cmd, core, eth: journal local transactions to disk (#14784)

* core: reduce txpool event loop goroutines and sync structs

* cmd, core, eth: journal local transactions to disk

* core: journal replacement pending transactions too

* core: separate transaction journal from pool

7 files changed, 416 insertions, 84 deletions

diff --git a/cmd/geth/main.go b/cmd/geth/main.go
index 607414bbb..e89f88ec9 100644
--- a/cmd/geth/main.go
+++ b/cmd/geth/main.go
@@ -67,6 +67,8 @@ var (
 		utils.EthashDatasetsInMemoryFlag,
 		utils.EthashDatasetsOnDiskFlag,
 		utils.TxPoolNoLocalsFlag,
+		utils.TxPoolJournalFlag,
+		utils.TxPoolRejournalFlag,
 		utils.TxPoolPriceLimitFlag,
 		utils.TxPoolPriceBumpFlag,
 		utils.TxPoolAccountSlotsFlag,
diff --git a/cmd/geth/usage.go b/cmd/geth/usage.go
index 275aad674..80861d852 100644
--- a/cmd/geth/usage.go
+++ b/cmd/geth/usage.go
@@ -96,6 +96,8 @@ var AppHelpFlagGroups = []flagGroup{
 		Name: "TRANSACTION POOL",
 		Flags: []cli.Flag{
 			utils.TxPoolNoLocalsFlag,
+			utils.TxPoolJournalFlag,
+			utils.TxPoolRejournalFlag,
 			utils.TxPoolPriceLimitFlag,
 			utils.TxPoolPriceBumpFlag,
 			utils.TxPoolAccountSlotsFlag,
diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index 0159364af..9f7b76c12 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -213,6 +213,16 @@ var (
 		Name:  "txpool.nolocals",
 		Usage: "Disables price exemptions for locally submitted transactions",
 	}
+	TxPoolJournalFlag = cli.StringFlag{
+		Name:  "txpool.journal",
+		Usage: "Disk journal for local transaction to survive node restarts",
+		Value: core.DefaultTxPoolConfig.Journal,
+	}
+	TxPoolRejournalFlag = cli.DurationFlag{
+		Name:  "txpool.rejournal",
+		Usage: "Time interval to regenerate the local transaction journal",
+		Value: core.DefaultTxPoolConfig.Rejournal,
+	}
 	TxPoolPriceLimitFlag = cli.Uint64Flag{
 		Name:  "txpool.pricelimit",
 		Usage: "Minimum gas price limit to enforce for acceptance into the pool",
@@ -838,6 +848,12 @@ func setTxPool(ctx *cli.Context, cfg *core.TxPoolConfig) {
 	if ctx.GlobalIsSet(TxPoolNoLocalsFlag.Name) {
 		cfg.NoLocals = ctx.GlobalBool(TxPoolNoLocalsFlag.Name)
 	}
+	if ctx.GlobalIsSet(TxPoolJournalFlag.Name) {
+		cfg.Journal = ctx.GlobalString(TxPoolJournalFlag.Name)
+	}
+	if ctx.GlobalIsSet(TxPoolRejournalFlag.Name) {
+		cfg.Rejournal = ctx.GlobalDuration(TxPoolRejournalFlag.Name)
+	}
 	if ctx.GlobalIsSet(TxPoolPriceLimitFlag.Name) {
 		cfg.PriceLimit = ctx.GlobalUint64(TxPoolPriceLimitFlag.Name)
 	}
diff --git a/core/tx_journal.go b/core/tx_journal.go
new file mode 100644
index 000000000..94a9ff9b8
--- /dev/null
+++ b/core/tx_journal.go
@@ -0,0 +1,150 @@
+// Copyright 2017 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/>.
+
+package core
+
+import (
+	"errors"
+	"io"
+	"os"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/rlp"
+)
+
+// errNoActiveJournal is returned if a transaction is attempted to be inserted
+// into the journal, but no such file is currently open.
+var errNoActiveJournal = errors.New("no active journal")
+
+// txJournal is a rotating log of transactions with the aim of storing locally
+// created transactions to allow non-executed ones to survive node restarts.
+type txJournal struct {
+	path   string         // Filesystem path to store the transactions at
+	writer io.WriteCloser // Output stream to write new transactions into
+}
+
+// newTxJournal creates a new transaction journal to
+func newTxJournal(path string) *txJournal {
+	return &txJournal{
+		path: path,
+	}
+}
+
+// load parses a transaction journal dump from disk, loading its contents into
+// the specified pool.
+func (journal *txJournal) load(add func(*types.Transaction) error) error {
+	// Skip the parsing if the journal file doens't exist at all
+	if _, err := os.Stat(journal.path); os.IsNotExist(err) {
+		return nil
+	}
+	// Open the journal for loading any past transactions
+	input, err := os.Open(journal.path)
+	if err != nil {
+		return err
+	}
+	defer input.Close()
+
+	// Inject all transactions from the journal into the pool
+	stream := rlp.NewStream(input, 0)
+	total, dropped := 0, 0
+
+	var failure error
+	for {
+		// Parse the next transaction and terminate on error
+		tx := new(types.Transaction)
+		if err = stream.Decode(tx); err != nil {
+			if err != io.EOF {
+				failure = err
+			}
+			break
+		}
+		// Import the transaction and bump the appropriate progress counters
+		total++
+		if err = add(tx); err != nil {
+			log.Debug("Failed to add journaled transaction", "err", err)
+			dropped++
+			continue
+		}
+	}
+	log.Info("Loaded local transaction journal", "transactions", total, "dropped", dropped)
+
+	return failure
+}
+
+// insert adds the specified transaction to the local disk journal.
+func (journal *txJournal) insert(tx *types.Transaction) error {
+	if journal.writer == nil {
+		return errNoActiveJournal
+	}
+	if err := rlp.Encode(journal.writer, tx); err != nil {
+		return err
+	}
+	return nil
+}
+
+// rotate regenerates the transaction journal based on the current contents of
+// the transaction pool.
+func (journal *txJournal) rotate(all map[common.Address]types.Transactions) error {
+	// Close the current journal (if any is open)
+	if journal.writer != nil {
+		if err := journal.writer.Close(); err != nil {
+			return err
+		}
+		journal.writer = nil
+	}
+	// Generate a new journal with the contents of the current pool
+	replacement, err := os.OpenFile(journal.path+".new", os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0755)
+	if err != nil {
+		return err
+	}
+	journaled := 0
+	for _, txs := range all {
+		for _, tx := range txs {
+			if err = rlp.Encode(replacement, tx); err != nil {
+				replacement.Close()
+				return err
+			}
+		}
+		journaled += len(txs)
+	}
+	replacement.Close()
+
+	// Replace the live journal with the newly generated one
+	if err = os.Rename(journal.path+".new", journal.path); err != nil {
+		return err
+	}
+	sink, err := os.OpenFile(journal.path, os.O_WRONLY|os.O_APPEND, 0755)
+	if err != nil {
+		return err
+	}
+	journal.writer = sink
+	log.Info("Regenerated local transaction journal", "transactions", journaled, "accounts", len(all))
+
+	return nil
+}
+
+// close flushes the transaction journal contents to disk and closes the file.
+func (journal *txJournal) close() error {
+	var err error
+
+	if journal.writer != nil {
+		err = journal.writer.Close()
+		journal.writer = nil
+	}
+	return err
+}
diff --git a/core/tx_pool.go b/core/tx_pool.go
index 8e2d1b31d..16f774265 100644
--- a/core/tx_pool.go
+++ b/core/tx_pool.go
@@ -99,7 +99,9 @@ type stateFn func() (*state.StateDB, error)
 
