diff --git a/core/src/blocktree_processor.rs b/core/src/blocktree_processor.rs
index 6160181662..fd8b89fdff 100644
--- a/core/src/blocktree_processor.rs
+++ b/core/src/blocktree_processor.rs
@@ -204,7 +204,7 @@ pub fn process_blocktree(
             if next_meta.is_full() {
                 let next_bank = Arc::new(Bank::new_from_parent(
                     &bank,
-                    leader_schedule_utils::slot_leader_at(next_slot, &bank),
+                    leader_schedule_utils::slot_leader_at(next_slot, &bank).unwrap(),
                     next_slot,
                 ));
                 trace!("Add child bank for slot={}", next_slot);
diff --git a/core/src/broadcast_stage.rs b/core/src/broadcast_stage.rs
index 41996262a1..6463123921 100644
--- a/core/src/broadcast_stage.rs
+++ b/core/src/broadcast_stage.rs
@@ -43,16 +43,8 @@ impl Broadcast {
         blocktree: &Arc<Blocktree>,
     ) -> Result<()> {
         let timer = Duration::new(1, 0);
-        let (bank, entries) = receiver.recv_timeout(timer)?;
-        let mut broadcast_table = cluster_info
-            .read()
-            .unwrap()
-            .sorted_tvu_peers(&staking_utils::delegated_stakes(&bank));
-        // Layer 1, leader nodes are limited to the fanout size.
-        broadcast_table.truncate(DATA_PLANE_FANOUT);
-        inc_new_counter_info!("broadcast_service-num_peers", broadcast_table.len() + 1);
-
-        let max_tick_height = (bank.slot() + 1) * bank.ticks_per_slot() - 1;
+        let (mut bank, entries) = receiver.recv_timeout(timer)?;
+        let mut max_tick_height = (bank.slot() + 1) * bank.ticks_per_slot() - 1;
 
         let now = Instant::now();
         let mut num_entries = entries.len();
@@ -60,17 +52,35 @@ impl Broadcast {
         let mut last_tick = entries.last().map(|v| v.1).unwrap_or(0);
         ventries.push(entries);
 
-        while let Ok((same_bank, entries)) = receiver.try_recv() {
-            num_entries += entries.len();
-            last_tick = entries.last().map(|v| v.1).unwrap_or(0);
-            ventries.push(entries);
-            assert!(last_tick <= max_tick_height);
-            assert!(same_bank.slot() == bank.slot());
-            if last_tick == max_tick_height {
-                break;
+        assert!(last_tick <= max_tick_height,);
+        if last_tick != max_tick_height {
+            while let Ok((same_bank, entries)) = receiver.try_recv() {
+                // If the bank changed, that implies the previous slot was interrupted and we do not have to
+                // broadcast its entries.
+                if same_bank.slot() != bank.slot() {
+                    num_entries = 0;
+                    ventries.clear();
+                    bank = same_bank.clone();
+                    max_tick_height = (bank.slot() + 1) * bank.ticks_per_slot() - 1;
+                }
+                num_entries += entries.len();
+                last_tick = entries.last().map(|v| v.1).unwrap_or(0);
+                ventries.push(entries);
+                assert!(last_tick <= max_tick_height,);
+                if last_tick == max_tick_height {
+                    break;
+                }
             }
         }
 
+        let mut broadcast_table = cluster_info
+            .read()
+            .unwrap()
+            .sorted_tvu_peers(&staking_utils::delegated_stakes(&bank));
+        // Layer 1, leader nodes are limited to the fanout size.
+        broadcast_table.truncate(DATA_PLANE_FANOUT);
+
+        inc_new_counter_info!("broadcast_service-num_peers", broadcast_table.len() + 1);
         inc_new_counter_info!("broadcast_service-entries_received", num_entries);
 
         let to_blobs_start = Instant::now();
diff --git a/core/src/cluster_tests.rs b/core/src/cluster_tests.rs
index 2ec8ef95b2..6292ffa60e 100644
--- a/core/src/cluster_tests.rs
+++ b/core/src/cluster_tests.rs
@@ -1,10 +1,13 @@
+use crate::blocktree::Blocktree;
 /// Cluster independant integration tests
 ///
 /// All tests must start from an entry point and a funding keypair and
 /// discover the rest of the network.
 use crate::client::mk_client;
 use crate::contact_info::ContactInfo;
+use crate::entry::{Entry, EntrySlice};
 use crate::gossip_service::discover;
+use solana_sdk::hash::Hash;
 use solana_sdk::signature::{Keypair, KeypairUtil};
 use solana_sdk::system_transaction::SystemTransaction;
 use solana_sdk::timing::{DEFAULT_SLOTS_PER_EPOCH, DEFAULT_TICKS_PER_SLOT, NUM_TICKS_PER_SECOND};
@@ -59,6 +62,39 @@ pub fn fullnode_exit(entry_point_info: &ContactInfo, nodes: usize) {
     }
 }
 
