lighthouse/beacon_node/http_api/tests/interactive_tests.rs
Michael Sproul b90c0c3fb1 Make re-org strat more cautious and add more config (#4151)
## Proposed Changes

This change attempts to prevent failed re-orgs by:

1. Lowering the re-org cutoff from 2s to 1s. This is informed by a failed re-org attempted by @yorickdowne's node. The failed block was requested in the 1.5-2s window due to a Vouch failure, and failed to propagate to the majority of the network before the attestation deadline at 4s.
2. Allow users to adjust their re-org cutoff depending on observed network conditions and their risk profile. The static 2 second cutoff was too rigid.
3. Add a `--proposer-reorg-disallowed-offsets` flag which can be used to prohibit reorgs at certain slots. This is intended to help workaround an issue whereby reorging blocks at slot 1 are currently taking ~1.6s to propagate on gossip rather than ~500ms. This is suspected to be due to a cache miss in current versions of Prysm, which should be fixed in their next release.

## Additional Info

I'm of two minds about removing the `shuffling_stable` check which checks for blocks at slot 0 in the epoch. If we removed it users would be able to configure Lighthouse to try reorging at slot 0, which likely wouldn't work very well due to interactions with the proposer index cache. I think we could leave it for now and revisit it later.
2023-04-13 07:05:01 +00:00

746 lines
25 KiB
Rust

//! Generic tests that make use of the (newer) `InteractiveApiTester`
use beacon_chain::{
chain_config::{DisallowedReOrgOffsets, ReOrgThreshold},
test_utils::{AttestationStrategy, BlockStrategy, SyncCommitteeStrategy},
};
use eth2::types::DepositContractData;
use execution_layer::{ForkchoiceState, PayloadAttributes};
use http_api::test_utils::InteractiveTester;
use parking_lot::Mutex;
use slot_clock::SlotClock;
use state_processing::{
per_block_processing::get_expected_withdrawals, state_advance::complete_state_advance,
};
use std::collections::HashMap;
use std::sync::Arc;
use std::time::Duration;
use tree_hash::TreeHash;
use types::{
Address, Epoch, EthSpec, ExecPayload, ExecutionBlockHash, ForkName, FullPayload,
MainnetEthSpec, ProposerPreparationData, Slot,
};
type E = MainnetEthSpec;
// Test that the deposit_contract endpoint returns the correct chain_id and address.
// Regression test for https://github.com/sigp/lighthouse/issues/2657
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
async fn deposit_contract_custom_network() {
let validator_count = 24;
let mut spec = E::default_spec();
// Rinkeby, which we don't use elsewhere.
spec.deposit_chain_id = 4;
spec.deposit_network_id = 4;
// Arbitrary contract address.
spec.deposit_contract_address = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa".parse().unwrap();
let tester = InteractiveTester::<E>::new(Some(spec.clone()), validator_count).await;
let client = &tester.client;
let result = client.get_config_deposit_contract().await.unwrap().data;
let expected = DepositContractData {
address: spec.deposit_contract_address,
chain_id: spec.deposit_chain_id,
};
assert_eq!(result, expected);
}
/// Data structure for tracking fork choice updates received by the mock execution layer.
#[derive(Debug, Default)]
struct ForkChoiceUpdates {
updates: HashMap<ExecutionBlockHash, Vec<ForkChoiceUpdateMetadata>>,
}
#[derive(Debug, Clone)]
struct ForkChoiceUpdateMetadata {
received_at: Duration,
state: ForkchoiceState,
payload_attributes: Option<PayloadAttributes>,
}
impl ForkChoiceUpdates {
fn insert(&mut self, update: ForkChoiceUpdateMetadata) {
self.updates
.entry(update.state.head_block_hash)
.or_insert_with(Vec::new)
.push(update);
}
fn contains_update_for(&self, block_hash: ExecutionBlockHash) -> bool {
self.updates.contains_key(&block_hash)
}
/// Find the first fork choice update for `head_block_hash` with payload attributes for a
/// block proposal at `proposal_timestamp`.
fn first_update_with_payload_attributes(
&self,
head_block_hash: ExecutionBlockHash,
proposal_timestamp: u64,
) -> Option<ForkChoiceUpdateMetadata> {
self.updates
.get(&head_block_hash)?