 // TxPoolConfig are the configuration parameters of the transaction pool.
 type TxPoolConfig struct {
-	NoLocals bool // Whether local transaction handling should be disabled
+	NoLocals  bool          // Whether local transaction handling should be disabled
+	Journal   string        // Journal of local transactions to survive node restarts
+	Rejournal time.Duration // Time interval to regenerate the local transaction journal
 
 	PriceLimit uint64 // Minimum gas price to enforce for acceptance into the pool
 	PriceBump  uint64 // Minimum price bump percentage to replace an already existing transaction (nonce)
@@ -115,6 +117,9 @@ type TxPoolConfig struct {
 // DefaultTxPoolConfig contains the default configurations for the transaction
 // pool.
 var DefaultTxPoolConfig = TxPoolConfig{
+	Journal:   "transactions.rlp",
+	Rejournal: time.Hour,
+
 	PriceLimit: 1,
 	PriceBump:  10,
 
@@ -130,6 +135,10 @@ var DefaultTxPoolConfig = TxPoolConfig{
 // unreasonable or unworkable.
 func (config *TxPoolConfig) sanitize() TxPoolConfig {
 	conf := *config
+	if conf.Rejournal < time.Second {
+		log.Warn("Sanitizing invalid txpool journal time", "provided", conf.Rejournal, "updated", time.Second)
+		conf.Rejournal = time.Second
+	}
 	if conf.PriceLimit < 1 {
 		log.Warn("Sanitizing invalid txpool price limit", "provided", conf.PriceLimit, "updated", DefaultTxPoolConfig.PriceLimit)
 		conf.PriceLimit = DefaultTxPoolConfig.PriceLimit
@@ -157,18 +166,19 @@ type TxPool struct {
 	gasPrice     *big.Int
 	eventMux     *event.TypeMux
 	events       *event.TypeMuxSubscription
-	locals       *accountSet
 	signer       types.Signer
 	mu           sync.RWMutex
 
