prysm-pulse/beacon-chain/p2p/gossip_scoring_params.go
2021-04-05 23:04:26 +00:00

406 lines
15 KiB
Go

package p2p
import (
"math"
"reflect"
"strings"
"time"
"github.com/libp2p/go-libp2p-core/peer"
pubsub "github.com/libp2p/go-libp2p-pubsub"
"github.com/pkg/errors"
"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
"github.com/prysmaticlabs/prysm/shared/params"
"github.com/sirupsen/logrus"
)
const (
// beaconBlockWeight specifies the scoring weight that we apply to
// our beacon block topic.
beaconBlockWeight = 0.8
// aggregateWeight specifies the scoring weight that we apply to
// our aggregate topic.
aggregateWeight = 0.5
// attestationTotalWeight specifies the scoring weight that we apply to
// our attestation subnet topic.
attestationTotalWeight = 1
// attesterSlashingWeight specifies the scoring weight that we apply to
// our attester slashing topic.
attesterSlashingWeight = 0.05
// proposerSlashingWeight specifies the scoring weight that we apply to
// our proposer slashing topic.
proposerSlashingWeight = 0.05
// voluntaryExitWeight specifies the scoring weight that we apply to
// our voluntary exit topic.
voluntaryExitWeight = 0.05
// maxInMeshScore describes the max score a peer can attain from being in the mesh.
maxInMeshScore = 10
// maxFirstDeliveryScore describes the max score a peer can obtain from first deliveries.
maxFirstDeliveryScore = 40
// decayToZero specifies the terminal value that we will use when decaying
// a value.
decayToZero = 0.01
// dampeningFactor reduces the amount by which the various thresholds and caps are created.
dampeningFactor = 90
)
var (
// a bool to check if we enable scoring for messages in the mesh sent for near first deliveries.
meshDeliveryIsScored = false
)
func peerScoringParams() (*pubsub.PeerScoreParams, *pubsub.PeerScoreThresholds) {
thresholds := &pubsub.PeerScoreThresholds{
GossipThreshold: -4000,
PublishThreshold: -8000,
GraylistThreshold: -16000,
AcceptPXThreshold: 100,
OpportunisticGraftThreshold: 5,
}
scoreParams := &pubsub.PeerScoreParams{
Topics: make(map[string]*pubsub.TopicScoreParams),
TopicScoreCap: 32.72,
AppSpecificScore: func(p peer.ID) float64 {
return 0
},
AppSpecificWeight: 1,
IPColocationFactorWeight: -35.11,
IPColocationFactorThreshold: 10,
IPColocationFactorWhitelist: nil,
BehaviourPenaltyWeight: -15.92,
BehaviourPenaltyThreshold: 6,
BehaviourPenaltyDecay: scoreDecay(10 * oneEpochDuration()),
DecayInterval: 1 * oneSlotDuration(),
DecayToZero: decayToZero,
RetainScore: 100 * oneEpochDuration(),
}
return scoreParams, thresholds
}
func (s *Service) topicScoreParams(topic string) (*pubsub.TopicScoreParams, error) {
activeValidators, err := s.retrieveActiveValidators()
if err != nil {
return nil, err
}
switch {
case strings.Contains(topic, "beacon_block"):
return defaultBlockTopicParams(), nil
case strings.Contains(topic, "beacon_aggregate_and_proof"):
return defaultAggregateTopicParams(activeValidators)
case strings.Contains(topic, "beacon_attestation"):
return defaultAggregateSubnetTopicParams(activeValidators)
case strings.Contains(topic, "voluntary_exit"):
return defaultVoluntaryExitTopicParams(), nil
case strings.Contains(topic, "proposer_slashing"):
return defaultProposerSlashingTopicParams(), nil
case strings.Contains(topic, "attester_slashing"):
return defaultAttesterSlashingTopicParams(), nil
default:
return nil, errors.Errorf("unrecognized topic provided for parameter registration: %s", topic)
}
}
func (s *Service) retrieveActiveValidators() (uint64, error) {
rt := s.cfg.DB.LastArchivedRoot(s.ctx)
if rt == params.BeaconConfig().ZeroHash {
genState, err := s.cfg.DB.GenesisState(s.ctx)
if err != nil {
return 0, err
}
if genState == nil {
return 0, errors.New("no genesis state exists")
}
return helpers.ActiveValidatorCount(genState, helpers.CurrentEpoch(genState))
}
bState, err := s.cfg.DB.State(s.ctx, rt)
if err != nil {
return 0, err
}
if bState == nil {
return 0, errors.Errorf("no state with root %#x exists", rt)
}
return helpers.ActiveValidatorCount(bState, helpers.CurrentEpoch(bState))
}
// Based on the lighthouse parameters.