.iter()
.find(|update| {
update
.payload_attributes
.as_ref()
.map_or(false, |payload_attributes| {
payload_attributes.timestamp() == proposal_timestamp
})
})
.cloned()
}
}
pub struct ReOrgTest {
head_slot: Slot,
/// Number of slots between parent block and canonical head.
parent_distance: u64,
/// Number of slots between head block and block proposal slot.
head_distance: u64,
re_org_threshold: u64,
max_epochs_since_finalization: u64,
percent_parent_votes: usize,
percent_empty_votes: usize,
percent_head_votes: usize,
should_re_org: bool,
misprediction: bool,
/// Whether to expect withdrawals to change on epoch boundaries.
expect_withdrawals_change_on_epoch: bool,
/// Epoch offsets to avoid proposing reorg blocks at.
disallowed_offsets: Vec<u64>,
}
impl Default for ReOrgTest {
/// Default config represents a regular easy re-org.
fn default() -> Self {
Self {
head_slot: Slot::new(E::slots_per_epoch() - 2),
parent_distance: 1,
head_distance: 1,
re_org_threshold: 20,
max_epochs_since_finalization: 2,
percent_parent_votes: 100,
percent_empty_votes: 100,
percent_head_votes: 0,
should_re_org: true,
misprediction: false,
expect_withdrawals_change_on_epoch: false,
disallowed_offsets: vec![],
}
}
}
// Test that the beacon node will try to perform proposer boost re-orgs on late blocks when
// configured.
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
pub async fn proposer_boost_re_org_zero_weight() {
proposer_boost_re_org_test(ReOrgTest::default()).await;
}
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
pub async fn proposer_boost_re_org_epoch_boundary() {
proposer_boost_re_org_test(ReOrgTest {
head_slot: Slot::new(E::slots_per_epoch() - 1),
should_re_org: false,
..Default::default()
})
.await;
}
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
pub async fn proposer_boost_re_org_epoch_boundary_skip1() {
// Proposing a block on a boundary after a skip will change the set of expected withdrawals
// sent in the payload attributes.
proposer_boost_re_org_test(ReOrgTest {
head_slot: Slot::new(2 * E::slots_per_epoch() - 2),
head_distance: 2,
should_re_org: false,
expect_withdrawals_change_on_epoch: true,
..Default::default()
})
.await;
}
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
pub async fn proposer_boost_re_org_epoch_boundary_skip32() {
// Propose a block at 64 after a whole epoch of skipped slots.
proposer_boost_re_org_test(ReOrgTest {
head_slot: Slot::new(E::slots_per_epoch() - 1),
head_distance: E::slots_per_epoch() + 1,
should_re_org: false,
expect_withdrawals_change_on_epoch: true,
..Default::default()
})
.await;
}
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
pub async fn proposer_boost_re_org_slot_after_epoch_boundary() {
proposer_boost_re_org_test(ReOrgTest {
head_slot: Slot::new(33),
..Default::default()
})
.await;
}
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
pub async fn proposer_boost_re_org_bad_ffg() {
proposer_boost_re_org_test(ReOrgTest {
head_slot: Slot::new(64 + 22),
should_re_org: false,
..Default::default()
})
.await;
}
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
pub async fn proposer_boost_re_org_no_finality() {
proposer_boost_re_org_test(ReOrgTest {
head_slot: Slot::new(96),
percent_parent_votes: 100,
percent_empty_votes: 0,
percent_head_votes: 100,
should_re_org: false,
..Default::default()
})
.await;
}
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
pub async fn proposer_boost_re_org_finality() {
proposer_boost_re_org_test(ReOrgTest {
head_slot: Slot::new(129),
..Default::default()
})
.await;
}
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
pub async fn proposer_boost_re_org_parent_distance() {
proposer_boost_re_org_test(ReOrgTest {
head_slot: Slot::new(E::slots_per_epoch() - 2),
parent_distance: 2,
should_re_org: false,
..Default::default()
})
.await;
}
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
pub async fn proposer_boost_re_org_head_distance() {
proposer_boost_re_org_test(ReOrgTest {
head_slot: Slot::new(E::slots_per_epoch() - 3),
head_distance: 2,
should_re_org: false,
..Default::default()
})
.await;
}
// Check that a re-org at a disallowed offset fails.
