Merge pull request #17492 from karalabe/eth-miner-threads-defaults

cmd, eth: clean up miner startup API, drop noop config field

cmd/geth/main.go

@@ -336,26 +336,18 @@ func startNode(ctx *cli.Context, stack *node.Node) {
 		if err := stack.Service(&ethereum); err != nil {
 			utils.Fatalf("Ethereum service not running: %v", err)
 		}
-		// Use a reduced number of threads if requested
-		threads := ctx.GlobalInt(utils.MinerLegacyThreadsFlag.Name)
-		if ctx.GlobalIsSet(utils.MinerThreadsFlag.Name) {
-			threads = ctx.GlobalInt(utils.MinerThreadsFlag.Name)
-		}
-		if threads > 0 {
-			type threaded interface {
-				SetThreads(threads int)
-			}
-			if th, ok := ethereum.Engine().(threaded); ok {
-				th.SetThreads(threads)
-			}
-		}
 		// Set the gas price to the limits from the CLI and start mining
 		gasprice := utils.GlobalBig(ctx, utils.MinerLegacyGasPriceFlag.Name)
 		if ctx.IsSet(utils.MinerGasPriceFlag.Name) {
 			gasprice = utils.GlobalBig(ctx, utils.MinerGasPriceFlag.Name)
 		}
 		ethereum.TxPool().SetGasPrice(gasprice)
-		if err := ethereum.StartMining(true); err != nil {
+
+		threads := ctx.GlobalInt(utils.MinerLegacyThreadsFlag.Name)
+		if ctx.GlobalIsSet(utils.MinerThreadsFlag.Name) {
+			threads = ctx.GlobalInt(utils.MinerThreadsFlag.Name)
+		}
+		if err := ethereum.StartMining(threads); err != nil {
 			utils.Fatalf("Failed to start mining: %v", err)
 		}
 	}

cmd/utils/flags.go

@@ -1130,12 +1130,6 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *eth.Config) {
 	if ctx.GlobalIsSet(CacheFlag.Name) || ctx.GlobalIsSet(CacheGCFlag.Name) {
 		cfg.TrieCache = ctx.GlobalInt(CacheFlag.Name) * ctx.GlobalInt(CacheGCFlag.Name) / 100
 	}
-	if ctx.GlobalIsSet(MinerLegacyThreadsFlag.Name) {
-		cfg.MinerThreads = ctx.GlobalInt(MinerLegacyThreadsFlag.Name)
-	}
-	if ctx.GlobalIsSet(MinerThreadsFlag.Name) {
-		cfg.MinerThreads = ctx.GlobalInt(MinerThreadsFlag.Name)
-	}
 	if ctx.GlobalIsSet(MinerNotifyFlag.Name) {
 		cfg.MinerNotify = strings.Split(ctx.GlobalString(MinerNotifyFlag.Name), ",")
 	}

eth/api.go

@@ -24,6 +24,7 @@ import (
 	"io"
 	"math/big"
 	"os"
+	"runtime"
 	"strings"
 	"time"
 
@@ -34,7 +35,6 @@ import (
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/internal/ethapi"
-	"github.com/ethereum/go-ethereum/log"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/rpc"
@@ -94,47 +94,22 @@ func NewPrivateMinerAPI(e *Ethereum) *PrivateMinerAPI {
 	return &PrivateMinerAPI{e: e}
 }
 
-// Start the miner with the given number of threads. If threads is nil the number
-// of workers started is equal to the number of logical CPUs that are usable by
-// this process. If mining is already running, this method adjust the number of
-// threads allowed to use and updates the minimum price required by the transaction
-// pool.
+// Start starts the miner with the given number of threads. If threads is nil,
+// the number of workers started is equal to the number of logical CPUs that are
+// usable by this process. If mining is already running, this method adjust the
+// number of threads allowed to use and updates the minimum price required by the
+// transaction pool.
 func (api *PrivateMinerAPI) Start(threads *int) error {
-	// Set the number of threads if the seal engine supports it
 	if threads == nil {
-		threads = new(int)
-	} else if *threads == 0 {
-		*threads = -1 // Disable the miner from within
+		return api.e.StartMining(runtime.NumCPU())
 	}
-	type threaded interface {
-		SetThreads(threads int)
-	}
-	if th, ok := api.e.engine.(threaded); ok {
-		log.Info("Updated mining threads", "threads", *threads)
-		th.SetThreads(*threads)
-	}
-	// Start the miner and return
-	if !api.e.IsMining() {
-		// Propagate the initial price point to the transaction pool
-		api.e.lock.RLock()
-		price := api.e.gasPrice
-		api.e.lock.RUnlock()
-		api.e.txPool.SetGasPrice(price)
-		return api.e.StartMining(true)
-	}
-	return nil
+	return api.e.StartMining(*threads)
 }
 
