Integrate proto_array into lighthouse

2026-03-14 10:22:38 +00:00 · 2020-01-14 17:05:59 +11:00
parent 0f9d0ff3b9
commit b8d33ae26b
12 changed files with 259 additions and 345 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -212,11 +212,11 @@ dependencies = [
 "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "lighthouse_bootstrap 0.1.0",
 "lighthouse_metrics 0.1.0",
- "lmd_ghost 0.1.0",
 "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
 "merkle_proof 0.1.0",
 "operation_pool 0.1.0",
 "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "proto_array_fork_choice 0.1.0",
 "rand 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "rayon 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "serde 1.0.104 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -526,7 +526,6 @@ dependencies = [
 "futures 0.1.29 (registry+https://github.com/rust-lang/crates.io-index)",
 "genesis 0.1.0",
 "lighthouse_bootstrap 0.1.0",
- "lmd_ghost 0.1.0",
 "network 0.1.0",
 "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
 "prometheus 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -2396,17 +2395,6 @@ name = "linked-hash-map"
 version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"

-[[package]]
-name = "lmd_ghost"
-version = "0.1.0"
-dependencies = [
- "eth2_ssz 0.1.2",
- "eth2_ssz_derive 0.1.0",
- "itertools 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "types 0.1.0",
-]
-
 [[package]]
 name = "lock_api"
 version = "0.1.5"
@@ -3015,6 +3003,17 @@ dependencies = [
 "spin 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]

+[[package]]
+name = "proto_array_fork_choice"
+version = "0.1.0"
+dependencies = [
+ "eth2_ssz 0.1.2",
+ "eth2_ssz_derive 0.1.0",
+ "itertools 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "types 0.1.0",
+]
+
 [[package]]
 name = "protobuf"
 version = "2.8.1"
@@ -3907,7 +3906,6 @@ dependencies = [
 "integer-sqrt 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "itertools 0.8.2 (registry+https://github.com/rust-lang/crates.io-index)",
 "lazy_static 1.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "lmd_ghost 0.1.0",
 "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
 "merkle_proof 0.1.0",
 "rayon 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
--- a/beacon_node/beacon_chain/Cargo.toml
+++ b/beacon_node/beacon_chain/Cargo.toml
@@ -33,7 +33,6 @@ eth2_ssz_derive = "0.1.0"
 state_processing = { path = "../../eth2/state_processing" }
 tree_hash = "0.1.0"
 types = { path = "../../eth2/types" }
-lmd_ghost = { path = "../../eth2/lmd_ghost" }
 eth1 = { path = "../eth1" }
 websocket_server = { path = "../websocket_server" }
 futures = "0.1.25"
@@ -41,6 +40,7 @@ exit-future = "0.1.3"
 genesis = { path = "../genesis" }
 integer-sqrt = "0.1"
 rand = "0.7.2"
+proto_array_fork_choice = { path = "../../eth2/proto_array_fork_choice" }

 [dev-dependencies]
 tempfile = "3.1.0"
--- a/beacon_node/beacon_chain/src/beacon_chain.rs
+++ b/beacon_node/beacon_chain/src/beacon_chain.rs
@@ -7,7 +7,6 @@ use crate::fork_choice::{Error as ForkChoiceError, ForkChoice};
 use crate::head_tracker::HeadTracker;
 use crate::metrics;
 use crate::persisted_beacon_chain::{PersistedBeaconChain, BEACON_CHAIN_DB_KEY};
-use lmd_ghost::LmdGhost;
 use operation_pool::{OperationPool, PersistedOperationPool};
 use parking_lot::RwLock;
 use slog::{debug, error, info, trace, warn, Logger};
@@ -109,7 +108,6 @@ pub trait BeaconChainTypes: Send + Sync + 'static {
    type Store: store::Store<Self::EthSpec>;
    type StoreMigrator: store::Migrate<Self::Store, Self::EthSpec>;
    type SlotClock: slot_clock::SlotClock;
-    type LmdGhost: LmdGhost<Self::Store, Self::EthSpec>;
    type Eth1Chain: Eth1ChainBackend<Self::EthSpec>;
    type EthSpec: types::EthSpec;
    type EventHandler: EventHandler<Self::EthSpec>;
@@ -1033,7 +1031,6 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
                    error!(
                        self.log,
                        "Add attestation to fork choice failed";
-                        "fork_choice_integrity" => format!("{:?}", self.fork_choice.verify_integrity()),
                        "beacon_block_root" =>  format!("{}", attestation.data.beacon_block_root),
                        "error" => format!("{:?}", e)
                    );
@@ -1366,7 +1363,6 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
            error!(
                self.log,
                "Add block to fork choice failed";
-                "fork_choice_integrity" => format!("{:?}", self.fork_choice.verify_integrity()),
                "block_root" =>  format!("{}", block_root),
                "error" => format!("{:?}", e),
            )
--- a/beacon_node/beacon_chain/src/builder.rs
+++ b/beacon_node/beacon_chain/src/builder.rs
@@ -8,9 +8,9 @@ use crate::{
    ForkChoice,
 };
 use eth1::Config as Eth1Config;
-use lmd_ghost::{LmdGhost, ThreadSafeReducedTree};
 use operation_pool::OperationPool;
 use parking_lot::RwLock;
+use proto_array_fork_choice::ProtoArrayForkChoice;
 use slog::{info, Logger};
 use slot_clock::{SlotClock, TestingSlotClock};
 use std::marker::PhantomData;
@@ -21,42 +21,23 @@ use types::{BeaconBlock, BeaconState, ChainSpec, EthSpec, Hash256, Slot};

 /// An empty struct used to "witness" all the `BeaconChainTypes` traits. It has no user-facing
 /// functionality and only exists to satisfy the type system.
-pub struct Witness<
-    TStore,
-    TStoreMigrator,
-    TSlotClock,
-    TLmdGhost,
-    TEth1Backend,
-    TEthSpec,
-    TEventHandler,
->(
+pub struct Witness<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>(
    PhantomData<(
        TStore,
        TStoreMigrator,
        TSlotClock,
-        TLmdGhost,
        TEth1Backend,
        TEthSpec,
        TEventHandler,
    )>,
 );

