diff --git a/VERSION b/VERSION
index 53ed4ba51e..d9a03a9e5a 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.8.9
+1.8.10
diff --git a/accounts/abi/bind/backends/simulated.go b/accounts/abi/bind/backends/simulated.go
index 7b605e1c1e..fd69538d53 100644
--- a/accounts/abi/bind/backends/simulated.go
+++ b/accounts/abi/bind/backends/simulated.go
@@ -454,7 +454,7 @@ func (fb *filterBackend) GetLogs(ctx context.Context, hash common.Hash) ([][]*ty
 	return logs, nil
 }
 
-func (fb *filterBackend) SubscribeTxPreEvent(ch chan<- core.TxPreEvent) event.Subscription {
+func (fb *filterBackend) SubscribeNewTxsEvent(ch chan<- core.NewTxsEvent) event.Subscription {
 	return event.NewSubscription(func(quit <-chan struct{}) error {
 		<-quit
 		return nil
diff --git a/common/bytes.go b/common/bytes.go
index e2adc80059..cbab2c3fa9 100644
--- a/common/bytes.go
+++ b/common/bytes.go
@@ -19,15 +19,20 @@ package common
 
 import "encoding/hex"
 
+// ToHex returns the hex representation of b, prefixed with '0x'.
+// For empty slices, the return value is "0x0".
+//
+// Deprecated: use hexutil.Encode instead.
 func ToHex(b []byte) string {
 	hex := Bytes2Hex(b)
-	// Prefer output of "0x0" instead of "0x"
 	if len(hex) == 0 {
 		hex = "0"
 	}
 	return "0x" + hex
 }
 
+// FromHex returns the bytes represented by the hexadecimal string s.
+// s may be prefixed with "0x".
 func FromHex(s string) []byte {
 	if len(s) > 1 {
 		if s[0:2] == "0x" || s[0:2] == "0X" {
@@ -40,9 +45,7 @@ func FromHex(s string) []byte {
 	return Hex2Bytes(s)
 }
 
-// Copy bytes
-//
-// Returns an exact copy of the provided bytes
+// CopyBytes returns an exact copy of the provided bytes.
 func CopyBytes(b []byte) (copiedBytes []byte) {
 	if b == nil {
 		return nil
@@ -53,14 +56,17 @@ func CopyBytes(b []byte) (copiedBytes []byte) {
 	return
 }
 
+// hasHexPrefix validates str begins with '0x' or '0X'.
 func hasHexPrefix(str string) bool {
 	return len(str) >= 2 && str[0] == '0' && (str[1] == 'x' || str[1] == 'X')
 }
 
+// isHexCharacter returns bool of c being a valid hexadecimal.
 func isHexCharacter(c byte) bool {
 	return ('0' <= c && c <= '9') || ('a' <= c && c <= 'f') || ('A' <= c && c <= 'F')
 }
 
+// isHex validates whether each byte is valid hexadecimal string.
 func isHex(str string) bool {
 	if len(str)%2 != 0 {
 		return false
@@ -73,16 +79,18 @@ func isHex(str string) bool {
 	return true
 }
 
+// Bytes2Hex returns the hexadecimal encoding of d.
 func Bytes2Hex(d []byte) string {
 	return hex.EncodeToString(d)
 }
 
+// Hex2Bytes returns the bytes represented by the hexadecimal string str.
 func Hex2Bytes(str string) []byte {
 	h, _ := hex.DecodeString(str)
-
 	return h
 }
 
+// Hex2BytesFixed returns bytes of a specified fixed length flen.
 func Hex2BytesFixed(str string, flen int) []byte {
 	h, _ := hex.DecodeString(str)
 	if len(h) == flen {
@@ -96,6 +104,7 @@ func Hex2BytesFixed(str string, flen int) []byte {
 	return hh
 }
 
+// RightPadBytes zero-pads slice to the right up to length l.
 func RightPadBytes(slice []byte, l int) []byte {
 	if l <= len(slice) {
 		return slice
@@ -107,6 +116,7 @@ func RightPadBytes(slice []byte, l int) []byte {
 	return padded
 }
 
+// LeftPadBytes zero-pads slice to the left up to length l.
 func LeftPadBytes(slice []byte, l int) []byte {
 	if l <= len(slice) {
 		return slice
diff --git a/common/math/big.go b/common/math/big.go
index 7872786503..dbf2770a94 100644
--- a/common/math/big.go
+++ b/common/math/big.go
@@ -78,7 +78,7 @@ func ParseBig256(s string) (*big.Int, bool) {
 	return bigint, ok
 }
 
-// MustParseBig parses s as a 256 bit big integer and panics if the string is invalid.
+// MustParseBig256 parses s as a 256 bit big integer and panics if the string is invalid.
 func MustParseBig256(s string) *big.Int {
 	v, ok := ParseBig256(s)
 	if !ok {
@@ -186,9 +186,8 @@ func U256(x *big.Int) *big.Int {
 func S256(x *big.Int) *big.Int {
 	if x.Cmp(tt255) < 0 {
 		return x
-	} else {
-		return new(big.Int).Sub(x, tt256)
 	}
+	return new(big.Int).Sub(x, tt256)
 }
 
 // Exp implements exponentiation by squaring.
diff --git a/common/number/int.go b/common/number/int.go
index 6dab2436de..5b50669703 100644
--- a/common/number/int.go
+++ b/common/number/int.go
@@ -34,13 +34,12 @@ func limitUnsigned256(x *Number) *Number {
 func limitSigned256(x *Number) *Number {
 	if x.num.Cmp(tt255) < 0 {
 		return x
-	} else {
-		x.num.Sub(x.num, tt256)
-		return x
 	}
+	x.num.Sub(x.num, tt256)
+	return x
 }
 
-// Number function
+// Initialiser is a Number function
 type Initialiser func(n int64) *Number
 
 // A Number represents a generic integer with a bounding function limiter. Limit is called after each operations
@@ -51,65 +50,65 @@ type Number struct {
 	limit func(n *Number) *Number
 }
 
-// Returns a new initialiser for a new *Number without having to expose certain fields
+// NewInitialiser returns a new initialiser for a new *Number without having to expose certain fields
 func NewInitialiser(limiter func(*Number) *Number) Initialiser {
 	return func(n int64) *Number {
 		return &Number{big.NewInt(n), limiter}
 	}
 }
 
-// Return a Number with a UNSIGNED limiter up to 256 bits
+// Uint256 returns a Number with a UNSIGNED limiter up to 256 bits
 func Uint256(n int64) *Number {
 	return &Number{big.NewInt(n), limitUnsigned256}
 }
 
-// Return a Number with a SIGNED limiter up to 256 bits
+// Int256 returns Number with a SIGNED limiter up to 256 bits
 func Int256(n int64) *Number {
 	return &Number{big.NewInt(n), limitSigned256}
 }
 
-// Returns a Number with a SIGNED unlimited size
+// Big returns a Number with a SIGNED unlimited size
 func Big(n int64) *Number {
 	return &Number{big.NewInt(n), func(x *Number) *Number { return x }}
 }
 
-// Sets i to sum of x+y
+// Add sets i to sum of x+y
 func (i *Number) Add(x, y *Number) *Number {
 	i.num.Add(x.num, y.num)
 	return i.limit(i)
 }
 
-// Sets i to difference of x-y
+// Sub sets i to difference of x-y
 func (i *Number) Sub(x, y *Number) *Number {
 	i.num.Sub(x.num, y.num)
 	return i.limit(i)
 }
 
-// Sets i to product of x*y
+// Mul sets i to product of x*y
 func (i *Number) Mul(x, y *Number) *Number {
 	i.num.Mul(x.num, y.num)
 	return i.limit(i)
 }
 
-// Sets i to the quotient prodject of x/y
+// Div sets i to the quotient prodject of x/y
 func (i *Number) Div(x, y *Number) *Number {
 	i.num.Div(x.num, y.num)
 	return i.limit(i)
 }
 
-// Sets i to x % y
+// Mod sets i to x % y
 func (i *Number) Mod(x, y *Number) *Number {
 	i.num.Mod(x.num, y.num)
 	return i.limit(i)
 }
 
-// Sets i to x << s
+// Lsh sets i to x << s
 func (i *Number) Lsh(x *Number, s uint) *Number {
 	i.num.Lsh(x.num, s)
 	return i.limit(i)
 }
 
-// Sets i to x^y
+// Pow sets i to x^y
 func (i *Number) Pow(x, y *Number) *Number {
 	i.num.Exp(x.num, y.num, big.NewInt(0))
 	return i.limit(i)
@@ -117,13 +116,13 @@ func (i *Number) Pow(x, y *Number) *Number {
 
 // Setters
 
-// Set x to i
+// Set sets x to i
 func (i *Number) Set(x *Number) *Number {
 	i.num.Set(x.num)
 	return i.limit(i)
 }
 
