Issue Addressed

#2377 

## Proposed Changes

Implement the same code used for block root lookups (from #2376) to state root lookups in order to improve performance and reduce associated memory spikes (e.g. from certain HTTP API requests).

## Additional Changes

- Tests using `rev_iter_state_roots` and `rev_iter_block_roots` have been refactored to use their `forwards` versions instead.
- The `rev_iter_state_roots` and `rev_iter_block_roots` functions are now unused and have been removed.
- The `state_at_slot` function has been changed to use the `forwards` iterator.

## Additional Info

- Some tests still need to be refactored to use their `forwards_iter` versions. These tests start their iteration from a specific beacon state and thus use the `rev_iter_state_roots_from` and `rev_iter_block_roots_from` functions. If they can be refactored, those functions can also be removed.
2021-07-06 02:38:53 +00:00
realbigsean
b84ff9f793 rust 1.53.0 updates (#2411)
## Issue Addressed

`make lint` failing on rust 1.53.0.

## Proposed Changes

1.53.0 updates

## Additional Info

I haven't figure out why yet, we were now hitting the recursion limit in a few crates. So I had to add `#![recursion_limit = "256"]` in a few places


Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
2021-06-18 05:58:01 +00:00
Michael Sproul
3dc1eb5eb6 Ignore inactive validators in validator monitor (#2396)
## Proposed Changes

A user on Discord (`@ChewsMacRibs`) reported that the validator monitor was logging `WARN Attested to an incorrect head` for their validator while it was awaiting activation.

This PR modifies the monitor so that it ignores inactive validators, by the logic that they are either awaiting activation, or have already exited. Either way, there's no way for an inactive validator to have their attestations included on chain, so no need for the monitor to report on them.

## Additional Info

To reproduce the bug requires registering validator keys manually with `--validator-monitor-pubkeys`. I don't think the bug will present itself with `--validator-monitor-auto`.
2021-06-17 02:10:48 +00:00
realbigsean
b1657a60e9 Reorg events (#2090)
## Issue Addressed

Resolves #2088

## Proposed Changes

Add the `chain_reorg` SSE event topic

## Additional Info


Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: Paul Hauner <paul@paulhauner.com>
2021-06-17 02:10:46 +00:00
Paul Hauner
d34f922c1d Add early check for RPC block relevancy (#2289)
## Issue Addressed

NA

## Proposed Changes

When observing `jemallocator` heap profiles and Grafana, it became clear that Lighthouse is spending significant RAM/CPU on processing blocks from the RPC. On investigation, it seems that we are loading the parent of the block *before* we check to see if the block is already known. This is a big waste of resources.

This PR adds an additional `check_block_relevancy` call as the first thing we do when we try to process a `SignedBeaconBlock` via the RPC (or other similar methods). Ultimately, `check_block_relevancy` will be called again later in the block processing flow. It's a very light function and I don't think trying to optimize it out is worth the risk of a bad block slipping through. 

Also adds a `New RPC block received` info log when we process a new RPC block. This seems like interesting and infrequent info.

## Additional Info

NA
2021-06-02 01:07:27 +00:00
Paul Hauner
4c7bb4984c Use the forwards iterator more often (#2376)
## 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.
2021-05-31 04:18:20 +00:00
ethDreamer
ba55e140ae Enable Compatibility with Windows (#2333)
## Issue Addressed

Windows incompatibility.

## Proposed Changes

On windows, lighthouse needs to default to STDIN as tty doesn't exist. Also Windows uses ACLs for file permissions. So to mirror chmod 600, we will remove every entry in a file's ACL and add only a single SID that is an alias for the file owner.

Beyond that, there were several changes made to different unit tests because windows has slightly different error messages as well as frustrating nuances around killing a process :/

## Additional Info

Tested on my Windows VM and it appears to work, also compiled & tested on Linux with these changes. Permissions look correct on both platforms now. Just waiting for my validator to activate on Prater so I can test running full validator client on windows.

Co-authored-by: ethDreamer <37123614+ethDreamer@users.noreply.github.com>
Co-authored-by: Michael Sproul <micsproul@gmail.com>
2021-05-19 23:05:16 +00:00
ethDreamer
cb47388ad7 Updated to comply with new clippy formatting rules (#2336)
## Issue Addressed

The latest version of Rust has new clippy rules & the codebase isn't up to date with them.

## Proposed Changes

Small formatting changes that clippy tells me are functionally equivalent
2021-05-10 00:53:09 +00:00
Mac L
bacc38c3da Add testing for beacon node and validator client CLI flags (#2311)
## Issue Addressed

N/A

## Proposed Changes

Add unit tests for the various CLI flags associated with the beacon node and validator client. These changes require the addition of two new flags: `dump-config` and `immediate-shutdown`.