-impl<TStore, TStoreMigrator, TSlotClock, TLmdGhost, TEth1Backend, TEthSpec, TEventHandler>
-    BeaconChainTypes
-    for Witness<
-        TStore,
-        TStoreMigrator,
-        TSlotClock,
-        TLmdGhost,
-        TEth1Backend,
-        TEthSpec,
-        TEventHandler,
-    >
+impl<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler> BeaconChainTypes
+    for Witness<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>
 where
    TStore: Store<TEthSpec> + 'static,
    TStoreMigrator: store::Migrate<TStore, TEthSpec> + 'static,
    TSlotClock: SlotClock + 'static,
-    TLmdGhost: LmdGhost<TStore, TEthSpec> + 'static,
    TEth1Backend: Eth1ChainBackend<TEthSpec> + 'static,
    TEthSpec: EthSpec + 'static,
    TEventHandler: EventHandler<TEthSpec> + 'static,
@@ -64,7 +45,6 @@ where
    type Store = TStore;
    type StoreMigrator = TStoreMigrator;
    type SlotClock = TSlotClock;
-    type LmdGhost = TLmdGhost;
    type Eth1Chain = TEth1Backend;
    type EthSpec = TEthSpec;
    type EventHandler = TEventHandler;
@@ -96,23 +76,14 @@ pub struct BeaconChainBuilder<T: BeaconChainTypes> {
    log: Option<Logger>,
 }

-impl<TStore, TStoreMigrator, TSlotClock, TLmdGhost, TEth1Backend, TEthSpec, TEventHandler>
+impl<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>
    BeaconChainBuilder<
-        Witness<
-            TStore,
-            TStoreMigrator,
-            TSlotClock,
-            TLmdGhost,
-            TEth1Backend,
-            TEthSpec,
-            TEventHandler,
-        >,
+        Witness<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>,
    >
 where
    TStore: Store<TEthSpec> + 'static,
    TStoreMigrator: store::Migrate<TStore, TEthSpec> + 'static,
    TSlotClock: SlotClock + 'static,
-    TLmdGhost: LmdGhost<TStore, TEthSpec> + 'static,
    TEth1Backend: Eth1ChainBackend<TEthSpec> + 'static,
    TEthSpec: EthSpec + 'static,
    TEventHandler: EventHandler<TEthSpec> + 'static,
@@ -192,15 +163,7 @@ where

        let key = Hash256::from_slice(&BEACON_CHAIN_DB_KEY.as_bytes());
        let p: PersistedBeaconChain<
-            Witness<
-                TStore,
-                TStoreMigrator,
-                TSlotClock,
-                TLmdGhost,
-                TEth1Backend,
-                TEthSpec,
-                TEventHandler,
-            >,
+            Witness<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>,
        > = match store.get(&key) {
            Err(e) => {
                return Err(format!(
@@ -315,15 +278,7 @@ where
        self,
    ) -> Result<
        BeaconChain<
-            Witness<
-                TStore,
-                TStoreMigrator,
-                TSlotClock,
-                TLmdGhost,
-                TEth1Backend,
-                TEthSpec,
-                TEventHandler,
-            >,
+            Witness<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>,
        >,
        String,
    > {
@@ -393,15 +348,7 @@ where

 impl<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>
    BeaconChainBuilder<
-        Witness<
-            TStore,
-            TStoreMigrator,
-            TSlotClock,
-            ThreadSafeReducedTree<TStore, TEthSpec>,
-            TEth1Backend,
-            TEthSpec,
-            TEventHandler,
-        >,
+        Witness<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>,
    >
 where
    TStore: Store<TEthSpec> + 'static,
@@ -416,17 +363,9 @@ where
    /// If this builder is being "resumed" from disk, then rebuild the last fork choice stored to
    /// the database. Otherwise, create a new, empty fork choice.
    pub fn reduced_tree_fork_choice(mut self) -> Result<Self, String> {
-        let store = self
-            .store
-            .clone()
-            .ok_or_else(|| "reduced_tree_fork_choice requires a store")?;
-
        let fork_choice = if let Some(persisted_beacon_chain) = &self.persisted_beacon_chain {
-            ForkChoice::from_ssz_container(
-                persisted_beacon_chain.fork_choice.clone(),
-                store.clone(),
-            )
-            .map_err(|e| format!("Unable to decode fork choice from db: {:?}", e))?
+            ForkChoice::from_ssz_container(persisted_beacon_chain.fork_choice.clone())
+                .map_err(|e| format!("Unable to decode fork choice from db: {:?}", e))?
        } else {
            let finalized_checkpoint = &self
                .finalized_checkpoint
@@ -436,13 +375,21 @@ where
                .genesis_block_root
                .ok_or_else(|| "fork_choice_backend requires a genesis_block_root")?;

-            let backend = ThreadSafeReducedTree::new(
-                store.clone(),
-                &finalized_checkpoint.beacon_block,
+            let backend = ProtoArrayForkChoice::new(
+                // Note: here we set the `justified_epoch` to be the same as the epoch of the
+                // finalized checkpoint. Whilst this finalized checkpoint may actually point to
+                // a _later_ justified checkpoint, that checkpoint won't yet exist in the fork
+                // choice.
+                finalized_checkpoint.beacon_state.current_epoch(),
+                finalized_checkpoint.beacon_state.current_epoch(),
                finalized_checkpoint.beacon_block_root,
-            );
+            )?;

-            ForkChoice::new(store, backend, genesis_block_root, self.spec.genesis_slot)
+            ForkChoice::new(
+                backend,
+                genesis_block_root,
+                &finalized_checkpoint.beacon_state,
+            )
        };

        self.fork_choice = Some(fork_choice);
@@ -451,13 +398,12 @@ where
    }
 }

-impl<TStore, TStoreMigrator, TSlotClock, TLmdGhost, TEthSpec, TEventHandler>
+impl<TStore, TStoreMigrator, TSlotClock, TEthSpec, TEventHandler>
    BeaconChainBuilder<
        Witness<
            TStore,
            TStoreMigrator,
            TSlotClock,
-            TLmdGhost,
            CachingEth1Backend<TEthSpec, TStore>,
            TEthSpec,
            TEventHandler,
@@ -467,7 +413,6 @@ where
    TStore: Store<TEthSpec> + 'static,
    TStoreMigrator: store::Migrate<TStore, TEthSpec> + 'static,
    TSlotClock: SlotClock + 'static,
-    TLmdGhost: LmdGhost<TStore, TEthSpec> + 'static,
    TEthSpec: EthSpec + 'static,
    TEventHandler: EventHandler<TEthSpec> + 'static,
 {
@@ -503,22 +448,13 @@ where
    }
 }