-// Set x bytes to i
+// SetBytes sets x bytes to i
 func (i *Number) SetBytes(x []byte) *Number {
 	i.num.SetBytes(x)
 	return i.limit(i)
@@ -140,12 +139,12 @@ func (i *Number) Cmp(x *Number) int {
 
 // Getters
 
-// Returns the string representation of i
+// String returns the string representation of i
 func (i *Number) String() string {
 	return i.num.String()
 }
 
-// Returns the byte representation of i
+// Bytes returns the byte representation of i
 func (i *Number) Bytes() []byte {
 	return i.num.Bytes()
 }
@@ -160,17 +159,17 @@ func (i *Number) Int64() int64 {
 	return i.num.Int64()
 }
 
-// Returns the signed version of i
+// Int256 returns the signed version of i
 func (i *Number) Int256() *Number {
 	return Int(0).Set(i)
 }
 
-// Returns the unsigned version of i
+// Uint256 returns the unsigned version of i
 func (i *Number) Uint256() *Number {
 	return Uint(0).Set(i)
 }
 
-// Returns the index of the first bit that's set to 1
+// FirstBitSet returns the index of the first bit that's set to 1
 func (i *Number) FirstBitSet() int {
 	for j := 0; j < i.num.BitLen(); j++ {
 		if i.num.Bit(j) > 0 {
diff --git a/common/path.go b/common/path.go
index bd8da86e74..69820cfe5d 100644
--- a/common/path.go
+++ b/common/path.go
@@ -30,6 +30,7 @@ func MakeName(name, version string) string {
 	return fmt.Sprintf("%s/v%s/%s/%s", name, version, runtime.GOOS, runtime.Version())
 }
 
+// FileExist checks if a file exists at filePath.
 func FileExist(filePath string) bool {
 	_, err := os.Stat(filePath)
 	if err != nil && os.IsNotExist(err) {
@@ -39,9 +40,10 @@ func FileExist(filePath string) bool {
 	return true
 }
 
-func AbsolutePath(Datadir string, filename string) string {
+// AbsolutePath returns datadir + filename, or filename if it is absolute.
+func AbsolutePath(datadir string, filename string) string {
 	if filepath.IsAbs(filename) {
 		return filename
 	}
-	return filepath.Join(Datadir, filename)
+	return filepath.Join(datadir, filename)
 }
diff --git a/common/types.go b/common/types.go
index 0b94fb2c25..12c26d94bc 100644
--- a/common/types.go
+++ b/common/types.go
@@ -42,19 +42,30 @@ var (
 // Hash represents the 32 byte Keccak256 hash of arbitrary data.
 type Hash [HashLength]byte
 
+// BytesToHash sets b to hash.
+// If b is larger than len(h), b will be cropped from the left.
 func BytesToHash(b []byte) Hash {
 	var h Hash
 	h.SetBytes(b)
 	return h
 }
-func BigToHash(b *big.Int) Hash { return BytesToHash(b.Bytes()) }
-func HexToHash(s string) Hash   { return BytesToHash(FromHex(s)) }
 
-// Get the string representation of the underlying hash
-func (h Hash) Str() string   { return string(h[:]) }
+// BigToHash sets byte representation of b to hash.
+// If b is larger than len(h), b will be cropped from the left.
+func BigToHash(b *big.Int) Hash { return BytesToHash(b.Bytes()) }
+
+// HexToHash sets byte representation of s to hash.
+// If b is larger than len(h), b will be cropped from the left.
+func HexToHash(s string) Hash { return BytesToHash(FromHex(s)) }
+
+// Bytes gets the byte representation of the underlying hash.
 func (h Hash) Bytes() []byte { return h[:] }
+
+// Big converts a hash to a big integer.
 func (h Hash) Big() *big.Int { return new(big.Int).SetBytes(h[:]) }
-func (h Hash) Hex() string   { return hexutil.Encode(h[:]) }
+
+// Hex converts a hash to a hex string.
+func (h Hash) Hex() string { return hexutil.Encode(h[:]) }
 
 // TerminalString implements log.TerminalStringer, formatting a string for console
 // output during logging.
@@ -89,7 +100,8 @@ func (h Hash) MarshalText() ([]byte, error) {
 	return hexutil.Bytes(h[:]).MarshalText()
 }
 
-// Sets the hash to the value of b. If b is larger than len(h), 'b' will be cropped (from the left).
+// SetBytes sets the hash to the value of b.
+// If b is larger than len(h), b will be cropped from the left.
 func (h *Hash) SetBytes(b []byte) {
 	if len(b) > len(h) {
 		b = b[len(b)-HashLength:]
@@ -98,16 +110,6 @@ func (h *Hash) SetBytes(b []byte) {
 	copy(h[HashLength-len(b):], b)
 }
 
-// Set string `s` to h. If s is larger than len(h) s will be cropped (from left) to fit.
-func (h *Hash) SetString(s string) { h.SetBytes([]byte(s)) }
-
-// Sets h to other
-func (h *Hash) Set(other Hash) {
-	for i, v := range other {
-		h[i] = v
-	}
-}
-
 // Generate implements testing/quick.Generator.
 func (h Hash) Generate(rand *rand.Rand, size int) reflect.Value {
 	m := rand.Intn(len(h))
@@ -117,10 +119,6 @@ func (h Hash) Generate(rand *rand.Rand, size int) reflect.Value {
 	return reflect.ValueOf(h)
 }
 
-func EmptyHash(h Hash) bool {
-	return h == Hash{}
-}
-
 // UnprefixedHash allows marshaling a Hash without 0x prefix.
 type UnprefixedHash Hash
 
@@ -139,13 +137,21 @@ func (h UnprefixedHash) MarshalText() ([]byte, error) {
 // Address represents the 20 byte address of an Ethereum account.
 type Address [AddressLength]byte
 
+// BytesToAddress returns Address with value b.
+// If b is larger than len(h), b will be cropped from the left.
 func BytesToAddress(b []byte) Address {
 	var a Address
 	a.SetBytes(b)
 	return a
 }
+
+// BigToAddress returns Address with byte values of b.
+// If b is larger than len(h), b will be cropped from the left.
 func BigToAddress(b *big.Int) Address { return BytesToAddress(b.Bytes()) }
-func HexToAddress(s string) Address   { return BytesToAddress(FromHex(s)) }
+
+// HexToAddress returns Address with byte values of s.
+// If s is larger than len(h), s will be cropped from the left.
+func HexToAddress(s string) Address { return BytesToAddress(FromHex(s)) }
 
 // IsHexAddress verifies whether a string can represent a valid hex-encoded
 // Ethereum address or not.
@@ -156,11 +162,14 @@ func IsHexAddress(s string) bool {
 	return len(s) == 2*AddressLength && isHex(s)
 }
 
-// Get the string representation of the underlying address
-func (a Address) Str() string   { return string(a[:]) }
+// Bytes gets the string representation of the underlying address.
 func (a Address) Bytes() []byte { return a[:] }
+
+// Big converts an address to a big integer.
 func (a Address) Big() *big.Int { return new(big.Int).SetBytes(a[:]) }
-func (a Address) Hash() Hash    { return BytesToHash(a[:]) }
+
+// Hash converts an address to a hash by left-padding it with zeros.
+func (a Address) Hash() Hash { return BytesToHash(a[:]) }
 
 // Hex returns an EIP55-compliant hex string representation of the address.
 func (a Address) Hex() string {
@@ -184,7 +193,7 @@ func (a Address) Hex() string {
 	return "0x" + string(result)
 }
 
-// String implements the stringer interface and is used also by the logger.
+// String implements fmt.Stringer.
 func (a Address) String() string {
 	return a.Hex()
 }
@@ -195,7 +204,8 @@ func (a Address) Format(s fmt.State, c rune) {
 	fmt.Fprintf(s, "%"+string(c), a[:])
 }
 
-// Sets the address to the value of b. If b is larger than len(a) it will panic
+// SetBytes sets the address to the value of b.
+// If b is larger than len(a) it will panic.
 func (a *Address) SetBytes(b []byte) {
 	if len(b) > len(a) {
 		b = b[len(b)-AddressLength:]
@@ -203,16 +213,6 @@ func (a *Address) SetBytes(b []byte) {
 	copy(a[AddressLength-len(b):], b)
 }
 
-// Set string `s` to a. If s is larger than len(a) it will panic
-func (a *Address) SetString(s string) { a.SetBytes([]byte(s)) }
-
-// Sets a to other
-func (a *Address) Set(other Address) {
-	for i, v := range other {
-		a[i] = v
-	}
-}
-
 // MarshalText returns the hex representation of a.
 func (a Address) MarshalText() ([]byte, error) {
 	return hexutil.Bytes(a[:]).MarshalText()
@@ -228,7 +228,7 @@ func (a *Address) UnmarshalJSON(input []byte) error {
 	return hexutil.UnmarshalFixedJSON(addressT, input, a[:])
 }
 
