Add is_parent_strong proposer re-org check (#5417)

* initial fork choice additions

* add helper fns

* add is_parent_strong

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into add_is_parent_strong_check

* disabling proposer reorg should set parent_threshold to u64 max

* add new flag, is_parent_strong check in override fcu params

* cherry-pick changes

* Merge branch 'unstable' of https://github.com/sigp/lighthouse into add_is_parent_strong_check

* cleanup

* fmt

* Minor review tweaks

beacon_node/beacon_chain/src/beacon_chain.rs

@@ -4262,7 +4262,8 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
         head_slot: Slot,
         canonical_head: Hash256,
     ) -> Option<BlockProductionPreState<T::EthSpec>> {
-        let re_org_threshold = self.config.re_org_threshold?;
+        let re_org_head_threshold = self.config.re_org_head_threshold?;
+        let re_org_parent_threshold = self.config.re_org_parent_threshold?;
 
         if self.spec.proposer_score_boost.is_none() {
             warn!(
@@ -4319,7 +4320,8 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
             .get_proposer_head(
                 slot,
                 canonical_head,
-                re_org_threshold,
+                re_org_head_threshold,
+                re_org_parent_threshold,
                 &self.config.re_org_disallowed_offsets,
                 self.config.re_org_max_epochs_since_finalization,
             )
@@ -4373,7 +4375,7 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
             "weak_head" => ?canonical_head,
             "parent" => ?re_org_parent_block,
             "head_weight" => proposer_head.head_node.weight,
-            "threshold_weight" => proposer_head.re_org_weight_threshold
+            "threshold_weight" => proposer_head.re_org_head_weight_threshold
         );
 
         Some(pre_state)
@@ -4593,9 +4595,14 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
         let _timer = metrics::start_timer(&metrics::FORK_CHOICE_OVERRIDE_FCU_TIMES);
 
         // Never override if proposer re-orgs are disabled.
-        let re_org_threshold = self
+        let re_org_head_threshold = self
             .config
-            .re_org_threshold
+            .re_org_head_threshold
+            .ok_or(DoNotReOrg::ReOrgsDisabled)?;
+
+        let re_org_parent_threshold = self
+            .config
+            .re_org_parent_threshold
             .ok_or(DoNotReOrg::ReOrgsDisabled)?;
 
         let head_block_root = canonical_forkchoice_params.head_root;
@@ -4606,7 +4613,8 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
             .fork_choice_read_lock()
             .get_preliminary_proposer_head(
                 head_block_root,
-                re_org_threshold,
+                re_org_head_threshold,
+                re_org_parent_threshold,
                 &self.config.re_org_disallowed_offsets,
                 self.config.re_org_max_epochs_since_finalization,
             )
@@ -4674,16 +4682,27 @@ impl<T: BeaconChainTypes> BeaconChain<T> {
         }
 
         // If the current slot is already equal to the proposal slot (or we are in the tail end of
-        // the prior slot), then check the actual weight of the head against the re-org threshold.
+        // the prior slot), then check the actual weight of the head against the head re-org threshold
-        let head_weak = if fork_choice_slot == re_org_block_slot {
+        // and the actual weight of the parent against the parent re-org threshold.
-            info.head_node.weight < info.re_org_weight_threshold
+        let (head_weak, parent_strong) = if fork_choice_slot == re_org_block_slot {
+            (
+                info.head_node.weight < info.re_org_head_weight_threshold,
+                info.parent_node.weight > info.re_org_parent_weight_threshold,
+            )
         } else {
-            true
+            (true, true)
         };
         if !head_weak {
             return Err(DoNotReOrg::HeadNotWeak {
                 head_weight: info.head_node.weight,
-                re_org_weight_threshold: info.re_org_weight_threshold,
+                re_org_head_weight_threshold: info.re_org_head_weight_threshold,
+            }
+            .into());
+        }
+        if !parent_strong {
+            return Err(DoNotReOrg::ParentNotStrong {
+                parent_weight: info.parent_node.weight,
+                re_org_parent_weight_threshold: info.re_org_parent_weight_threshold,
             }
             .into());
         }