-impl<TStore, TStoreMigrator, TLmdGhost, TEth1Backend, TEthSpec, TEventHandler>
+impl<TStore, TStoreMigrator, TEth1Backend, TEthSpec, TEventHandler>
    BeaconChainBuilder<
-        Witness<
-            TStore,
-            TStoreMigrator,
-            TestingSlotClock,
-            TLmdGhost,
-            TEth1Backend,
-            TEthSpec,
-            TEventHandler,
-        >,
+        Witness<TStore, TStoreMigrator, TestingSlotClock, TEth1Backend, TEthSpec, TEventHandler>,
    >
 where
    TStore: Store<TEthSpec> + 'static,
    TStoreMigrator: store::Migrate<TStore, TEthSpec> + 'static,
-    TLmdGhost: LmdGhost<TStore, TEthSpec> + 'static,
    TEth1Backend: Eth1ChainBackend<TEthSpec> + 'static,
    TEthSpec: EthSpec + 'static,
    TEventHandler: EventHandler<TEthSpec> + 'static,
@@ -544,13 +480,12 @@ where
    }
 }

-impl<TStore, TStoreMigrator, TSlotClock, TLmdGhost, TEth1Backend, TEthSpec>
+impl<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec>
    BeaconChainBuilder<
        Witness<
            TStore,
            TStoreMigrator,
            TSlotClock,
-            TLmdGhost,
            TEth1Backend,
            TEthSpec,
            NullEventHandler<TEthSpec>,
@@ -560,7 +495,6 @@ where
    TStore: Store<TEthSpec> + 'static,
    TStoreMigrator: store::Migrate<TStore, TEthSpec> + 'static,
    TSlotClock: SlotClock + 'static,
-    TLmdGhost: LmdGhost<TStore, TEthSpec> + 'static,
    TEth1Backend: Eth1ChainBackend<TEthSpec> + 'static,
    TEthSpec: EthSpec + 'static,
 {
--- a/beacon_node/beacon_chain/src/fork_choice.rs
+++ b/beacon_node/beacon_chain/src/fork_choice.rs
@@ -1,12 +1,13 @@
 use crate::{errors::BeaconChainError, metrics, BeaconChain, BeaconChainTypes};
-use lmd_ghost::LmdGhost;
 use parking_lot::RwLock;
+use proto_array_fork_choice::ProtoArrayForkChoice;
 use ssz_derive::{Decode, Encode};
-use state_processing::{common::get_attesting_indices, per_slot_processing};
-use std::sync::Arc;
-use store::{Error as StoreError, Store};
+use state_processing::common::get_attesting_indices;
+use std::marker::PhantomData;
+use store::Error as StoreError;
 use types::{
-    Attestation, BeaconBlock, BeaconState, BeaconStateError, Checkpoint, EthSpec, Hash256, Slot,
+    Attestation, BeaconBlock, BeaconState, BeaconStateError, Checkpoint, Epoch, EthSpec, Hash256,
+    Slot,
 };

 type Result<T> = std::result::Result<T, Error>;
@@ -21,18 +22,142 @@ pub enum Error {
    BeaconChainError(Box<BeaconChainError>),
 }