-// UnprefixedHash allows marshaling an Address without 0x prefix.
+// UnprefixedAddress allows marshaling an Address without 0x prefix.
 type UnprefixedAddress Address
 
 // UnmarshalText decodes the address from hex. The 0x prefix is optional.
diff --git a/common/types_template.go b/common/types_template.go
deleted file mode 100644
index 9a8f29977b..0000000000
--- a/common/types_template.go
+++ /dev/null
@@ -1,64 +0,0 @@
-// Copyright 2015 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
-//sed -e 's/_N_/Hash/g' -e 's/_S_/32/g' -e '1d' types_template.go | gofmt -w hash.go
-
-package common
-
-import "math/big"
-
-type _N_ [_S_]byte
-
-func BytesTo_N_(b []byte) _N_ {
-	var h _N_
-	h.SetBytes(b)
-	return h
-}
-func StringTo_N_(s string) _N_ { return BytesTo_N_([]byte(s)) }
-func BigTo_N_(b *big.Int) _N_  { return BytesTo_N_(b.Bytes()) }
-func HexTo_N_(s string) _N_    { return BytesTo_N_(FromHex(s)) }
-
-// Don't use the default 'String' method in case we want to overwrite
-
-// Get the string representation of the underlying hash
-func (h _N_) Str() string   { return string(h[:]) }
-func (h _N_) Bytes() []byte { return h[:] }
-func (h _N_) Big() *big.Int { return new(big.Int).SetBytes(h[:]) }
-func (h _N_) Hex() string   { return "0x" + Bytes2Hex(h[:]) }
-
-// Sets the hash to the value of b. If b is larger than len(h) it will panic
-func (h *_N_) SetBytes(b []byte) {
-	// Use the right most bytes
-	if len(b) > len(h) {
-		b = b[len(b)-_S_:]
-	}
-
-	// Reverse the loop
-	for i := len(b) - 1; i >= 0; i-- {
-		h[_S_-len(b)+i] = b[i]
-	}
-}
-
-// Set string `s` to h. If s is larger than len(h) it will panic
-func (h *_N_) SetString(s string) { h.SetBytes([]byte(s)) }
-
-// Sets h to other
-func (h *_N_) Set(other _N_) {
-	for i, v := range other {
-		h[i] = v
-	}
-}
diff --git a/consensus/clique/clique.go b/consensus/clique/clique.go
index 2bdad9092a..01df4d5c78 100644
--- a/consensus/clique/clique.go
+++ b/consensus/clique/clique.go
@@ -383,7 +383,7 @@ func (c *Clique) snapshot(chain consensus.ChainReader, number uint64, hash commo
 		// If an on-disk checkpoint snapshot can be found, use that
 		if number%checkpointInterval == 0 {
 			if s, err := loadSnapshot(c.config, c.signatures, c.db, hash); err == nil {
-				log.Trace("Loaded voting snapshot form disk", "number", number, "hash", hash)
+				log.Trace("Loaded voting snapshot from disk", "number", number, "hash", hash)
 				snap = s
 				break
 			}
diff --git a/core/events.go b/core/events.go
index 6f404f612b..8d200f2a29 100644
--- a/core/events.go
+++ b/core/events.go
@@ -21,8 +21,8 @@ import (
 	"github.com/ethereum/go-ethereum/core/types"
 )
 
-// TxPreEvent is posted when a transaction enters the transaction pool.
-type TxPreEvent struct{ Tx *types.Transaction }
+// NewTxsEvent is posted when a batch of transactions enter the transaction pool.
+type NewTxsEvent struct{ Txs []*types.Transaction }
 
 // PendingLogsEvent is posted pre mining and notifies of pending logs.
 type PendingLogsEvent struct {
@@ -35,9 +35,6 @@ type PendingStateEvent struct{}
 // NewMinedBlockEvent is posted when a block has been imported.
 type NewMinedBlockEvent struct{ Block *types.Block }
 
-// RemovedTransactionEvent is posted when a reorg happens
-type RemovedTransactionEvent struct{ Txs types.Transactions }
-
 // RemovedLogsEvent is posted when a reorg happens
 type RemovedLogsEvent struct{ Logs []*types.Log }
 
diff --git a/core/state/state_test.go b/core/state/state_test.go
index 12778f6f12..123559ea9b 100644
--- a/core/state/state_test.go
+++ b/core/state/state_test.go
@@ -99,7 +99,7 @@ func (s *StateSuite) TestNull(c *checker.C) {
 	s.state.SetState(address, common.Hash{}, value)
 	s.state.Commit(false)
 	value = s.state.GetState(address, common.Hash{})
-	if !common.EmptyHash(value) {
+	if value != (common.Hash{}) {
 		c.Errorf("expected empty hash. got %x", value)
 	}
 }
diff --git a/core/state/statedb.go b/core/state/statedb.go
index a952027d6d..ffea761d9f 100644
--- a/core/state/statedb.go
+++ b/core/state/statedb.go
@@ -358,7 +358,7 @@ func (self *StateDB) deleteStateObject(stateObject *stateObject) {
 	self.setError(self.trie.TryDelete(addr[:]))
 }
 
-// Retrieve a state object given my the address. Returns nil if not found.
+// Retrieve a state object given by the address. Returns nil if not found.
 func (self *StateDB) getStateObject(addr common.Address) (stateObject *stateObject) {
 	// Prefer 'live' objects.
 	if obj := self.stateObjects[addr]; obj != nil {
diff --git a/core/state/sync.go b/core/state/sync.go
index 28fcf6ae05..c566e79073 100644
--- a/core/state/sync.go
+++ b/core/state/sync.go
@@ -25,8 +25,8 @@ import (
 )
 
 // NewStateSync create a new state trie download scheduler.
-func NewStateSync(root common.Hash, database trie.DatabaseReader) *trie.TrieSync {
-	var syncer *trie.TrieSync
+func NewStateSync(root common.Hash, database trie.DatabaseReader) *trie.Sync {
+	var syncer *trie.Sync
 	callback := func(leaf []byte, parent common.Hash) error {
 		var obj Account
 		if err := rlp.Decode(bytes.NewReader(leaf), &obj); err != nil {
@@ -36,6 +36,6 @@ func NewStateSync(root common.Hash, database trie.DatabaseReader) *trie.TrieSync
 		syncer.AddRawEntry(common.BytesToHash(obj.CodeHash), 64, parent)
 		return nil
 	}
-	syncer = trie.NewTrieSync(root, database, callback)
+	syncer = trie.NewSync(root, database, callback)
 	return syncer
 }
diff --git a/core/tx_journal.go b/core/tx_journal.go
index e872d7b530..1397e9fd34 100644
--- a/core/tx_journal.go
+++ b/core/tx_journal.go
@@ -56,7 +56,7 @@ func newTxJournal(path string) *txJournal {
 
 // 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 {
+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
@@ -76,7 +76,21 @@ func (journal *txJournal) load(add func(*types.Transaction) error) error {
 	stream := rlp.NewStream(input, 0)
 	total, dropped := 0, 0
 
-	var failure error
+	// Create a method to load a limited batch of transactions and bump the
+	// appropriate progress counters. Then use this method to load all the
+	// journalled transactions in small-ish batches.
+	loadBatch := func(txs types.Transactions) {
+		for _, err := range add(txs) {
+			if err != nil {
+				log.Debug("Failed to add journaled transaction", "err", err)
+				dropped++
+			}
+		}
+	}
+	var (
+		failure error
+		batch   types.Transactions
+	)
 	for {
 		// Parse the next transaction and terminate on error
 		tx := new(types.Transaction)
@@ -84,14 +98,17 @@ func (journal *txJournal) load(add func(*types.Transaction) error) error {
 			if err != io.EOF {
 				failure = err
 			}
+			if batch.Len() > 0 {
+				loadBatch(batch)
+			}
 			break
 		}
-		// Import the transaction and bump the appropriate progress counters
+		// New transaction parsed, queue up for later, import if threnshold is reached
 		total++
-		if err = add(tx); err != nil {
-			log.Debug("Failed to add journaled transaction", "err", err)
-			dropped++
-			continue
+
+		if batch = append(batch, tx); batch.Len() > 1024 {
+			loadBatch(batch)
+			batch = batch[:0]
 		}
 	}
 	log.Info("Loaded local transaction journal", "transactions", total, "dropped", dropped)
diff --git a/core/tx_list.go b/core/tx_list.go
index ea6ee7019f..287dda4c33 100644
--- a/core/tx_list.go
+++ b/core/tx_list.go
@@ -397,13 +397,13 @@ func (h *priceHeap) Pop() interface{} {
 // txPricedList is a price-sorted heap to allow operating on transactions pool
 // contents in a price-incrementing way.
 type txPricedList struct {
-	all    *map[common.Hash]*types.Transaction // Pointer to the map of all transactions
-	items  *priceHeap                          // Heap of prices of all the stored transactions
-	stales int                                 // Number of stale price points to (re-heap trigger)
+	all    *txLookup  // Pointer to the map of all transactions
+	items  *priceHeap // Heap of prices of all the stored transactions
+	stales int        // Number of stale price points to (re-heap trigger)
 }
 