beacon_node/beacon_chain/src/builder.rs

@@ -172,8 +172,8 @@ where
     }
 
     /// Sets the proposer re-org threshold.
-    pub fn proposer_re_org_threshold(mut self, threshold: Option<ReOrgThreshold>) -> Self {
+    pub fn proposer_re_org_head_threshold(mut self, threshold: Option<ReOrgThreshold>) -> Self {
-        self.chain_config.re_org_threshold = threshold;
+        self.chain_config.re_org_head_threshold = threshold;
         self
     }
 

beacon_node/beacon_chain/src/chain_config.rs

@@ -3,7 +3,8 @@ use serde::{Deserialize, Serialize};
 use std::time::Duration;
 use types::{Checkpoint, Epoch};
 
-pub const DEFAULT_RE_ORG_THRESHOLD: ReOrgThreshold = ReOrgThreshold(20);
+pub const DEFAULT_RE_ORG_HEAD_THRESHOLD: ReOrgThreshold = ReOrgThreshold(20);
+pub const DEFAULT_RE_ORG_PARENT_THRESHOLD: ReOrgThreshold = ReOrgThreshold(160);
 pub const DEFAULT_RE_ORG_MAX_EPOCHS_SINCE_FINALIZATION: Epoch = Epoch::new(2);
 /// Default to 1/12th of the slot, which is 1 second on mainnet.
 pub const DEFAULT_RE_ORG_CUTOFF_DENOMINATOR: u32 = 12;
@@ -31,8 +32,10 @@ pub struct ChainConfig {
     pub enable_lock_timeouts: bool,
     /// The max size of a message that can be sent over the network.
     pub max_network_size: usize,
-    /// Maximum percentage of committee weight at which to attempt re-orging the canonical head.
+    /// Maximum percentage of the head committee weight at which to attempt re-orging the canonical head.
-    pub re_org_threshold: Option<ReOrgThreshold>,
+    pub re_org_head_threshold: Option<ReOrgThreshold>,
+    /// Minimum percentage of the parent committee weight at which to attempt re-orging the canonical head.
+    pub re_org_parent_threshold: Option<ReOrgThreshold>,
     /// Maximum number of epochs since finalization for attempting a proposer re-org.
     pub re_org_max_epochs_since_finalization: Epoch,
     /// Maximum delay after the start of the slot at which to propose a reorging block.
@@ -95,7 +98,8 @@ impl Default for ChainConfig {
             reconstruct_historic_states: false,
             enable_lock_timeouts: true,
             max_network_size: 10 * 1_048_576, // 10M
-            re_org_threshold: Some(DEFAULT_RE_ORG_THRESHOLD),
+            re_org_head_threshold: Some(DEFAULT_RE_ORG_HEAD_THRESHOLD),
+            re_org_parent_threshold: Some(DEFAULT_RE_ORG_PARENT_THRESHOLD),
             re_org_max_epochs_since_finalization: DEFAULT_RE_ORG_MAX_EPOCHS_SINCE_FINALIZATION,
             re_org_cutoff_millis: None,
             re_org_disallowed_offsets: DisallowedReOrgOffsets::default(),

beacon_node/http_api/tests/interactive_tests.rs

@@ -419,7 +419,7 @@ pub async fn proposer_boost_re_org_test(
         None,
         Some(Box::new(move |builder| {
             builder
-                .proposer_re_org_threshold(Some(ReOrgThreshold(re_org_threshold)))
+                .proposer_re_org_head_threshold(Some(ReOrgThreshold(re_org_threshold)))
                 .proposer_re_org_max_epochs_since_finalization(Epoch::new(
                     max_epochs_since_finalization,
                 ))