+pub fn verify_ledger_ticks(ledger_path: &str, ticks_per_slot: usize) {
+    let ledger = Blocktree::open(ledger_path).unwrap();
+    let zeroth_slot = ledger.get_slot_entries(0, 0, None).unwrap();
+    let last_id = zeroth_slot.last().unwrap().hash;
+    let next_slots = ledger.get_slots_since(&[0]).unwrap().remove(&0).unwrap();
+    let mut pending_slots: Vec<_> = next_slots
+        .into_iter()
+        .map(|slot| (slot, 0, last_id))
+        .collect();
+    while !pending_slots.is_empty() {
+        let (slot, parent_slot, last_id) = pending_slots.pop().unwrap();
+        let next_slots = ledger
+            .get_slots_since(&[slot])
+            .unwrap()
+            .remove(&slot)
+            .unwrap();
+
+        // If you're not the last slot, you should have a full set of ticks
+        let should_verify_ticks = if !next_slots.is_empty() {
+            Some((slot - parent_slot) as usize * ticks_per_slot)
+        } else {
+            None
+        };
+
+        let last_id = verify_slot_ticks(&ledger, slot, &last_id, should_verify_ticks);
+        pending_slots.extend(
+            next_slots
+                .into_iter()
+                .map(|child_slot| (child_slot, slot, last_id)),
+        );
+    }
+}
+
 pub fn kill_entry_and_spend_and_verify_rest(
     entry_point_info: &ContactInfo,
     funding_keypair: &Keypair,
@@ -105,3 +141,23 @@ pub fn kill_entry_and_spend_and_verify_rest(
         }
     }
 }
+
+fn get_and_verify_slot_entries(blocktree: &Blocktree, slot: u64, last_entry: &Hash) -> Vec<Entry> {
+    let entries = blocktree.get_slot_entries(slot, 0, None).unwrap();
+    assert!(entries.verify(last_entry));
+    entries
+}
+
+fn verify_slot_ticks(
+    blocktree: &Blocktree,
+    slot: u64,
+    last_entry: &Hash,
+    expected_num_ticks: Option<usize>,
+) -> Hash {
+    let entries = get_and_verify_slot_entries(blocktree, slot, last_entry);
+    let num_ticks: usize = entries.iter().map(|entry| entry.is_tick() as usize).sum();
+    if let Some(expected_num_ticks) = expected_num_ticks {
+        assert_eq!(num_ticks, expected_num_ticks);
+    }
+    entries.last().unwrap().hash
+}
diff --git a/core/src/leader_schedule_utils.rs b/core/src/leader_schedule_utils.rs
index 7cf68b9b70..acbb670357 100644
--- a/core/src/leader_schedule_utils.rs
+++ b/core/src/leader_schedule_utils.rs
@@ -4,14 +4,14 @@ use solana_runtime::bank::Bank;
 use solana_sdk::pubkey::Pubkey;
 
 /// Return the leader schedule for the given epoch.
-fn leader_schedule(epoch_height: u64, bank: &Bank) -> LeaderSchedule {
-    let stakes = staking_utils::delegated_stakes_at_epoch(bank, epoch_height)
-        .expect("epoch state must exist");
-    let mut seed = [0u8; 32];
-    seed[0..8].copy_from_slice(&epoch_height.to_le_bytes());
-    let mut stakes: Vec<_> = stakes.into_iter().collect();
-    sort_stakes(&mut stakes);
-    LeaderSchedule::new(&stakes, seed, bank.get_slots_in_epoch(epoch_height))
+fn leader_schedule(epoch_height: u64, bank: &Bank) -> Option<LeaderSchedule> {
+    staking_utils::delegated_stakes_at_epoch(bank, epoch_height).map(|stakes| {
+        let mut seed = [0u8; 32];
+        seed[0..8].copy_from_slice(&epoch_height.to_le_bytes());
+        let mut stakes: Vec<_> = stakes.into_iter().collect();
+        sort_stakes(&mut stakes);
+        LeaderSchedule::new(&stakes, seed, bank.get_slots_in_epoch(epoch_height))
+    })
 }
 
 fn sort_stakes(stakes: &mut Vec<(Pubkey, u64)>) {
@@ -31,11 +31,10 @@ fn sort_stakes(stakes: &mut Vec<(Pubkey, u64)>) {
 }
 