+	locals  *accountSet // Set of local transaction to exepmt from evicion rules
+	journal *txJournal  // Journal of local transaction to back up to disk
+
 	pending map[common.Address]*txList         // All currently processable transactions
 	queue   map[common.Address]*txList         // Queued but non-processable transactions
 	beats   map[common.Address]time.Time       // Last heartbeat from each known account
 	all     map[common.Hash]*types.Transaction // All transactions to allow lookups
 	priced  *txPricedList                      // All transactions sorted by price
 
-	wg   sync.WaitGroup // for shutdown sync
-	quit chan struct{}
+	wg sync.WaitGroup // for shutdown sync
 
 	homestead bool
 }
@@ -194,32 +204,48 @@ func NewTxPool(config TxPoolConfig, chainconfig *params.ChainConfig, eventMux *e
 		gasPrice:     new(big.Int).SetUint64(config.PriceLimit),
 		pendingState: nil,
 		events:       eventMux.Subscribe(ChainHeadEvent{}, RemovedTransactionEvent{}),
-		quit:         make(chan struct{}),
 	}
 	pool.locals = newAccountSet(pool.signer)
 	pool.priced = newTxPricedList(&pool.all)
 	pool.resetState()
 
-	// Start the various events loops and return
-	pool.wg.Add(2)
-	go pool.eventLoop()
-	go pool.expirationLoop()
+	// If local transactions and journaling is enabled, load from disk
+	if !config.NoLocals && config.Journal != "" {
+		pool.journal = newTxJournal(config.Journal)
+
+		if err := pool.journal.load(pool.AddLocal); err != nil {
+			log.Warn("Failed to load transaction journal", "err", err)
+		}
+		if err := pool.journal.rotate(pool.local()); err != nil {
+			log.Warn("Failed to rotate transaction journal", "err", err)
+		}
+	}
+	// Start the event loop and return
+	pool.wg.Add(1)
+	go pool.loop()
 
 	return pool
 }
 
-func (pool *TxPool) eventLoop() {
+// loop is the transaction pool's main event loop, waiting for and reacting to
+// outside blockchain events as well as for various reporting and transaction
+// eviction events.
+func (pool *TxPool) loop() {
 	defer pool.wg.Done()
 
-	// Start a ticker and keep track of interesting pool stats to report
+	// Start the stats reporting and transaction eviction tickers
 	var prevPending, prevQueued, prevStales int
 
 	report := time.NewTicker(statsReportInterval)
 	defer report.Stop()
 
-	// Track chain events. When a chain events occurs (new chain canon block)
-	// we need to know the new state. The new state will help us determine
-	// the nonces in the managed state
+	evict := time.NewTicker(evictionInterval)
+	defer evict.Stop()
+
+	journal := time.NewTicker(pool.config.Rejournal)
+	defer journal.Stop()
+
+	// Keep waiting for and reacting to the various events
 	for {
 		select {
 		// Handle any events fired by the system
@@ -253,6 +279,31 @@ func (pool *TxPool) eventLoop() {
 				log.Debug("Transaction pool status report", "executable", pending, "queued", queued, "stales", stales)
 				prevPending, prevQueued, prevStales = pending, queued, stales
 			}
+
+		// Handle inactive account transaction eviction
+		case <-evict.C:
+			pool.mu.Lock()
+			for addr := range pool.queue {
+				// Skip local transactions from the eviction mechanism
+				if pool.locals.contains(addr) {
+					continue
+				}
+				// Any non-locals old enough should be removed
+				if time.Since(pool.beats[addr]) > pool.config.Lifetime {
+					for _, tx := range pool.queue[addr].Flatten() {
+						pool.removeTx(tx.Hash())
+					}
+				}
+			}
+			pool.mu.Unlock()
+
+		// Handle local transaction journal rotation
+		case <-journal.C:
+			if pool.journal != nil {
+				if err := pool.journal.rotate(pool.local()); err != nil {
+					log.Warn("Failed to rotate local tx journal", "err", err)
+				}
+			}
 		}
 	}
 }
@@ -284,9 +335,11 @@ func (pool *TxPool) resetState() {
 // Stop terminates the transaction pool.
 func (pool *TxPool) Stop() {
 	pool.events.Unsubscribe()
-	close(pool.quit)
 	pool.wg.Wait()
 
+	if pool.journal != nil {
+		pool.journal.close()
+	}
 	log.Info("Transaction pool stopped")
 }
 
@@ -373,6 +426,22 @@ func (pool *TxPool) Pending() (map[common.Address]types.Transactions, error) {
 	return pending, nil
 }
 