+#[derive(PartialEq, Clone, Encode, Decode)]
+struct CheckpointBalances {
+    epoch: Epoch,
+    root: Hash256,
+    balances: Vec<u64>,
+}
+
+impl Into<Checkpoint> for CheckpointBalances {
+    fn into(self) -> Checkpoint {
+        Checkpoint {
+            epoch: self.epoch,
+            root: self.root,
+        }
+    }
+}
+
+#[derive(PartialEq, Clone, Encode, Decode)]
+struct JustificationManager {
+    /// The fork choice rule's current view of the justified checkpoint.
+    justified_checkpoint: CheckpointBalances,
+    /// The best justified checkpoint we've seen, which may be ahead of `justified_checkpoint`.
+    best_justified_checkpoint: CheckpointBalances,
+    /// If `Some`, the justified checkpoint should be updated at this epoch (or later).
+    update_justified_checkpoint_at: Option<Epoch>,
+}
+
+impl JustificationManager {
+    pub fn new(genesis_checkpoint: CheckpointBalances) -> Self {
+        Self {
+            justified_checkpoint: genesis_checkpoint.clone(),
+            best_justified_checkpoint: genesis_checkpoint.clone(),
+            update_justified_checkpoint_at: None,
+        }
+    }
+
+    pub fn update<T: BeaconChainTypes>(&mut self, chain: &BeaconChain<T>) -> Result<()> {
+        if self.best_justified_checkpoint.epoch > self.justified_checkpoint.epoch {
+            let current_slot = chain.slot()?;
+            let current_epoch = current_slot.epoch(T::EthSpec::slots_per_epoch());
+
+            match self.update_justified_checkpoint_at {
+                None => {
+                    if Self::compute_slots_since_epoch_start::<T>(current_slot)
+                        < chain.spec.safe_slots_to_update_justified
+                    {
+                        self.justified_checkpoint = self.best_justified_checkpoint.clone();
+                    } else {
+                        self.update_justified_checkpoint_at = Some(current_epoch + 1)
+                    }
+                }
+                Some(epoch) if epoch <= current_epoch => {
+                    self.justified_checkpoint = self.best_justified_checkpoint.clone();
+                    self.update_justified_checkpoint_at = None
+                }
+                _ => {}
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Checks the given `state` to see if it contains a `current_justified_checkpoint` that is
+    /// better than `self.best_justified_checkpoint`. If so, the value is updated.
+    ///
+    /// Note: this does not update `self.justified_checkpoint`.
+    pub fn process_state<T: BeaconChainTypes>(
+        &mut self,
+        state: &BeaconState<T::EthSpec>,
+        chain: &BeaconChain<T>,
+    ) -> Result<()> {
+        let new_checkpoint = &state.current_justified_checkpoint;
+
+        // Only proceeed if the new checkpoint is better than our best checkpoint.
+        if new_checkpoint.epoch > self.best_justified_checkpoint.epoch {
+            // From the given state, read the block root at first slot of
+            // `self.justified_checkpoint.epoch`. If that root matches, then
+            // `new_justified_checkpoint` is a descendant of `self.justified_checkpoint` and we may
+            // proceed (see next `if` statement).
+            let new_checkpoint_ancestor = Self::get_block_root_at_slot(
+                state,
+                chain,
+                new_checkpoint.root,
+                self.justified_checkpoint
+                    .epoch
+                    .start_slot(T::EthSpec::slots_per_epoch()),
+            )?;
+
+            if new_checkpoint_ancestor == Some(self.justified_checkpoint.root) {
+                self.best_justified_checkpoint = CheckpointBalances {
+                    epoch: state.current_justified_checkpoint.epoch,
+                    root: state.current_justified_checkpoint.root,
+                    balances: state.balances.clone().into(),
+                };
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Attempts to get the block root for the given `slot`.
+    ///
+    /// First, the `state` is used to see if the slot is within the distance of its historical
+    /// lists. Then, the `chain` is used which will anchor the search at the given
+    /// `justified_root`.
+    fn get_block_root_at_slot<T: BeaconChainTypes>(
+        state: &BeaconState<T::EthSpec>,
+        chain: &BeaconChain<T>,
+        justified_root: Hash256,
+        slot: Slot,
+    ) -> Result<Option<Hash256>> {
+        match state.get_block_root(slot) {
+            Ok(root) => Ok(Some(*root)),
+            Err(_) => chain
+                .get_ancestor_block_root(justified_root, slot)
+                .map_err(Into::into),
+        }
+    }
+
+    /// Calculate how far `slot` lies from the start of its epoch.
+    fn compute_slots_since_epoch_start<T: BeaconChainTypes>(slot: Slot) -> u64 {
+        let slots_per_epoch = T::EthSpec::slots_per_epoch();
+        (slot - slot.epoch(slots_per_epoch).start_slot(slots_per_epoch)).as_u64()
+    }
+}
+
 pub struct ForkChoice<T: BeaconChainTypes> {
-    store: Arc<T::Store>,
-    backend: T::LmdGhost,
+    backend: ProtoArrayForkChoice,
    /// Used for resolving the `0x00..00` alias back to genesis.
    ///
    /// Does not necessarily need to be the _actual_ genesis, it suffices to be the finalized root
    /// whenever the struct was instantiated.
    genesis_block_root: Hash256,
-    /// The fork choice rule's current view of the justified checkpoint.
-    justified_checkpoint: RwLock<Checkpoint>,
-    /// The best justified checkpoint we've seen, which may be ahead of `justified_checkpoint`.
-    best_justified_checkpoint: RwLock<Checkpoint>,
+    /// The fork choice rule's current view of the finalized checkpoint.
+    finalized_checkpoint: RwLock<Checkpoint>,
+    justification_manager: RwLock<JustificationManager>,
+    _phantom: PhantomData<T>,
 }

 impl<T: BeaconChainTypes> PartialEq for ForkChoice<T> {
@@ -40,8 +165,8 @@ impl<T: BeaconChainTypes> PartialEq for ForkChoice<T> {
    fn eq(&self, other: &Self) -> bool {
        self.backend == other.backend
            && self.genesis_block_root == other.genesis_block_root
-            && *self.justified_checkpoint.read() == *other.justified_checkpoint.read()
-            && *self.best_justified_checkpoint.read() == *other.best_justified_checkpoint.read()
+            && *self.justification_manager.read() == *other.justification_manager.read()
+            && *self.finalized_checkpoint.read() == *other.finalized_checkpoint.read()
    }
 }

@@ -51,128 +176,49 @@ impl<T: BeaconChainTypes> ForkChoice<T> {
    /// "Genesis" does not necessarily need to be the absolute genesis, it can be some finalized
    /// block.
    pub fn new(
-        store: Arc<T::Store>,
-        backend: T::LmdGhost,
+        backend: ProtoArrayForkChoice,
        genesis_block_root: Hash256,
-        genesis_slot: Slot,
+        genesis_state: &BeaconState<T::EthSpec>,
    ) -> Self {
-        let justified_checkpoint = Checkpoint {
-            epoch: genesis_slot.epoch(T::EthSpec::slots_per_epoch()),
+        let genesis_checkpoint = CheckpointBalances {
+            epoch: genesis_state.current_epoch(),
            root: genesis_block_root,
+            balances: genesis_state.balances.clone().into(),
        };
+
        Self {
-            store: store.clone(),
            backend,
            genesis_block_root,
-            justified_checkpoint: RwLock::new(justified_checkpoint.clone()),
-            best_justified_checkpoint: RwLock::new(justified_checkpoint),
+            justification_manager: RwLock::new(JustificationManager::new(
+                genesis_checkpoint.clone(),
+            )),
+            finalized_checkpoint: RwLock::new(genesis_checkpoint.into()),
+            _phantom: PhantomData,
        }
    }