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
pub async fn proposer_boost_re_org_disallowed_offset() {
let offset = 4;
proposer_boost_re_org_test(ReOrgTest {
head_slot: Slot::new(E::slots_per_epoch() + offset - 1),
disallowed_offsets: vec![offset],
should_re_org: false,
..Default::default()
})
.await;
}
// Check that a re-org at the *only* allowed offset succeeds.
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
pub async fn proposer_boost_re_org_disallowed_offset_exact() {
let offset = 4;
let disallowed_offsets = (0..E::slots_per_epoch()).filter(|o| *o != offset).collect();
proposer_boost_re_org_test(ReOrgTest {
head_slot: Slot::new(E::slots_per_epoch() + offset - 1),
disallowed_offsets,
..Default::default()
})
.await;
}
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
pub async fn proposer_boost_re_org_very_unhealthy() {
proposer_boost_re_org_test(ReOrgTest {
head_slot: Slot::new(E::slots_per_epoch() - 1),
parent_distance: 2,
head_distance: 2,
percent_parent_votes: 10,
percent_empty_votes: 10,
percent_head_votes: 10,
should_re_org: false,
..Default::default()
})
.await;
}
/// The head block is late but still receives 30% of the committee vote, leading to a misprediction.
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
pub async fn proposer_boost_re_org_weight_misprediction() {
proposer_boost_re_org_test(ReOrgTest {
percent_empty_votes: 70,
percent_head_votes: 30,
should_re_org: false,
misprediction: true,
..Default::default()
})
.await;
}
/// Run a proposer boost re-org test.
///
/// - `head_slot`: the slot of the canonical head to be reorged
/// - `reorg_threshold`: committee percentage value for reorging
/// - `num_empty_votes`: percentage of comm of attestations for the parent block
/// - `num_head_votes`: number of attestations for the head block
/// - `should_re_org`: whether the proposer should build on the parent rather than the head
pub async fn proposer_boost_re_org_test(
ReOrgTest {
head_slot,
parent_distance,
head_distance,
re_org_threshold,
max_epochs_since_finalization,
percent_parent_votes,
percent_empty_votes,
percent_head_votes,
should_re_org,
misprediction,
expect_withdrawals_change_on_epoch,
disallowed_offsets,
}: ReOrgTest,
) {
assert!(head_slot > 0);
// Test using Capella so that we simulate conditions as similar to mainnet as possible.
let mut spec = ForkName::Capella.make_genesis_spec(E::default_spec());
spec.terminal_total_difficulty = 1.into();
// Ensure there are enough validators to have `attesters_per_slot`.
let attesters_per_slot = 10;
let validator_count = E::slots_per_epoch() as usize * attesters_per_slot;
let all_validators = (0..validator_count).collect::<Vec<usize>>();
let num_initial = head_slot.as_u64().checked_sub(parent_distance + 1).unwrap();
// Check that the required vote percentages can be satisfied exactly using `attesters_per_slot`.
assert_eq!(100 % attesters_per_slot, 0);
let percent_per_attester = 100 / attesters_per_slot;
assert_eq!(percent_parent_votes % percent_per_attester, 0);
assert_eq!(percent_empty_votes % percent_per_attester, 0);
assert_eq!(percent_head_votes % percent_per_attester, 0);
let num_parent_votes = Some(attesters_per_slot * percent_parent_votes / 100);
let num_empty_votes = Some(attesters_per_slot * percent_empty_votes / 100);
let num_head_votes = Some(attesters_per_slot * percent_head_votes / 100);
let tester = InteractiveTester::<E>::new_with_initializer_and_mutator(
Some(spec),
validator_count,
None,
Some(Box::new(move |builder| {
builder
.proposer_re_org_threshold(Some(ReOrgThreshold(re_org_threshold)))
.proposer_re_org_max_epochs_since_finalization(Epoch::new(
max_epochs_since_finalization,
))
.proposer_re_org_disallowed_offsets(
DisallowedReOrgOffsets::new::<E>(disallowed_offsets).unwrap(),
)
})),
)
.await;
let harness = &tester.harness;
let mock_el = harness.mock_execution_layer.as_ref().unwrap();
let execution_ctx = mock_el.server.ctx.clone();
let slot_clock = &harness.chain.slot_clock;
// Move to terminal block.