 // newTxPricedList creates a new price-sorted transaction heap.
-func newTxPricedList(all *map[common.Hash]*types.Transaction) *txPricedList {
+func newTxPricedList(all *txLookup) *txPricedList {
 	return &txPricedList{
 		all:   all,
 		items: new(priceHeap),
@@ -425,12 +425,13 @@ func (l *txPricedList) Removed() {
 		return
 	}
 	// Seems we've reached a critical number of stale transactions, reheap
-	reheap := make(priceHeap, 0, len(*l.all))
+	reheap := make(priceHeap, 0, l.all.Count())
 
 	l.stales, l.items = 0, &reheap
-	for _, tx := range *l.all {
+	l.all.Range(func(hash common.Hash, tx *types.Transaction) bool {
 		*l.items = append(*l.items, tx)
-	}
+		return true
+	})
 	heap.Init(l.items)
 }
 
@@ -443,7 +444,7 @@ func (l *txPricedList) Cap(threshold *big.Int, local *accountSet) types.Transact
 	for len(*l.items) > 0 {
 		// Discard stale transactions if found during cleanup
 		tx := heap.Pop(l.items).(*types.Transaction)
-		if _, ok := (*l.all)[tx.Hash()]; !ok {
+		if l.all.Get(tx.Hash()) == nil {
 			l.stales--
 			continue
 		}
@@ -475,7 +476,7 @@ func (l *txPricedList) Underpriced(tx *types.Transaction, local *accountSet) boo
 	// Discard stale price points if found at the heap start
 	for len(*l.items) > 0 {
 		head := []*types.Transaction(*l.items)[0]
-		if _, ok := (*l.all)[head.Hash()]; !ok {
+		if l.all.Get(head.Hash()) == nil {
 			l.stales--
 			heap.Pop(l.items)
 			continue
@@ -500,7 +501,7 @@ func (l *txPricedList) Discard(count int, local *accountSet) types.Transactions
 	for len(*l.items) > 0 && count > 0 {
 		// Discard stale transactions if found during cleanup
 		tx := heap.Pop(l.items).(*types.Transaction)
-		if _, ok := (*l.all)[tx.Hash()]; !ok {
+		if l.all.Get(tx.Hash()) == nil {
 			l.stales--
 			continue
 		}
diff --git a/core/tx_pool.go b/core/tx_pool.go
index 388b40058f..7393c8286f 100644
--- a/core/tx_pool.go
+++ b/core/tx_pool.go
@@ -200,11 +200,11 @@ type TxPool struct {
 	locals  *accountSet // Set of local transaction to exempt from eviction 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
+	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     *txLookup                    // All transactions to allow lookups
+	priced  *txPricedList                // All transactions sorted by price
 
 	wg sync.WaitGroup // for shutdown sync
 
@@ -226,19 +226,19 @@ func NewTxPool(config TxPoolConfig, chainconfig *params.ChainConfig, chain block
 		pending:     make(map[common.Address]*txList),
 		queue:       make(map[common.Address]*txList),
 		beats:       make(map[common.Address]time.Time),
-		all:         make(map[common.Hash]*types.Transaction),
+		all:         newTxLookup(),
 		chainHeadCh: make(chan ChainHeadEvent, chainHeadChanSize),
 		gasPrice:    new(big.Int).SetUint64(config.PriceLimit),
 	}
 	pool.locals = newAccountSet(pool.signer)
-	pool.priced = newTxPricedList(&pool.all)
+	pool.priced = newTxPricedList(pool.all)
 	pool.reset(nil, chain.CurrentBlock().Header())
 
 	// 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 {
+		if err := pool.journal.load(pool.AddLocals); err != nil {
 			log.Warn("Failed to load transaction journal", "err", err)
 		}
 		if err := pool.journal.rotate(pool.local()); err != nil {
@@ -444,9 +444,9 @@ func (pool *TxPool) Stop() {
 	log.Info("Transaction pool stopped")
 }
 
-// SubscribeTxPreEvent registers a subscription of TxPreEvent and
+// SubscribeNewTxsEvent registers a subscription of NewTxsEvent and
 // starts sending event to the given channel.
-func (pool *TxPool) SubscribeTxPreEvent(ch chan<- TxPreEvent) event.Subscription {
+func (pool *TxPool) SubscribeNewTxsEvent(ch chan<- NewTxsEvent) event.Subscription {
 	return pool.scope.Track(pool.txFeed.Subscribe(ch))
 }
 
@@ -605,7 +605,7 @@ func (pool *TxPool) validateTx(tx *types.Transaction, local bool) error {
 func (pool *TxPool) add(tx *types.Transaction, local bool) (bool, error) {
 	// If the transaction is already known, discard it
 	hash := tx.Hash()
-	if pool.all[hash] != nil {
+	if pool.all.Get(hash) != nil {
 		log.Trace("Discarding already known transaction", "hash", hash)
 		return false, fmt.Errorf("known transaction: %x", hash)
 	}
@@ -616,7 +616,7 @@ func (pool *TxPool) add(tx *types.Transaction, local bool) (bool, error) {
 		return false, err
 	}
 	// If the transaction pool is full, discard underpriced transactions
-	if uint64(len(pool.all)) >= pool.config.GlobalSlots+pool.config.GlobalQueue {
+	if uint64(pool.all.Count()) >= pool.config.GlobalSlots+pool.config.GlobalQueue {
 		// If the new transaction is underpriced, don't accept it
 		if !local && pool.priced.Underpriced(tx, pool.locals) {
 			log.Trace("Discarding underpriced transaction", "hash", hash, "price", tx.GasPrice())
@@ -624,7 +624,7 @@ func (pool *TxPool) add(tx *types.Transaction, local bool) (bool, error) {
 			return false, ErrUnderpriced
 		}
 		// New transaction is better than our worse ones, make room for it
-		drop := pool.priced.Discard(len(pool.all)-int(pool.config.GlobalSlots+pool.config.GlobalQueue-1), pool.locals)
+		drop := pool.priced.Discard(pool.all.Count()-int(pool.config.GlobalSlots+pool.config.GlobalQueue-1), pool.locals)
 		for _, tx := range drop {
 			log.Trace("Discarding freshly underpriced transaction", "hash", tx.Hash(), "price", tx.GasPrice())
 			underpricedTxCounter.Inc(1)
@@ -642,18 +642,18 @@ func (pool *TxPool) add(tx *types.Transaction, local bool) (bool, error) {
 		}
 		// New transaction is better, replace old one
 		if old != nil {
-			delete(pool.all, old.Hash())
+			pool.all.Remove(old.Hash())
 			pool.priced.Removed()
 			pendingReplaceCounter.Inc(1)
 		}
-		pool.all[tx.Hash()] = tx
+		pool.all.Add(tx)
 		pool.priced.Put(tx)
 		pool.journalTx(from, tx)
 
 		log.Trace("Pooled new executable transaction", "hash", hash, "from", from, "to", tx.To())
 
 		// We've directly injected a replacement transaction, notify subsystems
-		go pool.txFeed.Send(TxPreEvent{tx})
+		go pool.txFeed.Send(NewTxsEvent{types.Transactions{tx}})
 
 		return old != nil, nil
 	}
@@ -689,12 +689,12 @@ func (pool *TxPool) enqueueTx(hash common.Hash, tx *types.Transaction) (bool, er
 	}
 	// Discard any previous transaction and mark this
 	if old != nil {
-		delete(pool.all, old.Hash())
+		pool.all.Remove(old.Hash())
 		pool.priced.Removed()
 		queuedReplaceCounter.Inc(1)
 	}
-	if pool.all[hash] == nil {
-		pool.all[hash] = tx
+	if pool.all.Get(hash) == nil {
+		pool.all.Add(tx)
 		pool.priced.Put(tx)
 	}
 	return old != nil, nil
@@ -712,10 +712,11 @@ func (pool *TxPool) journalTx(from common.Address, tx *types.Transaction) {
 	}
 }
 