+// local retrieves all currently known local transactions, groupped by origin
+// account and sorted by nonce. The returned transaction set is a copy and can be
+// freely modified by calling code.
+func (pool *TxPool) local() map[common.Address]types.Transactions {
+	txs := make(map[common.Address]types.Transactions)
+	for addr := range pool.locals.accounts {
+		if pending := pool.pending[addr]; pending != nil {
+			txs[addr] = append(txs[addr], pending.Flatten()...)
+		}
+		if queued := pool.queue[addr]; queued != nil {
+			txs[addr] = append(txs[addr], queued.Flatten()...)
+		}
+	}
+	return txs
+}
+
 // validateTx checks whether a transaction is valid according to the consensus
 // rules and adheres to some heuristic limits of the local node (price and size).
 func (pool *TxPool) validateTx(tx *types.Transaction, local bool) error {
@@ -473,18 +542,22 @@ func (pool *TxPool) add(tx *types.Transaction, local bool) (bool, error) {
 		}
 		pool.all[tx.Hash()] = tx
 		pool.priced.Put(tx)
+		pool.journalTx(from, tx)
 
 		log.Trace("Pooled new executable transaction", "hash", hash, "from", from, "to", tx.To())
 		return old != nil, nil
 	}
-	// New transaction isn't replacing a pending one, push into queue and potentially mark local
+	// New transaction isn't replacing a pending one, push into queue
 	replace, err := pool.enqueueTx(hash, tx)
 	if err != nil {
 		return false, err
 	}
+	// Mark local addresses and journal local transactions
 	if local {
 		pool.locals.add(from)
 	}
+	pool.journalTx(from, tx)
+
 	log.Trace("Pooled new future transaction", "hash", hash, "from", from, "to", tx.To())
 	return replace, nil
 }
@@ -515,6 +588,18 @@ func (pool *TxPool) enqueueTx(hash common.Hash, tx *types.Transaction) (bool, er
 	return old != nil, nil
 }
 
+// journalTx adds the specified transaction to the local disk journal if it is
+// deemed to have been sent from a local account.
+func (pool *TxPool) journalTx(from common.Address, tx *types.Transaction) {
+	// Only journal if it's enabled and the transaction is local
+	if pool.journal == nil || !pool.locals.contains(from) {
+		return
+	}
+	if err := pool.journal.insert(tx); err != nil {
+		log.Warn("Failed to journal local transaction", "err", err)
+	}
+}
+
 // promoteTx adds a transaction to the pending (processable) list of transactions.
 //
 // Note, this method assumes the pool lock is held!
@@ -910,39 +995,6 @@ func (pool *TxPool) demoteUnexecutables(state *state.StateDB) {
 	}
 }
 
-// expirationLoop is a loop that periodically iterates over all accounts with
-// queued transactions and drop all that have been inactive for a prolonged amount
-// of time.
-func (pool *TxPool) expirationLoop() {
-	defer pool.wg.Done()
-
-	evict := time.NewTicker(evictionInterval)
-	defer evict.Stop()
-
-	for {
-		select {
-		case <-evict.C:
-			pool.mu.Lock()
-			for addr := range pool.queue {
-				// Skip local transactions from the eviction mechanism
-				if pool.locals.contains(addr) {
-					continue
-				}
-				// Any non-locals old enough should be removed
-				if time.Since(pool.beats[addr]) > pool.config.Lifetime {
-					for _, tx := range pool.queue[addr].Flatten() {
-						pool.removeTx(tx.Hash())
-					}
-				}
-			}
-			pool.mu.Unlock()
-
-		case <-pool.quit:
-			return
-		}
-	}
-}
-
 // addressByHeartbeat is an account address tagged with its last activity timestamp.
 type addressByHeartbeat struct {
 	address   common.Address
@@ -955,7 +1007,7 @@ func (a addresssByHeartbeat) Len() int           { return len(a) }
 func (a addresssByHeartbeat) Less(i, j int) bool { return a[i].heartbeat.Before(a[j].heartbeat) }
 func (a addresssByHeartbeat) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
 
-// accountSet is simply a set of addresses to check for existance, and a signer
+// accountSet is simply a set of addresses to check for existence, and a signer
 // capable of deriving addresses from transactions.
 type accountSet struct {
 	accounts map[common.Address]struct{}
diff --git a/core/tx_pool_test.go b/core/tx_pool_test.go
index 03ece3886..80bc0b384 100644
--- a/core/tx_pool_test.go
+++ b/core/tx_pool_test.go
@@ -19,8 +19,10 @@ package core
 import (
 	"crypto/ecdsa"
 	"fmt"
+	"io/ioutil"
 	"math/big"
 	"math/rand"
+	"os"
 	"testing"
 	"time"
 
