package node
import (
"crypto/ecdsa"
"fmt"
"sync"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/harmony-one/harmony/accounts"
"github.com/harmony-one/harmony/api/client"
clientService "github.com/harmony-one/harmony/api/client/service"
msg_pb "github.com/harmony-one/harmony/api/proto/message"
proto_node "github.com/harmony-one/harmony/api/proto/node"
"github.com/harmony-one/harmony/api/service"
"github.com/harmony-one/harmony/api/service/syncing"
"github.com/harmony-one/harmony/api/service/syncing/downloader"
"github.com/harmony-one/harmony/block"
"github.com/harmony-one/harmony/consensus"
"github.com/harmony-one/harmony/consensus/reward"
"github.com/harmony-one/harmony/contracts"
"github.com/harmony-one/harmony/core"
"github.com/harmony-one/harmony/core/types"
"github.com/harmony-one/harmony/drand"
"github.com/harmony-one/harmony/internal/chain"
nodeconfig "github.com/harmony-one/harmony/internal/configs/node"
"github.com/harmony-one/harmony/internal/ctxerror"
"github.com/harmony-one/harmony/internal/params"
"github.com/harmony-one/harmony/internal/shardchain"
"github.com/harmony-one/harmony/internal/utils"
"github.com/harmony-one/harmony/msgq"
"github.com/harmony-one/harmony/node/worker"
"github.com/harmony-one/harmony/p2p"
p2p_host "github.com/harmony-one/harmony/p2p/host"
"github.com/harmony-one/harmony/shard"
"github.com/harmony-one/harmony/shard/committee"
staking "github.com/harmony-one/harmony/staking/types"
)
// State is a state of a node.
type State byte
// All constants except the NodeLeader below are for validators only.
const (
NodeInit State = iota // Node just started, before contacting BeaconChain
NodeWaitToJoin // Node contacted BeaconChain, wait to join Shard
NodeNotInSync // Node out of sync, might be just joined Shard or offline for a period of time
NodeOffline // Node is offline
NodeReadyForConsensus // Node is ready for doing consensus
NodeDoingConsensus // Node is already doing consensus
NodeLeader // Node is the leader of some shard.
)
const (
// NumTryBroadCast is the number of times trying to broadcast
NumTryBroadCast = 3
// ClientRxQueueSize is the number of client messages to queue before tail-dropping.
ClientRxQueueSize = 16384
// ShardRxQueueSize is the number of shard messages to queue before tail-dropping.
ShardRxQueueSize = 16384
// GlobalRxQueueSize is the number of global messages to queue before tail-dropping.
GlobalRxQueueSize = 16384
// ClientRxWorkers is the number of concurrent client message handlers.
ClientRxWorkers = 8
// ShardRxWorkers is the number of concurrent shard message handlers.
ShardRxWorkers = 32
// GlobalRxWorkers is the number of concurrent global message handlers.
GlobalRxWorkers = 32
)
func ( state State ) String ( ) string {
switch state {
case NodeInit :
return "NodeInit"
case NodeWaitToJoin :
return "NodeWaitToJoin"
case NodeNotInSync :
return "NodeNotInSync"
case NodeOffline :
return "NodeOffline"
case NodeReadyForConsensus :
return "NodeReadyForConsensus"
case NodeDoingConsensus :
return "NodeDoingConsensus"
case NodeLeader :
return "NodeLeader"
}
return "Unknown"
}
const (
maxBroadcastNodes = 10 // broadcast at most maxBroadcastNodes peers that need in sync
broadcastTimeout int64 = 60 * 1000000000 // 1 mins
//SyncIDLength is the length of bytes for syncID
SyncIDLength = 20
)
// use to push new block to outofsync node
type syncConfig struct {
timestamp int64
client * downloader . Client
}
// Node represents a protocol-participating node in the network
type Node struct {
Consensus * consensus . Consensus // Consensus object containing all Consensus related data (e.g. committee members, signatures, commits)
BlockChannel chan * types . Block // The channel to send newly proposed blocks
ConfirmedBlockChannel chan * types . Block // The channel to send confirmed blocks
BeaconBlockChannel chan * types . Block // The channel to send beacon blocks for non-beaconchain nodes
DRand * drand . DRand // The instance for distributed randomness protocol
pendingCrossLinks [ ] * block . Header
pendingClMutex sync . Mutex
pendingCXReceipts map [ string ] * types . CXReceiptsProof // All the receipts received but not yet processed for Consensus
pendingCXMutex sync . Mutex
// Shard databases
shardChains shardchain . Collection
Client * client . Client // The presence of a client object means this node will also act as a client
SelfPeer p2p . Peer // TODO(minhdoan): it could be duplicated with Self below whose is Alok work.