-// promoteTx adds a transaction to the pending (processable) list of transactions.
+// promoteTx adds a transaction to the pending (processable) list of transactions
+// and returns whether it was inserted or an older was better.
 //
 // Note, this method assumes the pool lock is held!
-func (pool *TxPool) promoteTx(addr common.Address, hash common.Hash, tx *types.Transaction) {
+func (pool *TxPool) promoteTx(addr common.Address, hash common.Hash, tx *types.Transaction) bool {
 	// Try to insert the transaction into the pending queue
 	if pool.pending[addr] == nil {
 		pool.pending[addr] = newTxList(true)
@@ -725,29 +726,29 @@ func (pool *TxPool) promoteTx(addr common.Address, hash common.Hash, tx *types.T
 	inserted, old := list.Add(tx, pool.config.PriceBump)
 	if !inserted {
 		// An older transaction was better, discard this
-		delete(pool.all, hash)
+		pool.all.Remove(hash)
 		pool.priced.Removed()
 
 		pendingDiscardCounter.Inc(1)
-		return
+		return false
 	}
 	// Otherwise discard any previous transaction and mark this
 	if old != nil {
-		delete(pool.all, old.Hash())
+		pool.all.Remove(old.Hash())
 		pool.priced.Removed()
 
 		pendingReplaceCounter.Inc(1)
 	}
 	// Failsafe to work around direct pending inserts (tests)
-	if pool.all[hash] == nil {
-		pool.all[hash] = tx
+	if pool.all.Get(hash) == nil {
+		pool.all.Add(tx)
 		pool.priced.Put(tx)
 	}
 	// Set the potentially new pending nonce and notify any subsystems of the new tx
 	pool.beats[addr] = time.Now()
 	pool.pendingState.SetNonce(addr, tx.Nonce()+1)
 
-	go pool.txFeed.Send(TxPreEvent{tx})
+	return true
 }
 
 // AddLocal enqueues a single transaction into the pool if it is valid, marking
@@ -839,7 +840,7 @@ func (pool *TxPool) Status(hashes []common.Hash) []TxStatus {
 
 	status := make([]TxStatus, len(hashes))
 	for i, hash := range hashes {
-		if tx := pool.all[hash]; tx != nil {
+		if tx := pool.all.Get(hash); tx != nil {
 			from, _ := types.Sender(pool.signer, tx) // already validated
 			if pool.pending[from] != nil && pool.pending[from].txs.items[tx.Nonce()] != nil {
 				status[i] = TxStatusPending
@@ -854,24 +855,21 @@ func (pool *TxPool) Status(hashes []common.Hash) []TxStatus {
 // Get returns a transaction if it is contained in the pool
 // and nil otherwise.
 func (pool *TxPool) Get(hash common.Hash) *types.Transaction {
-	pool.mu.RLock()
-	defer pool.mu.RUnlock()
-
-	return pool.all[hash]
+	return pool.all.Get(hash)
 }
 
 // removeTx removes a single transaction from the queue, moving all subsequent
 // transactions back to the future queue.
 func (pool *TxPool) removeTx(hash common.Hash, outofbound bool) {
 	// Fetch the transaction we wish to delete
-	tx, ok := pool.all[hash]
-	if !ok {
+	tx := pool.all.Get(hash)
+	if tx == nil {
 		return
 	}
 	addr, _ := types.Sender(pool.signer, tx) // already validated during insertion
 
 	// Remove it from the list of known transactions
-	delete(pool.all, hash)
+	pool.all.Remove(hash)
 	if outofbound {
 		pool.priced.Removed()
 	}
@@ -907,6 +905,9 @@ func (pool *TxPool) removeTx(hash common.Hash, outofbound bool) {
 // future queue to the set of pending transactions. During this process, all
 // invalidated transactions (low nonce, low balance) are deleted.
 func (pool *TxPool) promoteExecutables(accounts []common.Address) {
+	// Track the promoted transactions to broadcast them at once
+	var promoted []*types.Transaction
+
 	// Gather all the accounts potentially needing updates
 	if accounts == nil {
 		accounts = make([]common.Address, 0, len(pool.queue))
@@ -924,7 +925,7 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 		for _, tx := range list.Forward(pool.currentState.GetNonce(addr)) {
 			hash := tx.Hash()
 			log.Trace("Removed old queued transaction", "hash", hash)
-			delete(pool.all, hash)
+			pool.all.Remove(hash)
 			pool.priced.Removed()
 		}
 		// Drop all transactions that are too costly (low balance or out of gas)
@@ -932,21 +933,23 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 		for _, tx := range drops {
 			hash := tx.Hash()
 			log.Trace("Removed unpayable queued transaction", "hash", hash)
-			delete(pool.all, hash)
+			pool.all.Remove(hash)
 			pool.priced.Removed()
 			queuedNofundsCounter.Inc(1)
 		}
 		// Gather all executable transactions and promote them
 		for _, tx := range list.Ready(pool.pendingState.GetNonce(addr)) {
 			hash := tx.Hash()
-			log.Trace("Promoting queued transaction", "hash", hash)
-			pool.promoteTx(addr, hash, tx)
+			if pool.promoteTx(addr, hash, tx) {
+				log.Trace("Promoting queued transaction", "hash", hash)
+				promoted = append(promoted, tx)
+			}
 		}
 		// Drop all transactions over the allowed limit
 		if !pool.locals.contains(addr) {
 			for _, tx := range list.Cap(int(pool.config.AccountQueue)) {
 				hash := tx.Hash()
-				delete(pool.all, hash)
+				pool.all.Remove(hash)
 				pool.priced.Removed()
 				queuedRateLimitCounter.Inc(1)
 				log.Trace("Removed cap-exceeding queued transaction", "hash", hash)
@@ -957,6 +960,10 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 			delete(pool.queue, addr)
 		}
 	}
+	// Notify subsystem for new promoted transactions.
+	if len(promoted) > 0 {
+		go pool.txFeed.Send(NewTxsEvent{promoted})
+	}
 	// If the pending limit is overflown, start equalizing allowances
 	pending := uint64(0)
 	for _, list := range pool.pending {
@@ -991,7 +998,7 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 						for _, tx := range list.Cap(list.Len() - 1) {
 							// Drop the transaction from the global pools too
 							hash := tx.Hash()
-							delete(pool.all, hash)
+							pool.all.Remove(hash)
 							pool.priced.Removed()
 
 							// Update the account nonce to the dropped transaction
@@ -1013,7 +1020,7 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) {
 					for _, tx := range list.Cap(list.Len() - 1) {
 						// Drop the transaction from the global pools too
 						hash := tx.Hash()
-						delete(pool.all, hash)
+						pool.all.Remove(hash)
 						pool.priced.Removed()
 
 						// Update the account nonce to the dropped transaction
@@ -1082,7 +1089,7 @@ func (pool *TxPool) demoteUnexecutables() {
 		for _, tx := range list.Forward(nonce) {
 			hash := tx.Hash()
 			log.Trace("Removed old pending transaction", "hash", hash)
-			delete(pool.all, hash)
+			pool.all.Remove(hash)
 			pool.priced.Removed()
 		}
 		// Drop all transactions that are too costly (low balance or out of gas), and queue any invalids back for later
@@ -1090,7 +1097,7 @@ func (pool *TxPool) demoteUnexecutables() {
 		for _, tx := range drops {
 			hash := tx.Hash()
 			log.Trace("Removed unpayable pending transaction", "hash", hash)
-			delete(pool.all, hash)
+			pool.all.Remove(hash)
 			pool.priced.Removed()
 			pendingNofundsCounter.Inc(1)
 		}
@@ -1162,3 +1169,68 @@ func (as *accountSet) containsTx(tx *types.Transaction) bool {
 func (as *accountSet) add(addr common.Address) {
 	as.accounts[addr] = struct{}{}
 }
+
+// txLookup is used internally by TxPool to track transactions while allowing lookup without
+// mutex contention.
+//
+// Note, although this type is properly protected against concurrent access, it
+// is **not** a type that should ever be mutated or even exposed outside of the
+// transaction pool, since its internal state is tightly coupled with the pools
+// internal mechanisms. The sole purpose of the type is to permit out-of-bound
+// peeking into the pool in TxPool.Get without having to acquire the widely scoped
+// TxPool.mu mutex.
+type txLookup struct {
+	all  map[common.Hash]*types.Transaction
+	lock sync.RWMutex
+}
+
+// newTxLookup returns a new txLookup structure.
+func newTxLookup() *txLookup {
+	return &txLookup{
+		all: make(map[common.Hash]*types.Transaction),
+	}
+}
+
+// Range calls f on each key and value present in the map.
+func (t *txLookup) Range(f func(hash common.Hash, tx *types.Transaction) bool) {
+	t.lock.RLock()
+	defer t.lock.RUnlock()
+
+	for key, value := range t.all {
+		if !f(key, value) {
+			break
+		}
+	}
+}
+
+// Get returns a transaction if it exists in the lookup, or nil if not found.
+func (t *txLookup) Get(hash common.Hash) *types.Transaction {
+	t.lock.RLock()
+	defer t.lock.RUnlock()
+
+	return t.all[hash]
+}
+
+// Count returns the current number of items in the lookup.
+func (t *txLookup) Count() int {
+	t.lock.RLock()
+	defer t.lock.RUnlock()
+
+	return len(t.all)
+}
+
+// Add adds a transaction to the lookup.
+func (t *txLookup) Add(tx *types.Transaction) {
+	t.lock.Lock()
+	defer t.lock.Unlock()
+
+	t.all[tx.Hash()] = tx
+}
+
+// Remove removes a transaction from the lookup.
+func (t *txLookup) Remove(hash common.Hash) {
+	t.lock.Lock()
+	defer t.lock.Unlock()
+
+	delete(t.all, hash)
+}
diff --git a/core/tx_pool_test.go b/core/tx_pool_test.go
index e7f52075e5..5a59205442 100644
--- a/core/tx_pool_test.go
+++ b/core/tx_pool_test.go
@@ -94,7 +94,7 @@ func validateTxPoolInternals(pool *TxPool) error {
 
