Add local cluster tests that broadcast duplicate slots (#13995) (#17863)

* Add duplicate node local cluster test

* fix clippy

* remove dupe test

(cherry picked from commit 050bb54)

Co-authored-by: Justin Starry <justin@solana.com>

core/src/broadcast_stage.rs

@@ -1,6 +1,7 @@
 //! A stage to broadcast data from a leader node to validators
 #![allow(clippy::rc_buffer)]
 use self::{
+    broadcast_duplicates_run::BroadcastDuplicatesRun,
     broadcast_fake_shreds_run::BroadcastFakeShredsRun, broadcast_metrics::*,
     fail_entry_verification_broadcast_run::FailEntryVerificationBroadcastRun,
     standard_broadcast_run::StandardBroadcastRun,
@@ -35,6 +36,7 @@ use std::{
     time::{Duration, Instant},
 };
 
+mod broadcast_duplicates_run;
 mod broadcast_fake_shreds_run;
 pub mod broadcast_metrics;
 pub(crate) mod broadcast_utils;
@@ -52,11 +54,20 @@ pub enum BroadcastStageReturnType {
     ChannelDisconnected,
 }
 
+#[derive(PartialEq, Clone, Debug)]
+pub struct BroadcastDuplicatesConfig {
+    /// Percentage of stake to send different version of slots to
+    pub stake_partition: u8,
+    /// Number of slots to wait before sending duplicate shreds
+    pub duplicate_send_delay: usize,
+}
+
 #[derive(PartialEq, Clone, Debug)]
 pub enum BroadcastStageType {
     Standard,
     FailEntryVerification,
     BroadcastFakeShreds,
+    BroadcastDuplicates(BroadcastDuplicatesConfig),
 }
 
 impl BroadcastStageType {
@@ -101,6 +112,16 @@ impl BroadcastStageType {
                 blockstore,
                 BroadcastFakeShredsRun::new(keypair, 0, shred_version),
             ),
+
+            BroadcastStageType::BroadcastDuplicates(config) => BroadcastStage::new(
+                sock,
+                cluster_info,
+                receiver,
+                retransmit_slots_receiver,
+                exit_sender,
+                blockstore,
+                BroadcastDuplicatesRun::new(keypair, shred_version, config.clone()),
+            ),
         }
     }
 }