// https://gist.github.com/blacktemplar/5c1862cb3f0e32a1a7fb0b25e79e6e2c
func defaultBlockTopicParams() *pubsub.TopicScoreParams {
decayEpoch := time.Duration(5)
blocksPerEpoch := uint64(params.BeaconConfig().SlotsPerEpoch)
meshWeight := -0.717
if !meshDeliveryIsScored {
// Set the mesh weight as zero as a temporary measure, so as to prevent
// the average nodes from being penalised.
meshWeight = 0
}
return &pubsub.TopicScoreParams{
TopicWeight: beaconBlockWeight,
TimeInMeshWeight: maxInMeshScore / inMeshCap(),
TimeInMeshQuantum: inMeshTime(),
TimeInMeshCap: inMeshCap(),
FirstMessageDeliveriesWeight: 1,
FirstMessageDeliveriesDecay: scoreDecay(20 * oneEpochDuration()),
FirstMessageDeliveriesCap: 23,
MeshMessageDeliveriesWeight: meshWeight,
MeshMessageDeliveriesDecay: scoreDecay(decayEpoch * oneEpochDuration()),
MeshMessageDeliveriesCap: float64(blocksPerEpoch * uint64(decayEpoch)),
MeshMessageDeliveriesThreshold: float64(blocksPerEpoch*uint64(decayEpoch)) / 10,
MeshMessageDeliveriesWindow: 2 * time.Second,
MeshMessageDeliveriesActivation: 4 * oneEpochDuration(),
MeshFailurePenaltyWeight: meshWeight,
MeshFailurePenaltyDecay: scoreDecay(decayEpoch * oneEpochDuration()),
InvalidMessageDeliveriesWeight: -140.4475,
InvalidMessageDeliveriesDecay: scoreDecay(50 * oneEpochDuration()),
}
}
func defaultAggregateTopicParams(activeValidators uint64) (*pubsub.TopicScoreParams, error) {
// Determine the expected message rate for the particular gossip topic.
aggPerSlot := aggregatorsPerSlot(activeValidators)
firstMessageCap, err := decayLimit(scoreDecay(1*oneEpochDuration()), float64(aggPerSlot*2/gossipSubD))
if err != nil {
return nil, err
}
firstMessageWeight := maxFirstDeliveryScore / firstMessageCap
meshThreshold, err := decayThreshold(scoreDecay(1*oneEpochDuration()), float64(aggPerSlot)/dampeningFactor)
if err != nil {
return nil, err
}
meshWeight := -scoreByWeight(aggregateWeight, meshThreshold)
meshCap := 4 * meshThreshold
if !meshDeliveryIsScored {
// Set the mesh weight as zero as a temporary measure, so as to prevent
// the average nodes from being penalised.
meshWeight = 0
}
return &pubsub.TopicScoreParams{
TopicWeight: aggregateWeight,
TimeInMeshWeight: maxInMeshScore / inMeshCap(),
TimeInMeshQuantum: inMeshTime(),
TimeInMeshCap: inMeshCap(),
FirstMessageDeliveriesWeight: firstMessageWeight,
FirstMessageDeliveriesDecay: scoreDecay(1 * oneEpochDuration()),
FirstMessageDeliveriesCap: firstMessageCap,
MeshMessageDeliveriesWeight: meshWeight,
MeshMessageDeliveriesDecay: scoreDecay(1 * oneEpochDuration()),
MeshMessageDeliveriesCap: meshCap,
MeshMessageDeliveriesThreshold: meshThreshold,
MeshMessageDeliveriesWindow: 2 * time.Second,
MeshMessageDeliveriesActivation: 1 * oneEpochDuration(),
MeshFailurePenaltyWeight: meshWeight,
MeshFailurePenaltyDecay: scoreDecay(1 * oneEpochDuration()),
InvalidMessageDeliveriesWeight: -maxScore() / aggregateWeight,
InvalidMessageDeliveriesDecay: scoreDecay(50 * oneEpochDuration()),
}, nil
}
func defaultAggregateSubnetTopicParams(activeValidators uint64) (*pubsub.TopicScoreParams, error) {
subnetCount := params.BeaconNetworkConfig().AttestationSubnetCount
// Get weight for each specific subnet.
topicWeight := attestationTotalWeight / float64(subnetCount)
subnetWeight := activeValidators / subnetCount
// Determine the amount of validators expected in a subnet in a single slot.
numPerSlot := time.Duration(subnetWeight / uint64(params.BeaconConfig().SlotsPerEpoch))
comsPerSlot := committeeCountPerSlot(activeValidators)
exceedsThreshold := comsPerSlot >= 2*subnetCount/uint64(params.BeaconConfig().SlotsPerEpoch)
firstDecay := time.Duration(1)
meshDecay := time.Duration(4)
if exceedsThreshold {
firstDecay = 4
meshDecay = 16
}
// Determine expected first deliveries based on the message rate.
firstMessageCap, err := decayLimit(scoreDecay(firstDecay*oneEpochDuration()), float64(numPerSlot*2/gossipSubD))
if err != nil {
return nil, err
}
firstMessageWeight := maxFirstDeliveryScore / firstMessageCap
// Determine expected mesh deliveries based on message rate applied with a dampening factor.
meshThreshold, err := decayThreshold(scoreDecay(meshDecay*oneEpochDuration()), float64(numPerSlot)/dampeningFactor)
if err != nil {
return nil, err
}
meshWeight := -scoreByWeight(topicWeight, meshThreshold)
meshCap := 4 * meshThreshold
if !meshDeliveryIsScored {
// Set the mesh weight as zero as a temporary measure, so as to prevent
// the average nodes from being penalised.
meshWeight = 0
}
return &pubsub.TopicScoreParams{
TopicWeight: topicWeight,
TimeInMeshWeight: maxInMeshScore / inMeshCap(),
TimeInMeshQuantum: inMeshTime(),
TimeInMeshCap: inMeshCap(),
FirstMessageDeliveriesWeight: firstMessageWeight,
FirstMessageDeliveriesDecay: scoreDecay(firstDecay * oneEpochDuration()),
FirstMessageDeliveriesCap: firstMessageCap,
MeshMessageDeliveriesWeight: meshWeight,
MeshMessageDeliveriesDecay: scoreDecay(meshDecay * oneEpochDuration()),
MeshMessageDeliveriesCap: meshCap,
MeshMessageDeliveriesThreshold: meshThreshold,
MeshMessageDeliveriesWindow: 2 * time.Second,
MeshMessageDeliveriesActivation: 1 * oneEpochDuration(),
MeshFailurePenaltyWeight: meshWeight,
MeshFailurePenaltyDecay: scoreDecay(meshDecay * oneEpochDuration()),
InvalidMessageDeliveriesWeight: -maxScore() / topicWeight,
InvalidMessageDeliveriesDecay: scoreDecay(50 * oneEpochDuration()),
}, nil
}
func defaultAttesterSlashingTopicParams() *pubsub.TopicScoreParams {
return &pubsub.TopicScoreParams{
TopicWeight: attesterSlashingWeight,
TimeInMeshWeight: maxInMeshScore / inMeshCap(),
TimeInMeshQuantum: inMeshTime(),
TimeInMeshCap: inMeshCap(),
FirstMessageDeliveriesWeight: 36,
FirstMessageDeliveriesDecay: scoreDecay(100 * oneEpochDuration()),
FirstMessageDeliveriesCap: 1,
MeshMessageDeliveriesWeight: 0,
MeshMessageDeliveriesDecay: 0,
MeshMessageDeliveriesCap: 0,
MeshMessageDeliveriesThreshold: 0,
MeshMessageDeliveriesWindow: 0,
MeshMessageDeliveriesActivation: 0,
MeshFailurePenaltyWeight: 0,
MeshFailurePenaltyDecay: 0,
InvalidMessageDeliveriesWeight: -2000,
InvalidMessageDeliveriesDecay: scoreDecay(50 * oneEpochDuration()),
}
}
func defaultProposerSlashingTopicParams() *pubsub.TopicScoreParams {
return &pubsub.TopicScoreParams{
TopicWeight: proposerSlashingWeight,
TimeInMeshWeight: maxInMeshScore / inMeshCap(),
TimeInMeshQuantum: inMeshTime(),
TimeInMeshCap: inMeshCap(),
FirstMessageDeliveriesWeight: 36,
FirstMessageDeliveriesDecay: scoreDecay(100 * oneEpochDuration()),
FirstMessageDeliveriesCap: 1,
MeshMessageDeliveriesWeight: 0,
MeshMessageDeliveriesDecay: 0,
MeshMessageDeliveriesCap: 0,
MeshMessageDeliveriesThreshold: 0,
MeshMessageDeliveriesWindow: 0,
MeshMessageDeliveriesActivation: 0,
MeshFailurePenaltyWeight: 0,
MeshFailurePenaltyDecay: 0,
InvalidMessageDeliveriesWeight: -2000,