-    /// Determine whether the fork choice's view of the justified checkpoint should be updated.
-    ///
-    /// To prevent the bouncing attack, an update is allowed only in these conditions:
-    ///
-    /// * We're in the first SAFE_SLOTS_TO_UPDATE_JUSTIFIED slots of the epoch, or
-    /// * The new justified checkpoint is a descendant of the current justified checkpoint
-    fn should_update_justified_checkpoint(
-        &self,
-        chain: &BeaconChain<T>,
-        new_justified_checkpoint: &Checkpoint,
-    ) -> Result<bool> {
-        if Self::compute_slots_since_epoch_start(chain.slot()?)
-            < chain.spec.safe_slots_to_update_justified
-        {
-            return Ok(true);
-        }
-
-        let justified_checkpoint = self.justified_checkpoint.read().clone();
-
-        let current_justified_block = chain
-            .get_block(&justified_checkpoint.root)?
-            .ok_or_else(|| Error::MissingBlock(justified_checkpoint.root))?;
-
-        let new_justified_block = chain
-            .get_block(&new_justified_checkpoint.root)?
-            .ok_or_else(|| Error::MissingBlock(new_justified_checkpoint.root))?;
-
-        let slots_per_epoch = T::EthSpec::slots_per_epoch();
-
-        Ok(
-            new_justified_block.slot > justified_checkpoint.epoch.start_slot(slots_per_epoch)
-                && chain.get_ancestor_block_root(
-                    new_justified_checkpoint.root,
-                    current_justified_block.slot,
-                )? == Some(justified_checkpoint.root),
-        )
-    }
-
-    /// Calculate how far `slot` lies from the start of its epoch.
-    fn compute_slots_since_epoch_start(slot: Slot) -> u64 {
-        let slots_per_epoch = T::EthSpec::slots_per_epoch();
-        (slot - slot.epoch(slots_per_epoch).start_slot(slots_per_epoch)).as_u64()
-    }
-
    /// Run the fork choice rule to determine the head.
    pub fn find_head(&self, chain: &BeaconChain<T>) -> Result<Hash256> {
        let timer = metrics::start_timer(&metrics::FORK_CHOICE_FIND_HEAD_TIMES);

-        let (start_state, start_block_root, start_block_slot) = {
-            // Check if we should update our view of the justified checkpoint.
-            // Doing this check here should be quasi-equivalent to the update in the `on_tick`
-            // function of the spec, so long as `find_head` is called at least once during the first
-            // SAFE_SLOTS_TO_UPDATE_JUSTIFIED slots.
-            let best_justified_checkpoint = self.best_justified_checkpoint.read();
-            if self.should_update_justified_checkpoint(chain, &best_justified_checkpoint)? {
-                *self.justified_checkpoint.write() = best_justified_checkpoint.clone();
-            }
+        self.justification_manager.write().update(chain)?;

-            let current_justified_checkpoint = self.justified_checkpoint.read().clone();
-
-            let (block_root, block_justified_slot) = (
-                current_justified_checkpoint.root,
-                current_justified_checkpoint
-                    .epoch
-                    .start_slot(T::EthSpec::slots_per_epoch()),
-            );
-
-            let block = chain
-                .store
-                .get::<BeaconBlock<T::EthSpec>>(&block_root)?
-                .ok_or_else(|| Error::MissingBlock(block_root))?;
-
-            // Resolve the `0x00.. 00` alias back to genesis
-            let block_root = if block_root == Hash256::zero() {
-                self.genesis_block_root
-            } else {
-                block_root
-            };
-
-            let mut state: BeaconState<T::EthSpec> = chain
-                .store
-                .get_state(&block.state_root, Some(block.slot))?
-                .ok_or_else(|| Error::MissingState(block.state_root))?;
-
-            // Fast-forward the state to the start slot of the epoch where it was justified.
-            for _ in block.slot.as_u64()..block_justified_slot.as_u64() {
-                per_slot_processing(&mut state, None, &chain.spec)
-                    .map_err(BeaconChainError::SlotProcessingError)?
-            }
-
-            (state, block_root, block_justified_slot)
-        };
-
-        // A function that returns the weight for some validator index.
-        let weight = |validator_index: usize| -> Option<u64> {
-            start_state
-                .validators
-                .get(validator_index)
-                .map(|v| v.effective_balance)
-        };
+        let justified_checkpoint = self
+            .justification_manager
+            .read()
+            .justified_checkpoint
+            .clone();
+        let finalized_checkpoint = self.finalized_checkpoint.read();

        let result = self
            .backend
-            .find_head(start_block_slot, start_block_root, weight)
+            .find_head(
+                justified_checkpoint.epoch,
+                justified_checkpoint.root,
+                finalized_checkpoint.epoch,
+                finalized_checkpoint.root,
+                &justified_checkpoint.balances,
+            )
            .map_err(Into::into);

        metrics::stop_timer(timer);
@@ -192,39 +238,32 @@ impl<T: BeaconChainTypes> ForkChoice<T> {
        block_root: Hash256,
    ) -> Result<()> {
        let timer = metrics::start_timer(&metrics::FORK_CHOICE_PROCESS_BLOCK_TIMES);
-        // Note: we never count the block as a latest message, only attestations.
-        //
-        // I (Paul H) do not have an explicit reference to this, but I derive it from this
-        // document:
-        //
-        // https://github.com/ethereum/eth2.0-specs/blob/v0.7.0/specs/core/0_fork-choice.md
-        for attestation in &block.body.attestations {
-            // If the `data.beacon_block_root` block is not known to us, simply ignore the latest
-            // vote.
-            if let Some(block) = self
-                .store
-                .get::<BeaconBlock<T::EthSpec>>(&attestation.data.beacon_block_root)?
-            {
-                self.process_attestation(state, attestation, &block)?;
-            }
-        }

-        // Check if we should update our view of the justified checkpoint
-        if state.current_justified_checkpoint.epoch > self.justified_checkpoint.read().epoch {
-            *self.best_justified_checkpoint.write() = state.current_justified_checkpoint.clone();
+        self.justification_manager
+            .write()
+            .process_state(state, chain)?;
+        self.justification_manager.write().update(chain)?;
+
+        // Note: we never count the block as a latest message, only attestations.
+        for attestation in &block.body.attestations {
+            // If the `data.beacon_block_root` block is not known to the fork choice, simply ignore
+            // the vote.
            if self
-                .should_update_justified_checkpoint(chain, &state.current_justified_checkpoint)?
+                .backend
+                .contains_block(&attestation.data.beacon_block_root)
            {
-                *self.justified_checkpoint.write() = state.current_justified_checkpoint.clone();
+                self.process_attestation(state, attestation, block)?;
            }
        }

