fix: nodes keep out of sync when missing gossiped block (issue #284)

block/block.go

@@ -19,6 +19,7 @@
 func (m *Manager) applyBlock(ctx context.Context, block *types.Block, commit *types.Commit, blockMetaData blockMetaData) error {
 	if block.Header.Height != m.store.Height()+1 {
 		// We crashed after the commit and before updating the store height.
+		m.logger.Error("Block not applied. Wrong height", "block height", block.Header.Height, "store height", m.store.Height())
 		return nil
 	}
 
@@ -112,6 +113,32 @@
 	return nil
 }
 
+func (m *Manager) attemptApplyCachedBlocks(ctx context.Context) error {
+	m.applyCachedBlockMutex.Lock()
+	defer m.applyCachedBlockMutex.Unlock()
+
+	prevCachedBlock, exists := m.prevBlock[m.store.Height()+1]
+
+	for exists {
+		m.logger.Debug("Applying cached block", "height", m.store.Height()+1)
+
+		err := m.applyBlock(ctx, prevCachedBlock, m.prevCommit[m.store.Height()+1], blockMetaData{source: gossipedBlock})
+		if err != nil {
+			m.logger.Debug("Failed to apply previously cached block", "err", err)
+			return err
+		}
+		prevCachedBlock, exists = m.prevBlock[m.store.Height()+1]
+	}
+
+	for k := range m.prevBlock {
+		if k <= m.store.Height() {
+			delete(m.prevBlock, k)
+			delete(m.prevCommit, k)
+		}
+	}
+	return nil
+}
+
 // alignStoreWithApp is responsible for aligning the state of the store and the abci app if necessary.
 func (m *Manager) alignStoreWithApp(ctx context.Context, block *types.Block) (bool, error) {
 	isRequired := false

block/manager.go

@@ -70,15 +70,19 @@
 	shouldProduceBlocksCh chan bool
 	produceEmptyBlockCh   chan bool
 
-	syncTarget         uint64
-	lastSubmissionTime int64
-	batchInProcess     atomic.Value
-	isSyncedCond       sync.Cond
-	produceBlockMutex  sync.Mutex
+	syncTarget            uint64
+	lastSubmissionTime    int64
+	batchInProcess        atomic.Value
+	isSyncedCond          sync.Cond
+	produceBlockMutex     sync.Mutex
+	applyCachedBlockMutex sync.Mutex
 
 	syncCache map[uint64]*types.Block
 
 	logger log.Logger
+
+	prevBlock  map[uint64]*types.Block
+	prevCommit map[uint64]*types.Commit
 }
 
 // getInitialState tries to load lastState from Store, and if it's not available it reads GenesisDoc.
@@ -168,6 +172,8 @@
 		shouldProduceBlocksCh: make(chan bool, 1),
 		produceEmptyBlockCh:   make(chan bool, 1),
 		logger:                logger,
+		prevBlock:             make(map[uint64]*types.Block),
+		prevCommit:            make(map[uint64]*types.Commit),
 	}
 
 	return agg, nil
@@ -212,13 +218,26 @@
 }
 
 func (m *Manager) applyBlockCallback(event pubsub.Message) {
-	m.logger.Debug("Received new block event", "eventData", event.Data())
+	m.logger.Debug("Received new block event", "eventData", event.Data(), "cachedBlocks", len(m.prevBlock))
 	eventData := event.Data().(p2p.GossipedBlock)
 	block := eventData.Block
 	commit := eventData.Commit
-	err := m.applyBlock(context.Background(), &block, &commit, blockMetaData{source: gossipedBlock})
+
+	if block.Header.Height != m.store.Height()+1 {
+		if block.Header.Height > m.store.Height() {
+			m.prevBlock[block.Header.Height] = &block
+			m.prevCommit[block.Header.Height] = &commit
+			m.logger.Debug("Caching block", "block height", block.Header.Height, "store height", m.store.Height())
+		}
+	} else {
+		err := m.applyBlock(context.Background(), &block, &commit, blockMetaData{source: gossipedBlock})
+		if err != nil {
+			m.logger.Debug("Failed to apply block", "err", err)
+		}
+	}
+	err := m.attemptApplyCachedBlocks(context.Background())
 	if err != nil {
-		m.logger.Debug("Failed to apply block", "err", err)
+		m.logger.Debug("Failed to apply previous cached blocks", "err", err)
 	}
 }
 

block/manager_test.go

@@ -57,7 +57,7 @@ func TestInitialState(t *testing.T) {
 
 	// Init p2p client
 	privKey, _, _ := crypto.GenerateEd25519Key(rand.Reader)
-	p2pClient, err := p2p.NewClient(config.P2PConfig{}, privKey, "TestChain", logger)
+	p2pClient, err := p2p.NewClient(config.P2PConfig{}, privKey, "TestChain", 50, logger)
 	assert.NoError(err)
 	assert.NotNil(p2pClient)
 

block/production_test.go

@@ -177,11 +177,12 @@ func TestBatchSubmissionAfterTimeout(t *testing.T) {
 
 	// Init manager with empty blocks feature enabled
 	managerConfig := config.BlockManagerConfig{
-		BlockTime:              blockTime,
-		EmptyBlocksMaxTime:     0,
-		BatchSubmitMaxTime:     submitTimeout,
-		BlockBatchSize:         batchSize,
-		BlockBatchMaxSizeBytes: 1000,
+		BlockTime:               blockTime,
+		EmptyBlocksMaxTime:      0,
+		BatchSubmitMaxTime:      submitTimeout,
+		BlockBatchSize:          batchSize,
+		BlockBatchMaxSizeBytes:  1000,
+		GossipedBlocksCacheSize: 50,
 	}
 