 /// Return the leader for the given slot.
-pub fn slot_leader_at(slot: u64, bank: &Bank) -> Pubkey {
+pub fn slot_leader_at(slot: u64, bank: &Bank) -> Option<Pubkey> {
     let (epoch, slot_index) = bank.get_epoch_and_slot_index(slot);
 
-    let leader_schedule = leader_schedule(epoch, bank);
-    leader_schedule[slot_index as usize]
+    leader_schedule(epoch, bank).map(|leader_schedule| leader_schedule[slot_index as usize])
 }
 
 // Returns the number of ticks remaining from the specified tick_height to the end of the
@@ -85,7 +84,7 @@ mod tests {
         )
         .0;
         let bank = Bank::new(&genesis_block);
-        assert_eq!(slot_leader_at(bank.slot(), &bank), pubkey);
+        assert_eq!(slot_leader_at(bank.slot(), &bank).unwrap(), pubkey);
     }
 
     #[test]
diff --git a/core/src/local_cluster.rs b/core/src/local_cluster.rs
index 9e6c9cb310..767c841aac 100644
--- a/core/src/local_cluster.rs
+++ b/core/src/local_cluster.rs
@@ -21,33 +21,26 @@ pub struct LocalCluster {
     pub funding_keypair: Keypair,
     /// Entry point from which the rest of the network can be discovered
     pub entry_point_info: NodeInfo,
+    pub ledger_paths: Vec<String>,
     fullnodes: Vec<Fullnode>,
-    ledger_paths: Vec<String>,
 }
 
 impl LocalCluster {
     pub fn new(num_nodes: usize, cluster_lamports: u64, lamports_per_node: u64) -> Self {
-        Self::new_with_config(
-            num_nodes,
-            cluster_lamports,
-            lamports_per_node,
-            &FullnodeConfig::default(),
-        )
+        let stakes: Vec<_> = (0..num_nodes).map(|_| lamports_per_node).collect();
+        Self::new_with_config(&stakes, cluster_lamports, &FullnodeConfig::default())
     }
 
     pub fn new_with_config(
-        num_nodes: usize,
+        node_stakes: &[u64],
         cluster_lamports: u64,
-        lamports_per_node: u64,
         fullnode_config: &FullnodeConfig,
     ) -> Self {
-        // Must have enough tokens to fund vote account and set delegate
-        assert!(lamports_per_node > 2);
         let leader_keypair = Arc::new(Keypair::new());
         let leader_pubkey = leader_keypair.pubkey();
         let leader_node = Node::new_localhost_with_pubkey(leader_keypair.pubkey());
         let (genesis_block, mint_keypair) =
-            GenesisBlock::new_with_leader(cluster_lamports, leader_pubkey, lamports_per_node);
+            GenesisBlock::new_with_leader(cluster_lamports, leader_pubkey, node_stakes[0]);
         let (genesis_ledger_path, _blockhash) = create_new_tmp_ledger!(&genesis_block);
         let leader_ledger_path = tmp_copy_blocktree!(&genesis_ledger_path);
         let mut ledger_paths = vec![];
@@ -65,7 +58,9 @@ impl LocalCluster {
         );
         let mut fullnodes = vec![leader_server];
         let mut client = mk_client(&leader_node_info);
-        for _ in 0..(num_nodes - 1) {
+        for stake in &node_stakes[1..] {
+            // Must have enough tokens to fund vote account and set delegate
+            assert!(*stake > 2);
             let validator_keypair = Arc::new(Keypair::new());
             let voting_keypair = Keypair::new();
             let validator_pubkey = validator_keypair.pubkey();
@@ -74,12 +69,8 @@ impl LocalCluster {
             ledger_paths.push(ledger_path.clone());
 
             // Send each validator some lamports to vote
-            let validator_balance = Self::transfer(
-                &mut client,
-                &mint_keypair,
-                &validator_pubkey,
-                lamports_per_node,
-            );
+            let validator_balance =
+                Self::transfer(&mut client, &mint_keypair, &validator_pubkey, *stake);
             info!(
                 "validator {} balance {}",
                 validator_pubkey, validator_balance
@@ -89,7 +80,7 @@ impl LocalCluster {
                 &mut client,
                 &voting_keypair,
                 &validator_keypair,
-                lamports_per_node - 1,
+                stake - 1,
             )
             .unwrap();
             let validator_server = Fullnode::new(
@@ -102,7 +93,7 @@ impl LocalCluster {
             );
             fullnodes.push(validator_server);
         }
-        discover(&leader_node_info, num_nodes).unwrap();
+        discover(&leader_node_info, node_stakes.len()).unwrap();
         Self {
             funding_keypair: mint_keypair,
             entry_point_info: leader_node_info,
@@ -116,11 +107,16 @@ impl LocalCluster {
             node.exit();
         }
     }
-    pub fn close(&mut self) {
+
+    pub fn close_preserve_ledgers(&mut self) {
         self.exit();
         while let Some(node) = self.fullnodes.pop() {
             node.join().unwrap();
         }
+    }
+
+    pub fn close(&mut self) {
+        self.close_preserve_ledgers();
         for path in &self.ledger_paths {
             remove_dir_all(path).unwrap();
         }
@@ -204,7 +200,7 @@ impl LocalCluster {
 