@@ -33,6 +35,15 @@ import (
 	"github.com/ethereum/go-ethereum/params"
 )
 
+// testTxPoolConfig is a transaction pool configuration without stateful disk
+// sideeffects used during testing.
+var testTxPoolConfig TxPoolConfig
+
+func init() {
+	testTxPoolConfig = DefaultTxPoolConfig
+	testTxPoolConfig.Journal = ""
+}
+
 func transaction(nonce uint64, gaslimit *big.Int, key *ecdsa.PrivateKey) *types.Transaction {
 	return pricedTransaction(nonce, gaslimit, big.NewInt(1), key)
 }
@@ -47,8 +58,7 @@ func setupTxPool() (*TxPool, *ecdsa.PrivateKey) {
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(db))
 
 	key, _ := crypto.GenerateKey()
-	pool := NewTxPool(DefaultTxPoolConfig, params.TestChainConfig, new(event.TypeMux), func() (*state.StateDB, error) { return statedb, nil }, func() *big.Int { return big.NewInt(1000000) })
-	pool.resetState()
+	pool := NewTxPool(testTxPoolConfig, params.TestChainConfig, new(event.TypeMux), func() (*state.StateDB, error) { return statedb, nil }, func() *big.Int { return big.NewInt(1000000) })
 
 	return pool, key
 }
@@ -125,9 +135,8 @@ func TestStateChangeDuringPoolReset(t *testing.T) {
 
 	gasLimitFunc := func() *big.Int { return big.NewInt(1000000000) }
 
-	pool := NewTxPool(DefaultTxPoolConfig, params.TestChainConfig, mux, stateFunc, gasLimitFunc)
+	pool := NewTxPool(testTxPoolConfig, params.TestChainConfig, mux, stateFunc, gasLimitFunc)
 	defer pool.Stop()
-	pool.resetState()
 
 	nonce := pool.State().GetNonce(address)
 	if nonce != 0 {
@@ -618,25 +627,25 @@ func TestTransactionQueueAccountLimiting(t *testing.T) {
 	pool.resetState()
 
 	// Keep queuing up transactions and make sure all above a limit are dropped
-	for i := uint64(1); i <= DefaultTxPoolConfig.AccountQueue+5; i++ {
+	for i := uint64(1); i <= testTxPoolConfig.AccountQueue+5; i++ {
 		if err := pool.AddRemote(transaction(i, big.NewInt(100000), key)); err != nil {
 			t.Fatalf("tx %d: failed to add transaction: %v", i, err)
 		}
 		if len(pool.pending) != 0 {
 			t.Errorf("tx %d: pending pool size mismatch: have %d, want %d", i, len(pool.pending), 0)
 		}
-		if i <= DefaultTxPoolConfig.AccountQueue {
+		if i <= testTxPoolConfig.AccountQueue {
 			if pool.queue[account].Len() != int(i) {
 				t.Errorf("tx %d: queue size mismatch: have %d, want %d", i, pool.queue[account].Len(), i)
 			}
 		} else {
-			if pool.queue[account].Len() != int(DefaultTxPoolConfig.AccountQueue) {
-				t.Errorf("tx %d: queue limit mismatch: have %d, want %d", i, pool.queue[account].Len(), DefaultTxPoolConfig.AccountQueue)
+			if pool.queue[account].Len() != int(testTxPoolConfig.AccountQueue) {
+				t.Errorf("tx %d: queue limit mismatch: have %d, want %d", i, pool.queue[account].Len(), testTxPoolConfig.AccountQueue)
 			}
 		}
 	}
-	if len(pool.all) != int(DefaultTxPoolConfig.AccountQueue) {
-		t.Errorf("total transaction mismatch: have %d, want %d", len(pool.all), DefaultTxPoolConfig.AccountQueue)
+	if len(pool.all) != int(testTxPoolConfig.AccountQueue) {
+		t.Errorf("total transaction mismatch: have %d, want %d", len(pool.all), testTxPoolConfig.AccountQueue)
 	}
 }
 
@@ -657,13 +666,12 @@ func testTransactionQueueGlobalLimiting(t *testing.T, nolocals bool) {
 	db, _ := ethdb.NewMemDatabase()
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(db))
 
-	config := DefaultTxPoolConfig
+	config := testTxPoolConfig
 	config.NoLocals = nolocals
 	config.GlobalQueue = config.AccountQueue*3 - 1 // reduce the queue limits to shorten test time (-1 to make it non divisible)
 
 	pool := NewTxPool(config, params.TestChainConfig, new(event.TypeMux), func() (*state.StateDB, error) { return statedb, nil }, func() *big.Int { return big.NewInt(1000000) })
 	defer pool.Stop()
-	pool.resetState()
 