mock_el.server.all_payloads_valid();
execution_ctx
.execution_block_generator
.write()
.move_to_terminal_block()
.unwrap();
// Send proposer preparation data for all validators.
let proposer_preparation_data = all_validators
.iter()
.map(|i| ProposerPreparationData {
validator_index: *i as u64,
fee_recipient: Address::from_low_u64_be(*i as u64),
})
.collect::<Vec<_>>();
harness
.chain
.execution_layer
.as_ref()
.unwrap()
.update_proposer_preparation(
head_slot.epoch(E::slots_per_epoch()) + 1,
&proposer_preparation_data,
)
.await;
// Create some chain depth. Sign sync committee signatures so validator balances don't dip
// below 32 ETH and become ineligible for withdrawals.
harness.advance_slot();
harness
.extend_chain_with_sync(
num_initial as usize,
BlockStrategy::OnCanonicalHead,
AttestationStrategy::AllValidators,
SyncCommitteeStrategy::AllValidators,
)
.await;
// Start collecting fork choice updates.
let forkchoice_updates = Arc::new(Mutex::new(ForkChoiceUpdates::default()));
let forkchoice_updates_inner = forkchoice_updates.clone();
let chain_inner = harness.chain.clone();
execution_ctx
.hook
.lock()
.set_forkchoice_updated_hook(Box::new(move |state, payload_attributes| {
let received_at = chain_inner.slot_clock.now_duration().unwrap();
let state = ForkchoiceState::from(state);
let payload_attributes = payload_attributes.map(Into::into);
let update = ForkChoiceUpdateMetadata {
received_at,
state,
payload_attributes,
};
forkchoice_updates_inner.lock().insert(update);
None
}));
// We set up the following block graph, where B is a block that arrives late and is re-orged
// by C.
//
// A | B | - |
// ^ | - | C |
let slot_a = Slot::new(num_initial + 1);
let slot_b = slot_a + parent_distance;
let slot_c = slot_b + head_distance;
// We need to transition to at least epoch 2 in order to trigger
// `process_rewards_and_penalties`. This allows us to test withdrawals changes at epoch
// boundaries.
if expect_withdrawals_change_on_epoch {
assert!(
slot_c.epoch(E::slots_per_epoch()) >= 2,
"for withdrawals to change, test must end at an epoch >= 2"
);
}
harness.advance_slot();
let (block_a_root, block_a, state_a) = harness
.add_block_at_slot(slot_a, harness.get_current_state())
.await
.unwrap();
// Attest to block A during slot A.
let (block_a_parent_votes, _) = harness.make_attestations_with_limit(
&all_validators,
&state_a,
state_a.canonical_root(),
block_a_root,
slot_a,
num_parent_votes,
);
harness.process_attestations(block_a_parent_votes);
// Attest to block A during slot B.
for _ in 0..parent_distance {
harness.advance_slot();
}
let (block_a_empty_votes, block_a_attesters) = harness.make_attestations_with_limit(
&all_validators,
&state_a,
state_a.canonical_root(),
block_a_root,
slot_b,
num_empty_votes,
);
harness.process_attestations(block_a_empty_votes);
let remaining_attesters = all_validators
.iter()
.copied()
.filter(|index| !block_a_attesters.contains(index))
.collect::<Vec<_>>();
// Produce block B and process it halfway through the slot.
