Add proposerMinBlockDelay to subnet config (ava-labs#2202)

chains/manager.go

@@ -857,10 +857,20 @@ func (m *manager) createSnowmanChain(
 		return nil, fmt.Errorf("error while fetching chain config: %w", err)
 	}
 
+	minBlockDelay := proposervm.DefaultMinBlockDelay
+	if subnetCfg, ok := m.SubnetConfigs[ctx.SubnetID]; ok {
+		minBlockDelay = subnetCfg.ProposerMinBlockDelay
+	}
+	m.Log.Info("creating proposervm wrapper",
+		zap.Time("activationTime", m.ApricotPhase4Time),
+		zap.Uint64("minPChainHeight", m.ApricotPhase4MinPChainHeight),
+		zap.Duration("minBlockDelay", minBlockDelay),
+	)
 	vm = proposervm.New(
 		vm,
 		m.ApricotPhase4Time,
 		m.ApricotPhase4MinPChainHeight,
+		minBlockDelay,
 	)
 
 	if m.MeterVMEnabled {

chains/subnet.go

@@ -5,6 +5,7 @@ package chains
 
 import (
 	"sync"
+	"time"
 
 	"github.com/ava-labs/avalanchego/ids"
 	"github.com/ava-labs/avalanchego/snow/consensus/avalanche"
@@ -31,6 +32,11 @@ type SubnetConfig struct {
 	// ValidatorOnly indicates that this Subnet's Chains are available to only subnet validators.
 	ValidatorOnly       bool                 `json:"validatorOnly" yaml:"validatorOnly"`
 	ConsensusParameters avalanche.Parameters `json:"consensusParameters" yaml:"consensusParameters"`
+
+	// ProposerMinBlockDelay is the minimum delay this node will enforce when
+	// building a snowman++ block.
+	// TODO: Remove this flag once all VMs throttle their own block production.
+	ProposerMinBlockDelay time.Duration `json:"proposerMinBlockDelay" yaml:"proposerMinBlockDelay"`
 }
 
 type subnet struct {

config/config.go

@@ -49,6 +49,7 @@ import (
 	"github.com/ava-labs/avalanchego/utils/timer"
 	"github.com/ava-labs/avalanchego/vms"
 	"github.com/ava-labs/avalanchego/vms/platformvm/reward"
+	"github.com/ava-labs/avalanchego/vms/proposervm"
 )
 
 const (
@@ -1145,9 +1146,10 @@ func parseSubnetConfigs(data []byte, defaultSubnetConfig chains.SubnetConfig) (c
 
 func getDefaultSubnetConfig(v *viper.Viper) chains.SubnetConfig {
 	return chains.SubnetConfig{
-		ConsensusParameters: getConsensusConfig(v),
-		ValidatorOnly:       false,
-		GossipConfig:        getGossipConfig(v),
+		ConsensusParameters:   getConsensusConfig(v),
+		ValidatorOnly:         false,
+		GossipConfig:          getGossipConfig(v),
+		ProposerMinBlockDelay: proposervm.DefaultMinBlockDelay,
 	}
 }
 

vms/proposervm/batched_vm_test.go

@@ -891,7 +891,7 @@ func initTestRemoteProposerVM(
 		}
 	}
 
-	proVM := New(coreVM, proBlkStartTime, 0)
+	proVM := New(coreVM, proBlkStartTime, 0, DefaultMinBlockDelay)
 
 	valState := &validators.TestState{
 		T: t,

vms/proposervm/post_fork_option_test.go

@@ -726,7 +726,7 @@ func TestOptionTimestampValidity(t *testing.T) {
 	// Restart the node.
 
 	ctx := proVM.ctx
-	proVM = New(coreVM, time.Time{}, 0)
+	proVM = New(coreVM, time.Time{}, 0, DefaultMinBlockDelay)
 
 	coreVM.InitializeF = func(
 		*snow.Context,

vms/proposervm/state_syncable_vm_test.go

@@ -86,7 +86,7 @@ func helperBuildStateSyncTestObjects(t *testing.T) (*fullVM, *VM) {
 	innerVM.GetBlockF = func(i ids.ID) (snowman.Block, error) { return innerGenesisBlk, nil }
 
 	// createVM
-	vm := New(innerVM, time.Time{}, 0)
+	vm := New(innerVM, time.Time{}, 0, DefaultMinBlockDelay)
 
 	ctx := snow.DefaultContextTest()
 	ctx.NodeID = ids.NodeIDFromCert(pTestCert.Leaf)

vms/proposervm/vm.go

@@ -38,9 +38,10 @@ import (
 )
 
 const (
-	// minBlockDelay should be kept as whole seconds because block timestamps
-	// are only specific to the second.
-	minBlockDelay         = time.Second
+	// DefaultMinBlockDelay should be kept as whole seconds because block
+	// timestamps are only specific to the second.
+	DefaultMinBlockDelay = time.Second
+
 	checkIndexedFrequency = 10 * time.Second
 	innerBlkCacheSize     = 512
 )
@@ -62,6 +63,7 @@ type VM struct {
 
 	activationTime      time.Time
 	minimumPChainHeight uint64
+	minBlkDelay         time.Duration
 
 	state.State
 	hIndexer                indexer.HeightIndexer
@@ -99,10 +101,13 @@ type VM struct {
 	lastAcceptedHeight uint64
 }
 