 	manager, err := getManager(managerConfig, nil, nil, 1, 1, 0, proxyApp, nil)

block/retriever.go

@@ -50,19 +50,12 @@
 			return err
 		}
 
-		if settlementBatch.StartHeight != currentHeight+1 {
-			return fmt.Errorf("settlement batch start height (%d) on index (%d) is not the expected", settlementBatch.StartHeight, currStateIdx)
-		}
-
 		err = m.processNextDABatch(ctx, settlementBatch.MetaData.DA.Height)
 		if err != nil {
 			return err
 		}
 
 		currentHeight = m.store.Height()
-		if currentHeight != settlementBatch.EndHeight {
-			return fmt.Errorf("after applying state index (%d), the height (%d) is not as expected (%d)", currStateIdx, currentHeight, settlementBatch.EndHeight)
-		}
 
 		err = m.updateStateIndex(settlementBatch.StateIndex)
 		if err != nil {
@@ -99,6 +92,10 @@
 			}
 		}
 	}
+	err = m.attemptApplyCachedBlocks(ctx)
+	if err != nil {
+		m.logger.Debug("Error applying previous cached blocks", "err", err)
+	}
 	return nil
 }
 

block/testutil.go

@@ -95,7 +95,7 @@ func getManager(conf config.BlockManagerConfig, settlementlc settlement.LayerI,
 
 	// Init p2p client and validator
 	p2pKey, _, _ := crypto.GenerateEd25519Key(rand.Reader)
-	p2pClient, err := p2p.NewClient(config.P2PConfig{}, p2pKey, "TestChain", logger)
+	p2pClient, err := p2p.NewClient(config.P2PConfig{}, p2pKey, "TestChain", 50, logger)
 	if err != nil {
 		return nil, err
 	}
@@ -143,10 +143,11 @@ func initSettlementLayerMock(settlementlc settlement.LayerI, proposer string, pu
 
 func getManagerConfig() config.BlockManagerConfig {
 	return config.BlockManagerConfig{
-		BlockTime:              100 * time.Millisecond,
-		BlockBatchSize:         defaultBatchSize,
-		BlockBatchMaxSizeBytes: 1000,
-		BatchSubmitMaxTime:     30 * time.Minute,
-		NamespaceID:            "0102030405060708",
+		BlockTime:               100 * time.Millisecond,
+		BlockBatchSize:          defaultBatchSize,
+		BlockBatchMaxSizeBytes:  1000,
+		BatchSubmitMaxTime:      30 * time.Minute,
+		NamespaceID:             "0102030405060708",
+		GossipedBlocksCacheSize: 50,
 	}
 }

config/config.go

@@ -47,6 +47,8 @@
 	BlockBatchSize uint64 `mapstructure:"block_batch_size"`
 	// The size of the batch in Bytes. Every batch we'll write to the DA and the settlement layer.
 	BlockBatchMaxSizeBytes uint64 `mapstructure:"block_batch_max_size_bytes"`
+	// The number of messages cached by gossipsub protocol
+	GossipedBlocksCacheSize int `mapstructure:"gossiped_blocks_cache_size"`
 }
 
 // GetViperConfig reads configuration parameters from Viper instance.
@@ -114,6 +116,10 @@
 		return fmt.Errorf("block_batch_size_bytes must be positive")
 	}
 
+	if c.GossipedBlocksCacheSize <= 0 {
+		return fmt.Errorf("gossiped_blocks_cache_size must be positive")
+	}
+
 	return nil
 }
 

config/defaults.go

@@ -26,12 +26,13 @@ func DefaultConfig(home, chainId string) *NodeConfig {
 			Seeds:         ""},
 		Aggregator: true,
 		BlockManagerConfig: BlockManagerConfig{
-			BlockTime:              200 * time.Millisecond,
-			EmptyBlocksMaxTime:     3 * time.Second,
-			BatchSubmitMaxTime:     30 * time.Second,
-			NamespaceID:            "000000000000ffff",
-			BlockBatchSize:         500,
-			BlockBatchMaxSizeBytes: 500000},
+			BlockTime:               200 * time.Millisecond,
+			EmptyBlocksMaxTime:      3 * time.Second,
+			BatchSubmitMaxTime:      30 * time.Second,
+			NamespaceID:             "000000000000ffff",
+			BlockBatchSize:          500,
+			BlockBatchMaxSizeBytes:  500000,
+			GossipedBlocksCacheSize: 50},
 		DALayer:         "mock",
 		SettlementLayer: "mock",
 		Instrumentation: &InstrumentationConfig{

config/toml.go

@@ -84,6 +84,9 @@ da_config = "{{ .DAConfig }}"
 # max size of batch in bytes that can be accepted by DA
 block_batch_max_size_bytes = {{ .BlockManagerConfig.BlockBatchMaxSizeBytes }}
 
+# max number of cached messages by gossipsub protocol
+gossiped_blocks_cache_size = {{ .BlockManagerConfig.GossipedBlocksCacheSize }}
+
 #celestia config example:
 # da_config = "{\"base_url\": \"http://127.0.0.1:26659\", \"timeout\": 60000000000, \"gas_prices\":0.1, \"gas_adjustment\": 1.3, \"namespace_id\":\"000000000000ffff\"}"
 # Avail config example: