CreateEmptyBlocks and CreateEmptyBlocksInterval

CHANGELOG.md

@@ -3,7 +3,8 @@
 ## 0.10.3 (TBD)
 
 FEATURES:
-- New `--consensus.no_empty_blocks` flag prevents the creation of blocks until there are transactions available
+- New `--consensus.create_empty_blocks` flag; when set to false, only creates blocks when there are txs or when the AppHash changes
+- New `consensus.create_empty_blocks_interval` config option; when greater than 0, will create an empty block after waiting that many seconds
 
 ## 0.10.2 (July 10, 2017)
 

cmd/tendermint/commands/run_node.go

@@ -47,7 +47,7 @@ func AddNodeFlags(cmd *cobra.Command) {
 	cmd.Flags().Bool("p2p.pex", config.P2P.PexReactor, "Enable Peer-Exchange (dev feature)")
 
 	// consensus flags
-	cmd.Flags().Bool("consensus.no_empty_blocks", config.Consensus.NoEmptyBlocks, "Only produce blocks when there are txs and when the AppHash changes")
+	cmd.Flags().Bool("consensus.create_empty_blocks", config.Consensus.CreateEmptyBlocks, "Set this to false to only produce blocks when there are txs or when the AppHash changes")
 }
 
 // Users wishing to:

config/config.go

@@ -301,9 +301,12 @@ type ConsensusConfig struct {
 	SkipTimeoutCommit bool `mapstructure:"skip_timeout_commit"`
 
 	// BlockSize
-	MaxBlockSizeTxs   int  `mapstructure:"max_block_size_txs"`
-	MaxBlockSizeBytes int  `mapstructure:"max_block_size_bytes"`
-	NoEmptyBlocks     bool `mapstructure:"no_empty_blocks"`
+	MaxBlockSizeTxs   int `mapstructure:"max_block_size_txs"`
+	MaxBlockSizeBytes int `mapstructure:"max_block_size_bytes"`
+
+	// EmptyBlocks mode and possible interval between empty blocks in seconds
+	CreateEmptyBlocks         bool `mapstructure:"create_empty_blocks"`
+	CreateEmptyBlocksInterval int  `mapstructure:"create_empty_blocks_interval"`
 
 	// TODO: This probably shouldn't be exposed but it makes it
 	// easy to write tests for the wal/replay
@@ -314,6 +317,16 @@ type ConsensusConfig struct {
 	PeerQueryMaj23SleepDuration int `mapstructure:"peer_query_maj23_sleep_duration"`
 }
 
+// WaitForTxs returns true if the consensus should wait for transactions before entering the propose step
+func (cfg *ConsensusConfig) WaitForTxs() bool {
+	return !cfg.CreateEmptyBlocks || cfg.CreateEmptyBlocksInterval > 0
+}
+
+// EmptyBlocks returns the amount of time to wait before proposing an empty block or starting the propose timer if there are no txs available
+func (cfg *ConsensusConfig) EmptyBlocks() time.Duration {
+	return time.Duration(cfg.CreateEmptyBlocksInterval) * time.Second
+}
+
 // Propose returns the amount of time to wait for a proposal
 func (cfg *ConsensusConfig) Propose(round int) time.Duration {
 	return time.Duration(cfg.TimeoutPropose+cfg.TimeoutProposeDelta*round) * time.Millisecond
@@ -359,7 +372,8 @@ func DefaultConsensusConfig() *ConsensusConfig {
 		SkipTimeoutCommit:           false,
 		MaxBlockSizeTxs:             10000,
 		MaxBlockSizeBytes:           1, // TODO
-		NoEmptyBlocks:               false,
+		CreateEmptyBlocks:           true,
+		CreateEmptyBlocksInterval:   0,
 		BlockPartSize:               types.DefaultBlockPartSize, // TODO: we shouldnt be importing types
 		PeerGossipSleepDuration:     100,
 		PeerQueryMaj23SleepDuration: 2000,

consensus/common_test.go

@@ -242,7 +242,7 @@ func newConsensusStateWithConfig(thisConfig *cfg.Config, state *sm.State, pv *ty
 	// Make Mempool
 	mempool := mempl.NewMempool(thisConfig.Mempool, proxyAppConnMem, 0)
 	mempool.SetLogger(log.TestingLogger().With("module", "mempool"))
-	if thisConfig.Consensus.NoEmptyBlocks {
+	if thisConfig.Consensus.WaitForTxs() {
 		mempool.EnableTxsAvailable()
 	}
 