InvalidMessageDeliveriesDecay: scoreDecay(50 * oneEpochDuration()),
}
}
func defaultVoluntaryExitTopicParams() *pubsub.TopicScoreParams {
return &pubsub.TopicScoreParams{
TopicWeight: voluntaryExitWeight,
TimeInMeshWeight: maxInMeshScore / inMeshCap(),
TimeInMeshQuantum: inMeshTime(),
TimeInMeshCap: inMeshCap(),
FirstMessageDeliveriesWeight: 2,
FirstMessageDeliveriesDecay: scoreDecay(100 * oneEpochDuration()),
FirstMessageDeliveriesCap: 5,
MeshMessageDeliveriesWeight: 0,
MeshMessageDeliveriesDecay: 0,
MeshMessageDeliveriesCap: 0,
MeshMessageDeliveriesThreshold: 0,
MeshMessageDeliveriesWindow: 0,
MeshMessageDeliveriesActivation: 0,
MeshFailurePenaltyWeight: 0,
MeshFailurePenaltyDecay: 0,
InvalidMessageDeliveriesWeight: -2000,
InvalidMessageDeliveriesDecay: scoreDecay(50 * oneEpochDuration()),
}
}
func oneSlotDuration() time.Duration {
return time.Duration(params.BeaconConfig().SecondsPerSlot) * time.Second
}
func oneEpochDuration() time.Duration {
return time.Duration(params.BeaconConfig().SlotsPerEpoch) * oneSlotDuration()
}
// determines the decay rate from the provided time period till
// the decayToZero value. Ex: ( 1 -> 0.01)
func scoreDecay(totalDurationDecay time.Duration) float64 {
numOfTimes := totalDurationDecay / oneSlotDuration()
return math.Pow(decayToZero, 1/float64(numOfTimes))
}
// is used to determine the threshold from the decay limit with
// a provided growth rate. This applies the decay rate to a
// computed limit.
func decayThreshold(decayRate, rate float64) (float64, error) {
d, err := decayLimit(decayRate, rate)
if err != nil {
return 0, err
}
return d * decayRate, nil
}
// decayLimit provides the value till which a decay process will
// limit till provided with an expected growth rate.
func decayLimit(decayRate, rate float64) (float64, error) {
if 1 <= decayRate {
return 0, errors.Errorf("got an invalid decayLimit rate: %f", decayRate)
}
return rate / (1 - decayRate), nil
}
func committeeCountPerSlot(activeValidators uint64) uint64 {
// Use a static parameter for now rather than a dynamic one, we can use
// the actual parameter later when we have figured out how to fix a circular
// dependency in service startup order.
return helpers.SlotCommitteeCount(activeValidators)
}
// Uses a very rough gauge for total aggregator size per slot.
func aggregatorsPerSlot(activeValidators uint64) uint64 {
comms := committeeCountPerSlot(activeValidators)
totalAggs := comms * params.BeaconConfig().TargetAggregatorsPerCommittee
return totalAggs
}
// provides the relevant score by the provided weight and threshold.
func scoreByWeight(weight, threshold float64) float64 {
return maxScore() / (weight * threshold * threshold)
}
// maxScore attainable by a peer.
func maxScore() float64 {
totalWeight := beaconBlockWeight + aggregateWeight + attestationTotalWeight +
attesterSlashingWeight + proposerSlashingWeight + voluntaryExitWeight
return (maxInMeshScore + maxFirstDeliveryScore) * totalWeight
}
// denotes the unit time in mesh for scoring tallying.
func inMeshTime() time.Duration {
return 1 * oneSlotDuration()
}
// the cap for `inMesh` time scoring.
func inMeshCap() float64 {
return float64((3600 * time.Second) / inMeshTime())
}
func logGossipParameters(topic string, params *pubsub.TopicScoreParams) {
// Exit early in the event the parameter struct is nil.
if params == nil {
return
}
rawParams := reflect.ValueOf(params).Elem()
numOfFields := rawParams.NumField()
fields := make(logrus.Fields, numOfFields)
for i := 0; i < numOfFields; i++ {
fields[reflect.TypeOf(params).Elem().Field(i).Name] = rawParams.Field(i).Interface()
}
log.WithFields(fields).Debugf("Topic Parameters for %s", topic)
}