        // This does not apply a vote to the block, it just makes fork choice aware of the block so
        // it can still be identified as the head even if it doesn't have any votes.
-        //
-        // A case where a block without any votes can be the head is where it is the only child of
-        // a block that has the majority of votes applied to it.
-        self.backend.process_block(block, block_root)?;
+        self.backend.process_block(
+            block_root,
+            block.parent_root,
+            state.current_justified_checkpoint.epoch,
+            state.finalized_checkpoint.epoch,
+        )?;

        metrics::stop_timer(timer);

@@ -264,8 +303,11 @@ impl<T: BeaconChainTypes> ForkChoice<T> {
                get_attesting_indices(state, &attestation.data, &attestation.aggregation_bits)?;

            for validator_index in validator_indices {
-                self.backend
-                    .process_attestation(validator_index, block_hash, block.slot)?;
+                self.backend.process_attestation(
+                    validator_index,
+                    block_hash,
+                    block.slot.epoch(T::EthSpec::slots_per_epoch()),
+                )?;
            }
        }

@@ -277,18 +319,10 @@ impl<T: BeaconChainTypes> ForkChoice<T> {
    /// Returns the latest message for a given validator, if any.
    ///
    /// Returns `(block_root, block_slot)`.
-    pub fn latest_message(&self, validator_index: usize) -> Option<(Hash256, Slot)> {
+    pub fn latest_message(&self, validator_index: usize) -> Option<(Hash256, Epoch)> {
        self.backend.latest_message(validator_index)
    }

-    /// Runs an integrity verification function on the underlying fork choice algorithm.
-    ///
-    /// Returns `Ok(())` if the underlying fork choice has maintained it's integrity,
-    /// `Err(description)` otherwise.
-    pub fn verify_integrity(&self) -> core::result::Result<(), String> {
-        self.backend.verify_integrity()
-    }
-
    /// Inform the fork choice that the given block (and corresponding root) have been finalized so
    /// it may prune it's storage.
    ///
@@ -299,7 +333,10 @@ impl<T: BeaconChainTypes> ForkChoice<T> {
        finalized_block_root: Hash256,
    ) -> Result<()> {
        self.backend
-            .update_finalized_root(finalized_block, finalized_block_root)
+            .update_finalized_root(
+                finalized_block.slot.epoch(T::EthSpec::slots_per_epoch()),
+                finalized_block_root,
+            )
            .map_err(Into::into)
    }

@@ -307,8 +344,8 @@ impl<T: BeaconChainTypes> ForkChoice<T> {
    pub fn as_ssz_container(&self) -> SszForkChoice {
        SszForkChoice {
            genesis_block_root: self.genesis_block_root.clone(),
-            justified_checkpoint: self.justified_checkpoint.read().clone(),
-            best_justified_checkpoint: self.best_justified_checkpoint.read().clone(),
+            finalized_checkpoint: self.finalized_checkpoint.read().clone(),
+            justification_manager: self.justification_manager.read().clone(),
            backend_bytes: self.backend.as_bytes(),
        }
    }
@@ -316,15 +353,15 @@ impl<T: BeaconChainTypes> ForkChoice<T> {
    /// Instantiates `Self` from a prior `SszForkChoice`.
    ///
    /// The created `Self` will have the same state as the `Self` that created the `SszForkChoice`.
-    pub fn from_ssz_container(ssz_container: SszForkChoice, store: Arc<T::Store>) -> Result<Self> {
-        let backend = LmdGhost::from_bytes(&ssz_container.backend_bytes, store.clone())?;
+    pub fn from_ssz_container(ssz_container: SszForkChoice) -> Result<Self> {
+        let backend = ProtoArrayForkChoice::from_bytes(&ssz_container.backend_bytes)?;

        Ok(Self {
-            store,
            backend,
            genesis_block_root: ssz_container.genesis_block_root,
-            justified_checkpoint: RwLock::new(ssz_container.justified_checkpoint),
-            best_justified_checkpoint: RwLock::new(ssz_container.best_justified_checkpoint),
+            finalized_checkpoint: RwLock::new(ssz_container.finalized_checkpoint),
+            justification_manager: RwLock::new(ssz_container.justification_manager),
+            _phantom: PhantomData,
        })
    }
 }
@@ -335,8 +372,8 @@ impl<T: BeaconChainTypes> ForkChoice<T> {
 #[derive(Encode, Decode, Clone)]
 pub struct SszForkChoice {
    genesis_block_root: Hash256,
-    justified_checkpoint: Checkpoint,
-    best_justified_checkpoint: Checkpoint,
+    finalized_checkpoint: Checkpoint,
+    justification_manager: JustificationManager,
    backend_bytes: Vec<u8>,
 }

--- a/beacon_node/beacon_chain/src/lib.rs
+++ b/beacon_node/beacon_chain/src/lib.rs
@@ -23,7 +23,6 @@ pub use self::errors::{BeaconChainError, BlockProductionError};
 pub use eth1_chain::{Eth1Chain, Eth1ChainBackend};
 pub use events::EventHandler;
 pub use fork_choice::ForkChoice;
-pub use lmd_ghost;
 pub use metrics::scrape_for_metrics;
 pub use parking_lot;
 pub use slot_clock;
--- a/beacon_node/beacon_chain/src/test_utils.rs
+++ b/beacon_node/beacon_chain/src/test_utils.rs
@@ -5,7 +5,6 @@ use crate::{
    AttestationProcessingOutcome, BeaconChain, BeaconChainTypes, BlockProcessingOutcome,
 };
 use genesis::interop_genesis_state;
-use lmd_ghost::ThreadSafeReducedTree;
 use rayon::prelude::*;
 use sloggers::{terminal::TerminalLoggerBuilder, types::Severity, Build};
 use slot_clock::TestingSlotClock;
@@ -34,7 +33,6 @@ pub type BaseHarnessType<TStore, TStoreMigrator, TEthSpec> = Witness<
    TStore,
    TStoreMigrator,
    TestingSlotClock,
-    ThreadSafeReducedTree<TStore, TEthSpec>,
    CachingEth1Backend<TEthSpec, TStore>,
    TEthSpec,
    NullEventHandler<TEthSpec>,
--- a/beacon_node/client/Cargo.toml
+++ b/beacon_node/client/Cargo.toml
@@ -33,7 +33,6 @@ exit-future = "0.1.4"
 futures = "0.1.29"
 reqwest = "0.9.22"
 url = "2.1.0"
-lmd_ghost = { path = "../../eth2/lmd_ghost" }
 eth1 = { path = "../eth1" }
 genesis = { path = "../genesis" }
 environment = { path = "../../lighthouse/environment" }
--- a/beacon_node/client/src/builder.rs
+++ b/beacon_node/client/src/builder.rs
@@ -4,7 +4,6 @@ use crate::Client;
 use beacon_chain::{
    builder::{BeaconChainBuilder, Witness},
    eth1_chain::CachingEth1Backend,
-    lmd_ghost::ThreadSafeReducedTree,
    slot_clock::{SlotClock, SystemTimeSlotClock},
    store::{
        migrate::{BackgroundMigrator, Migrate, NullMigrator},
@@ -21,7 +20,6 @@ use genesis::{
    generate_deterministic_keypairs, interop_genesis_state, state_from_ssz_file, Eth1GenesisService,
 };
 use lighthouse_bootstrap::Bootstrapper;
-use lmd_ghost::LmdGhost;
 use network::{NetworkConfig, NetworkMessage, Service as NetworkService};
 use slog::info;
 use ssz::Decode;
@@ -67,23 +65,14 @@ pub struct ClientBuilder<T: BeaconChainTypes> {
    eth_spec_instance: T::EthSpec,
 }