## Additional Info

Both `dump-config` and `immediate-shutdown` are marked as hidden since they should only be used in testing and other advanced use cases.
**Note:** This requires changing `main.rs` so that the flags can adjust the program behavior as necessary.

Co-authored-by: Paul Hauner <paul@paulhauner.com>
2021-05-06 00:36:22 +00:00
realbigsean
2c2c443718 404's on API requests for slots that have been skipped or orphaned (#2272)
## Issue Addressed

Resolves #2186

## Proposed Changes

404 for any block-related information on a slot that was skipped or orphaned

Affected endpoints:
- `/eth/v1/beacon/blocks/{block_id}`
- `/eth/v1/beacon/blocks/{block_id}/root`
- `/eth/v1/beacon/blocks/{block_id}/attestations`
- `/eth/v1/beacon/headers/{block_id}`

## Additional Info



Co-authored-by: realbigsean <seananderson33@gmail.com>
2021-04-25 03:59:59 +00:00
Michael Sproul
3b901dc5ec Pack attestations into blocks in parallel (#2307)
## Proposed Changes

Use two instances of max cover when packing attestations into blocks: one for the previous epoch, and one for the current epoch. This reduces the amount of computation done by roughly half due to the `O(n^2)` running time of max cover (`2 * (n/2)^2 = n^2/2`). This should help alleviate some load on block proposal, particularly on Prater.
2021-04-13 05:27:42 +00:00
Paul Hauner
c1203f5e52 Add specific log and metric for delayed blocks (#2308)
## Issue Addressed

NA

## Proposed Changes

- Adds a specific log and metric for when a block is enshrined as head with a delay that will caused bad attestations
    - We *technically* already expose this information, but it's a little tricky to determine during debugging. This makes it nice and explicit.
- Fixes a minor reporting bug with the validator monitor where it was expecting agg. attestations too early (at half-slot rather than two-thirds-slot).

## Additional Info

NA
2021-04-13 02:16:59 +00:00
Paul Hauner
0df7be1814 Add check for aggregate target (#2306)
## Issue Addressed
NA

## Proposed Changes

- Ensure that the [target consistency check](b356f52c5c) is always performed on aggregates.
- Add a regression test.

## Additional Info

NA
2021-04-13 00:24:39 +00:00
Age Manning
aaa14073ff Clean up warnings (#2240)
This is a small PR that cleans up compiler warnings. 

The most controversial change is removing the `data_dir` field from the `BeaconChainBuilder`. 

It was removed because it was never read.


Co-authored-by: Paul Hauner <paul@paulhauner.com>
Co-authored-by: Herman Junge <hermanjunge@protonmail.com>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
2021-04-12 00:57:43 +00:00
Paul Hauner
e7e5878953 Avoid BeaconState clone during metrics scrape (#2298)
## Issue Addressed

Which issue # does this PR address?

## Proposed Changes

Avoids cloning the `BeaconState` each time Prometheus scrapes our metrics (generally every 5s 😱).

I think the original motivation behind this was *"don't hold the lock on the head whilst we do computation on it"*, however I think is flawed since our computation here is so small that it'll be quicker than the clone.

The primary motivation here is to maintain a small memory footprint by holding less in memory (i.e., the cloned `BeaconState`) and to avoid the fragmentation-creep that occurs when cloning the big contiguous slabs of memory in the `BeaconState`.

I also collapsed the active/slashed/withdrawn counters into a single loop to increase efficiency.

## Additional Info

NA
2021-04-07 01:02:56 +00:00
Paul Hauner
03cefd0065 Expand observed attestations capacity (#2266)
## Issue Addressed

NA

## Proposed Changes

I noticed the following error on one of our nodes:

```
Mar 18 00:03:35 ip-xxxx lighthouse-bn[333503]: Mar 18 00:03:35.103 ERRO Unable to validate aggregate            error: ObservedAttestersError(EpochTooLow { epoch: Epoch(23961), lowest_permissible_epoch: Epoch(23962) }), peer_id: 16Uiu2HAm5GL5KzPLhvfg9MBBFSpBqTVGRFSiTg285oezzWcZzwEv
```

The slot during this log was 766,815 (the last slot of the epoch). I believe this is due to an off-by-one error in `observed_attesters` where we were failing to provide enough capacity to store observations from the previous, current and next epochs. See code comments for further reasoning.

