Add local cluster test to repro slot hash expiry bug (#21873)

core/src/consensus.rs

@@ -105,7 +105,7 @@ pub(crate) struct ComputedBankState {
 #[frozen_abi(digest = "GMs1FxKteU7K4ZFRofMBqNhBpM4xkPVxfYod6R8DQmpT")]
 #[derive(Clone, Serialize, Deserialize, Debug, PartialEq, AbiExample)]
 pub struct Tower {
-    pub(crate) node_pubkey: Pubkey,
+    pub node_pubkey: Pubkey,
     threshold_depth: usize,
     threshold_size: f64,
     vote_state: VoteState,
@@ -432,6 +432,13 @@ impl Tower {
         self.record_bank_vote_and_update_lockouts(slot, hash, self.last_voted_slot())
     }
 
+    /// Used for tests
+    pub fn increase_lockout(&mut self, confirmation_count_increase: u32) {
+        for vote in self.vote_state.votes.iter_mut() {
+            vote.confirmation_count += confirmation_count_increase;
+        }
+    }
+
     pub fn last_voted_slot(&self) -> Option<Slot> {
         self.last_vote.slots.last().copied()
     }

local-cluster/src/local_cluster.rs

@@ -66,6 +66,8 @@ pub struct ClusterConfig {
     pub validator_keys: Option<Vec<(Arc<Keypair>, bool)>>,
     /// The stakes of each node
     pub node_stakes: Vec<u64>,
+    /// Optional vote keypairs to use for each node
+    pub node_vote_keys: Option<Vec<Arc<Keypair>>>,
     /// The total lamports available to the cluster
     pub cluster_lamports: u64,
     pub ticks_per_slot: u64,
@@ -85,6 +87,7 @@ impl Default for ClusterConfig {
             num_listeners: 0,
             validator_keys: None,
             node_stakes: vec![],
+            node_vote_keys: None,
             cluster_lamports: 0,
             ticks_per_slot: DEFAULT_TICKS_PER_SLOT,
             slots_per_epoch: DEFAULT_DEV_SLOTS_PER_EPOCH,
@@ -129,6 +132,7 @@ impl LocalCluster {
 
     pub fn new(config: &mut ClusterConfig, socket_addr_space: SocketAddrSpace) -> Self {
         assert_eq!(config.validator_configs.len(), config.node_stakes.len());
+
         let mut validator_keys = {
             if let Some(ref keys) = config.validator_keys {
                 assert_eq!(config.validator_configs.len(), keys.len());
@@ -140,16 +144,29 @@ impl LocalCluster {
             }
         };
 
+        let vote_keys = {
+            if let Some(ref node_vote_keys) = config.node_vote_keys {
+                assert_eq!(config.validator_configs.len(), node_vote_keys.len());
+                node_vote_keys.clone()
+            } else {
+                iter::repeat_with(|| Arc::new(Keypair::new()))
+                    .take(config.validator_configs.len())
+                    .collect()
+            }
+        };
+
         // Bootstrap leader should always be in genesis block
         validator_keys[0].1 = true;
         let (keys_in_genesis, stakes_in_genesis): (Vec<ValidatorVoteKeypairs>, Vec<u64>) =
             validator_keys
                 .iter()
                 .zip(&config.node_stakes)
-                .filter_map(|((node_keypair, in_genesis), stake)| {
+                .zip(&vote_keys)
+                .filter_map(|(((node_keypair, in_genesis), stake), vote_keypair)| {
                     info!(
-                        "STARTING LOCAL CLUSTER: key {} has {} stake",
+                        "STARTING LOCAL CLUSTER: key {} vote_key {} has {} stake",
                         node_keypair.pubkey(),
+                        vote_keypair.pubkey(),
                         stake
                     );
                     if *in_genesis {
@@ -157,7 +174,8 @@ impl LocalCluster {
                             ValidatorVoteKeypairs {
                                 node_keypair: Keypair::from_bytes(&node_keypair.to_bytes())
                                     .unwrap(),
-                                vote_keypair: Keypair::new(),
+                                vote_keypair: Keypair::from_bytes(&vote_keypair.to_bytes())
+                                    .unwrap(),
                                 stake_keypair: Keypair::new(),
                             },
                             stake,
@@ -171,6 +189,7 @@ impl LocalCluster {
         let leader_vote_keypair = &keys_in_genesis[0].vote_keypair;
         let leader_pubkey = leader_keypair.pubkey();
         let leader_node = Node::new_localhost_with_pubkey(&leader_pubkey);
+
         let GenesisConfigInfo {
             mut genesis_config,
             mint_keypair,

