properly weight bootstrapping validators by stake

chains/manager.go

@@ -27,6 +27,7 @@ import (
 	"github.com/ava-labs/gecko/snow/triggers"
 	"github.com/ava-labs/gecko/snow/validators"
 	"github.com/ava-labs/gecko/utils/logging"
+	"github.com/ava-labs/gecko/utils/math"
 	"github.com/ava-labs/gecko/vms"
 
 	avacon "github.com/ava-labs/gecko/snow/consensus/avalanche"
@@ -390,13 +391,22 @@ func (m *manager) createAvalancheChain(
 		},
 	}
 
+	bootstrapWeight := uint64(0)
+	for _, beacon := range beacons.List() {
+		newWeight, err := math.Add64(bootstrapWeight, beacon.Weight())
+		if err != nil {
+			return err
+		}
+		bootstrapWeight = newWeight
+	}
+
 	engine.Initialize(avaeng.Config{
 		BootstrapConfig: avaeng.BootstrapConfig{
 			Config: common.Config{
 				Context:    ctx,
 				Validators: validators,
 				Beacons:    beacons,
-				Alpha:      beacons.Len()/2 + 1, // must be > 50%
+				Alpha:      bootstrapWeight/2 + 1, // must be > 50%
 				Sender:     &sender,
 			},
 			VtxBlocked: vtxBlocker,
@@ -417,6 +427,8 @@ func (m *manager) createAvalancheChain(
 	go ctx.Log.RecoverAndPanic(handler.Dispatch)
 
 	awaiting := &networking.AwaitingConnections{
+		Requested:      beacons,
+		WeightRequired: (3*bootstrapWeight + 3) / 4, // 75% must be connected to
 		Finish: func() {
 			ctx.Lock.Lock()
 			defer ctx.Lock.Unlock()
@@ -424,10 +436,6 @@ func (m *manager) createAvalancheChain(
 			engine.Startup()
 		},
 	}
-	for _, vdr := range beacons.List() {
-		awaiting.Requested.Add(vdr.ID())
-	}
-	awaiting.NumRequired = (3*awaiting.Requested.Len() + 3) / 4 // 75% must be connected to
 	m.awaiter.AwaitConnections(awaiting)
 
 	return nil
@@ -468,6 +476,15 @@ func (m *manager) createSnowmanChain(
 	sender := sender.Sender{}
 	sender.Initialize(ctx, m.sender, m.chainRouter, m.timeoutManager)
 
+	bootstrapWeight := uint64(0)
+	for _, beacon := range beacons.List() {
+		newWeight, err := math.Add64(bootstrapWeight, beacon.Weight())
+		if err != nil {
+			return err
+		}
+		bootstrapWeight = newWeight
+	}
+
 	// The engine handles consensus
 	engine := smeng.Transitive{}
 	engine.Initialize(smeng.Config{
@@ -476,7 +493,7 @@ func (m *manager) createSnowmanChain(
 				Context:    ctx,
 				Validators: validators,
 				Beacons:    beacons,
-				Alpha:      beacons.Len()/2 + 1, // must be > 50%
+				Alpha:      bootstrapWeight/2 + 1, // must be > 50%
 				Sender:     &sender,
 			},
 			Blocked:      blocked,
@@ -496,6 +513,8 @@ func (m *manager) createSnowmanChain(
 	go ctx.Log.RecoverAndPanic(handler.Dispatch)
 
 	awaiting := &networking.AwaitingConnections{
+		Requested:      beacons,
+		WeightRequired: (3*bootstrapWeight + 3) / 4, // 75% must be connected to
 		Finish: func() {
 			ctx.Lock.Lock()
 			defer ctx.Lock.Unlock()
@@ -503,10 +522,6 @@ func (m *manager) createSnowmanChain(
 			engine.Startup()
 		},
 	}
-	for _, vdr := range beacons.List() {
-		awaiting.Requested.Add(vdr.ID())
-	}
-	awaiting.NumRequired = (3*awaiting.Requested.Len() + 3) / 4 // 75% must be connected to
 	m.awaiter.AwaitConnections(awaiting)
 	return nil
 }

snow/engine/avalanche/bootstrapper_test.go

@@ -69,7 +69,7 @@ func newConfig(t *testing.T) (BootstrapConfig, ids.ShortID, *common.SenderTest,
 		Context:    ctx,
 		Validators: peers,
 		Beacons:    peers,
-		Alpha:      peers.Len()/2 + 1,
+		Alpha:      uint64(peers.Len()/2 + 1),
 		Sender:     sender,
 	}
 	return BootstrapConfig{

snow/engine/common/bootstrapper.go

@@ -4,7 +4,10 @@
 package common
 
 import (
+	stdmath "math"
+
 	"github.com/ava-labs/gecko/ids"
+	"github.com/ava-labs/gecko/utils/math"
 )
 
 // Bootstrapper implements the Engine interface.
@@ -15,7 +18,7 @@ type Bootstrapper struct {
 	acceptedFrontier        ids.Set
 
 	pendingAccepted ids.ShortSet
-	accepted        ids.Bag
+	acceptedVotes   map[[32]byte]uint64
 
 	RequestID uint32
 }
@@ -30,7 +33,7 @@ func (b *Bootstrapper) Initialize(config Config) {
 		b.pendingAccepted.Add(vdrID)
 	}
 
-	b.accepted.SetThreshold(config.Alpha)
+	b.acceptedVotes = make(map[[32]byte]uint64)
 }
 