beacon_node/src/cli.rs

@@ -1040,10 +1040,18 @@ pub fn cli_app<'a, 'b>() -> App<'a, 'b> {
             Arg::with_name("proposer-reorg-threshold")
                 .long("proposer-reorg-threshold")
                 .value_name("PERCENT")
-                .help("Percentage of vote weight below which to attempt a proposer reorg. \
+                .help("Percentage of head vote weight below which to attempt a proposer reorg. \
                        Default: 20%")
                 .conflicts_with("disable-proposer-reorgs")
         )
+        .arg(
+            Arg::with_name("proposer-reorg-parent-threshold")
+                .long("proposer-reorg-parent-threshold")
+                .value_name("PERCENT")
+                .help("Percentage of parent vote weight above which to attempt a proposer reorg. \
+                       Default: 160%")
+                .conflicts_with("disable-proposer-reorgs")
+        )
         .arg(
             Arg::with_name("proposer-reorg-epochs-since-finalization")
                 .long("proposer-reorg-epochs-since-finalization")

beacon_node/src/config.rs

@@ -1,6 +1,7 @@
 use beacon_chain::chain_config::{
     DisallowedReOrgOffsets, ReOrgThreshold, DEFAULT_PREPARE_PAYLOAD_LOOKAHEAD_FACTOR,
-    DEFAULT_RE_ORG_MAX_EPOCHS_SINCE_FINALIZATION, DEFAULT_RE_ORG_THRESHOLD,
+    DEFAULT_RE_ORG_HEAD_THRESHOLD, DEFAULT_RE_ORG_MAX_EPOCHS_SINCE_FINALIZATION,
+    DEFAULT_RE_ORG_PARENT_THRESHOLD,
 };
 use beacon_chain::TrustedSetup;
 use clap::ArgMatches;
@@ -749,12 +750,13 @@ pub fn get_config<E: EthSpec>(
     }
 
     if cli_args.is_present("disable-proposer-reorgs") {
-        client_config.chain.re_org_threshold = None;
+        client_config.chain.re_org_head_threshold = None;
+        client_config.chain.re_org_parent_threshold = None;
     } else {
-        client_config.chain.re_org_threshold = Some(
+        client_config.chain.re_org_head_threshold = Some(
             clap_utils::parse_optional(cli_args, "proposer-reorg-threshold")?
                 .map(ReOrgThreshold)
-                .unwrap_or(DEFAULT_RE_ORG_THRESHOLD),
+                .unwrap_or(DEFAULT_RE_ORG_HEAD_THRESHOLD),
         );
         client_config.chain.re_org_max_epochs_since_finalization =
             clap_utils::parse_optional(cli_args, "proposer-reorg-epochs-since-finalization")?
@@ -762,6 +764,12 @@ pub fn get_config<E: EthSpec>(
         client_config.chain.re_org_cutoff_millis =
             clap_utils::parse_optional(cli_args, "proposer-reorg-cutoff")?;
 
+        client_config.chain.re_org_parent_threshold = Some(
+            clap_utils::parse_optional(cli_args, "proposer-reorg-parent-threshold")?
+                .map(ReOrgThreshold)
+                .unwrap_or(DEFAULT_RE_ORG_PARENT_THRESHOLD),
+        );
+
         if let Some(disallowed_offsets_str) =
             clap_utils::parse_optional::<String>(cli_args, "proposer-reorg-disallowed-offsets")?
         {

book/src/help_bn.md

@@ -383,8 +383,11 @@ OPTIONS:
         --proposer-reorg-epochs-since-finalization <EPOCHS>
             Maximum number of epochs since finalization at which proposer reorgs are allowed. Default: 2
 
+        --proposer-reorg-parent-threshold <PERCENT>
+            Percentage of parent vote weight above which to attempt a proposer reorg. Default: 160%
+
         --proposer-reorg-threshold <PERCENT>
-            Percentage of vote weight below which to attempt a proposer reorg. Default: 20%
+            Percentage of head vote weight below which to attempt a proposer reorg. Default: 20%
 