core/src/broadcast_stage/broadcast_duplicates_run.rs

@@ -0,0 +1,333 @@
+use super::broadcast_utils::ReceiveResults;
+use super::*;
+use log::*;
+use solana_ledger::entry::{create_ticks, Entry, EntrySlice};
+use solana_ledger::shred::Shredder;
+use solana_runtime::blockhash_queue::BlockhashQueue;
+use solana_sdk::clock::Slot;
+use solana_sdk::fee_calculator::FeeCalculator;
+use solana_sdk::hash::Hash;
+use solana_sdk::signature::{Keypair, Signer};
+use solana_sdk::transaction::Transaction;
+use std::collections::VecDeque;
+use std::sync::Mutex;
+
+// Queue which facilitates delivering shreds with a delay
+type DelayedQueue = VecDeque<(Option<Pubkey>, Option<Vec<Shred>>)>;
+
+#[derive(Clone)]
+pub(super) struct BroadcastDuplicatesRun {
+    config: BroadcastDuplicatesConfig,
+    // Local queue for broadcast to track which duplicate blockhashes we've sent
+    duplicate_queue: BlockhashQueue,
+    // Shared queue between broadcast and transmit threads
+    delayed_queue: Arc<Mutex<DelayedQueue>>,
+    // Buffer for duplicate entries
+    duplicate_entries_buffer: Vec<Entry>,
+    last_duplicate_entry_hash: Hash,
+    last_broadcast_slot: Slot,
+    next_shred_index: u32,
+    shred_version: u16,
+    keypair: Arc<Keypair>,
+}
+
+impl BroadcastDuplicatesRun {
+    pub(super) fn new(
+        keypair: Arc<Keypair>,
+        shred_version: u16,
+        config: BroadcastDuplicatesConfig,
+    ) -> Self {
+        let mut delayed_queue = DelayedQueue::new();
+        delayed_queue.resize(config.duplicate_send_delay, (None, None));
+        Self {
+            config,
+            delayed_queue: Arc::new(Mutex::new(delayed_queue)),
+            duplicate_queue: BlockhashQueue::default(),
+            duplicate_entries_buffer: vec![],
+            next_shred_index: u32::MAX,
+            last_broadcast_slot: 0,
+            last_duplicate_entry_hash: Hash::default(),
+            shred_version,
+            keypair,
+        }
+    }
+
+    fn queue_or_create_duplicate_entries(
+        &mut self,
+        bank: &Arc<Bank>,
+        receive_results: &ReceiveResults,
+    ) -> (Vec<Entry>, u32) {
+        // If the last entry hash is default, grab the last blockhash from the parent bank
+        if self.last_duplicate_entry_hash == Hash::default() {
+            self.last_duplicate_entry_hash = bank.last_blockhash();
+        }
+
+        // Create duplicate entries by..
+        //  1) rearranging real entries so that all transaction entries are moved to
+        //     the front and tick entries are moved to the back.
+        //  2) setting all transaction entries to zero hashes and all tick entries to `hashes_per_tick`.
+        //  3) removing any transactions which reference blockhashes which aren't in the
+        //     duplicate blockhash queue.
+        let (duplicate_entries, next_shred_index) = if bank.slot() > MINIMUM_DUPLICATE_SLOT {
+            let mut tx_entries: Vec<Entry> = receive_results
+                .entries
+                .iter()
+                .filter_map(|entry| {
+                    if entry.is_tick() {
+                        return None;
+                    }
+
+                    let transactions: Vec<Transaction> = entry
+                        .transactions
+                        .iter()
+                        .filter(|tx| {
+                            self.duplicate_queue
+                                .get_hash_age(&tx.message.recent_blockhash)
+                                .is_some()
+                        })
+                        .cloned()
+                        .collect();
+                    if !transactions.is_empty() {
+                        Some(Entry::new_mut(
+                            &mut self.last_duplicate_entry_hash,
+                            &mut 0,
+                            transactions,
+                        ))
+                    } else {
+                        None
+                    }
+                })
+                .collect();
+            let mut tick_entries = create_ticks(
+                receive_results.entries.tick_count(),
+                bank.hashes_per_tick().unwrap_or_default(),
+                self.last_duplicate_entry_hash,
+            );
+            self.duplicate_entries_buffer.append(&mut tx_entries);
+            self.duplicate_entries_buffer.append(&mut tick_entries);
+
+            // Only send out duplicate entries when the block is finished otherwise the
+            // recipient will start repairing for shreds they haven't received yet and
+            // hit duplicate slot issues before we want them to.
+            let entries = if receive_results.last_tick_height == bank.max_tick_height() {
+                self.duplicate_entries_buffer.drain(..).collect()
+            } else {
+                vec![]
+            };
+
+            // Set next shred index to 0 since we are sending the full slot
+            (entries, 0)
+        } else {
+            // Send real entries until we hit min duplicate slot
+            (receive_results.entries.clone(), self.next_shred_index)
+        };
+
+        // Save last duplicate entry hash to avoid invalid entry hash errors
+        if let Some(last_duplicate_entry) = duplicate_entries.last() {
+            self.last_duplicate_entry_hash = last_duplicate_entry.hash;
+        }
+
+        (duplicate_entries, next_shred_index)
+    }
+}
+
+/// Duplicate slots should only be sent once all validators have started.
+/// This constant is intended to be used as a buffer so that all validators
+/// are live before sending duplicate slots.
+pub const MINIMUM_DUPLICATE_SLOT: Slot = 20;
+
+impl BroadcastRun for BroadcastDuplicatesRun {
+    fn run(
+        &mut self,
+        blockstore: &Arc<Blockstore>,
+        receiver: &Receiver<WorkingBankEntry>,
+        socket_sender: &Sender<(TransmitShreds, Option<BroadcastShredBatchInfo>)>,
+        blockstore_sender: &Sender<(Arc<Vec<Shred>>, Option<BroadcastShredBatchInfo>)>,
+    ) -> Result<()> {
+        // 1) Pull entries from banking stage
+        let receive_results = broadcast_utils::recv_slot_entries(receiver)?;
+        let bank = receive_results.bank.clone();
+        let last_tick_height = receive_results.last_tick_height;
+
+        if self.next_shred_index == u32::MAX {
+            self.next_shred_index = blockstore
+                .meta(bank.slot())
+                .expect("Database error")
+                .map(|meta| meta.consumed)
+                .unwrap_or(0) as u32
+        }
+
+        // We were not the leader, but just became leader again