-impl<TStore, TStoreMigrator, TSlotClock, TLmdGhost, TEth1Backend, TEthSpec, TEventHandler>
+impl<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>
    ClientBuilder<
-        Witness<
-            TStore,
-            TStoreMigrator,
-            TSlotClock,
-            TLmdGhost,
-            TEth1Backend,
-            TEthSpec,
-            TEventHandler,
-        >,
+        Witness<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>,
    >
 where
    TStore: Store<TEthSpec> + 'static,
    TStoreMigrator: store::Migrate<TStore, TEthSpec>,
    TSlotClock: SlotClock + Clone + 'static,
-    TLmdGhost: LmdGhost<TStore, TEthSpec> + 'static,
    TEth1Backend: Eth1ChainBackend<TEthSpec> + 'static,
    TEthSpec: EthSpec + 'static,
    TEventHandler: EventHandler<TEthSpec> + 'static,
@@ -364,17 +353,8 @@ where
    /// If type inference errors are being raised, see the comment on the definition of `Self`.
    pub fn build(
        self,
-    ) -> Client<
-        Witness<
-            TStore,
-            TStoreMigrator,
-            TSlotClock,
-            TLmdGhost,
-            TEth1Backend,
-            TEthSpec,
-            TEventHandler,
-        >,
-    > {
+    ) -> Client<Witness<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>>
+    {
        Client {
            beacon_chain: self.beacon_chain,
            libp2p_network: self.libp2p_network,
@@ -387,15 +367,7 @@ where

 impl<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>
    ClientBuilder<
-        Witness<
-            TStore,
-            TStoreMigrator,
-            TSlotClock,
-            ThreadSafeReducedTree<TStore, TEthSpec>,
-            TEth1Backend,
-            TEthSpec,
-            TEventHandler,
-        >,
+        Witness<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>,
    >
 where
    TStore: Store<TEthSpec> + 'static,
@@ -432,13 +404,12 @@ where
    }
 }

-impl<TStore, TStoreMigrator, TSlotClock, TLmdGhost, TEth1Backend, TEthSpec>
+impl<TStore, TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec>
    ClientBuilder<
        Witness<
            TStore,
            TStoreMigrator,
            TSlotClock,
-            TLmdGhost,
            TEth1Backend,
            TEthSpec,
            WebSocketSender<TEthSpec>,
@@ -448,7 +419,6 @@ where
    TStore: Store<TEthSpec> + 'static,
    TStoreMigrator: store::Migrate<TStore, TEthSpec>,
    TSlotClock: SlotClock + 'static,
-    TLmdGhost: LmdGhost<TStore, TEthSpec> + 'static,
    TEth1Backend: Eth1ChainBackend<TEthSpec> + 'static,
    TEthSpec: EthSpec + 'static,
 {
@@ -482,13 +452,12 @@ where
    }
 }

-impl<TStoreMigrator, TSlotClock, TLmdGhost, TEth1Backend, TEthSpec, TEventHandler>
+impl<TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>
    ClientBuilder<
        Witness<
            DiskStore<TEthSpec>,
            TStoreMigrator,
            TSlotClock,
-            TLmdGhost,
            TEth1Backend,
            TEthSpec,
            TEventHandler,
@@ -497,7 +466,6 @@ impl<TStoreMigrator, TSlotClock, TLmdGhost, TEth1Backend, TEthSpec, TEventHandle
 where
    TSlotClock: SlotClock + 'static,
    TStoreMigrator: store::Migrate<DiskStore<TEthSpec>, TEthSpec> + 'static,
-    TLmdGhost: LmdGhost<DiskStore<TEthSpec>, TEthSpec> + 'static,
    TEth1Backend: Eth1ChainBackend<TEthSpec> + 'static,
    TEthSpec: EthSpec + 'static,
    TEventHandler: EventHandler<TEthSpec> + 'static,
@@ -532,13 +500,12 @@ where
    }
 }

-impl<TStoreMigrator, TSlotClock, TLmdGhost, TEth1Backend, TEthSpec, TEventHandler>
+impl<TStoreMigrator, TSlotClock, TEth1Backend, TEthSpec, TEventHandler>
    ClientBuilder<
        Witness<
            SimpleDiskStore<TEthSpec>,
            TStoreMigrator,
            TSlotClock,
-            TLmdGhost,
            TEth1Backend,
            TEthSpec,
            TEventHandler,
@@ -547,7 +514,6 @@ impl<TStoreMigrator, TSlotClock, TLmdGhost, TEth1Backend, TEthSpec, TEventHandle
 where
    TSlotClock: SlotClock + 'static,
    TStoreMigrator: store::Migrate<SimpleDiskStore<TEthSpec>, TEthSpec> + 'static,
-    TLmdGhost: LmdGhost<SimpleDiskStore<TEthSpec>, TEthSpec> + 'static,
    TEth1Backend: Eth1ChainBackend<TEthSpec> + 'static,
    TEthSpec: EthSpec + 'static,
    TEventHandler: EventHandler<TEthSpec> + 'static,
@@ -561,13 +527,12 @@ where
    }
 }