         --prune-blobs <BOOLEAN>
             Prune blobs from Lighthouse's database when they are older than the data data availability boundary relative

common/eth2_network_config/built_in_network_configs/gnosis/config.yaml

@@ -81,6 +81,12 @@ CHURN_LIMIT_QUOTIENT: 4096
 # ---------------------------------------------------------------
 # 40%
 PROPOSER_SCORE_BOOST: 40
+# 20%
+REORG_HEAD_WEIGHT_THRESHOLD: 20
+# 160%
+REORG_PARENT_WEIGHT_THRESHOLD: 160
+# `2` epochs
+REORG_MAX_EPOCHS_SINCE_FINALIZATION: 2
 
 # Deposit contract
 # ---------------------------------------------------------------

common/eth2_network_config/built_in_network_configs/holesky/config.yaml

@@ -71,6 +71,12 @@ MAX_PER_EPOCH_ACTIVATION_CHURN_LIMIT: 8
 # ---------------------------------------------------------------
 # 40%
 PROPOSER_SCORE_BOOST: 40
+# 20%
+REORG_HEAD_WEIGHT_THRESHOLD: 20
+# 160%
+REORG_PARENT_WEIGHT_THRESHOLD: 160
+# `2` epochs
+REORG_MAX_EPOCHS_SINCE_FINALIZATION: 2
 
 # Deposit contract
 # ---------------------------------------------------------------

common/eth2_network_config/built_in_network_configs/prater/config.yaml

@@ -78,6 +78,12 @@ MAX_PER_EPOCH_ACTIVATION_CHURN_LIMIT: 8
 # ---------------------------------------------------------------
 # 40%
 PROPOSER_SCORE_BOOST: 40
+# 20%
+REORG_HEAD_WEIGHT_THRESHOLD: 20
+# 160%
+REORG_PARENT_WEIGHT_THRESHOLD: 160
+# `2` epochs
+REORG_MAX_EPOCHS_SINCE_FINALIZATION: 2
 
 # Deposit contract
 # ---------------------------------------------------------------

common/eth2_network_config/built_in_network_configs/sepolia/config.yaml

@@ -69,6 +69,10 @@ MAX_PER_EPOCH_ACTIVATION_CHURN_LIMIT: 8
 # ---------------------------------------------------------------
 # 40%
 PROPOSER_SCORE_BOOST: 40
+# 20%
+REORG_HEAD_WEIGHT_THRESHOLD: 20
+# 160%
+REORG_PARENT_WEIGHT_THRESHOLD: 160
 
 # Deposit contract
 # ---------------------------------------------------------------

consensus/fork_choice/src/fork_choice.rs

@@ -517,7 +517,8 @@ where
         &self,
         current_slot: Slot,
         canonical_head: Hash256,
-        re_org_threshold: ReOrgThreshold,
+        re_org_head_threshold: ReOrgThreshold,
+        re_org_parent_threshold: ReOrgThreshold,
         disallowed_offsets: &DisallowedReOrgOffsets,
         max_epochs_since_finalization: Epoch,
     ) -> Result<ProposerHeadInfo, ProposerHeadError<Error<proto_array::Error>>> {
@@ -549,7 +550,8 @@ where
                 current_slot,
                 canonical_head,
                 self.fc_store.justified_balances(),
-                re_org_threshold,
+                re_org_head_threshold,
+                re_org_parent_threshold,
                 disallowed_offsets,
                 max_epochs_since_finalization,
             )
@@ -559,7 +561,8 @@ where
     pub fn get_preliminary_proposer_head(
         &self,
         canonical_head: Hash256,
-        re_org_threshold: ReOrgThreshold,
+        re_org_head_threshold: ReOrgThreshold,
+        re_org_parent_threshold: ReOrgThreshold,
         disallowed_offsets: &DisallowedReOrgOffsets,
         max_epochs_since_finalization: Epoch,
     ) -> Result<ProposerHeadInfo, ProposerHeadError<Error<proto_array::Error>>> {
@@ -569,7 +572,8 @@ where
                 current_slot,
                 canonical_head,
                 self.fc_store.justified_balances(),
-                re_org_threshold,
+                re_org_head_threshold,
+                re_org_parent_threshold,
                 disallowed_offsets,
                 max_epochs_since_finalization,
             )
@@ -706,6 +710,7 @@ where
         // Add proposer score boost if the block is timely.
         let is_before_attesting_interval =
             block_delay < Duration::from_secs(spec.seconds_per_slot / INTERVALS_PER_SLOT);
+
         let is_first_block = self.fc_store.proposer_boost_root().is_zero();
         if current_slot == block.slot() && is_before_attesting_interval && is_first_block {
             self.fc_store.set_proposer_boost_root(block_root);