 	// Create a number of test accounts and fund them (last one will be the local)
 	state, _ := pool.currentState()
@@ -748,13 +756,12 @@ func testTransactionQueueTimeLimiting(t *testing.T, nolocals bool) {
 	db, _ := ethdb.NewMemDatabase()
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(db))
 
-	config := DefaultTxPoolConfig
+	config := testTxPoolConfig
 	config.Lifetime = 250 * time.Millisecond
 	config.NoLocals = nolocals
 
 	pool := NewTxPool(config, params.TestChainConfig, new(event.TypeMux), func() (*state.StateDB, error) { return statedb, nil }, func() *big.Int { return big.NewInt(1000000) })
 	defer pool.Stop()
-	pool.resetState()
 
 	// Create two test accounts to ensure remotes expire but locals do not
 	local, _ := crypto.GenerateKey()
@@ -817,7 +824,7 @@ func TestTransactionPendingLimiting(t *testing.T) {
 	pool.resetState()
 
 	// Keep queuing up transactions and make sure all above a limit are dropped
-	for i := uint64(0); i < DefaultTxPoolConfig.AccountQueue+5; i++ {
+	for i := uint64(0); i < testTxPoolConfig.AccountQueue+5; i++ {
 		if err := pool.AddRemote(transaction(i, big.NewInt(100000), key)); err != nil {
 			t.Fatalf("tx %d: failed to add transaction: %v", i, err)
 		}
@@ -828,8 +835,8 @@ func TestTransactionPendingLimiting(t *testing.T) {
 			t.Errorf("tx %d: queue size mismatch: have %d, want %d", i, pool.queue[account].Len(), 0)
 		}
 	}
-	if len(pool.all) != int(DefaultTxPoolConfig.AccountQueue+5) {
-		t.Errorf("total transaction mismatch: have %d, want %d", len(pool.all), DefaultTxPoolConfig.AccountQueue+5)
+	if len(pool.all) != int(testTxPoolConfig.AccountQueue+5) {
+		t.Errorf("total transaction mismatch: have %d, want %d", len(pool.all), testTxPoolConfig.AccountQueue+5)
 	}
 }
 
@@ -845,7 +852,7 @@ func testTransactionLimitingEquivalency(t *testing.T, origin uint64) {
 	state1, _ := pool1.currentState()
 	state1.AddBalance(account1, big.NewInt(1000000))
 
-	for i := uint64(0); i < DefaultTxPoolConfig.AccountQueue+5; i++ {
+	for i := uint64(0); i < testTxPoolConfig.AccountQueue+5; i++ {
 		if err := pool1.AddRemote(transaction(origin+i, big.NewInt(100000), key1)); err != nil {
 			t.Fatalf("tx %d: failed to add transaction: %v", i, err)
 		}
@@ -857,7 +864,7 @@ func testTransactionLimitingEquivalency(t *testing.T, origin uint64) {
 	state2.AddBalance(account2, big.NewInt(1000000))
 
 	txns := []*types.Transaction{}
-	for i := uint64(0); i < DefaultTxPoolConfig.AccountQueue+5; i++ {
+	for i := uint64(0); i < testTxPoolConfig.AccountQueue+5; i++ {
 		txns = append(txns, transaction(origin+i, big.NewInt(100000), key2))
 	}
 	pool2.AddRemotes(txns)
@@ -888,12 +895,11 @@ func TestTransactionPendingGlobalLimiting(t *testing.T) {
 	db, _ := ethdb.NewMemDatabase()
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(db))
 
-	config := DefaultTxPoolConfig
+	config := testTxPoolConfig
 	config.GlobalSlots = config.AccountSlots * 10
 
 	pool := NewTxPool(config, params.TestChainConfig, new(event.TypeMux), func() (*state.StateDB, error) { return statedb, nil }, func() *big.Int { return big.NewInt(1000000) })
 	defer pool.Stop()
-	pool.resetState()
 
 	// Create a number of test accounts and fund them
 	state, _ := pool.currentState()
@@ -935,14 +941,13 @@ func TestTransactionCapClearsFromAll(t *testing.T) {
 	db, _ := ethdb.NewMemDatabase()
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(db))
 
-	config := DefaultTxPoolConfig
+	config := testTxPoolConfig
 	config.AccountSlots = 2
 	config.AccountQueue = 2
 	config.GlobalSlots = 8
 
 	pool := NewTxPool(config, params.TestChainConfig, new(event.TypeMux), func() (*state.StateDB, error) { return statedb, nil }, func() *big.Int { return big.NewInt(1000000) })
 	defer pool.Stop()
-	pool.resetState()
 
 	// Create a number of test accounts and fund them
 	state, _ := pool.currentState()
@@ -970,12 +975,11 @@ func TestTransactionPendingMinimumAllowance(t *testing.T) {
 	db, _ := ethdb.NewMemDatabase()
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(db))
 
