Limit leader schedule search space (#8468) (#8485)

automerge

core/src/poh_recorder.rs

@@ -28,8 +28,8 @@ use std::sync::{Arc, Mutex};
 use std::time::Instant;
 use thiserror::Error;
 
-const GRACE_TICKS_FACTOR: u64 = 2;
+pub const GRACE_TICKS_FACTOR: u64 = 2;
-const MAX_GRACE_SLOTS: u64 = 2;
+pub const MAX_GRACE_SLOTS: u64 = 2;
 
 #[derive(Error, Debug, Clone)]
 pub enum PohRecorderError {
@@ -85,6 +85,7 @@ impl PohRecorder {
                 bank.slot(),
                 &bank,
                 Some(&self.blockstore),
+                GRACE_TICKS_FACTOR * MAX_GRACE_SLOTS,
             );
             assert_eq!(self.ticks_per_slot, bank.ticks_per_slot());
             let (leader_first_tick_height, leader_last_tick_height, grace_ticks) =

core/src/replay_stage.rs

@@ -4,7 +4,7 @@ use crate::{
     cluster_info::ClusterInfo,
     commitment::{AggregateCommitmentService, BlockCommitmentCache, CommitmentAggregationData},
     consensus::{StakeLockout, Tower},
-    poh_recorder::PohRecorder,
+    poh_recorder::{PohRecorder, GRACE_TICKS_FACTOR, MAX_GRACE_SLOTS},
     result::Result,
     rewards_recorder_service::RewardsRecorderSender,
     rpc_subscriptions::RpcSubscriptions,
@@ -690,6 +690,7 @@ impl ReplayStage {
             bank.slot(),
             &bank,
             Some(blockstore),
+            GRACE_TICKS_FACTOR * MAX_GRACE_SLOTS,
         );
         poh_recorder
             .lock()

core/src/validator.rs

@@ -6,7 +6,7 @@ use crate::{
     commitment::BlockCommitmentCache,
     contact_info::ContactInfo,
     gossip_service::{discover_cluster, GossipService},
-    poh_recorder::PohRecorder,
+    poh_recorder::{PohRecorder, GRACE_TICKS_FACTOR, MAX_GRACE_SLOTS},
     poh_service::PohService,
     rewards_recorder_service::RewardsRecorderService,
     rpc::JsonRpcConfig,
@@ -308,7 +308,13 @@ impl Validator {
             bank.tick_height(),
             bank.last_blockhash(),
             bank.slot(),
-            leader_schedule_cache.next_leader_slot(&id, bank.slot(), &bank, Some(&blockstore)),
+            leader_schedule_cache.next_leader_slot(
+                &id,
+                bank.slot(),
+                &bank,
+                Some(&blockstore),
+                GRACE_TICKS_FACTOR * MAX_GRACE_SLOTS,
+            ),
             bank.ticks_per_slot(),
             &id,
             &blockstore,

ledger/src/leader_schedule_cache.rs

@@ -106,6 +106,7 @@ impl LeaderScheduleCache {
         mut current_slot: Slot,
         bank: &Bank,
         blockstore: Option<&Blockstore>,
+        max_slot_range: u64,
     ) -> Option<(Slot, Slot)> {
         let (mut epoch, mut start_index) = bank.get_epoch_and_slot_index(current_slot + 1);
         let mut first_slot = None;
@@ -141,9 +142,14 @@ impl LeaderScheduleCache {
                         }
                     }
 