let (block_b, mut state_b) = harness.make_block(state_a.clone(), slot_b).await;
let block_b_root = block_b.canonical_root();
let obs_time = slot_clock.start_of(slot_b).unwrap() + slot_clock.slot_duration() / 2;
slot_clock.set_current_time(obs_time);
harness.chain.block_times_cache.write().set_time_observed(
block_b_root,
slot_b,
obs_time,
None,
None,
);
harness.process_block_result(block_b.clone()).await.unwrap();
// Add attestations to block B.
let (block_b_head_votes, _) = harness.make_attestations_with_limit(
&remaining_attesters,
&state_b,
state_b.canonical_root(),
block_b_root.into(),
slot_b,
num_head_votes,
);
harness.process_attestations(block_b_head_votes);
let payload_lookahead = harness.chain.config.prepare_payload_lookahead;
let fork_choice_lookahead = Duration::from_millis(500);
while harness.get_current_slot() != slot_c {
let current_slot = harness.get_current_slot();
let next_slot = current_slot + 1;
// Simulate the scheduled call to prepare proposers at 8 seconds into the slot.
harness.advance_to_slot_lookahead(next_slot, payload_lookahead);
harness
.chain
.prepare_beacon_proposer(current_slot)
.await
.unwrap();
// Simulate the scheduled call to fork choice + prepare proposers 500ms before the
// next slot.
harness.advance_to_slot_lookahead(next_slot, fork_choice_lookahead);
harness.chain.recompute_head_at_slot(next_slot).await;
harness
.chain
.prepare_beacon_proposer(current_slot)
.await
.unwrap();
harness.advance_slot();
harness.chain.per_slot_task().await;
}
// Produce block C.
// Advance state_b so we can get the proposer.
assert_eq!(state_b.slot(), slot_b);
let pre_advance_withdrawals = get_expected_withdrawals(&state_b, &harness.chain.spec)
.unwrap()
.to_vec();
complete_state_advance(&mut state_b, None, slot_c, &harness.chain.spec).unwrap();
let proposer_index = state_b
.get_beacon_proposer_index(slot_c, &harness.chain.spec)
.unwrap();
let randao_reveal = harness
.sign_randao_reveal(&state_b, proposer_index, slot_c)
.into();
let unsigned_block_c = tester
.client
.get_validator_blocks(slot_c, &randao_reveal, None)
.await
.unwrap()
.data;
let block_c = harness.sign_beacon_block(unsigned_block_c, &state_b);
if should_re_org {
// Block C should build on A.
assert_eq!(block_c.parent_root(), block_a_root.into());
} else {
// Block C should build on B.
assert_eq!(block_c.parent_root(), block_b_root);
}
// Applying block C should cause it to become head regardless (re-org or continuation).
let block_root_c = harness
.process_block_result(block_c.clone())
.await
.unwrap()
.into();
assert_eq!(harness.head_block_root(), block_root_c);
// Check the fork choice updates that were sent.
let forkchoice_updates = forkchoice_updates.lock();
let block_a_exec_hash = block_a.message().execution_payload().unwrap().block_hash();
let block_b_exec_hash = block_b.message().execution_payload().unwrap().block_hash();
let block_c_timestamp = block_c.message().execution_payload().unwrap().timestamp();
// If we re-orged then no fork choice update for B should have been sent.
assert_eq!(
should_re_org,
!forkchoice_updates.contains_update_for(block_b_exec_hash),
"{block_b_exec_hash:?}"
);
// Check the timing of the first fork choice update with payload attributes for block C.
let c_parent_hash = if should_re_org {
block_a_exec_hash
} else {
block_b_exec_hash
};
let first_update = forkchoice_updates
.first_update_with_payload_attributes(c_parent_hash, block_c_timestamp)
.unwrap();
let payload_attribs = first_update.payload_attributes.as_ref().unwrap();
// Check that withdrawals from the payload attributes match those computed from the parent's
// advanced state.