consensus/proto_array/src/proto_array_fork_choice.rs

@@ -195,8 +195,10 @@ pub struct ProposerHeadInfo {
     /// Information about the parent of the current head, which should be selected as the parent
     /// for a new proposal *if* a re-org is decided on.
     pub parent_node: ProtoNode,
-    /// The computed fraction of the active committee balance below which we can re-org.
+    /// The computed fraction of the active head committee balance below which we can re-org.
-    pub re_org_weight_threshold: u64,
+    pub re_org_head_weight_threshold: u64,
+    /// The computed fraction of the active parent committee balance above which we can re-org.
+    pub re_org_parent_weight_threshold: u64,
     /// The current slot from fork choice's point of view, may lead the wall-clock slot by upto
     /// 500ms.
     pub current_slot: Slot,
@@ -259,7 +261,11 @@ pub enum DoNotReOrg {
     },
     HeadNotWeak {
         head_weight: u64,
-        re_org_weight_threshold: u64,
+        re_org_head_weight_threshold: u64,
+    },
+    ParentNotStrong {
+        parent_weight: u64,
+        re_org_parent_weight_threshold: u64,
     },
     HeadNotLate,
     NotProposing,
@@ -288,9 +294,21 @@ impl std::fmt::Display for DoNotReOrg {
             ),
             Self::HeadNotWeak {
                 head_weight,
-                re_org_weight_threshold,
+                re_org_head_weight_threshold,
             } => {
-                write!(f, "head not weak ({head_weight}/{re_org_weight_threshold})")
+                write!(
+                    f,
+                    "head not weak ({head_weight}/{re_org_head_weight_threshold})"
+                )
+            }
+            Self::ParentNotStrong {
+                parent_weight,
+                re_org_parent_weight_threshold,
+            } => {
+                write!(
+                    f,
+                    "parent not strong ({parent_weight}/{re_org_parent_weight_threshold})"
+                )
             }
             Self::HeadNotLate => {
                 write!(f, "head arrived on time")
@@ -486,12 +504,14 @@ impl ProtoArrayForkChoice {
     /// Get the block to propose on during `current_slot`.
     ///
     /// This function returns a *definitive* result which should be acted on.
+    #[allow(clippy::too_many_arguments)]
     pub fn get_proposer_head<E: EthSpec>(
         &self,
         current_slot: Slot,
         canonical_head: Hash256,
         justified_balances: &JustifiedBalances,
-        re_org_threshold: ReOrgThreshold,
+        re_org_head_threshold: ReOrgThreshold,
+        re_org_parent_threshold: ReOrgThreshold,
         disallowed_offsets: &DisallowedReOrgOffsets,
         max_epochs_since_finalization: Epoch,
     ) -> Result<ProposerHeadInfo, ProposerHeadError<Error>> {
@@ -499,7 +519,8 @@ impl ProtoArrayForkChoice {
             current_slot,
             canonical_head,
             justified_balances,
-            re_org_threshold,
+            re_org_head_threshold,
+            re_org_parent_threshold,
             disallowed_offsets,
             max_epochs_since_finalization,
         )?;
@@ -510,14 +531,26 @@ impl ProtoArrayForkChoice {
             return Err(DoNotReOrg::HeadDistance.into());
         }
 