 impl Drop for LocalCluster {
     fn drop(&mut self) {
-        self.close()
+        self.close();
     }
 }
 
@@ -224,7 +220,7 @@ mod test {
         solana_logger::setup();
         let mut fullnode_exit = FullnodeConfig::default();
         fullnode_exit.rpc_config.enable_fullnode_exit = true;
-        let cluster = LocalCluster::new_with_config(1, 100, 3, &fullnode_exit);
+        let cluster = LocalCluster::new_with_config(&[3], 100, &fullnode_exit);
         drop(cluster)
     }
 }
diff --git a/core/src/replay_stage.rs b/core/src/replay_stage.rs
index abf82f662e..1d52d39c78 100644
--- a/core/src/replay_stage.rs
+++ b/core/src/replay_stage.rs
@@ -90,6 +90,7 @@ impl ReplayStage {
                     let active_banks = bank_forks.read().unwrap().active_banks();
                     trace!("active banks {:?}", active_banks);
                     let mut votable: Vec<u64> = vec![];
+                    let mut is_tpu_bank_active = poh_recorder.lock().unwrap().bank().is_some();
                     for bank_slot in &active_banks {
                         let bank = bank_forks.read().unwrap().get(*bank_slot).unwrap().clone();
                         if bank.collector_id() != my_id {
@@ -141,9 +142,13 @@ impl ReplayStage {
                             .lock()
                             .unwrap()
                             .reset(parent.tick_height(), parent.last_blockhash());
+                        is_tpu_bank_active = false;
+                    }
+
+                    if !is_tpu_bank_active {
+                        Self::start_leader(my_id, &bank_forks, &poh_recorder, &cluster_info);
                     }
 
-                    Self::start_leader(my_id, &bank_forks, &poh_recorder, &cluster_info);
                     inc_new_counter_info!(
                         "replicate_stage-duration",
                         duration_as_ms(&now.elapsed()) as usize
@@ -182,30 +187,36 @@ impl ReplayStage {
             assert!(frozen.get(&poh_slot).is_none());
             trace!("checking poh slot for leader {}", poh_slot);
             if bank_forks.read().unwrap().get(poh_slot).is_none() {
-                let next_leader = leader_schedule_utils::slot_leader_at(poh_slot, parent);
-                debug!(
-                    "me: {} leader {} at poh slot {}",
-                    my_id, next_leader, poh_slot
-                );
-                cluster_info.write().unwrap().set_leader(next_leader);
-                if next_leader == my_id {
-                    debug!("starting tpu for slot {}", poh_slot);
-                    let tpu_bank = Bank::new_from_parent(parent, my_id, poh_slot);
-                    bank_forks.write().unwrap().insert(poh_slot, tpu_bank);
-                    if let Some(tpu_bank) = bank_forks.read().unwrap().get(poh_slot).cloned() {
-                        assert_eq!(
-                            bank_forks.read().unwrap().working_bank().slot(),
-                            tpu_bank.slot()
-                        );
+                leader_schedule_utils::slot_leader_at(poh_slot, parent)
+                    .map(|next_leader| {
                         debug!(
-                            "poh_recorder new working bank: me: {} next_slot: {} next_leader: {}",
-                            my_id,
-                            tpu_bank.slot(),
-                            next_leader
+                            "me: {} leader {} at poh slot {}",
+                            my_id, next_leader, poh_slot
                         );
-                        poh_recorder.lock().unwrap().set_bank(&tpu_bank);
-                    }
-                }
+                        cluster_info.write().unwrap().set_leader(next_leader);
+                        if next_leader == my_id {
+                            debug!("starting tpu for slot {}", poh_slot);
+                            let tpu_bank = Bank::new_from_parent(parent, my_id, poh_slot);
+                            bank_forks.write().unwrap().insert(poh_slot, tpu_bank);
+                            if let Some(tpu_bank) = bank_forks.read().unwrap().get(poh_slot).cloned() {
+                                assert_eq!(
+                                    bank_forks.read().unwrap().working_bank().slot(),
+                                    tpu_bank.slot()
+                                );
+                                debug!(
+                                    "poh_recorder new working bank: me: {} next_slot: {} next_leader: {}",
+                                    my_id,
+                                    tpu_bank.slot(),
+                                    next_leader
+                                );
+                                poh_recorder.lock().unwrap().set_bank(&tpu_bank);
+                            }
+                        }
+                    })
+                    .or_else(|| {
+                        error!("No next leader found");
+                        None
+                    });
             }
         } else {
             error!("No frozen banks available!");
@@ -308,7 +319,7 @@ impl ReplayStage {
                     trace!("child already active {}", child_id);
                     continue;
                 }
-                let leader = leader_schedule_utils::slot_leader_at(child_id, &parent_bank);
+                let leader = leader_schedule_utils::slot_leader_at(child_id, &parent_bank).unwrap();
                 info!("new fork:{} parent:{}", child_id, parent_id);
                 forks.insert(
                     child_id,
diff --git a/tests/local_cluster.rs b/tests/local_cluster.rs
index 807021a873..842dc6dd00 100644
--- a/tests/local_cluster.rs
+++ b/tests/local_cluster.rs
@@ -3,6 +3,10 @@ extern crate solana;
 use solana::cluster_tests;
 use solana::fullnode::FullnodeConfig;
 use solana::local_cluster::LocalCluster;
+use solana::poh_service::PohServiceConfig;
+use solana_sdk::timing::{DEFAULT_SLOTS_PER_EPOCH, DEFAULT_TICKS_PER_SLOT};
+use std::thread::sleep;
+use std::time::Duration;
 