-// Stop the miner
-func (api *PrivateMinerAPI) Stop() bool {
-	type threaded interface {
-		SetThreads(threads int)
-	}
-	if th, ok := api.e.engine.(threaded); ok {
-		th.SetThreads(-1)
-	}
+// Stop terminates the miner, both at the consensus engine level as well as at
+// the block creation level.
+func (api *PrivateMinerAPI) Stop() {
 	api.e.StopMining()
-	return true
 }
 
 // SetExtra sets the extra data string that is included when this miner mines a block.

eth/backend.go

@@ -102,12 +102,18 @@ func (s *Ethereum) AddLesServer(ls LesServer) {
 // New creates a new Ethereum object (including the
 // initialisation of the common Ethereum object)
 func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
+	// Ensure configuration values are compatible and sane
 	if config.SyncMode == downloader.LightSync {
 		return nil, errors.New("can't run eth.Ethereum in light sync mode, use les.LightEthereum")
 	}
 	if !config.SyncMode.IsValid() {
 		return nil, fmt.Errorf("invalid sync mode %d", config.SyncMode)
 	}
+	if config.MinerGasPrice == nil || config.MinerGasPrice.Cmp(common.Big0) <= 0 {
+		log.Warn("Sanitizing invalid miner gas price", "provided", config.MinerGasPrice, "updated", DefaultConfig.MinerGasPrice)
+		config.MinerGasPrice = new(big.Int).Set(DefaultConfig.MinerGasPrice)
+	}
+	// Assemble the Ethereum object
 	chainDb, err := CreateDB(ctx, config, "chaindata")
 	if err != nil {
 		return nil, err
@@ -333,32 +339,66 @@ func (s *Ethereum) SetEtherbase(etherbase common.Address) {
 	s.miner.SetEtherbase(etherbase)
 }
 
-func (s *Ethereum) StartMining(local bool) error {
-	eb, err := s.Etherbase()
-	if err != nil {
-		log.Error("Cannot start mining without etherbase", "err", err)
-		return fmt.Errorf("etherbase missing: %v", err)
+// StartMining starts the miner with the given number of CPU threads. If mining
+// is already running, this method adjust the number of threads allowed to use
+// and updates the minimum price required by the transaction pool.
+func (s *Ethereum) StartMining(threads int) error {
+	// Update the thread count within the consensus engine
+	type threaded interface {
+		SetThreads(threads int)
 	}
-	if clique, ok := s.engine.(*clique.Clique); ok {
-		wallet, err := s.accountManager.Find(accounts.Account{Address: eb})
-		if wallet == nil || err != nil {
-			log.Error("Etherbase account unavailable locally", "err", err)
-			return fmt.Errorf("signer missing: %v", err)
+	if th, ok := s.engine.(threaded); ok {
+		log.Info("Updated mining threads", "threads", threads)
+		if threads == 0 {
+			threads = -1 // Disable the miner from within
 		}
-		clique.Authorize(eb, wallet.SignHash)
+		th.SetThreads(threads)
 	}
-	if local {
-		// If local (CPU) mining is started, we can disable the transaction rejection
-		// mechanism introduced to speed sync times. CPU mining on mainnet is ludicrous
-		// so none will ever hit this path, whereas marking sync done on CPU mining
-		// will ensure that private networks work in single miner mode too.
+	// If the miner was not running, initialize it
+	if !s.IsMining() {
+		// Propagate the initial price point to the transaction pool
+		s.lock.RLock()
+		price := s.gasPrice
+		s.lock.RUnlock()
+		s.txPool.SetGasPrice(price)
+
+		// Configure the local mining addess
+		eb, err := s.Etherbase()
+		if err != nil {
+			log.Error("Cannot start mining without etherbase", "err", err)
+			return fmt.Errorf("etherbase missing: %v", err)
+		}
+		if clique, ok := s.engine.(*clique.Clique); ok {
+			wallet, err := s.accountManager.Find(accounts.Account{Address: eb})
+			if wallet == nil || err != nil {
+				log.Error("Etherbase account unavailable locally", "err", err)
+				return fmt.Errorf("signer missing: %v", err)
+			}
+			clique.Authorize(eb, wallet.SignHash)
+		}
+		// If mining is started, we can disable the transaction rejection mechanism
+		// introduced to speed sync times.
 		atomic.StoreUint32(&s.protocolManager.acceptTxs, 1)
+
+		go s.miner.Start(eb)
 	}
-	go s.miner.Start(eb)
 	return nil
 }
 
-func (s *Ethereum) StopMining()         { s.miner.Stop() }
+// StopMining terminates the miner, both at the consensus engine level as well as
+// at the block creation level.
+func (s *Ethereum) StopMining() {
+	// Update the thread count within the consensus engine
+	type threaded interface {
+		SetThreads(threads int)
+	}
+	if th, ok := s.engine.(threaded); ok {
+		th.SetThreads(-1)
+	}
+	// Stop the block creating itself
+	s.miner.Stop()
+}
+
 func (s *Ethereum) IsMining() bool      { return s.miner.Mining() }
 func (s *Ethereum) Miner() *miner.Miner { return s.miner }
 

eth/config.go

@@ -97,7 +97,6 @@ type Config struct {
 
 	// Mining-related options
 	Etherbase      common.Address `toml:",omitempty"`
-	MinerThreads   int            `toml:",omitempty"`
 	MinerNotify    []string       `toml:",omitempty"`
 	MinerExtraData []byte         `toml:",omitempty"`
 	MinerGasPrice  *big.Int

eth/gen_config.go

@@ -31,7 +31,6 @@ func (c Config) MarshalTOML() (interface{}, error) {
 		TrieCache               int
 		TrieTimeout             time.Duration
 		Etherbase               common.Address `toml:",omitempty"`
-		MinerThreads            int            `toml:",omitempty"`
 		MinerNotify             []string       `toml:",omitempty"`
 		MinerExtraData          hexutil.Bytes  `toml:",omitempty"`
 		MinerGasPrice           *big.Int
@@ -55,7 +54,6 @@ func (c Config) MarshalTOML() (interface{}, error) {
 	enc.TrieCache = c.TrieCache
 	enc.TrieTimeout = c.TrieTimeout
 	enc.Etherbase = c.Etherbase
-	enc.MinerThreads = c.MinerThreads
 	enc.MinerNotify = c.MinerNotify
 	enc.MinerExtraData = c.MinerExtraData
 	enc.MinerGasPrice = c.MinerGasPrice
@@ -134,9 +132,6 @@ func (c *Config) UnmarshalTOML(unmarshal func(interface{}) error) error {
 	if dec.Etherbase != nil {
 		c.Etherbase = *dec.Etherbase
 	}
-	if dec.MinerThreads != nil {
-		c.MinerThreads = *dec.MinerThreads
-	}
 	if dec.MinerNotify != nil {
 		c.MinerNotify = dec.MinerNotify
 	}