-        // Only re-org if the head's weight is less than the configured committee fraction.
+        // Only re-org if the head's weight is less than the heads configured committee fraction.
         let head_weight = info.head_node.weight;
-        let re_org_weight_threshold = info.re_org_weight_threshold;
+        let re_org_head_weight_threshold = info.re_org_head_weight_threshold;
-        let weak_head = head_weight < re_org_weight_threshold;
+        let weak_head = head_weight < re_org_head_weight_threshold;
         if !weak_head {
             return Err(DoNotReOrg::HeadNotWeak {
                 head_weight,
-                re_org_weight_threshold,
+                re_org_head_weight_threshold,
+            }
+            .into());
+        }
+
+        // Only re-org if the parent's weight is greater than the parents configured committee fraction.
+        let parent_weight = info.parent_node.weight;
+        let re_org_parent_weight_threshold = info.re_org_parent_weight_threshold;
+        let parent_strong = parent_weight > re_org_parent_weight_threshold;
+        if !parent_strong {
+            return Err(DoNotReOrg::ParentNotStrong {
+                parent_weight,
+                re_org_parent_weight_threshold,
             }
             .into());
         }
@@ -529,12 +562,14 @@ impl ProtoArrayForkChoice {
     /// Get information about the block to propose on during `current_slot`.
     ///
     /// This function returns a *partial* result which must be processed further.
+    #[allow(clippy::too_many_arguments)]
     pub fn get_proposer_head_info<E: EthSpec>(
         &self,
         current_slot: Slot,
         canonical_head: Hash256,
         justified_balances: &JustifiedBalances,
-        re_org_threshold: ReOrgThreshold,
+        re_org_head_threshold: ReOrgThreshold,
+        re_org_parent_threshold: ReOrgThreshold,
         disallowed_offsets: &DisallowedReOrgOffsets,
         max_epochs_since_finalization: Epoch,
     ) -> Result<ProposerHeadInfo, ProposerHeadError<Error>> {
@@ -595,15 +630,20 @@ impl ProtoArrayForkChoice {
             return Err(DoNotReOrg::JustificationAndFinalizationNotCompetitive.into());
         }
 
-        // Compute re-org weight threshold.
+        // Compute re-org weight thresholds for head and parent.
-        let re_org_weight_threshold =
+        let re_org_head_weight_threshold =
-            calculate_committee_fraction::<E>(justified_balances, re_org_threshold.0)
+            calculate_committee_fraction::<E>(justified_balances, re_org_head_threshold.0)
+                .ok_or(Error::ReOrgThresholdOverflow)?;
+
+        let re_org_parent_weight_threshold =
+            calculate_committee_fraction::<E>(justified_balances, re_org_parent_threshold.0)
                 .ok_or(Error::ReOrgThresholdOverflow)?;
 
         Ok(ProposerHeadInfo {
             head_node,
             parent_node,
-            re_org_weight_threshold,
+            re_org_head_weight_threshold,
+            re_org_parent_weight_threshold,
             current_slot,
         })
     }

consensus/types/src/chain_spec.rs

@@ -114,6 +114,8 @@ pub struct ChainSpec {
      */
     pub safe_slots_to_update_justified: u64,
     pub proposer_score_boost: Option<u64>,
+    pub reorg_head_weight_threshold: Option<u64>,
+    pub reorg_parent_weight_threshold: Option<u64>,
 
     /*
      * Eth1
@@ -642,6 +644,8 @@ impl ChainSpec {
              */
             safe_slots_to_update_justified: 8,
             proposer_score_boost: Some(40),
+            reorg_head_weight_threshold: Some(20),
+            reorg_parent_weight_threshold: Some(160),
 
             /*
              * Eth1
@@ -912,6 +916,8 @@ impl ChainSpec {
              */
             safe_slots_to_update_justified: 8,
             proposer_score_boost: Some(40),
+            reorg_head_weight_threshold: Some(20),
+            reorg_parent_weight_threshold: Some(160),
 