BCPeers [ ] p2p . Peer // list of Beacon Chain Peers. This is needed by all nodes.
// TODO: Neighbors should store only neighbor nodes in the same shard
Neighbors sync . Map // All the neighbor nodes, key is the sha256 of Peer IP/Port, value is the p2p.Peer
numPeers int // Number of Peers
State State // State of the Node
stateMutex sync . Mutex // mutex for change node state
// BeaconNeighbors store only neighbor nodes in the beacon chain shard
BeaconNeighbors sync . Map // All the neighbor nodes, key is the sha256 of Peer IP/Port, value is the p2p.Peer
TxPool * core . TxPool // TODO migrate to TxPool from pendingTransactions list below
CxPool * core . CxPool // pool for missing cross shard receipts resend
pendingTransactions map [ common . Hash ] * types . Transaction // All the transactions received but not yet processed for Consensus
pendingTxMutex sync . Mutex
recentTxsStats types . RecentTxsStats
pendingStakingTransactions map [ common . Hash ] * staking . StakingTransaction // All the staking transactions received but not yet processed for Consensus
pendingStakingTxMutex sync . Mutex
Worker * worker . Worker
BeaconWorker * worker . Worker // worker for beacon chain
// Client server (for wallet requests)
clientServer * clientService . Server
// Syncing component.
syncID [ SyncIDLength ] byte // a unique ID for the node during the state syncing process with peers
downloaderServer * downloader . Server
stateSync * syncing . StateSync
beaconSync * syncing . StateSync
peerRegistrationRecord map [ string ] * syncConfig // record registration time (unixtime) of peers begin in syncing
SyncingPeerProvider SyncingPeerProvider
// syncing frequency parameters
syncFreq int
beaconSyncFreq int
// The p2p host used to send/receive p2p messages
host p2p . Host
// Incoming messages to process.
clientRxQueue * msgq . Queue
shardRxQueue * msgq . Queue
globalRxQueue * msgq . Queue
// Service manager.
serviceManager * service . Manager
// Demo account.
DemoContractAddress common . Address
LotteryManagerPrivateKey * ecdsa . PrivateKey
// Puzzle account.
PuzzleContractAddress common . Address
PuzzleManagerPrivateKey * ecdsa . PrivateKey
// For test only; TODO ek – remove this
TestBankKeys [ ] * ecdsa . PrivateKey
ContractDeployerKey * ecdsa . PrivateKey
ContractDeployerCurrentNonce uint64 // The nonce of the deployer contract at current block
ContractAddresses [ ] common . Address
// For puzzle contracts
AddressNonce sync . Map
// Shard group Message Receiver
shardGroupReceiver p2p . GroupReceiver
// Global group Message Receiver, communicate with beacon chain, or cross-shard TX
globalGroupReceiver p2p . GroupReceiver
// Client Message Receiver to handle light client messages
// Beacon leader needs to use this receiver to talk to new node
clientReceiver p2p . GroupReceiver
// Duplicated Ping Message Received
duplicatedPing sync . Map
// Channel to notify consensus service to really start consensus
startConsensus chan struct { }
// node configuration, including group ID, shard ID, etc
NodeConfig * nodeconfig . ConfigType
// Chain configuration.
chainConfig params . ChainConfig
// map of service type to its message channel.
serviceMessageChan map [ service . Type ] chan * msg_pb . Message
// Used to call smart contract locally
ContractCaller * contracts . ContractCaller
accountManager * accounts . Manager
// Next shard state
nextShardState struct {
// The received master shard state
master * shard . EpochShardState
// When for a leader to propose the next shard state,
// or for a validator to wait for a proposal before view change.
// TODO ek – replace with retry-based logic instead of delay
proposeTime time . Time
}
isFirstTime bool // the node was started with a fresh database
// How long in second the leader needs to wait to propose a new block.