+        if bank.slot() > self.last_broadcast_slot + 1 {
+            self.last_duplicate_entry_hash = Hash::default();
+        }
+        self.last_broadcast_slot = bank.slot();
+
+        let shredder = Shredder::new(
+            bank.slot(),
+            bank.parent().unwrap().slot(),
+            self.keypair.clone(),
+            (bank.tick_height() % bank.ticks_per_slot()) as u8,
+            self.shred_version,
+        )
+        .expect("Expected to create a new shredder");
+
+        let (data_shreds, coding_shreds, last_shred_index) = shredder.entries_to_shreds(
+            &receive_results.entries,
+            last_tick_height == bank.max_tick_height(),
+            self.next_shred_index,
+        );
+
+        let (duplicate_entries, next_duplicate_shred_index) =
+            self.queue_or_create_duplicate_entries(&bank, &receive_results);
+        let (duplicate_data_shreds, duplicate_coding_shreds, _) = if !duplicate_entries.is_empty() {
+            shredder.entries_to_shreds(
+                &duplicate_entries,
+                last_tick_height == bank.max_tick_height(),
+                next_duplicate_shred_index,
+            )
+        } else {
+            (vec![], vec![], 0)
+        };
+
+        // Manually track the shred index because relying on slot meta consumed is racy
+        if last_tick_height == bank.max_tick_height() {
+            self.next_shred_index = 0;
+            self.duplicate_queue
+                .register_hash(&self.last_duplicate_entry_hash, &FeeCalculator::default());
+        } else {
+            self.next_shred_index = last_shred_index;
+        }
+
+        // Partition network with duplicate and real shreds based on stake
+        let bank_epoch = bank.get_leader_schedule_epoch(bank.slot());
+        let mut duplicate_recipients = HashMap::new();
+        let mut real_recipients = HashMap::new();
+
+        let mut stakes: Vec<(Pubkey, u64)> = bank
+            .epoch_staked_nodes(bank_epoch)
+            .unwrap()
+            .into_iter()
+            .filter(|(pubkey, _)| *pubkey != self.keypair.pubkey())
+            .collect();
+        stakes.sort_by(|(l_key, l_stake), (r_key, r_stake)| {
+            if r_stake == l_stake {
+                l_key.cmp(&r_key)
+            } else {
+                r_stake.cmp(&l_stake)
+            }
+        });
+
+        let highest_staked_node = stakes.first().cloned().map(|x| x.0);
+        let stake_total: u64 = stakes.iter().map(|(_, stake)| *stake).sum();
+        let mut cumulative_stake: u64 = 0;
+        for (pubkey, stake) in stakes.into_iter().rev() {
+            cumulative_stake += stake;
+            if (100 * cumulative_stake / stake_total) as u8 <= self.config.stake_partition {
+                duplicate_recipients.insert(pubkey, stake);
+            } else {
+                real_recipients.insert(pubkey, stake);
+            }
+        }
+
+        if let Some(highest_staked_node) = highest_staked_node {
+            if bank.slot() > MINIMUM_DUPLICATE_SLOT && last_tick_height == bank.max_tick_height() {
+                warn!(
+                    "{} sent duplicate slot {} to nodes: {:?}",
+                    self.keypair.pubkey(),
+                    bank.slot(),
+                    &duplicate_recipients,
+                );
+                warn!(
+                    "Duplicate shreds for slot {} will be broadcast in {} slot(s)",
+                    bank.slot(),
+                    self.config.duplicate_send_delay
+                );
+
+                let delayed_shreds: Option<Vec<Shred>> = vec![
+                    duplicate_data_shreds.last().cloned(),
+                    data_shreds.last().cloned(),
+                ]
+                .into_iter()
+                .collect();
+                self.delayed_queue
+                    .lock()
+                    .unwrap()
+                    .push_back((Some(highest_staked_node), delayed_shreds));
+            }
+        }
+
+        let duplicate_recipients = Arc::new(duplicate_recipients);
+        let real_recipients = Arc::new(real_recipients);
+
+        let data_shreds = Arc::new(data_shreds);
+        blockstore_sender.send((data_shreds.clone(), None))?;
+
+        // 3) Start broadcast step
+        socket_sender.send((
+            (
+                Some(duplicate_recipients.clone()),
+                Arc::new(duplicate_data_shreds),
+            ),
+            None,
+        ))?;
+        socket_sender.send((
+            (
+                Some(duplicate_recipients),
+                Arc::new(duplicate_coding_shreds),
+            ),
+            None,
+        ))?;
+        socket_sender.send(((Some(real_recipients.clone()), data_shreds), None))?;
+        socket_sender.send(((Some(real_recipients), Arc::new(coding_shreds)), None))?;
+
+        Ok(())
+    }
+    fn transmit(
+        &mut self,
+        receiver: &Arc<Mutex<TransmitReceiver>>,
+        cluster_info: &ClusterInfo,
+        sock: &UdpSocket,
+    ) -> Result<()> {
+        // Check the delay queue for shreds that are ready to be sent
+        let (delayed_recipient, delayed_shreds) = {
+            let mut delayed_deque = self.delayed_queue.lock().unwrap();
+            if delayed_deque.len() > self.config.duplicate_send_delay {
+                delayed_deque.pop_front().unwrap()
+            } else {
+                (None, None)
+            }
+        };
+
+        let ((stakes, shreds), _) = receiver.lock().unwrap().recv()?;
+        let stakes = stakes.unwrap();
+        for peer in cluster_info.tvu_peers() {
+            // Forward shreds to circumvent gossip
+            if stakes.get(&peer.id).is_some() {
+                shreds.iter().for_each(|shred| {
+                    sock.send_to(&shred.payload, &peer.tvu_forwards).unwrap();
+                });
+            }
+
+            // After a delay, broadcast duplicate shreds to a single node
+            if let Some(shreds) = delayed_shreds.as_ref() {
+                if Some(peer.id) == delayed_recipient {
+                    shreds.iter().for_each(|shred| {
+                        sock.send_to(&shred.payload, &peer.tvu).unwrap();
+                    });
+                }
+            }
+        }
+
+        Ok(())
+    }
+    fn record(
+        &mut self,
+        receiver: &Arc<Mutex<RecordReceiver>>,
+        blockstore: &Arc<Blockstore>,
+    ) -> Result<()> {
+        let (data_shreds, _) = receiver.lock().unwrap().recv()?;
+        blockstore.insert_shreds(data_shreds.to_vec(), None, true)?;
+        Ok(())
+    }
+}