local-cluster/tests/local_cluster.rs

@@ -2,9 +2,10 @@
 use {
     assert_matches::assert_matches,
     common::{
-        create_custom_leader_schedule, last_vote_in_tower, ms_for_n_slots, open_blockstore,
-        purge_slots, remove_tower, restore_tower, run_cluster_partition,
-        run_kill_partition_switch_threshold, test_faulty_node, RUST_LOG_FILTER,
+        copy_blocks, create_custom_leader_schedule, last_vote_in_tower, ms_for_n_slots,
+        open_blockstore, purge_slots, remove_tower, restore_tower, run_cluster_partition,
+        run_kill_partition_switch_threshold, test_faulty_node,
+        wait_for_last_vote_in_tower_to_land_in_ledger, RUST_LOG_FILTER,
     },
     crossbeam_channel::{unbounded, Receiver},
     gag::BufferRedirect,
@@ -1920,6 +1921,206 @@ fn root_in_tower(tower_path: &Path, node_pubkey: &Pubkey) -> Option<Slot> {
     restore_tower(tower_path, node_pubkey).map(|tower| tower.root())
 }
 
+// This test verifies that even if votes from a validator end up taking too long to land, and thus
+// some of the referenced slots are slots are no longer present in the slot hashes sysvar,
+// consensus can still be attained.
+//
+// Validator A (60%)
+// Validator B (40%)
+//                                  / --- 10 --- [..] --- 16 (B is voting, due to network issues is initally not able to see the other fork at all)
+//                                 /
+// 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 (A votes 1 - 9 votes are landing normally. B does the same however votes are not landing)
+//                                 \
+//                                  \--[..]-- 73  (majority fork)
+// A is voting on the majority fork and B wants to switch to this fork however in this majority fork
+// the earlier votes for B (1 - 9) never landed so when B eventually goes to vote on 73, slots in
+// its local vote state are no longer present in slot hashes.
+//
+// 1. Wait for B's tower to see local vote state was updated to new fork
+// 2. Wait X blocks, check B's vote state on chain has been properly updated
+//
+// NOTE: it is not reliable for B to organically have 1 to reach 2^16 lockout, so we simulate the 6
+// consecutive votes on the minor fork by manually incrementing the confirmation levels for the
+// common ancestor votes in tower.
+// To allow this test to run in a reasonable time we change the
+// slot_hash expiry to 64 slots.
+
+#[test]
+#[ignore]
+fn test_slot_hash_expiry() {
+    solana_logger::setup_with_default(RUST_LOG_FILTER);
+    solana_sdk::slot_hashes::set_entries_for_tests_only(64);
+
+    let slots_per_epoch = 2048;
+    let node_stakes = vec![60, 40];
+    let validator_keys = vec![
+        "28bN3xyvrP4E8LwEgtLjhnkb7cY4amQb6DrYAbAYjgRV4GAGgkVM2K7wnxnAS7WDneuavza7x21MiafLu1HkwQt4",
+        "2saHBBoTkLMmttmPQP8KfBkcCw45S5cwtV3wTdGCscRC8uxdgvHxpHiWXKx4LvJjNJtnNcbSv5NdheokFFqnNDt8",
+    ]
+    .iter()
+    .map(|s| (Arc::new(Keypair::from_base58_string(s)), true))
+    .collect::<Vec<_>>();
+    let node_vote_keys = vec![
+        "3NDQ3ud86RTVg8hTy2dDWnS4P8NfjhZ2gDgQAJbr3heaKaUVS1FW3sTLKA1GmDrY9aySzsa4QxpDkbLv47yHxzr3",
+        "46ZHpHE6PEvXYPu3hf9iQqjBk2ZNDaJ9ejqKWHEjxaQjpAGasKaWKbKHbP3646oZhfgDRzx95DH9PCBKKsoCVngk",
+    ]
+    .iter()
+    .map(|s| Arc::new(Keypair::from_base58_string(s)))
+    .collect::<Vec<_>>();
+    let vs = validator_keys
+        .iter()
+        .map(|(kp, _)| kp.pubkey())
+        .collect::<Vec<_>>();
+    let (a_pubkey, b_pubkey) = (vs[0], vs[1]);
+
+    // We want B to not vote (we are trying to simulate its votes not landing until it gets to the
+    // minority fork)
+    let mut validator_configs =
+        make_identical_validator_configs(&ValidatorConfig::default(), node_stakes.len());
+    validator_configs[1].voting_disabled = true;
+
+    let mut config = ClusterConfig {
+        cluster_lamports: 100_000,
+        node_stakes,
+        validator_configs,
+        validator_keys: Some(validator_keys),
+        node_vote_keys: Some(node_vote_keys),
+        slots_per_epoch,
+        stakers_slot_offset: slots_per_epoch,
+        skip_warmup_slots: true,
+        ..ClusterConfig::default()
+    };
+    let mut cluster = LocalCluster::new(&mut config, SocketAddrSpace::Unspecified);
+
+    let mut common_ancestor_slot = 8;
+
+    let a_ledger_path = cluster.ledger_path(&a_pubkey);
+    let b_ledger_path = cluster.ledger_path(&b_pubkey);
+
+    // Immediately kill B (we just needed it for the initial stake distribution)
+    info!("Killing B");
+    let mut b_info = cluster.exit_node(&b_pubkey);
+
+    // Let A run for a while until we get to the common ancestor
+    info!("Letting A run until common_ancestor_slot");
+    loop {
+        if let Some((last_vote, _)) = last_vote_in_tower(&a_ledger_path, &a_pubkey) {