BlockPeriod time . Duration
// last time consensus reached for metrics
lastConsensusTime int64
}
// Blockchain returns the blockchain for the node's current shard.
func ( node * Node ) Blockchain ( ) * core . BlockChain {
shardID := node . NodeConfig . ShardID
bc , err := node . shardChains . ShardChain ( shardID )
if err != nil {
utils . Logger ( ) . Error ( ) .
Uint32 ( "shardID" , shardID ) .
Err ( err ) .
Msg ( "cannot get shard chain" )
}
return bc
}
// Beaconchain returns the beaconchain from node.
func ( node * Node ) Beaconchain ( ) * core . BlockChain {
bc , err := node . shardChains . ShardChain ( 0 )
if err != nil {
utils . Logger ( ) . Error ( ) . Err ( err ) . Msg ( "cannot get beaconchain" )
}
return bc
}
func ( node * Node ) tryBroadcast ( tx * types . Transaction ) {
msg := proto_node . ConstructTransactionListMessageAccount ( types . Transactions { tx } )
shardGroupID := nodeconfig . NewGroupIDByShardID ( nodeconfig . ShardID ( tx . ShardID ( ) ) )
utils . Logger ( ) . Info ( ) . Str ( "shardGroupID" , string ( shardGroupID ) ) . Msg ( "tryBroadcast" )
for attempt := 0 ; attempt < NumTryBroadCast ; attempt ++ {
if err := node . host . SendMessageToGroups ( [ ] nodeconfig . GroupID { shardGroupID } , p2p_host . ConstructP2pMessage ( byte ( 0 ) , msg ) ) ; err != nil && attempt < NumTryBroadCast {
utils . Logger ( ) . Error ( ) . Int ( "attempt" , attempt ) . Msg ( "Error when trying to broadcast tx" )
} else {
break
}
}
}
// Add new transactions to the pending transaction list.
func ( node * Node ) addPendingTransactions ( newTxs types . Transactions ) {
node . pendingTxMutex . Lock ( )
node . TxPool . AddRemotes ( newTxs )
node . pendingTxMutex . Unlock ( )
pendingCount , queueCount := node . TxPool . Stats ( )
utils . Logger ( ) . Info ( ) . Int ( "length of newTxs" , len ( newTxs ) ) . Int ( "totalPending" , pendingCount ) . Int ( "totalQueued" , queueCount ) . Msg ( "Got more transactions" )
}
// Add new staking transactions to the pending staking transaction list.
func ( node * Node ) addPendingStakingTransactions ( newStakingTxs staking . StakingTransactions ) {
txPoolLimit := 1000 // TODO: incorporate staking txn into TxPool
node . pendingStakingTxMutex . Lock ( )
for _ , tx := range newStakingTxs {
if _ , ok := node . pendingStakingTransactions [ tx . Hash ( ) ] ; ! ok {
node . pendingStakingTransactions [ tx . Hash ( ) ] = tx
}
if len ( node . pendingStakingTransactions ) > txPoolLimit {
break
}
}
node . pendingStakingTxMutex . Unlock ( )
utils . Logger ( ) . Info ( ) . Int ( "length of newStakingTxs" , len ( newStakingTxs ) ) . Int ( "totalPending" , len ( node . pendingStakingTransactions ) ) . Msg ( "Got more staking transactions" )
}
// AddPendingStakingTransaction staking transactions
func ( node * Node ) AddPendingStakingTransaction (
newStakingTx * staking . StakingTransaction ) {
node . addPendingStakingTransactions ( staking . StakingTransactions { newStakingTx } )
}
// AddPendingTransaction adds one new transaction to the pending transaction list.
// This is only called from SDK.
func ( node * Node ) AddPendingTransaction ( newTx * types . Transaction ) {
if node . Consensus . IsLeader ( ) && newTx . ShardID ( ) == node . NodeConfig . ShardID {
node . addPendingTransactions ( types . Transactions { newTx } )
} else {
utils . Logger ( ) . Info ( ) . Str ( "Hash" , newTx . Hash ( ) . Hex ( ) ) . Msg ( "Broadcasting Tx" )
node . tryBroadcast ( newTx )
}
}
// AddPendingReceipts adds one receipt message to pending list.