-                    if first_slot.is_none() {
+                    if let Some(first_slot) = first_slot {
+                        if current_slot - first_slot + 1 >= max_slot_range {
+                            return Some((first_slot, current_slot));
+                        }
+                    } else {
                         first_slot = Some(current_slot);
                     }
+
                     last_slot = current_slot;
                 } else if first_slot.is_some() {
                     return Some((first_slot.unwrap(), last_slot));
@@ -264,6 +270,7 @@ mod tests {
         staking_utils::tests::setup_vote_and_stake_accounts,
     };
     use solana_runtime::bank::Bank;
+    use solana_sdk::clock::NUM_CONSECUTIVE_LEADER_SLOTS;
     use solana_sdk::epoch_schedule::{
         EpochSchedule, DEFAULT_LEADER_SCHEDULE_SLOT_OFFSET, DEFAULT_SLOTS_PER_EPOCH,
         MINIMUM_SLOTS_PER_EPOCH,
@@ -395,11 +402,11 @@ mod tests {
             pubkey
         );
         assert_eq!(
-            cache.next_leader_slot(&pubkey, 0, &bank, None),
+            cache.next_leader_slot(&pubkey, 0, &bank, None, std::u64::MAX),
             Some((1, 863999))
         );
         assert_eq!(
-            cache.next_leader_slot(&pubkey, 1, &bank, None),
+            cache.next_leader_slot(&pubkey, 1, &bank, None, std::u64::MAX),
             Some((2, 863999))
         );
         assert_eq!(
@@ -407,7 +414,8 @@ mod tests {
                 &pubkey,
                 2 * genesis_config.epoch_schedule.slots_per_epoch - 1, // no schedule generated for epoch 2
                 &bank,
-                None
+                None,
+                std::u64::MAX
             ),
             None
         );
@@ -417,7 +425,8 @@ mod tests {
                 &Pubkey::new_rand(), // not in leader_schedule
                 0,
                 &bank,
-                None
+                None,
+                std::u64::MAX
             ),
             None
         );
@@ -450,7 +459,7 @@ mod tests {
             // Check that the next leader slot after 0 is slot 1
             assert_eq!(
                 cache
-                    .next_leader_slot(&pubkey, 0, &bank, Some(&blockstore))
+                    .next_leader_slot(&pubkey, 0, &bank, Some(&blockstore), std::u64::MAX)
                     .unwrap()
                     .0,
                 1
@@ -462,7 +471,7 @@ mod tests {
             blockstore.insert_shreds(shreds, None, false).unwrap();
             assert_eq!(
                 cache
-                    .next_leader_slot(&pubkey, 0, &bank, Some(&blockstore))
+                    .next_leader_slot(&pubkey, 0, &bank, Some(&blockstore), std::u64::MAX)
                     .unwrap()
                     .0,
                 1
@@ -475,7 +484,7 @@ mod tests {
             blockstore.insert_shreds(shreds, None, false).unwrap();
             assert_eq!(
                 cache
-                    .next_leader_slot(&pubkey, 0, &bank, Some(&blockstore))
+                    .next_leader_slot(&pubkey, 0, &bank, Some(&blockstore), std::u64::MAX)
                     .unwrap()
                     .0,
                 3
@@ -487,7 +496,8 @@ mod tests {
                     &pubkey,
                     2 * genesis_config.epoch_schedule.slots_per_epoch - 1, // no schedule generated for epoch 2
                     &bank,
-                    Some(&blockstore)
+                    Some(&blockstore),
+                    std::u64::MAX
                 ),
                 None
             );
@@ -497,7 +507,8 @@ mod tests {
                     &Pubkey::new_rand(), // not in leader_schedule
                     0,
                     &bank,
-                    Some(&blockstore)
+                    Some(&blockstore),
+                    std::u64::MAX
                 ),
                 None
             );
@@ -553,17 +564,29 @@ mod tests {
 
         // If the max root isn't set, we'll get None
         assert!(cache
-            .next_leader_slot(&node_pubkey, 0, &bank, None)
+            .next_leader_slot(&node_pubkey, 0, &bank, None, std::u64::MAX)
             .is_none());
 
         cache.set_root(&bank);
-        assert_eq!(
+        let res = cache
-            cache
+            .next_leader_slot(&node_pubkey, 0, &bank, None, std::u64::MAX)
-                .next_leader_slot(&node_pubkey, 0, &bank, None)
+            .unwrap();
-                .unwrap()
+
-                .0,
+        assert_eq!(res.0, expected_slot);
-            expected_slot
+        assert!(res.1 >= expected_slot + NUM_CONSECUTIVE_LEADER_SLOTS - 1);
-        );
+
+        let res = cache
+            .next_leader_slot(
+                &node_pubkey,
+                0,
+                &bank,
+                None,
+                NUM_CONSECUTIVE_LEADER_SLOTS - 1,
+            )
+            .unwrap();
+
+        assert_eq!(res.0, expected_slot);
+        assert_eq!(res.1, expected_slot + NUM_CONSECUTIVE_LEADER_SLOTS - 2);
     }
 
     #[test]