 #[test]
 fn test_spend_and_verify_all_nodes_1() {
@@ -55,7 +59,7 @@ fn test_fullnode_exit_2() {
     let num_nodes = 2;
     let mut fullnode_config = FullnodeConfig::default();
     fullnode_config.rpc_config.enable_fullnode_exit = true;
-    let local = LocalCluster::new_with_config(num_nodes, 10_000, 100, &fullnode_config);
+    let local = LocalCluster::new_with_config(&[100; 2], 10_000, &fullnode_config);
     cluster_tests::fullnode_exit(&local.entry_point_info, num_nodes);
 }
 
@@ -64,7 +68,7 @@ fn test_leader_failure_2() {
     let num_nodes = 2;
     let mut fullnode_config = FullnodeConfig::default();
     fullnode_config.rpc_config.enable_fullnode_exit = true;
-    let local = LocalCluster::new_with_config(num_nodes, 10_000, 100, &fullnode_config);
+    let local = LocalCluster::new_with_config(&[100; 2], 10_000, &fullnode_config);
     cluster_tests::kill_entry_and_spend_and_verify_rest(
         &local.entry_point_info,
         &local.funding_keypair,
@@ -77,10 +81,31 @@ fn test_leader_failure_3() {
     let num_nodes = 3;
     let mut fullnode_config = FullnodeConfig::default();
     fullnode_config.rpc_config.enable_fullnode_exit = true;
-    let local = LocalCluster::new_with_config(num_nodes, 10_000, 100, &fullnode_config);
+    let local = LocalCluster::new_with_config(&[100; 3], 10_000, &fullnode_config);
     cluster_tests::kill_entry_and_spend_and_verify_rest(
         &local.entry_point_info,
         &local.funding_keypair,
         num_nodes,
     );
 }
+
+#[test]
+fn test_two_unbalanced_stakes() {
+    let mut fullnode_config = FullnodeConfig::default();
+    let num_ticks_per_second = 100;
+    fullnode_config.tick_config =
+        PohServiceConfig::Sleep(Duration::from_millis(100 / num_ticks_per_second));
+    fullnode_config.rpc_config.enable_fullnode_exit = true;
+    let mut cluster = LocalCluster::new_with_config(&[999_990, 3], 1_000_000, &fullnode_config);
+    let num_epochs_to_sleep = 10;
+    let num_ticks_to_sleep = num_epochs_to_sleep * DEFAULT_TICKS_PER_SLOT * DEFAULT_SLOTS_PER_EPOCH;
+    sleep(Duration::from_millis(
+        num_ticks_to_sleep / num_ticks_per_second * 100,
+    ));
+
+    cluster.close_preserve_ledgers();
+    let leader_ledger = cluster.ledger_paths[1].clone();
+    cluster_tests::verify_ledger_ticks(&leader_ledger, DEFAULT_TICKS_PER_SLOT as usize);
+
+    drop(cluster);
+}