-	config := DefaultTxPoolConfig
+	config := testTxPoolConfig
 	config.GlobalSlots = 0
 
 	pool := NewTxPool(config, params.TestChainConfig, new(event.TypeMux), func() (*state.StateDB, error) { return statedb, nil }, func() *big.Int { return big.NewInt(1000000) })
 	defer pool.Stop()
-	pool.resetState()
 
 	// Create a number of test accounts and fund them
 	state, _ := pool.currentState()
@@ -1019,9 +1023,8 @@ func TestTransactionPoolRepricing(t *testing.T) {
 	db, _ := ethdb.NewMemDatabase()
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(db))
 
-	pool := NewTxPool(DefaultTxPoolConfig, params.TestChainConfig, new(event.TypeMux), func() (*state.StateDB, error) { return statedb, nil }, func() *big.Int { return big.NewInt(1000000) })
+	pool := NewTxPool(testTxPoolConfig, params.TestChainConfig, new(event.TypeMux), func() (*state.StateDB, error) { return statedb, nil }, func() *big.Int { return big.NewInt(1000000) })
 	defer pool.Stop()
-	pool.resetState()
 
 	// Create a number of test accounts and fund them
 	state, _ := pool.currentState()
@@ -1104,13 +1107,12 @@ func TestTransactionPoolUnderpricing(t *testing.T) {
 	db, _ := ethdb.NewMemDatabase()
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(db))
 
-	config := DefaultTxPoolConfig
+	config := testTxPoolConfig
 	config.GlobalSlots = 2
 	config.GlobalQueue = 2
 
 	pool := NewTxPool(config, params.TestChainConfig, new(event.TypeMux), func() (*state.StateDB, error) { return statedb, nil }, func() *big.Int { return big.NewInt(1000000) })
 	defer pool.Stop()
-	pool.resetState()
 
 	// Create a number of test accounts and fund them
 	state, _ := pool.currentState()
@@ -1192,9 +1194,8 @@ func TestTransactionReplacement(t *testing.T) {
 	db, _ := ethdb.NewMemDatabase()
 	statedb, _ := state.New(common.Hash{}, state.NewDatabase(db))
 
-	pool := NewTxPool(DefaultTxPoolConfig, params.TestChainConfig, new(event.TypeMux), func() (*state.StateDB, error) { return statedb, nil }, func() *big.Int { return big.NewInt(1000000) })
+	pool := NewTxPool(testTxPoolConfig, params.TestChainConfig, new(event.TypeMux), func() (*state.StateDB, error) { return statedb, nil }, func() *big.Int { return big.NewInt(1000000) })
 	defer pool.Stop()
-	pool.resetState()
 
 	// Create a test account to add transactions with
 	key, _ := crypto.GenerateKey()
@@ -1204,7 +1205,7 @@ func TestTransactionReplacement(t *testing.T) {
 
 	// Add pending transactions, ensuring the minimum price bump is enforced for replacement (for ultra low prices too)
 	price := int64(100)
-	threshold := (price * (100 + int64(DefaultTxPoolConfig.PriceBump))) / 100
+	threshold := (price * (100 + int64(testTxPoolConfig.PriceBump))) / 100
 
 	if err := pool.AddRemote(pricedTransaction(0, big.NewInt(100000), big.NewInt(1), key)); err != nil {
 		t.Fatalf("failed to add original cheap pending transaction: %v", err)
@@ -1250,6 +1251,113 @@ func TestTransactionReplacement(t *testing.T) {
 	}
 }
 