             /*
              * Eth1

lighthouse/tests/beacon_node.rs

@@ -2,8 +2,8 @@ use beacon_node::ClientConfig as Config;
 
 use crate::exec::{CommandLineTestExec, CompletedTest};
 use beacon_node::beacon_chain::chain_config::{
-    DisallowedReOrgOffsets, DEFAULT_RE_ORG_CUTOFF_DENOMINATOR,
+    DisallowedReOrgOffsets, DEFAULT_RE_ORG_CUTOFF_DENOMINATOR, DEFAULT_RE_ORG_HEAD_THRESHOLD,
-    DEFAULT_RE_ORG_MAX_EPOCHS_SINCE_FINALIZATION, DEFAULT_RE_ORG_THRESHOLD,
+    DEFAULT_RE_ORG_MAX_EPOCHS_SINCE_FINALIZATION,
 };
 use beacon_processor::BeaconProcessorConfig;
 use eth1::Eth1Endpoint;
@@ -2200,8 +2200,8 @@ fn enable_proposer_re_orgs_default() {
         .run_with_zero_port()
         .with_config(|config| {
             assert_eq!(
-                config.chain.re_org_threshold,
+                config.chain.re_org_head_threshold,
-                Some(DEFAULT_RE_ORG_THRESHOLD)
+                Some(DEFAULT_RE_ORG_HEAD_THRESHOLD)
             );
             assert_eq!(
                 config.chain.re_org_max_epochs_since_finalization,
@@ -2219,15 +2219,26 @@ fn disable_proposer_re_orgs() {
     CommandLineTest::new()
         .flag("disable-proposer-reorgs", None)
         .run_with_zero_port()
-        .with_config(|config| assert_eq!(config.chain.re_org_threshold, None));
+        .with_config(|config| {
+            assert_eq!(config.chain.re_org_head_threshold, None);
+            assert_eq!(config.chain.re_org_parent_threshold, None)
+        });
 }
 
 #[test]
-fn proposer_re_org_threshold() {
+fn proposer_re_org_parent_threshold() {
+    CommandLineTest::new()
+        .flag("proposer-reorg-parent-threshold", Some("90"))
+        .run_with_zero_port()
+        .with_config(|config| assert_eq!(config.chain.re_org_parent_threshold.unwrap().0, 90));
+}
+
+#[test]
+fn proposer_re_org_head_threshold() {
     CommandLineTest::new()
         .flag("proposer-reorg-threshold", Some("90"))
         .run_with_zero_port()
-        .with_config(|config| assert_eq!(config.chain.re_org_threshold.unwrap().0, 90));
+        .with_config(|config| assert_eq!(config.chain.re_org_head_threshold.unwrap().0, 90));
 }
 
 #[test]

testing/ef_tests/src/cases/fork_choice.rs

@@ -4,7 +4,8 @@ use ::fork_choice::{PayloadVerificationStatus, ProposerHeadError};
 use beacon_chain::beacon_proposer_cache::compute_proposer_duties_from_head;
 use beacon_chain::blob_verification::GossipBlobError;
 use beacon_chain::chain_config::{
-    DisallowedReOrgOffsets, DEFAULT_RE_ORG_MAX_EPOCHS_SINCE_FINALIZATION, DEFAULT_RE_ORG_THRESHOLD,
+    DisallowedReOrgOffsets, DEFAULT_RE_ORG_HEAD_THRESHOLD,
+    DEFAULT_RE_ORG_MAX_EPOCHS_SINCE_FINALIZATION, DEFAULT_RE_ORG_PARENT_THRESHOLD,
 };
 use beacon_chain::slot_clock::SlotClock;
 use beacon_chain::{
@@ -746,7 +747,8 @@ impl<E: EthSpec> Tester<E> {
         let proposer_head_result = fc.get_proposer_head(
             slot,
             canonical_head,
-            DEFAULT_RE_ORG_THRESHOLD,
+            DEFAULT_RE_ORG_HEAD_THRESHOLD,
+            DEFAULT_RE_ORG_PARENT_THRESHOLD,
             &DisallowedReOrgOffsets::default(),
             DEFAULT_RE_ORG_MAX_EPOCHS_SINCE_FINALIZATION,
         );