let expected_withdrawals = if should_re_org {
let mut state_a_advanced = state_a.clone();
complete_state_advance(&mut state_a_advanced, None, slot_c, &harness.chain.spec).unwrap();
get_expected_withdrawals(&state_a_advanced, &harness.chain.spec)
} else {
get_expected_withdrawals(&state_b, &harness.chain.spec)
}
.unwrap()
.to_vec();
let payload_attribs_withdrawals = payload_attribs.withdrawals().unwrap();
assert_eq!(expected_withdrawals, *payload_attribs_withdrawals);
assert!(!expected_withdrawals.is_empty());
if should_re_org
|| expect_withdrawals_change_on_epoch
&& slot_c.epoch(E::slots_per_epoch()) != slot_b.epoch(E::slots_per_epoch())
{
assert_ne!(expected_withdrawals, pre_advance_withdrawals);
}
let lookahead = slot_clock
.start_of(slot_c)
.unwrap()
.checked_sub(first_update.received_at)
.unwrap();
if !misprediction {
assert_eq!(
lookahead,
payload_lookahead,
"lookahead={lookahead:?}, timestamp={}, prev_randao={:?}",
payload_attribs.timestamp(),
payload_attribs.prev_randao(),
);
} else {
// On a misprediction we issue the first fcU 500ms before creating a block!
assert_eq!(
lookahead,
fork_choice_lookahead,
"timestamp={}, prev_randao={:?}",
payload_attribs.timestamp(),
payload_attribs.prev_randao(),
);
}
}
// Test that running fork choice before proposing results in selection of the correct head.
#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
pub async fn fork_choice_before_proposal() {
// Validator count needs to be at least 32 or proposer boost gets set to 0 when computing
// `validator_count // 32`.
let validator_count = 64;
let all_validators = (0..validator_count).collect::<Vec<_>>();
let num_initial: u64 = 31;
let tester = InteractiveTester::<E>::new(None, validator_count).await;
let harness = &tester.harness;
// Create some chain depth.
harness.advance_slot();
harness
.extend_chain(
num_initial as usize,
BlockStrategy::OnCanonicalHead,
AttestationStrategy::AllValidators,
)
.await;
// We set up the following block graph, where B is a block that is temporarily orphaned by C,
// but is then reinstated and built upon by D.
//
// A | B | - | D |
// ^ | - | C |
let slot_a = Slot::new(num_initial);
let slot_b = slot_a + 1;
let slot_c = slot_a + 2;
let slot_d = slot_a + 3;
let state_a = harness.get_current_state();
let (block_b, state_b) = harness.make_block(state_a.clone(), slot_b).await;
let block_root_b = harness
.process_block(slot_b, block_b.canonical_root(), block_b)
.await
.unwrap();
// Create attestations to B but keep them in reserve until after C has been processed.
let attestations_b = harness.make_attestations(
&all_validators,
&state_b,
state_b.tree_hash_root(),
block_root_b,
slot_b,
);
let (block_c, state_c) = harness.make_block(state_a, slot_c).await;
let block_root_c = harness
.process_block(slot_c, block_c.canonical_root(), block_c.clone())
.await
.unwrap();
// Create attestations to C from a small number of validators and process them immediately.
let attestations_c = harness.make_attestations(
&all_validators[..validator_count / 2],
&state_c,
state_c.tree_hash_root(),
block_root_c,
slot_c,
);
harness.process_attestations(attestations_c);
// Apply the attestations to B, but don't re-run fork choice.
harness.process_attestations(attestations_b);
// Due to proposer boost, the head should be C during slot C.
assert_eq!(
harness.chain.canonical_head.cached_head().head_block_root(),
block_root_c.into()
);
// Ensure that building a block via the HTTP API re-runs fork choice and builds block D upon B.
// Manually prod the per-slot task, because the slot timer doesn't run in the background in
// these tests.
harness.advance_slot();
harness.chain.per_slot_task().await;
let proposer_index = state_b
.get_beacon_proposer_index(slot_d, &harness.chain.spec)
.unwrap();
let randao_reveal = harness
.sign_randao_reveal(&state_b, proposer_index, slot_d)
.into();
let block_d = tester
.client
.get_validator_blocks::<E, FullPayload<E>>(slot_d, &randao_reveal, None)
.await
.unwrap()
.data;
// Head is now B.
assert_eq!(
harness.chain.canonical_head.cached_head().head_block_root(),
block_root_b.into()
);
// D's parent is B.
assert_eq!(block_d.parent_root(), block_root_b.into());
}