+            if last_vote >= common_ancestor_slot {
+                break;
+            }
+        }
+        sleep(Duration::from_millis(100));
+    }
+
+    // Keep A running, but setup B so that it thinks it has voted up until common ancestor (but
+    // doesn't know anything past that)
+    {
+        info!("Copying A's ledger to B");
+        std::fs::remove_dir_all(&b_info.info.ledger_path).unwrap();
+        let mut opt = fs_extra::dir::CopyOptions::new();
+        opt.copy_inside = true;
+        fs_extra::dir::copy(&a_ledger_path, &b_ledger_path, &opt).unwrap();
+
+        // remove A's tower in B's new copied ledger
+        info!("Removing A's tower in B's ledger dir");
+        remove_tower(&b_ledger_path, &a_pubkey);
+
+        // load A's tower and save it as B's tower
+        info!("Loading A's tower");
+        if let Some(mut a_tower) = restore_tower(&a_ledger_path, &a_pubkey) {
+            a_tower.node_pubkey = b_pubkey;
+            // Update common_ancestor_slot because A is still running
+            if let Some(s) = a_tower.last_voted_slot() {
+                common_ancestor_slot = s;
+                info!("New common_ancestor_slot {}", common_ancestor_slot);
+            } else {
+                panic!("A's tower has no votes");
+            }
+            info!("Increase lockout by 6 confirmation levels and save as B's tower");
+            a_tower.increase_lockout(6);
+            save_tower(&b_ledger_path, &a_tower, &b_info.info.keypair);
+            info!("B's new tower: {:?}", a_tower.tower_slots());
+        } else {
+            panic!("A's tower is missing");
+        }
+
+        // Get rid of any slots past common_ancestor_slot
+        info!("Removing extra slots from B's blockstore");
+        let blockstore = open_blockstore(&b_ledger_path);
+        purge_slots(&blockstore, common_ancestor_slot + 1, 100);
+    }
+
+    info!(
+        "Run A on majority fork until it reaches slot hash expiry {}",
+        solana_sdk::slot_hashes::get_entries()
+    );
+    let mut last_vote_on_a;
+    // Keep A running for a while longer so the majority fork has some decent size
+    loop {
+        last_vote_on_a = wait_for_last_vote_in_tower_to_land_in_ledger(&a_ledger_path, &a_pubkey);
+        if last_vote_on_a
+            >= common_ancestor_slot + 2 * (solana_sdk::slot_hashes::get_entries() as u64)
+        {
+            let blockstore = open_blockstore(&a_ledger_path);
+            info!(
+                "A majority fork: {:?}",
+                AncestorIterator::new(last_vote_on_a, &blockstore).collect::<Vec<Slot>>()
+            );
+            break;
+        }
+        sleep(Duration::from_millis(100));
+    }
+
+    // Kill A and restart B with voting. B should now fork off
+    info!("Killing A");
+    let a_info = cluster.exit_node(&a_pubkey);
+
+    info!("Restarting B");
+    b_info.config.voting_disabled = false;
+    cluster.restart_node(&b_pubkey, b_info, SocketAddrSpace::Unspecified);
+
+    // B will fork off and accumulate enough lockout
+    info!("Allowing B to fork");
+    loop {
+        let blockstore = open_blockstore(&b_ledger_path);
+        let last_vote = wait_for_last_vote_in_tower_to_land_in_ledger(&b_ledger_path, &b_pubkey);
+        let mut ancestors = AncestorIterator::new(last_vote, &blockstore);
+        if let Some(index) = ancestors.position(|x| x == common_ancestor_slot) {
+            if index > 7 {
+                info!(
+                    "B has forked for enough lockout: {:?}",
+                    AncestorIterator::new(last_vote, &blockstore).collect::<Vec<Slot>>()
+                );
+                break;
+            }
+        }
+        sleep(Duration::from_millis(1000));
+    }
+
+    info!("Kill B");
+    b_info = cluster.exit_node(&b_pubkey);
+
+    info!("Resolve the partition");
+    {
+        // Here we let B know about the missing blocks that A had produced on its partition
+        let a_blockstore = open_blockstore(&a_ledger_path);
+        let b_blockstore = open_blockstore(&b_ledger_path);
+        copy_blocks(last_vote_on_a, &a_blockstore, &b_blockstore);
+    }
+
+    // Now restart A and B and see if B is able to eventually switch onto the majority fork
+    info!("Restarting A & B");
+    cluster.restart_node(&a_pubkey, a_info, SocketAddrSpace::Unspecified);
+    cluster.restart_node(&b_pubkey, b_info, SocketAddrSpace::Unspecified);
+
+    info!("Waiting for B to switch to majority fork and make a root");
+    cluster_tests::check_for_new_roots(
+        16,
+        &[cluster.get_contact_info(&a_pubkey).unwrap().clone()],
+        "test_slot_hashes_expiry",
+    );
+}
+
 enum ClusterMode {
     MasterOnly,
     MasterSlave,