miner/stress_clique.go

+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// +build none
+
+// This file contains a miner stress test based on the Clique consensus engine.
+package main
+
+import (
+	"bytes"
+	"crypto/ecdsa"
+	"fmt"
+	"io/ioutil"
+	"math/big"
+	"math/rand"
+	"os"
+	"time"
+
+	"github.com/ethereum/go-ethereum/accounts/keystore"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/fdlimit"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/eth/downloader"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/node"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+func main() {
+	log.Root().SetHandler(log.LvlFilterHandler(log.LvlInfo, log.StreamHandler(os.Stderr, log.TerminalFormat(true))))
+	fdlimit.Raise(2048)
+
+	// Generate a batch of accounts to seal and fund with
+	faucets := make([]*ecdsa.PrivateKey, 128)
+	for i := 0; i < len(faucets); i++ {
+		faucets[i], _ = crypto.GenerateKey()
+	}
+	sealers := make([]*ecdsa.PrivateKey, 4)
+	for i := 0; i < len(sealers); i++ {
+		sealers[i], _ = crypto.GenerateKey()
+	}
+	// Create a Clique network based off of the Rinkeby config
+	genesis := makeGenesis(faucets, sealers)
+
+	var (
+		nodes  []*node.Node
+		enodes []string
+	)
+	for _, sealer := range sealers {
+		// Start the node and wait until it's up
+		node, err := makeSealer(genesis, enodes)
+		if err != nil {
+			panic(err)
+		}
+		defer node.Stop()
+
+		for node.Server().NodeInfo().Ports.Listener == 0 {
+			time.Sleep(250 * time.Millisecond)
+		}
+		// Connect the node to al the previous ones
+		for _, enode := range enodes {
+			enode, err := discover.ParseNode(enode)
+			if err != nil {
+				panic(err)
+			}
+			node.Server().AddPeer(enode)
+		}
+		// Start tracking the node and it's enode url
+		nodes = append(nodes, node)
+
+		enode := fmt.Sprintf("enode://%s@127.0.0.1:%d", node.Server().NodeInfo().ID, node.Server().NodeInfo().Ports.Listener)
+		enodes = append(enodes, enode)
+
+		// Inject the signer key and start sealing with it
+		store := node.AccountManager().Backends(keystore.KeyStoreType)[0].(*keystore.KeyStore)
+		signer, err := store.ImportECDSA(sealer, "")
+		if err != nil {
+			panic(err)
+		}
+		if err := store.Unlock(signer, ""); err != nil {
+			panic(err)
+		}
+	}
+	// Iterate over all the nodes and start signing with them
+	time.Sleep(3 * time.Second)
+
+	for _, node := range nodes {
+		var ethereum *eth.Ethereum
+		if err := node.Service(&ethereum); err != nil {
+			panic(err)
+		}
+		if err := ethereum.StartMining(1); err != nil {
+			panic(err)
+		}
+	}
+	time.Sleep(3 * time.Second)
+
+	// Start injecting transactions from the faucet like crazy
+	nonces := make([]uint64, len(faucets))
+	for {
+		index := rand.Intn(len(faucets))
+
+		// Fetch the accessor for the relevant signer
+		var ethereum *eth.Ethereum
+		if err := nodes[index%len(nodes)].Service(&ethereum); err != nil {
+			panic(err)
+		}
+		// Create a self transaction and inject into the pool