Here's a link to the spec: https://github.com/ethereum/eth2.0-specs/blob/v1.0.1/specs/phase0/p2p-interface.md#beacon_aggregate_and_proof

## Additional Info

NA
2021-03-29 23:42:34 +00:00
Paul Hauner
015ab7d0a7 Optimize validator duties (#2243)
## 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>
2021-03-17 05:09:57 +00:00
Michael Sproul
770a2ca030 Fix proposer cache priming upon state advance (#2252)
## Proposed Changes

While investigating an incorrect head + target vote for the epoch boundary block 708544, I noticed that the state advance failed to prime the proposer cache, as per these logs:

```
Mar 09 21:42:47.448 DEBG Subscribing to subnet                   target_slot: 708544, subnet: Y, service: attestation_service
Mar 09 21:49:08.063 DEBG Advanced head state one slot            current_slot: 708543, state_slot: 708544, head_root: 0xaf5e69de09f384ee3b4fb501458b7000c53bb6758a48817894ec3d2b030e3e6f, service: state_advance
Mar 09 21:49:08.063 DEBG Completed state advance                 initial_slot: 708543, advanced_slot: 708544, head_root: 0xaf5e69de09f384ee3b4fb501458b7000c53bb6758a48817894ec3d2b030e3e6f, service: state_advance
Mar 09 21:49:14.787 DEBG Proposer shuffling cache miss           block_slot: 708544, block_root: 0x9b14bf68667ab1d9c35e6fd2c95ff5d609aa9e8cf08e0071988ae4aa00b9f9fe, parent_slot: 708543, parent_root: 0xaf5e69de09f384ee3b4fb501458b7000c53bb6758a48817894ec3d2b030e3e6f, service: beacon
Mar 09 21:49:14.800 DEBG Successfully processed gossip block     root: 0x9b14bf68667ab1d9c35e6fd2c95ff5d609aa9e8cf08e0071988ae4aa00b9f9fe, slot: 708544, graffiti: , service: beacon
Mar 09 21:49:14.800 INFO New block received                      hash: 0x9b14…f9fe, slot: 708544
Mar 09 21:49:14.984 DEBG Head beacon block                       slot: 708544, root: 0x9b14…f9fe, finalized_epoch: 22140, finalized_root: 0x28ec…29a7, justified_epoch: 22141, justified_root: 0x59db…e451, service: beacon
Mar 09 21:49:15.055 INFO Unaggregated attestation                validator: XXXXX, src: api, slot: 708544, epoch: 22142, delay_ms: 53, index: Y, head: 0xaf5e69de09f384ee3b4fb501458b7000c53bb6758a48817894ec3d2b030e3e6f, service: val_mon
Mar 09 21:49:17.001 DEBG Slot timer                              sync_state: Synced, current_slot: 708544, head_slot: 708544, head_block: 0x9b14…f9fe, finalized_epoch: 22140, finalized_root: 0x28ec…29a7, peers: 55, service: slot_notifier
```

The reason for this is that the condition was backwards, so that whole block of code was unreachable.

Looking at the attestations for the block included in the block after, we can see that lots of validators missed it. Some of them may be Lighthouse v1.1.1-v1.2.0-rc.0, but it's probable that they would have missed even with the proposer cache primed, given how late the block 708544 arrived (the cache miss occurred 3.787s after the slot start): https://beaconcha.in/block/708545#attestations
2021-03-10 00:20:50 +00:00
Paul Hauner
e4eb0eb168 Use advanced state for block production (#2241)
## Issue Addressed

NA

## Proposed Changes

- Use the pre-states from #2174 during block production.
    - Running this on Pyrmont shows block production times dropping from ~550ms to ~150ms.
- Create `crit` and `warn` logs when a block is published to the API later than we expect.
    - On mainnet we are issuing a warn if the block is published more than 1s later than the slot start and a crit for more than 3s.
- Rename some methods on the `SnapshotCache` for clarity.
- Add the ability to pass the state root to `BeaconChain::produce_block_on_state` to avoid computing a state root. This is a very common LH optimization.
- Add a metric that tracks how late we broadcast blocks received from the HTTP API. This is *technically* a duplicate of a `ValidatorMonitor` log, but I wanted to have it for the case where we aren't monitoring validators too.
2021-03-04 04:43:31 +00:00
Michael Sproul
363f15f362 Use the database to persist the pubkey cache (#2234)
## Issue Addressed