 	// Ensure the total transaction set is consistent with pending + queued
 	pending, queued := pool.stats()
-	if total := len(pool.all); total != pending+queued {
+	if total := pool.all.Count(); total != pending+queued {
 		return fmt.Errorf("total transaction count %d != %d pending + %d queued", total, pending, queued)
 	}
 	if priced := pool.priced.items.Len() - pool.priced.stales; priced != pending+queued {
@@ -118,21 +118,27 @@ func validateTxPoolInternals(pool *TxPool) error {
 
 // validateEvents checks that the correct number of transaction addition events
 // were fired on the pool's event feed.
-func validateEvents(events chan TxPreEvent, count int) error {
-	for i := 0; i < count; i++ {
+func validateEvents(events chan NewTxsEvent, count int) error {
+	var received []*types.Transaction
+
+	for len(received) < count {
 		select {
-		case <-events:
+		case ev := <-events:
+			received = append(received, ev.Txs...)
 		case <-time.After(time.Second):
-			return fmt.Errorf("event #%d not fired", i)
+			return fmt.Errorf("event #%d not fired", received)
 		}
 	}
+	if len(received) > count {
+		return fmt.Errorf("more than %d events fired: %v", count, received[count:])
+	}
 	select {
-	case tx := <-events:
-		return fmt.Errorf("more than %d events fired: %v", count, tx.Tx)
+	case ev := <-events:
+		return fmt.Errorf("more than %d events fired: %v", count, ev.Txs)
 
 	case <-time.After(50 * time.Millisecond):
 		// This branch should be "default", but it's a data race between goroutines,
-		// reading the event channel and pushng into it, so better wait a bit ensuring
+		// reading the event channel and pushing into it, so better wait a bit ensuring
 		// really nothing gets injected.
 	}
 	return nil
@@ -395,8 +401,8 @@ func TestTransactionDoubleNonce(t *testing.T) {
 		t.Errorf("transaction mismatch: have %x, want %x", tx.Hash(), tx2.Hash())
 	}
 	// Ensure the total transaction count is correct
-	if len(pool.all) != 1 {
-		t.Error("expected 1 total transactions, got", len(pool.all))
+	if pool.all.Count() != 1 {
+		t.Error("expected 1 total transactions, got", pool.all.Count())
 	}
 }
 
@@ -418,8 +424,8 @@ func TestTransactionMissingNonce(t *testing.T) {
 	if pool.queue[addr].Len() != 1 {
 		t.Error("expected 1 queued transaction, got", pool.queue[addr].Len())
 	}
-	if len(pool.all) != 1 {
-		t.Error("expected 1 total transactions, got", len(pool.all))
+	if pool.all.Count() != 1 {
+		t.Error("expected 1 total transactions, got", pool.all.Count())
 	}
 }
 
@@ -482,8 +488,8 @@ func TestTransactionDropping(t *testing.T) {
 	if pool.queue[account].Len() != 3 {
 		t.Errorf("queued transaction mismatch: have %d, want %d", pool.queue[account].Len(), 3)
 	}
-	if len(pool.all) != 6 {
-		t.Errorf("total transaction mismatch: have %d, want %d", len(pool.all), 6)
+	if pool.all.Count() != 6 {
+		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), 6)
 	}
 	pool.lockedReset(nil, nil)
 	if pool.pending[account].Len() != 3 {
@@ -492,8 +498,8 @@ func TestTransactionDropping(t *testing.T) {
 	if pool.queue[account].Len() != 3 {
 		t.Errorf("queued transaction mismatch: have %d, want %d", pool.queue[account].Len(), 3)
 	}
-	if len(pool.all) != 6 {
-		t.Errorf("total transaction mismatch: have %d, want %d", len(pool.all), 6)
+	if pool.all.Count() != 6 {
+		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), 6)
 	}
 	// Reduce the balance of the account, and check that invalidated transactions are dropped
 	pool.currentState.AddBalance(account, big.NewInt(-650))
@@ -517,8 +523,8 @@ func TestTransactionDropping(t *testing.T) {
 	if _, ok := pool.queue[account].txs.items[tx12.Nonce()]; ok {
 		t.Errorf("out-of-fund queued transaction present: %v", tx11)
 	}
-	if len(pool.all) != 4 {
-		t.Errorf("total transaction mismatch: have %d, want %d", len(pool.all), 4)
+	if pool.all.Count() != 4 {
+		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), 4)
 	}
 	// Reduce the block gas limit, check that invalidated transactions are dropped
 	pool.chain.(*testBlockChain).gasLimit = 100
@@ -536,8 +542,8 @@ func TestTransactionDropping(t *testing.T) {
 	if _, ok := pool.queue[account].txs.items[tx11.Nonce()]; ok {
 		t.Errorf("over-gased queued transaction present: %v", tx11)
 	}
-	if len(pool.all) != 2 {
-		t.Errorf("total transaction mismatch: have %d, want %d", len(pool.all), 2)
+	if pool.all.Count() != 2 {
+		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), 2)
 	}
 }
 
@@ -590,8 +596,8 @@ func TestTransactionPostponing(t *testing.T) {
 	if len(pool.queue) != 0 {
 		t.Errorf("queued accounts mismatch: have %d, want %d", len(pool.queue), 0)
 	}
-	if len(pool.all) != len(txs) {
-		t.Errorf("total transaction mismatch: have %d, want %d", len(pool.all), len(txs))
+	if pool.all.Count() != len(txs) {
+		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), len(txs))
 	}
 	pool.lockedReset(nil, nil)
 	if pending := pool.pending[accs[0]].Len() + pool.pending[accs[1]].Len(); pending != len(txs) {
@@ -600,8 +606,8 @@ func TestTransactionPostponing(t *testing.T) {
 	if len(pool.queue) != 0 {
 		t.Errorf("queued accounts mismatch: have %d, want %d", len(pool.queue), 0)
 	}
-	if len(pool.all) != len(txs) {
-		t.Errorf("total transaction mismatch: have %d, want %d", len(pool.all), len(txs))
+	if pool.all.Count() != len(txs) {
+		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), len(txs))
 	}
 	// Reduce the balance of the account, and check that transactions are reorganised
 	for _, addr := range accs {
@@ -650,8 +656,8 @@ func TestTransactionPostponing(t *testing.T) {
 			}
 		}
 	}
-	if len(pool.all) != len(txs)/2 {
-		t.Errorf("total transaction mismatch: have %d, want %d", len(pool.all), len(txs)/2)
+	if pool.all.Count() != len(txs)/2 {
+		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), len(txs)/2)
 	}
 }
 
@@ -669,7 +675,7 @@ func TestTransactionGapFilling(t *testing.T) {
 	pool.currentState.AddBalance(account, big.NewInt(1000000))
 
 	// Keep track of transaction events to ensure all executables get announced
-	events := make(chan TxPreEvent, testTxPoolConfig.AccountQueue+5)
+	events := make(chan NewTxsEvent, testTxPoolConfig.AccountQueue+5)
 	sub := pool.txFeed.Subscribe(events)
 	defer sub.Unsubscribe()
 
@@ -742,8 +748,8 @@ func TestTransactionQueueAccountLimiting(t *testing.T) {
 			}
 		}
 	}
-	if len(pool.all) != int(testTxPoolConfig.AccountQueue) {
-		t.Errorf("total transaction mismatch: have %d, want %d", len(pool.all), testTxPoolConfig.AccountQueue)
+	if pool.all.Count() != int(testTxPoolConfig.AccountQueue) {
+		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), testTxPoolConfig.AccountQueue)
 	}
 }
 
@@ -920,7 +926,7 @@ func TestTransactionPendingLimiting(t *testing.T) {
 	pool.currentState.AddBalance(account, big.NewInt(1000000))
 
 	// Keep track of transaction events to ensure all executables get announced
-	events := make(chan TxPreEvent, testTxPoolConfig.AccountQueue+5)
+	events := make(chan NewTxsEvent, testTxPoolConfig.AccountQueue+5)
 	sub := pool.txFeed.Subscribe(events)
 	defer sub.Unsubscribe()
 