+		tx, err := types.SignTx(types.NewTransaction(nonces[index], crypto.PubkeyToAddress(faucets[index].PublicKey), new(big.Int), 21000, big.NewInt(100000000000), nil), types.HomesteadSigner{}, faucets[index])
+		if err != nil {
+			panic(err)
+		}
+		if err := ethereum.TxPool().AddLocal(tx); err != nil {
+			panic(err)
+		}
+		nonces[index]++
+
+		// Wait if we're too saturated
+		if pend, _ := ethereum.TxPool().Stats(); pend > 2048 {
+			time.Sleep(100 * time.Millisecond)
+		}
+	}
+}
+
+// makeGenesis creates a custom Clique genesis block based on some pre-defined
+// signer and faucet accounts.
+func makeGenesis(faucets []*ecdsa.PrivateKey, sealers []*ecdsa.PrivateKey) *core.Genesis {
+	// Create a Clique network based off of the Rinkeby config
+	genesis := core.DefaultRinkebyGenesisBlock()
+	genesis.GasLimit = 25000000
+
+	genesis.Config.ChainID = big.NewInt(18)
+	genesis.Config.Clique.Period = 1
+	genesis.Config.EIP150Hash = common.Hash{}
+
+	genesis.Alloc = core.GenesisAlloc{}
+	for _, faucet := range faucets {
+		genesis.Alloc[crypto.PubkeyToAddress(faucet.PublicKey)] = core.GenesisAccount{
+			Balance: new(big.Int).Exp(big.NewInt(2), big.NewInt(128), nil),
+		}
+	}
+	// Sort the signers and embed into the extra-data section
+	signers := make([]common.Address, len(sealers))
+	for i, sealer := range sealers {
+		signers[i] = crypto.PubkeyToAddress(sealer.PublicKey)
+	}
+	for i := 0; i < len(signers); i++ {
+		for j := i + 1; j < len(signers); j++ {
+			if bytes.Compare(signers[i][:], signers[j][:]) > 0 {
+				signers[i], signers[j] = signers[j], signers[i]
+			}
+		}
+	}
+	genesis.ExtraData = make([]byte, 32+len(signers)*common.AddressLength+65)
+	for i, signer := range signers {
+		copy(genesis.ExtraData[32+i*common.AddressLength:], signer[:])
+	}
+	// Return the genesis block for initialization
+	return genesis
+}
+
+func makeSealer(genesis *core.Genesis, nodes []string) (*node.Node, error) {
+	// Define the basic configurations for the Ethereum node
+	datadir, _ := ioutil.TempDir("", "")
+
+	config := &node.Config{
+		Name:    "geth",
+		Version: params.Version,
+		DataDir: datadir,
+		P2P: p2p.Config{
+			ListenAddr:  "0.0.0.0:0",
+			NoDiscovery: true,
+			MaxPeers:    25,
+		},
+		NoUSB: true,
+	}
+	// Start the node and configure a full Ethereum node on it
+	stack, err := node.New(config)
+	if err != nil {
+		return nil, err
+	}
+	if err := stack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
+		return eth.New(ctx, &eth.Config{
+			Genesis:         genesis,
+			NetworkId:       genesis.Config.ChainID.Uint64(),
+			SyncMode:        downloader.FullSync,
+			DatabaseCache:   256,
+			DatabaseHandles: 256,
+			TxPool:          core.DefaultTxPoolConfig,
+			GPO:             eth.DefaultConfig.GPO,
+			MinerGasPrice:   big.NewInt(1),
+			MinerRecommit:   time.Second,
+		})
+	}); err != nil {
+		return nil, err
+	}
+	// Start the node and return if successful
+	return stack, stack.Start()
+}