Closes #1787

## Proposed Changes

* Abstract the `ValidatorPubkeyCache` over a "backing" which is either a file (legacy), or the database.
* Implement a migration from schema v2 to schema v3, whereby the contents of the cache file are copied to the DB, and then the file is deleted. The next release to include this change must be a minor version bump, and we will need to warn users of the inability to downgrade (this is our first DB schema change since mainnet genesis).
* Move the schema migration code from the `store` crate into the `beacon_chain` crate so that it can access the datadir and the `ValidatorPubkeyCache`, etc. It gets injected back into the `store` via a closure (similar to what we do in fork choice).
2021-03-04 01:25:12 +00:00
Paul Hauner
a764c3b247 Handle early blocks (#2155)
## Issue Addressed

NA

## Problem this PR addresses

There's an issue where Lighthouse is banning a lot of peers due to the following sequence of events:

1. Gossip block 0xabc arrives ~200ms early
    - It is propagated across the network, with respect to [`MAXIMUM_GOSSIP_CLOCK_DISPARITY`](https://github.com/ethereum/eth2.0-specs/blob/v1.0.0/specs/phase0/p2p-interface.md#why-is-there-maximum_gossip_clock_disparity-when-validating-slot-ranges-of-messages-in-gossip-subnets).
    - However, it is not imported to our database since the block is early.
2. Attestations for 0xabc arrive, but the block was not imported.
    - The peer that sent the attestation is down-voted.
        - Each unknown-block attestation causes a score loss of 1, the peer is banned at -100.
        - When the peer is on an attestation subnet there can be hundreds of attestations, so the peer is banned quickly (before the missed block can be obtained via rpc).

## Potential solutions

I can think of three solutions to this:

1. Wait for attestation-queuing (#635) to arrive and solve this.
    - Easy
    - Not immediate fix.
    - Whilst this would work, I don't think it's a perfect solution for this particular issue, rather (3) is better.
1. Allow importing blocks with a tolerance of `MAXIMUM_GOSSIP_CLOCK_DISPARITY`.
    - Easy
    - ~~I have implemented this, for now.~~
1. If a block is verified for gossip propagation (i.e., signature verified) and it's within `MAXIMUM_GOSSIP_CLOCK_DISPARITY`, then queue it to be processed at the start of the appropriate slot.
    - More difficult
    - Feels like the best solution, I will try to implement this.
    
    
**This PR takes approach (3).**

## Changes included

- Implement the `block_delay_queue`, based upon a [`DelayQueue`](https://docs.rs/tokio-util/0.6.3/tokio_util/time/delay_queue/struct.DelayQueue.html) which can store blocks until it's time to import them.
- Add a new `DelayedImportBlock` variant to the `beacon_processor::WorkEvent` enum to handle this new event.
- In the `BeaconProcessor`, refactor a `tokio::select!` to a struct with an explicit `Stream` implementation. I experienced some issues with `tokio::select!` in the block delay queue and I also found it hard to debug. I think this explicit implementation is nicer and functionally equivalent (apart from the fact that `tokio::select!` randomly chooses futures to poll, whereas now we're deterministic).
- Add a testing framework to the `beacon_processor` module that tests this new block delay logic. I also tested a handful of other operations in the beacon processor (attns, slashings, exits) since it was super easy to copy-pasta the code from the `http_api` tester.
    - To implement these tests I added the concept of an optional `work_journal_tx` to the `BeaconProcessor` which will spit out a log of events. I used this in the tests to ensure that things were happening as I expect.
    - The tests are a little racey, but it's hard to avoid that when testing timing-based code. If we see CI failures I can revise. I haven't observed *any* failures due to races on my machine or on CI yet.
    - To assist with testing I allowed for directly setting the time on the `ManualSlotClock`.
- I gave the `beacon_processor::Worker` a `Toolbox` for two reasons; (a) it avoids changing tons of function sigs when you want to pass a new object to the worker and (b) it seemed cute.
2021-02-24 03:08:52 +00:00
Paul Hauner
4362ea4f98 Fix false positive "State advance too slow" logs (#2218)
## Issue Addressed

- Resolves #2214

## Proposed Changes

Fix the false positive warning log described in #2214.

## Additional Info

NA
2021-02-21 23:47:53 +00:00
Pawan Dhananjay
4a357c9947 Upgrade rand_core (#2201)
## Issue Addressed

N/A

## Proposed Changes

Upgrade `rand_core` to latest version to fix https://rustsec.org/advisories/RUSTSEC-2021-0023
2021-02-15 20:34:49 +00:00
Paul Hauner
88cc222204 Advance state to next slot after importing block (#2174)
## 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`?~~
2021-02-15 07:17:52 +00:00