@@ -936,8 +942,8 @@ 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(testTxPoolConfig.AccountQueue+5) {
-		t.Errorf("total transaction mismatch: have %d, want %d", len(pool.all), testTxPoolConfig.AccountQueue+5)
+	if pool.all.Count() != int(testTxPoolConfig.AccountQueue+5) {
+		t.Errorf("total transaction mismatch: have %d, want %d", pool.all.Count(), testTxPoolConfig.AccountQueue+5)
 	}
 	if err := validateEvents(events, int(testTxPoolConfig.AccountQueue+5)); err != nil {
 		t.Fatalf("event firing failed: %v", err)
@@ -987,8 +993,8 @@ func testTransactionLimitingEquivalency(t *testing.T, origin uint64) {
 	if len(pool1.queue) != len(pool2.queue) {
 		t.Errorf("queued transaction count mismatch: one-by-one algo: %d, batch algo: %d", len(pool1.queue), len(pool2.queue))
 	}
-	if len(pool1.all) != len(pool2.all) {
-		t.Errorf("total transaction count mismatch: one-by-one algo %d, batch algo %d", len(pool1.all), len(pool2.all))
+	if pool1.all.Count() != pool2.all.Count() {
+		t.Errorf("total transaction count mismatch: one-by-one algo %d, batch algo %d", pool1.all.Count(), pool2.all.Count())
 	}
 	if err := validateTxPoolInternals(pool1); err != nil {
 		t.Errorf("pool 1 internal state corrupted: %v", err)
@@ -1140,7 +1146,7 @@ func TestTransactionPoolRepricing(t *testing.T) {
 	defer pool.Stop()
 
 	// Keep track of transaction events to ensure all executables get announced
-	events := make(chan TxPreEvent, 32)
+	events := make(chan NewTxsEvent, 32)
 	sub := pool.txFeed.Subscribe(events)
 	defer sub.Unsubscribe()
 
@@ -1327,7 +1333,7 @@ func TestTransactionPoolUnderpricing(t *testing.T) {
 	defer pool.Stop()
 
 	// Keep track of transaction events to ensure all executables get announced
-	events := make(chan TxPreEvent, 32)
+	events := make(chan NewTxsEvent, 32)
 	sub := pool.txFeed.Subscribe(events)
 	defer sub.Unsubscribe()
 
@@ -1433,7 +1439,7 @@ func TestTransactionPoolStableUnderpricing(t *testing.T) {
 	defer pool.Stop()
 
 	// Keep track of transaction events to ensure all executables get announced
-	events := make(chan TxPreEvent, 32)
+	events := make(chan NewTxsEvent, 32)
 	sub := pool.txFeed.Subscribe(events)
 	defer sub.Unsubscribe()
 
@@ -1495,7 +1501,7 @@ func TestTransactionReplacement(t *testing.T) {
 	defer pool.Stop()
 
 	// Keep track of transaction events to ensure all executables get announced
-	events := make(chan TxPreEvent, 32)
+	events := make(chan NewTxsEvent, 32)
 	sub := pool.txFeed.Subscribe(events)
 	defer sub.Unsubscribe()
 
diff --git a/core/types/gen_receipt_json.go b/core/types/gen_receipt_json.go
index c297adebb6..5c807a4ccb 100644
--- a/core/types/gen_receipt_json.go
+++ b/core/types/gen_receipt_json.go
@@ -12,10 +12,11 @@ import (
 
 var _ = (*receiptMarshaling)(nil)
 
+// MarshalJSON marshals as JSON.
 func (r Receipt) MarshalJSON() ([]byte, error) {
 	type Receipt struct {
 		PostState         hexutil.Bytes  `json:"root"`
-		Status            hexutil.Uint   `json:"status"`
+		Status            hexutil.Uint64 `json:"status"`
 		CumulativeGasUsed hexutil.Uint64 `json:"cumulativeGasUsed" gencodec:"required"`
 		Bloom             Bloom          `json:"logsBloom"         gencodec:"required"`
 		Logs              []*Log         `json:"logs"              gencodec:"required"`
@@ -25,7 +26,7 @@ func (r Receipt) MarshalJSON() ([]byte, error) {
 	}
 	var enc Receipt
 	enc.PostState = r.PostState
-	enc.Status = hexutil.Uint(r.Status)
+	enc.Status = hexutil.Uint64(r.Status)
 	enc.CumulativeGasUsed = hexutil.Uint64(r.CumulativeGasUsed)
 	enc.Bloom = r.Bloom
 	enc.Logs = r.Logs
@@ -35,10 +36,11 @@ func (r Receipt) MarshalJSON() ([]byte, error) {
 	return json.Marshal(&enc)
 }
 
+// UnmarshalJSON unmarshals from JSON.
 func (r *Receipt) UnmarshalJSON(input []byte) error {
 	type Receipt struct {
 		PostState         *hexutil.Bytes  `json:"root"`
-		Status            *hexutil.Uint   `json:"status"`
+		Status            *hexutil.Uint64 `json:"status"`
 		CumulativeGasUsed *hexutil.Uint64 `json:"cumulativeGasUsed" gencodec:"required"`
 		Bloom             *Bloom          `json:"logsBloom"         gencodec:"required"`
 		Logs              []*Log          `json:"logs"              gencodec:"required"`
@@ -54,7 +56,7 @@ func (r *Receipt) UnmarshalJSON(input []byte) error {
 		r.PostState = *dec.PostState
 	}
 	if dec.Status != nil {
-		r.Status = uint(*dec.Status)
+		r.Status = uint64(*dec.Status)
 	}
 	if dec.CumulativeGasUsed == nil {
 		return errors.New("missing required field 'cumulativeGasUsed' for Receipt")
diff --git a/core/types/receipt.go b/core/types/receipt.go
index 613f03d50f..3d1fc95aab 100644
--- a/core/types/receipt.go
+++ b/core/types/receipt.go
@@ -36,17 +36,17 @@ var (
 
 const (
 	// ReceiptStatusFailed is the status code of a transaction if execution failed.
-	ReceiptStatusFailed = uint(0)
+	ReceiptStatusFailed = uint64(0)
 
 	// ReceiptStatusSuccessful is the status code of a transaction if execution succeeded.
-	ReceiptStatusSuccessful = uint(1)
+	ReceiptStatusSuccessful = uint64(1)
 )
 
 // Receipt represents the results of a transaction.
 type Receipt struct {
 	// Consensus fields
 	PostState         []byte `json:"root"`
-	Status            uint   `json:"status"`
+	Status            uint64 `json:"status"`
 	CumulativeGasUsed uint64 `json:"cumulativeGasUsed" gencodec:"required"`
 	Bloom             Bloom  `json:"logsBloom"         gencodec:"required"`
 	Logs              []*Log `json:"logs"              gencodec:"required"`
@@ -59,7 +59,7 @@ type Receipt struct {
 
 type receiptMarshaling struct {
 	PostState         hexutil.Bytes
-	Status            hexutil.Uint
+	Status            hexutil.Uint64
 	CumulativeGasUsed hexutil.Uint64
 	GasUsed           hexutil.Uint64
 }
diff --git a/core/types/transaction_test.go b/core/types/transaction_test.go
index d1861b14cd..b390f45c67 100644
--- a/core/types/transaction_test.go
+++ b/core/types/transaction_test.go
@@ -165,28 +165,13 @@ func TestTransactionPriceNonceSort(t *testing.T) {
 				t.Errorf("invalid nonce ordering: tx #%d (A=%x N=%v) < tx #%d (A=%x N=%v)", i, fromi[:4], txi.Nonce(), i+j, fromj[:4], txj.Nonce())
 			}
 		}
-		// Find the previous and next nonce of this account
-		prev, next := i-1, i+1
-		for j := i - 1; j >= 0; j-- {
-			if fromj, _ := Sender(signer, txs[j]); fromi == fromj {
-				prev = j
-				break
-			}
-		}
-		for j := i + 1; j < len(txs); j++ {
-			if fromj, _ := Sender(signer, txs[j]); fromi == fromj {
-				next = j
-				break
-			}
-		}
-		// Make sure that in between the neighbor nonces, the transaction is correctly positioned price wise
-		for j := prev + 1; j < next; j++ {
-			fromj, _ := Sender(signer, txs[j])
-			if j < i && txs[j].GasPrice().Cmp(txi.GasPrice()) < 0 {
-				t.Errorf("invalid gasprice ordering: tx #%d (A=%x P=%v) < tx #%d (A=%x P=%v)", j, fromj[:4], txs[j].GasPrice(), i, fromi[:4], txi.GasPrice())
-			}
-			if j > i && txs[j].GasPrice().Cmp(txi.GasPrice()) > 0 {
-				t.Errorf("invalid gasprice ordering: tx #%d (A=%x P=%v) > tx #%d (A=%x P=%v)", j, fromj[:4], txs[j].GasPrice(), i, fromi[:4], txi.GasPrice())
+
+		// If the next tx has different from account, the price must be lower than the current one
+		if i+1 < len(txs) {
+			next := txs[i+1]
+			fromNext, _ := Sender(signer, next)
+			if fromi != fromNext && txi.GasPrice().Cmp(next.GasPrice()) < 0 {
+				t.Errorf("invalid gasprice ordering: tx #%d (A=%x P=%v) < tx #%d (A=%x P=%v)", i, fromi[:4], txi.GasPrice(), i+1, fromNext[:4], next.GasPrice())
 			}
 		}
 	}
diff --git a/core/vm/gas_table.go b/core/vm/gas_table.go
index 83adba428e..0764c67a4d 100644
--- a/core/vm/gas_table.go
+++ b/core/vm/gas_table.go
@@ -124,12 +124,12 @@ func gasSStore(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, m
 	// 1. From a zero-value address to a non-zero value         (NEW VALUE)
 	// 2. From a non-zero value address to a zero-value address (DELETE)
 	// 3. From a non-zero to a non-zero                         (CHANGE)
-	if common.EmptyHash(val) && !common.EmptyHash(common.BigToHash(y)) {
+	if val == (common.Hash{}) && y.Sign() != 0 {
 		// 0 => non 0
 		return params.SstoreSetGas, nil
-	} else if !common.EmptyHash(val) && common.EmptyHash(common.BigToHash(y)) {
+	} else if val != (common.Hash{}) && y.Sign() == 0 {
+		// non 0 => 0
 		evm.StateDB.AddRefund(params.SstoreRefundGas)
-
 		return params.SstoreClearGas, nil
 	} else {
 		// non 0 => non 0 (or 0 => 0)
diff --git a/core/vm/instructions.go b/core/vm/instructions.go
index 0689ee39cf..3a67e1865f 100644
--- a/core/vm/instructions.go
+++ b/core/vm/instructions.go
@@ -850,7 +850,7 @@ func makePush(size uint64, pushByteSize int) executionFunc {
 	}
 }
 