func ( node * Node ) AddPendingReceipts ( receipts * types . CXReceiptsProof ) {
node . pendingCXMutex . Lock ( )
defer node . pendingCXMutex . Unlock ( )
if receipts . ContainsEmptyField ( ) {
utils . Logger ( ) . Info ( ) . Int ( "totalPendingReceipts" , len ( node . pendingCXReceipts ) ) . Msg ( "CXReceiptsProof contains empty field" )
return
}
blockNum := receipts . Header . Number ( ) . Uint64 ( )
shardID := receipts . Header . ShardID ( )
key := utils . GetPendingCXKey ( shardID , blockNum )
if _ , ok := node . pendingCXReceipts [ key ] ; ok {
utils . Logger ( ) . Info ( ) . Int ( "totalPendingReceipts" , len ( node . pendingCXReceipts ) ) . Msg ( "Already Got Same Receipt message" )
return
}
node . pendingCXReceipts [ key ] = receipts
utils . Logger ( ) . Info ( ) . Int ( "totalPendingReceipts" , len ( node . pendingCXReceipts ) ) . Msg ( "Got ONE more receipt message" )
}
func ( node * Node ) startRxPipeline (
receiver p2p . GroupReceiver , queue * msgq . Queue , numWorkers int ,
) {
// consumers
for i := 0 ; i < numWorkers ; i ++ {
go queue . HandleMessages ( node )
}
// provider
go node . receiveGroupMessage ( receiver , queue )
}
// StartServer starts a server and process the requests by a handler.
func ( node * Node ) StartServer ( ) {
// client messages are sent by clients, like txgen, wallet
node . startRxPipeline ( node . clientReceiver , node . clientRxQueue , ClientRxWorkers )
// start the goroutine to receive group message
node . startRxPipeline ( node . shardGroupReceiver , node . shardRxQueue , ShardRxWorkers )
// start the goroutine to receive global message, used for cross-shard TX
// FIXME (leo): we use beacon client topic as the global topic for now
node . startRxPipeline ( node . globalGroupReceiver , node . globalRxQueue , GlobalRxWorkers )
select { }
}
// Count the total number of transactions in the blockchain
// Currently used for stats reporting purpose
func ( node * Node ) countNumTransactionsInBlockchain ( ) int {
count := 0
for block := node . Blockchain ( ) . CurrentBlock ( ) ; block != nil ; block = node . Blockchain ( ) . GetBlockByHash ( block . Header ( ) . ParentHash ( ) ) {
count += len ( block . Transactions ( ) )
}
return count
}
// GetSyncID returns the syncID of this node
func ( node * Node ) GetSyncID ( ) [ SyncIDLength ] byte {
return node . syncID
}
// New creates a new node.
func New ( host p2p . Host , consensusObj * consensus . Consensus , chainDBFactory shardchain . DBFactory , isArchival bool ) * Node {
node := Node { }
node . syncFreq = SyncFrequency
node . beaconSyncFreq = SyncFrequency
// Get the node config that's created in the harmony.go program.
if consensusObj != nil {
node . NodeConfig = nodeconfig . GetShardConfig ( consensusObj . ShardID )
} else {
node . NodeConfig = nodeconfig . GetDefaultConfig ( )
}
copy ( node . syncID [ : ] , GenerateRandomString ( SyncIDLength ) )
if host != nil {
node . host = host
node . SelfPeer = host . GetSelfPeer ( )
}
chainConfig := * params . TestnetChainConfig
switch node . NodeConfig . GetNetworkType ( ) {
case nodeconfig . Mainnet :
chainConfig = * params . MainnetChainConfig
case nodeconfig . Pangaea :
chainConfig = * params . PangaeaChainConfig
}
node . chainConfig = chainConfig
collection := shardchain . NewCollection (
chainDBFactory , & genesisInitializer { & node } , chain . Engine , & chainConfig ,
)
if isArchival {
collection . DisableCache ( )
}
node . shardChains = collection
if host != nil && consensusObj != nil {
// Consensus and associated channel to communicate blocks
node . Consensus = consensusObj
// Load the chains.