+// Tests that local transactions are journaled to disk, but remote transactions
+// get discarded between restarts.
+func TestTransactionJournaling(t *testing.T)         { testTransactionJournaling(t, false) }
+func TestTransactionJournalingNoLocals(t *testing.T) { testTransactionJournaling(t, true) }
+
+func testTransactionJournaling(t *testing.T, nolocals bool) {
+	// Create a temporary file for the journal
+	file, err := ioutil.TempFile("", "")
+	if err != nil {
+		t.Fatalf("failed to create temporary journal: %v", err)
+	}
+	journal := file.Name()
+	defer os.Remove(journal)
+
+	// Clean up the temporary file, we only need the path for now
+	file.Close()
+	os.Remove(journal)
+
+	// Create the original pool to inject transaction into the journal
+	db, _ := ethdb.NewMemDatabase()
+	statedb, _ := state.New(common.Hash{}, state.NewDatabase(db))
+
+	config := testTxPoolConfig
+	config.NoLocals = nolocals
+	config.Journal = journal
+	config.Rejournal = time.Second
+
+	pool := NewTxPool(config, params.TestChainConfig, new(event.TypeMux), func() (*state.StateDB, error) { return statedb, nil }, func() *big.Int { return big.NewInt(1000000) })
+
+	// Create two test accounts to ensure remotes expire but locals do not
+	local, _ := crypto.GenerateKey()
+	remote, _ := crypto.GenerateKey()
+
+	statedb, _ = pool.currentState()
+	statedb.AddBalance(crypto.PubkeyToAddress(local.PublicKey), big.NewInt(1000000000))
+	statedb.AddBalance(crypto.PubkeyToAddress(remote.PublicKey), big.NewInt(1000000000))
+
+	// Add three local and a remote transactions and ensure they are queued up
+	if err := pool.AddLocal(pricedTransaction(0, big.NewInt(100000), big.NewInt(1), local)); err != nil {
+		t.Fatalf("failed to add local transaction: %v", err)
+	}
+	if err := pool.AddLocal(pricedTransaction(1, big.NewInt(100000), big.NewInt(1), local)); err != nil {
+		t.Fatalf("failed to add local transaction: %v", err)
+	}
+	if err := pool.AddLocal(pricedTransaction(2, big.NewInt(100000), big.NewInt(1), local)); err != nil {
+		t.Fatalf("failed to add local transaction: %v", err)
+	}
+	if err := pool.AddRemote(pricedTransaction(0, big.NewInt(100000), big.NewInt(1), remote)); err != nil {
+		t.Fatalf("failed to add remote transaction: %v", err)
+	}
+	pending, queued := pool.stats()
+	if pending != 4 {
+		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 4)
+	}
+	if queued != 0 {
+		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 0)
+	}
+	if err := validateTxPoolInternals(pool); err != nil {
+		t.Fatalf("pool internal state corrupted: %v", err)
+	}
+	// Terminate the old pool, bump the local nonce, create a new pool and ensure relevant transaction survive
+	pool.Stop()
+	statedb.SetNonce(crypto.PubkeyToAddress(local.PublicKey), 1)
+	pool = NewTxPool(config, params.TestChainConfig, new(event.TypeMux), func() (*state.StateDB, error) { return statedb, nil }, func() *big.Int { return big.NewInt(1000000) })
+
+	pending, queued = pool.stats()
+	if queued != 0 {
+		t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 0)
+	}
+	if nolocals {
+		if pending != 0 {
+			t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 0)
+		}
+	} else {
+		if pending != 2 {
+			t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 2)
+		}
+	}
+	if err := validateTxPoolInternals(pool); err != nil {
+		t.Fatalf("pool internal state corrupted: %v", err)
+	}
+	// Bump the nonce temporarily and ensure the newly invalidated transaction is removed
+	statedb.SetNonce(crypto.PubkeyToAddress(local.PublicKey), 2)
+	pool.resetState()
+	time.Sleep(2 * config.Rejournal)
+	pool.Stop()
+	statedb.SetNonce(crypto.PubkeyToAddress(local.PublicKey), 1)
+	pool = NewTxPool(config, params.TestChainConfig, new(event.TypeMux), func() (*state.StateDB, error) { return statedb, nil }, func() *big.Int { return big.NewInt(1000000) })
+
+	pending, queued = pool.stats()
+	if pending != 0 {
+		t.Fatalf("pending transactions mismatched: have %d, want %d", pending, 0)
+	}
+	if nolocals {
+		if queued != 0 {
+			t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 0)
+		}
+	} else {
+		if queued != 1 {
+			t.Fatalf("queued transactions mismatched: have %d, want %d", queued, 1)
+		}
+	}
+	if err := validateTxPoolInternals(pool); err != nil {
+		t.Fatalf("pool internal state corrupted: %v", err)
+	}
+}
+
 // Benchmarks the speed of validating the contents of the pending queue of the
 // transaction pool.
 func BenchmarkPendingDemotion100(b *testing.B)   { benchmarkPendingDemotion(b, 100) }
diff --git a/eth/backend.go b/eth/backend.go
index c7df517c0..8a837f7b8 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -148,8 +148,10 @@ func New(ctx *node.ServiceContext, config *Config) (*Ethereum, error) {
 		core.WriteChainConfig(chainDb, genesisHash, chainConfig)
 	}
 
-	newPool := core.NewTxPool(config.TxPool, eth.chainConfig, eth.EventMux(), eth.blockchain.State, eth.blockchain.GasLimit)
-	eth.txPool = newPool
+	if config.TxPool.Journal != "" {
+		config.TxPool.Journal = ctx.ResolvePath(config.TxPool.Journal)
+	}
+	eth.txPool = core.NewTxPool(config.TxPool, eth.chainConfig, eth.EventMux(), eth.blockchain.State, eth.blockchain.GasLimit)
 
 	maxPeers := config.MaxPeers
 	if config.LightServ > 0 {