sdk/program/src/slot_hashes.rs

@@ -7,9 +7,23 @@ use {
     std::{iter::FromIterator, ops::Deref},
 };
 
+pub use crate::clock::Slot;
+
 pub const MAX_ENTRIES: usize = 512; // about 2.5 minutes to get your vote in
 
-pub use crate::clock::Slot;
+// This is to allow tests with custom slot hash expiry to avoid having to generate
+// 512 blocks for such tests.
+static mut NUM_ENTRIES: usize = MAX_ENTRIES;
+
+pub fn get_entries() -> usize {
+    unsafe { NUM_ENTRIES }
+}
+
+pub fn set_entries_for_tests_only(_entries: usize) {
+    unsafe {
+        NUM_ENTRIES = _entries;
+    }
+}
 
 pub type SlotHash = (Slot, Hash);
 
@@ -23,7 +37,7 @@ impl SlotHashes {
             Ok(index) => (self.0)[index] = (slot, hash),
             Err(index) => (self.0).insert(index, (slot, hash)),
         }
-        (self.0).truncate(MAX_ENTRIES);
+        (self.0).truncate(get_entries());
     }
     pub fn position(&self, slot: &Slot) -> Option<usize> {
         self.binary_search_by(|(probe, _)| slot.cmp(probe)).ok()