blockchain := node . Blockchain ( ) // this also sets node.isFirstTime if the DB is fresh
beaconChain := node . Beaconchain ( )
node . BlockChannel = make ( chan * types . Block )
node . ConfirmedBlockChannel = make ( chan * types . Block )
node . BeaconBlockChannel = make ( chan * types . Block )
node . recentTxsStats = make ( types . RecentTxsStats )
node . TxPool = core . NewTxPool ( core . DefaultTxPoolConfig , node . Blockchain ( ) . Config ( ) , blockchain )
node . CxPool = core . NewCxPool ( core . CxPoolSize )
node . Worker = worker . New ( node . Blockchain ( ) . Config ( ) , blockchain , chain . Engine )
if node . Blockchain ( ) . ShardID ( ) != shard . BeaconChainShardID {
node . BeaconWorker = worker . New ( node . Beaconchain ( ) . Config ( ) , beaconChain , chain . Engine )
}
node . pendingCXReceipts = make ( map [ string ] * types . CXReceiptsProof )
node . pendingTransactions = make ( map [ common . Hash ] * types . Transaction )
node . pendingStakingTransactions = make ( map [ common . Hash ] * staking . StakingTransaction )
node . Consensus . VerifiedNewBlock = make ( chan * types . Block )
chain . Engine . SetRewarder ( node . Consensus . Decider . ( reward . Distributor ) )
// the sequence number is the next block number to be added in consensus protocol, which is always one more than current chain header block
node . Consensus . SetBlockNum ( blockchain . CurrentBlock ( ) . NumberU64 ( ) + 1 )
// Add Faucet contract to all shards, so that on testnet, we can demo wallet in explorer
// TODO (leo): we need to have support of cross-shard tx later so that the token can be transferred from beacon chain shard to other tx shards.
if node . NodeConfig . GetNetworkType ( ) != nodeconfig . Mainnet {
if node . isFirstTime {
// Setup one time smart contracts
node . AddFaucetContractToPendingTransactions ( )
} else {
node . AddContractKeyAndAddress ( scFaucet )
}
node . ContractCaller = contracts . NewContractCaller ( node . Blockchain ( ) , node . Blockchain ( ) . Config ( ) )
// Create test keys. Genesis will later need this.
var err error
node . TestBankKeys , err = CreateTestBankKeys ( TestAccountNumber )
if err != nil {
utils . Logger ( ) . Error ( ) . Err ( err ) . Msg ( "Error while creating test keys" )
}
}
}
utils . Logger ( ) . Info ( ) .
Interface ( "genesis block header" , node . Blockchain ( ) . GetHeaderByNumber ( 0 ) ) .
Msg ( "Genesis block hash" )
node . clientRxQueue = msgq . New ( ClientRxQueueSize )
node . shardRxQueue = msgq . New ( ShardRxQueueSize )
node . globalRxQueue = msgq . New ( GlobalRxQueueSize )
// Setup initial state of syncing.
node . peerRegistrationRecord = make ( map [ string ] * syncConfig )
node . startConsensus = make ( chan struct { } )
go node . bootstrapConsensus ( )
return & node
}
// InitConsensusWithValidators initialize shard state from latest epoch and update committee pub
// keys for consensus and drand
func ( node * Node ) InitConsensusWithValidators ( ) ( err error ) {
if node . Consensus == nil {
utils . Logger ( ) . Error ( ) . Msg ( "[InitConsensusWithValidators] consenus is nil; Cannot figure out shardID" )
return ctxerror . New ( "[InitConsensusWithValidators] consenus is nil; Cannot figure out shardID" )
}
shardID := node . Consensus . ShardID
blockNum := node . Blockchain ( ) . CurrentBlock ( ) . NumberU64 ( )
node . Consensus . SetMode ( consensus . Listening )
epoch := shard . Schedule . CalcEpochNumber ( blockNum )
utils . Logger ( ) . Info ( ) .
Uint64 ( "blockNum" , blockNum ) .
Uint32 ( "shardID" , shardID ) .
Uint64 ( "epoch" , epoch . Uint64 ( ) ) .
Msg ( "[InitConsensusWithValidators] Try To Get PublicKeys" )
_ , pubKeys := committee . WithStakingEnabled . ComputePublicKeys (
epoch , node . Consensus . ChainReader , int ( shardID ) ,
)
if len ( pubKeys ) == 0 {
utils . Logger ( ) . Error ( ) .
Uint32 ( "shardID" , shardID ) .
Uint64 ( "blockNum" , blockNum ) .