miner/stress_ethash.go

+// Copyright 2018 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// +build none
+
+// This file contains a miner stress test based on the Ethash consensus engine.
+package main
+
+import (
+	"crypto/ecdsa"
+	"fmt"
+	"io/ioutil"
+	"math/big"
+	"math/rand"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/ethereum/go-ethereum/accounts/keystore"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/fdlimit"
+	"github.com/ethereum/go-ethereum/consensus/ethash"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/eth"
+	"github.com/ethereum/go-ethereum/eth/downloader"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/node"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/p2p/discover"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+func main() {
+	log.Root().SetHandler(log.LvlFilterHandler(log.LvlInfo, log.StreamHandler(os.Stderr, log.TerminalFormat(true))))
+	fdlimit.Raise(2048)
+
+	// Generate a batch of accounts to seal and fund with
+	faucets := make([]*ecdsa.PrivateKey, 128)
+	for i := 0; i < len(faucets); i++ {
+		faucets[i], _ = crypto.GenerateKey()
+	}
+	// Pre-generate the ethash mining DAG so we don't race
+	ethash.MakeDataset(1, filepath.Join(os.Getenv("HOME"), ".ethash"))
+
+	// Create an Ethash network based off of the Ropsten config
+	genesis := makeGenesis(faucets)
+
+	var (
+		nodes  []*node.Node
+		enodes []string
+	)
+	for i := 0; i < 4; i++ {
+		// Start the node and wait until it's up
+		node, err := makeMiner(genesis, enodes)
+		if err != nil {
+			panic(err)
+		}
+		defer node.Stop()
+
+		for node.Server().NodeInfo().Ports.Listener == 0 {
+			time.Sleep(250 * time.Millisecond)
+		}
+		// Connect the node to al the previous ones
+		for _, enode := range enodes {
+			enode, err := discover.ParseNode(enode)
+			if err != nil {
+				panic(err)
+			}
+			node.Server().AddPeer(enode)
+		}
+		// Start tracking the node and it's enode url
+		nodes = append(nodes, node)
+
+		enode := fmt.Sprintf("enode://%s@127.0.0.1:%d", node.Server().NodeInfo().ID, node.Server().NodeInfo().Ports.Listener)
+		enodes = append(enodes, enode)
+
+		// Inject the signer key and start sealing with it
+		store := node.AccountManager().Backends(keystore.KeyStoreType)[0].(*keystore.KeyStore)
+		if _, err := store.NewAccount(""); err != nil {
+			panic(err)
+		}
+	}
+	// Iterate over all the nodes and start signing with them
+	time.Sleep(3 * time.Second)
+
+	for _, node := range nodes {
+		var ethereum *eth.Ethereum
+		if err := node.Service(&ethereum); err != nil {
+			panic(err)
+		}
+		if err := ethereum.StartMining(1); err != nil {
+			panic(err)
+		}
+	}
+	time.Sleep(3 * time.Second)
+
+	// Start injecting transactions from the faucets like crazy
+	nonces := make([]uint64, len(faucets))
+	for {
+		index := rand.Intn(len(faucets))
+
+		// Fetch the accessor for the relevant signer
+		var ethereum *eth.Ethereum
+		if err := nodes[index%len(nodes)].Service(&ethereum); err != nil {
+			panic(err)
+		}
+		// Create a self transaction and inject into the pool
+		tx, err := types.SignTx(types.NewTransaction(nonces[index], crypto.PubkeyToAddress(faucets[index].PublicKey), new(big.Int), 21000, big.NewInt(100000000000+rand.Int63n(65536)), nil), types.HomesteadSigner{}, faucets[index])
+		if err != nil {
+			panic(err)
+		}
+		if err := ethereum.TxPool().AddLocal(tx); err != nil {
+			panic(err)
+		}
+		nonces[index]++
+
+		// Wait if we're too saturated
+		if pend, _ := ethereum.TxPool().Stats(); pend > 2048 {
+			time.Sleep(100 * time.Millisecond)
+		}
+	}
+}
+
+// makeGenesis creates a custom Ethash genesis block based on some pre-defined
+// faucet accounts.
+func makeGenesis(faucets []*ecdsa.PrivateKey) *core.Genesis {
+	genesis := core.DefaultTestnetGenesisBlock()
+	genesis.Difficulty = params.MinimumDifficulty
+	genesis.GasLimit = 25000000
+
+	genesis.Config.ChainID = big.NewInt(18)
+	genesis.Config.EIP150Hash = common.Hash{}
+
+	genesis.Alloc = core.GenesisAlloc{}
+	for _, faucet := range faucets {
+		genesis.Alloc[crypto.PubkeyToAddress(faucet.PublicKey)] = core.GenesisAccount{
+			Balance: new(big.Int).Exp(big.NewInt(2), big.NewInt(128), nil),
+		}
+	}
+	return genesis
+}
+
+func makeMiner(genesis *core.Genesis, nodes []string) (*node.Node, error) {
+	// Define the basic configurations for the Ethereum node
+	datadir, _ := ioutil.TempDir("", "")
+
+	config := &node.Config{
+		Name:    "geth",
+		Version: params.Version,
+		DataDir: datadir,
+		P2P: p2p.Config{
+			ListenAddr:  "0.0.0.0:0",
+			NoDiscovery: true,
+			MaxPeers:    25,
+		},
+		NoUSB:             true,
+		UseLightweightKDF: true,
+	}
+	// Start the node and configure a full Ethereum node on it
+	stack, err := node.New(config)
+	if err != nil {
+		return nil, err
+	}
+	if err := stack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
+		return eth.New(ctx, &eth.Config{
+			Genesis:         genesis,
+			NetworkId:       genesis.Config.ChainID.Uint64(),
+			SyncMode:        downloader.FullSync,
+			DatabaseCache:   256,
+			DatabaseHandles: 256,
+			TxPool:          core.DefaultTxPoolConfig,
+			GPO:             eth.DefaultConfig.GPO,
+			Ethash:          eth.DefaultConfig.Ethash,
+			MinerGasPrice:   big.NewInt(1),
+			MinerRecommit:   time.Second,
+		})
+	}); err != nil {
+		return nil, err
+	}
+	// Start the node and return if successful
+	return stack, stack.Start()
+}