+// New performs best when [minBlkDelay] is whole seconds. This is because block
+// timestamps are only specific to the second.
 func New(
 	vm block.ChainVM,
 	activationTime time.Time,
 	minimumPChainHeight uint64,
+	minBlkDelay time.Duration,
 ) *VM {
 	bVM, _ := vm.(block.BatchedChainVM)
 	hVM, _ := vm.(block.HeightIndexedChainVM)
@@ -115,6 +120,7 @@ func New(
 
 		activationTime:      activationTime,
 		minimumPChainHeight: minimumPChainHeight,
+		minBlkDelay:         minBlkDelay,
 	}
 }
 
@@ -284,8 +290,15 @@ func (vm *VM) SetPreference(preferred ids.ID) error {
 		// until the P-chain's height has advanced.
 		return nil
 	}
-	if minDelay < minBlockDelay {
-		minDelay = minBlockDelay
+
+	// Note: The P-chain does not currently try to target any block time. It
+	// notifies the consensus engine as soon as a new block may be built. To
+	// avoid fast runs of blocks there is an additional minimum delay that
+	// validators can specify. This delay may be an issue for high performance,
+	// custom VMs. Until the P-chain is modified to target a specific block
+	// time, ProposerMinBlockDelay can be configured in the subnet config.
+	if minDelay < vm.minBlkDelay {
+		minDelay = vm.minBlkDelay
 	}
 
 	preferredTime := blk.Timestamp()

vms/proposervm/vm_test.go

@@ -127,7 +127,7 @@ func initTestProposerVM(
 		}
 	}
 
-	proVM := New(coreVM, proBlkStartTime, minPChainHeight)
+	proVM := New(coreVM, proBlkStartTime, minPChainHeight, DefaultMinBlockDelay)
 
 	valState := &validators.TestState{
 		T: t,
@@ -866,7 +866,7 @@ func TestExpiredBuildBlock(t *testing.T) {
 		}
 	}
 
-	proVM := New(coreVM, time.Time{}, 0)
+	proVM := New(coreVM, time.Time{}, 0, DefaultMinBlockDelay)
 
 	valState := &validators.TestState{
 		T: t,
@@ -1196,7 +1196,7 @@ func TestInnerVMRollback(t *testing.T) {
 
 	dbManager := manager.NewMemDB(version.Semantic1_0_0)
 
-	proVM := New(coreVM, time.Time{}, 0)
+	proVM := New(coreVM, time.Time{}, 0, DefaultMinBlockDelay)
 
 	if err := proVM.Initialize(ctx, dbManager, nil, nil, nil, nil, nil, nil); err != nil {
 		t.Fatalf("failed to initialize proposerVM with %s", err)
@@ -1287,7 +1287,7 @@ func TestInnerVMRollback(t *testing.T) {
 
 	coreBlk.StatusV = choices.Processing
 
-	proVM = New(coreVM, time.Time{}, 0)
+	proVM = New(coreVM, time.Time{}, 0, DefaultMinBlockDelay)
 
 	if err := proVM.Initialize(ctx, dbManager, nil, nil, nil, nil, nil, nil); err != nil {
 		t.Fatalf("failed to initialize proposerVM with %s", err)
@@ -1813,7 +1813,7 @@ func TestRejectedHeightNotIndexed(t *testing.T) {
 		}
 	}
 
-	proVM := New(coreVM, time.Time{}, 0)
+	proVM := New(coreVM, time.Time{}, 0, DefaultMinBlockDelay)
 
 	valState := &validators.TestState{
 		T: t,
@@ -1991,7 +1991,7 @@ func TestRejectedOptionHeightNotIndexed(t *testing.T) {
 		}
 	}
 
-	proVM := New(coreVM, time.Time{}, 0)
+	proVM := New(coreVM, time.Time{}, 0, DefaultMinBlockDelay)
 
 	valState := &validators.TestState{
 		T: t,
@@ -2128,6 +2128,7 @@ func TestVMInnerBlkCache(t *testing.T) {
 		innerVM,
 		time.Time{}, // fork is active
 		0,           // minimum P-Chain height
+		DefaultMinBlockDelay,
 	)
 
 	dummyDBManager := manager.NewMemDB(version.Semantic1_0_0)