 // Startup implements the Engine interface.
@@ -95,10 +98,29 @@ func (b *Bootstrapper) Accepted(validatorID ids.ShortID, requestID uint32, conta
 	}
 	b.pendingAccepted.Remove(validatorID)
 
-	b.accepted.Add(containerIDs.List()...)
+	weight := uint64(0)
+	if vdr, ok := b.Validators.Get(validatorID); ok {
+		weight = vdr.Weight()
+	}
+
+	for _, containerID := range containerIDs.List() {
+		key := containerID.Key()
+		previousWeight := b.acceptedVotes[key]
+		newWeight, err := math.Add64(weight, previousWeight)
+		if err != nil {
+			newWeight = stdmath.MaxUint64
+		}
+		b.acceptedVotes[key] = newWeight
+	}
 
 	if b.pendingAccepted.Len() == 0 {
-		accepted := b.accepted.Threshold()
+		accepted := ids.Set{}
+		for key, weight := range b.acceptedVotes {
+			if weight >= b.Config.Alpha {
+				accepted.Add(ids.NewID(key))
+			}
+		}
+
 		if size := accepted.Len(); size == 0 && b.Config.Beacons.Len() > 0 {
 			b.Context.Log.Warn("Bootstrapping finished with no accepted frontier. This is likely a result of failing to be able to connect to the specified bootstraps, or no transactions have been issued on this network yet")
 		} else {

snow/engine/common/config.go

@@ -15,7 +15,7 @@ type Config struct {
 	Validators validators.Set
 	Beacons    validators.Set
 
-	Alpha         int
+	Alpha         uint64
 	Sender        Sender
 	Bootstrapable Bootstrapable
 }

snow/engine/snowman/bootstrapper_test.go

@@ -62,7 +62,7 @@ func newConfig(t *testing.T) (BootstrapConfig, ids.ShortID, *common.SenderTest,
 		Context:    ctx,
 		Validators: peers,
 		Beacons:    peers,
-		Alpha:      peers.Len()/2 + 1,
+		Alpha:      uint64(peers.Len()/2 + 1),
 		Sender:     sender,
 	}
 	return BootstrapConfig{

snow/networking/awaiting_connections.go

@@ -4,31 +4,43 @@
 package networking
 
 import (
+	stdmath "math"
+
 	"github.com/ava-labs/gecko/ids"
+	"github.com/ava-labs/gecko/snow/validators"
+	"github.com/ava-labs/gecko/utils/math"
 )
 
 // AwaitingConnections ...
 type AwaitingConnections struct {
-	Requested   ids.ShortSet
-	NumRequired int
-	Finish      func()
+	Requested      validators.Set
+	WeightRequired uint64
+	Finish         func()
 
-	connected ids.ShortSet
+	weight uint64
 }
 
 // Add ...
 func (aw *AwaitingConnections) Add(conn ids.ShortID) {
-	if aw.Requested.Contains(conn) {
-		aw.connected.Add(conn)
+	vdr, ok := aw.Requested.Get(conn)
+	if !ok {
+		return
 	}
+	weight, err := math.Add64(vdr.Weight(), aw.weight)
+	if err != nil {
+		weight = stdmath.MaxUint64
+	}
+	aw.weight = weight
 }
 
 // Remove ...
 func (aw *AwaitingConnections) Remove(conn ids.ShortID) {
-	aw.connected.Remove(conn)
+	vdr, ok := aw.Requested.Get(conn)
+	if !ok {
+		return
+	}
+	aw.weight -= vdr.Weight()
 }
 
 // Ready ...
-func (aw *AwaitingConnections) Ready() bool {
-	return aw.connected.Len() >= aw.NumRequired
-}
+func (aw *AwaitingConnections) Ready() bool { return aw.weight >= aw.WeightRequired }

snow/validators/set.go

@@ -24,6 +24,9 @@ type Set interface {
 	// Add the provided validator to the set.
 	Add(Validator)
 
+	// Get the validator from the set.
+	Get(ids.ShortID) (Validator, bool)
+
 	// Remove the validator with the specified ID.
 	Remove(ids.ShortID)
 
@@ -102,6 +105,22 @@ func (s *set) add(vdr Validator) {
 	s.sampler.Weights = append(s.sampler.Weights, w)
 }
 
+// Get implements the Set interface.
+func (s *set) Get(vdrID ids.ShortID) (Validator, bool) {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	return s.get(vdrID)
+}
+
+func (s *set) get(vdrID ids.ShortID) (Validator, bool) {
+	index, ok := s.vdrMap[vdrID.Key()]
+	if !ok {
+		return nil, false
+	}
+	return s.vdrSlice[index], true
+}
+
 // Remove implements the Set interface.
 func (s *set) Remove(vdrID ids.ShortID) {
 	s.lock.Lock()

vms/spchainvm/consensus_benchmark_test.go

@@ -86,7 +86,7 @@ func ConsensusLeader(numBlocks, numTxsPerBlock int, b *testing.B) {
 					Context:    ctx,
 					Validators: vdrs,
 					Beacons:    beacons,
-					Alpha:      (beacons.Len() + 1) / 2,
+					Alpha:      uint64(beacons.Len()/2 + 1),
 					Sender:     &sender,
 				},
 				Blocked: blocked,
@@ -217,7 +217,7 @@ func ConsensusFollower(numBlocks, numTxsPerBlock int, b *testing.B) {
 					Context:    ctx,
 					Validators: vdrs,
 					Beacons:    beacons,
-					Alpha:      (beacons.Len() + 1) / 2,
+					Alpha:      uint64(beacons.Len()/2 + 1),
 					Sender:     &sender,
 				},
 				Blocked: blocked,