-impl<TSlotClock, TLmdGhost, TEth1Backend, TEthSpec, TEventHandler>
+impl<TSlotClock, TEth1Backend, TEthSpec, TEventHandler>
    ClientBuilder<
        Witness<
            MemoryStore<TEthSpec>,
            NullMigrator,
            TSlotClock,
-            TLmdGhost,
            TEth1Backend,
            TEthSpec,
            TEventHandler,
@@ -575,7 +540,6 @@ impl<TSlotClock, TLmdGhost, TEth1Backend, TEthSpec, TEventHandler>
    >
 where
    TSlotClock: SlotClock + 'static,
-    TLmdGhost: LmdGhost<MemoryStore<TEthSpec>, TEthSpec> + 'static,
    TEth1Backend: Eth1ChainBackend<TEthSpec> + 'static,
    TEthSpec: EthSpec + 'static,
    TEventHandler: EventHandler<TEthSpec> + 'static,
@@ -591,13 +555,12 @@ where
    }
 }

-impl<TSlotClock, TLmdGhost, TEth1Backend, TEthSpec, TEventHandler>
+impl<TSlotClock, TEth1Backend, TEthSpec, TEventHandler>
    ClientBuilder<
        Witness<
            DiskStore<TEthSpec>,
            BackgroundMigrator<TEthSpec>,
            TSlotClock,
-            TLmdGhost,
            TEth1Backend,
            TEthSpec,
            TEventHandler,
@@ -605,7 +568,6 @@ impl<TSlotClock, TLmdGhost, TEth1Backend, TEthSpec, TEventHandler>
    >
 where
    TSlotClock: SlotClock + 'static,
-    TLmdGhost: LmdGhost<DiskStore<TEthSpec>, TEthSpec> + 'static,
    TEth1Backend: Eth1ChainBackend<TEthSpec> + 'static,
    TEthSpec: EthSpec + 'static,
    TEventHandler: EventHandler<TEthSpec> + 'static,
@@ -619,13 +581,12 @@ where
    }
 }

-impl<TStore, TStoreMigrator, TSlotClock, TLmdGhost, TEthSpec, TEventHandler>
+impl<TStore, TStoreMigrator, TSlotClock, TEthSpec, TEventHandler>
    ClientBuilder<
        Witness<
            TStore,
            TStoreMigrator,
            TSlotClock,
-            TLmdGhost,
            CachingEth1Backend<TEthSpec, TStore>,
            TEthSpec,
            TEventHandler,
@@ -635,7 +596,6 @@ where
    TStore: Store<TEthSpec> + 'static,
    TStoreMigrator: store::Migrate<TStore, TEthSpec>,
    TSlotClock: SlotClock + 'static,
-    TLmdGhost: LmdGhost<TStore, TEthSpec> + 'static,
    TEthSpec: EthSpec + 'static,
    TEventHandler: EventHandler<TEthSpec> + 'static,
 {
@@ -721,22 +681,13 @@ where
    }
 }

-impl<TStore, TStoreMigrator, TLmdGhost, TEth1Backend, TEthSpec, TEventHandler>
+impl<TStore, TStoreMigrator, TEth1Backend, TEthSpec, TEventHandler>
    ClientBuilder<
-        Witness<
-            TStore,
-            TStoreMigrator,
-            SystemTimeSlotClock,
-            TLmdGhost,
-            TEth1Backend,
-            TEthSpec,
-            TEventHandler,
-        >,
+        Witness<TStore, TStoreMigrator, SystemTimeSlotClock, TEth1Backend, TEthSpec, TEventHandler>,
    >
 where
    TStore: Store<TEthSpec> + 'static,
    TStoreMigrator: store::Migrate<TStore, TEthSpec>,
-    TLmdGhost: LmdGhost<TStore, TEthSpec> + 'static,
    TEth1Backend: Eth1ChainBackend<TEthSpec> + 'static,
    TEthSpec: EthSpec + 'static,
    TEventHandler: EventHandler<TEthSpec> + 'static,
--- a/beacon_node/src/lib.rs
+++ b/beacon_node/src/lib.rs
@@ -11,7 +11,7 @@ pub use eth2_config::Eth2Config;

 use beacon_chain::{
    builder::Witness, eth1_chain::CachingEth1Backend, events::WebSocketSender,
-    lmd_ghost::ThreadSafeReducedTree, slot_clock::SystemTimeSlotClock,
+    slot_clock::SystemTimeSlotClock,
 };
 use clap::ArgMatches;
 use config::get_configs;
@@ -28,7 +28,6 @@ pub type ProductionClient<E> = Client<
        DiskStore<E>,
        BackgroundMigrator<E>,
        SystemTimeSlotClock,
-        ThreadSafeReducedTree<DiskStore<E>, E>,
        CachingEth1Backend<E, DiskStore<E>>,
        E,
        WebSocketSender<E>,
--- a/eth2/proto_array_fork_choice/src/lib.rs
+++ b/eth2/proto_array_fork_choice/src/lib.rs
@@ -201,6 +201,10 @@ impl ProtoArrayForkChoice {
        self.proto_array.read().nodes.len()
    }

+    pub fn contains_block(&self, block_root: &Hash256) -> bool {
+        self.proto_array.read().indices.contains_key(block_root)
+    }
+
    pub fn latest_message(&self, validator_index: usize) -> Option<(Hash256, Epoch)> {
        let votes = self.votes.read();

--- a/eth2/state_processing/Cargo.toml
+++ b/eth2/state_processing/Cargo.toml
@@ -18,7 +18,6 @@ serde_yaml = "0.8.11"
 eth2_ssz = "0.1.2"
 beacon_chain = { path = "../../beacon_node/beacon_chain" }
 store = { path = "../../beacon_node/store" }
-lmd_ghost = { path = "../lmd_ghost" }


 [dependencies]