Msg ( "[InitConsensusWithValidators] PublicKeys is Empty, Cannot update public keys" )
return ctxerror . New (
"[InitConsensusWithValidators] PublicKeys is Empty, Cannot update public keys" ,
"shardID" , shardID ,
"blockNum" , blockNum )
}
for i := range pubKeys {
if pubKeys [ i ] . IsEqual ( node . Consensus . PubKey ) {
utils . Logger ( ) . Info ( ) .
Uint64 ( "blockNum" , blockNum ) .
Int ( "numPubKeys" , len ( pubKeys ) ) .
Msg ( "[InitConsensusWithValidators] Successfully updated public keys" )
node . Consensus . UpdatePublicKeys ( pubKeys )
node . Consensus . SetMode ( consensus . Normal )
return nil
}
}
// TODO: Disable drand. Currently drand isn't functioning but we want to compeletely turn it off for full protection.
// node.DRand.UpdatePublicKeys(pubKeys)
return nil
}
// AddPeers adds neighbors nodes
func ( node * Node ) AddPeers ( peers [ ] * p2p . Peer ) int {
count := 0
for _ , p := range peers {
key := fmt . Sprintf ( "%s:%s:%s" , p . IP , p . Port , p . PeerID )
_ , ok := node . Neighbors . LoadOrStore ( key , * p )
if ! ok {
// !ok means new peer is stored
count ++
node . host . AddPeer ( p )
node . numPeers ++
continue
}
}
return count
}
// AddBeaconPeer adds beacon chain neighbors nodes
// Return false means new neighbor peer was added
// Return true means redundant neighbor peer wasn't added
func ( node * Node ) AddBeaconPeer ( p * p2p . Peer ) bool {
key := fmt . Sprintf ( "%s:%s:%s" , p . IP , p . Port , p . PeerID )
_ , ok := node . BeaconNeighbors . LoadOrStore ( key , * p )
return ok
}
// isBeacon = true if the node is beacon node
// isClient = true if the node light client(wallet)
func ( node * Node ) initNodeConfiguration ( ) ( service . NodeConfig , chan p2p . Peer ) {
chanPeer := make ( chan p2p . Peer )
nodeConfig := service . NodeConfig {
PushgatewayIP : node . NodeConfig . GetPushgatewayIP ( ) ,
PushgatewayPort : node . NodeConfig . GetPushgatewayPort ( ) ,
IsClient : node . NodeConfig . IsClient ( ) ,
Beacon : nodeconfig . NewGroupIDByShardID ( 0 ) ,
ShardGroupID : node . NodeConfig . GetShardGroupID ( ) ,
Actions : make ( map [ nodeconfig . GroupID ] nodeconfig . ActionType ) ,
}
if nodeConfig . IsClient {
nodeConfig . Actions [ nodeconfig . NewClientGroupIDByShardID ( 0 ) ] = nodeconfig . ActionStart
} else {
nodeConfig . Actions [ node . NodeConfig . GetShardGroupID ( ) ] = nodeconfig . ActionStart
}
var err error
node . shardGroupReceiver , err = node . host . GroupReceiver ( node . NodeConfig . GetShardGroupID ( ) )
if err != nil {
utils . Logger ( ) . Error ( ) . Err ( err ) . Msg ( "Failed to create shard receiver" )
}
node . globalGroupReceiver , err = node . host . GroupReceiver ( nodeconfig . NewClientGroupIDByShardID ( 0 ) )
if err != nil {
utils . Logger ( ) . Error ( ) . Err ( err ) . Msg ( "Failed to create global receiver" )
}
node . clientReceiver , err = node . host . GroupReceiver ( node . NodeConfig . GetClientGroupID ( ) )
if err != nil {
utils . Logger ( ) . Error ( ) . Err ( err ) . Msg ( "Failed to create client receiver" )
}
return nodeConfig , chanPeer
}
// AccountManager ...
func ( node * Node ) AccountManager ( ) * accounts . Manager {
return node . accountManager
}
// ServiceManager ...
func ( node * Node ) ServiceManager ( ) * service . Manager {
return node . serviceManager
}
// SetSyncFreq sets the syncing frequency in the loop
func ( node * Node ) SetSyncFreq ( syncFreq int ) {
node . syncFreq = syncFreq
}
// SetBeaconSyncFreq sets the syncing frequency in the loop
func ( node * Node ) SetBeaconSyncFreq ( syncFreq int ) {
node . beaconSyncFreq = syncFreq
}