consensus/mempool_test.go

@@ -17,7 +17,7 @@ func init() {
 
 func TestNoProgressUntilTxsAvailable(t *testing.T) {
 	config := ResetConfig("consensus_mempool_txs_available_test")
-	config.Consensus.NoEmptyBlocks = true
+	config.Consensus.CreateEmptyBlocks = false
 	state, privVals := randGenesisState(1, false, 10)
 	cs := newConsensusStateWithConfig(config, state, privVals[0], NewCounterApplication())
 	cs.mempool.EnableTxsAvailable()
@@ -36,7 +36,7 @@ func TestNoProgressUntilTxsAvailable(t *testing.T) {
 
 func TestProgressInHigherRound(t *testing.T) {
 	config := ResetConfig("consensus_mempool_txs_available_test")
-	config.Consensus.NoEmptyBlocks = true
+	config.Consensus.CreateEmptyBlocks = false
 	state, privVals := randGenesisState(1, false, 10)
 	cs := newConsensusStateWithConfig(config, state, privVals[0], NewCounterApplication())
 	cs.mempool.EnableTxsAvailable()

consensus/state.go

@@ -718,6 +718,8 @@ func (cs *ConsensusState) handleTimeout(ti timeoutInfo, rs RoundState) {
 		// NewRound event fired from enterNewRound.
 		// XXX: should we fire timeout here (for timeout commit)?
 		cs.enterNewRound(ti.Height, 0)
+	case RoundStepNewRound:
+		cs.enterPropose(ti.Height, 0)
 	case RoundStepPropose:
 		types.FireEventTimeoutPropose(cs.evsw, cs.RoundStateEvent())
 		cs.enterPrevote(ti.Height, ti.Round)
@@ -790,8 +792,11 @@ func (cs *ConsensusState) enterNewRound(height int, round int) {
 	// Wait for txs to be available in the mempool
 	// before we enterPropose in round 0. If the last block changed the app hash,
 	// we may need an empty "proof" block, and enterPropose immediately.
-	waitForTxs := cs.config.NoEmptyBlocks && round == 0 && !cs.needProofBlock(height)
+	waitForTxs := cs.config.WaitForTxs() && round == 0 && !cs.needProofBlock(height)
 	if waitForTxs {
+		if cs.config.CreateEmptyBlocksInterval > 0 {
+			cs.scheduleTimeout(cs.config.EmptyBlocks(), height, round, RoundStepNewRound)
+		}
 		go cs.proposalHeartbeat(height, round)
 	} else {
 		cs.enterPropose(height, round)
@@ -841,8 +846,9 @@ func (cs *ConsensusState) proposalHeartbeat(height, round int) {
 	}
 }
 
-// Enter (!NoEmptyBlocks): from enterNewRound(height,round)
-// Enter (NoEmptyBlocks) : after enterNewRound(height,round), once txs are in the mempool
+// Enter (CreateEmptyBlocks): from enterNewRound(height,round)
+// Enter (CreateEmptyBlocks, CreateEmptyBlocksInterval > 0 ): after enterNewRound(height,round), after timeout of CreateEmptyBlocksInterval
+// Enter (!CreateEmptyBlocks) : after enterNewRound(height,round), once txs are in the mempool
 func (cs *ConsensusState) enterPropose(height int, round int) {
 	if cs.Height != height || round < cs.Round || (cs.Round == round && RoundStepPropose <= cs.Step) {
 		cs.Logger.Debug(cmn.Fmt("enterPropose(%v/%v): Invalid args. Current step: %v/%v/%v", height, round, cs.Height, cs.Round, cs.Step))

node/node.go

@@ -142,7 +142,7 @@ func NewNode(config *cfg.Config, privValidator *types.PrivValidator, clientCreat
 	mempoolReactor := mempl.NewMempoolReactor(config.Mempool, mempool)
 	mempoolReactor.SetLogger(mempoolLogger)
 
-	if config.Consensus.NoEmptyBlocks {
+	if config.Consensus.WaitForTxs() {
 		mempool.EnableTxsAvailable()
 	}