-// make push instruction function
+// make dup instruction function
 func makeDup(size int64) executionFunc {
 	return func(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
 		stack.dup(evm.interpreter.intPool, int(size))
diff --git a/core/vm/jump_table.go b/core/vm/jump_table.go
index 3389941353..49a94d9646 100644
--- a/core/vm/jump_table.go
+++ b/core/vm/jump_table.go
@@ -33,7 +33,7 @@ type (
 var errGasUintOverflow = errors.New("gas uint64 overflow")
 
 type operation struct {
-	// op is the operation function
+	// execute is the operation function
 	execute executionFunc
 	// gasCost is the gas function and returns the gas required for execution
 	gasCost gasFunc
diff --git a/eth/api_backend.go b/eth/api_backend.go
index 4ace9b5945..91a7dc7e0e 100644
--- a/eth/api_backend.go
+++ b/eth/api_backend.go
@@ -188,8 +188,8 @@ func (b *EthAPIBackend) TxPoolContent() (map[common.Address]types.Transactions,
 	return b.eth.TxPool().Content()
 }
 
-func (b *EthAPIBackend) SubscribeTxPreEvent(ch chan<- core.TxPreEvent) event.Subscription {
-	return b.eth.TxPool().SubscribeTxPreEvent(ch)
+func (b *EthAPIBackend) SubscribeNewTxsEvent(ch chan<- core.NewTxsEvent) event.Subscription {
+	return b.eth.TxPool().SubscribeNewTxsEvent(ch)
 }
 
 func (b *EthAPIBackend) Downloader() *downloader.Downloader {
diff --git a/eth/backend.go b/eth/backend.go
index ea70e3826c..e07d5efc9a 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -215,14 +215,14 @@ func CreateConsensusEngine(ctx *node.ServiceContext, config *ethash.Config, chai
 		return clique.New(chainConfig.Clique, db)
 	}
 	// Otherwise assume proof-of-work
-	switch {
-	case config.PowMode == ethash.ModeFake:
+	switch config.PowMode {
+	case ethash.ModeFake:
 		log.Warn("Ethash used in fake mode")
 		return ethash.NewFaker()
-	case config.PowMode == ethash.ModeTest:
+	case ethash.ModeTest:
 		log.Warn("Ethash used in test mode")
 		return ethash.NewTester()
-	case config.PowMode == ethash.ModeShared:
+	case ethash.ModeShared:
 		log.Warn("Ethash used in shared mode")
 		return ethash.NewShared()
 	default:
@@ -239,7 +239,7 @@ func CreateConsensusEngine(ctx *node.ServiceContext, config *ethash.Config, chai
 	}
 }
 
-// APIs returns the collection of RPC services the ethereum package offers.
+// APIs return the collection of RPC services the ethereum package offers.
 // NOTE, some of these services probably need to be moved to somewhere else.
 func (s *Ethereum) APIs() []rpc.API {
 	apis := ethapi.GetAPIs(s.APIBackend)
diff --git a/eth/downloader/downloader.go b/eth/downloader/downloader.go
index dc23354929..51c5936015 100644
--- a/eth/downloader/downloader.go
+++ b/eth/downloader/downloader.go
@@ -680,7 +680,7 @@ func (d *Downloader) findAncestor(p *peerConnection, height uint64) (uint64, err
 		}
 	}
 	// If the head fetch already found an ancestor, return
-	if !common.EmptyHash(hash) {
+	if hash != (common.Hash{}) {
 		if int64(number) <= floor {
 			p.log.Warn("Ancestor below allowance", "number", number, "hash", hash, "allowance", floor)
 			return 0, errInvalidAncestor
diff --git a/eth/downloader/statesync.go b/eth/downloader/statesync.go
index 5b4b9ba1b7..8d33dfec74 100644
--- a/eth/downloader/statesync.go
+++ b/eth/downloader/statesync.go
@@ -214,7 +214,7 @@ func (d *Downloader) runStateSync(s *stateSync) *stateSync {
 type stateSync struct {
 	d *Downloader // Downloader instance to access and manage current peerset
 
-	sched  *trie.TrieSync             // State trie sync scheduler defining the tasks
+	sched  *trie.Sync                 // State trie sync scheduler defining the tasks
 	keccak hash.Hash                  // Keccak256 hasher to verify deliveries with
 	tasks  map[common.Hash]*stateTask // Set of tasks currently queued for retrieval
 
diff --git a/eth/fetcher/fetcher.go b/eth/fetcher/fetcher.go
index 0c679cec3a..a2e7cdecf9 100644
--- a/eth/fetcher/fetcher.go
+++ b/eth/fetcher/fetcher.go
@@ -292,20 +292,20 @@ func (f *Fetcher) loop() {
 		height := f.chainHeight()
 		for !f.queue.Empty() {
 			op := f.queue.PopItem().(*inject)
+			hash := op.block.Hash()
 			if f.queueChangeHook != nil {
-				f.queueChangeHook(op.block.Hash(), false)
+				f.queueChangeHook(hash, false)
 			}
 			// If too high up the chain or phase, continue later
 			number := op.block.NumberU64()
 			if number > height+1 {
-				f.queue.Push(op, -float32(op.block.NumberU64()))
+				f.queue.Push(op, -float32(number))
 				if f.queueChangeHook != nil {
-					f.queueChangeHook(op.block.Hash(), true)
+					f.queueChangeHook(hash, true)
 				}
 				break
 			}
 			// Otherwise if fresh and still unknown, try and import
-			hash := op.block.Hash()
 			if number+maxUncleDist < height || f.getBlock(hash) != nil {
 				f.forgetBlock(hash)
 				continue
diff --git a/eth/filters/api.go b/eth/filters/api.go
index 1297b74788..592ad3b82f 100644
--- a/eth/filters/api.go
+++ b/eth/filters/api.go
@@ -104,8 +104,8 @@ func (api *PublicFilterAPI) timeoutLoop() {
 // https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_newpendingtransactionfilter
 func (api *PublicFilterAPI) NewPendingTransactionFilter() rpc.ID {
 	var (
-		pendingTxs   = make(chan common.Hash)
-		pendingTxSub = api.events.SubscribePendingTxEvents(pendingTxs)
+		pendingTxs   = make(chan []common.Hash)
+		pendingTxSub = api.events.SubscribePendingTxs(pendingTxs)
 	)
 
 	api.filtersMu.Lock()
@@ -118,7 +118,7 @@ func (api *PublicFilterAPI) NewPendingTransactionFilter() rpc.ID {
 			case ph := <-pendingTxs:
 				api.filtersMu.Lock()
 				if f, found := api.filters[pendingTxSub.ID]; found {
-					f.hashes = append(f.hashes, ph)
+					f.hashes = append(f.hashes, ph...)
 				}
 				api.filtersMu.Unlock()
 			case <-pendingTxSub.Err():
@@ -144,13 +144,17 @@ func (api *PublicFilterAPI) NewPendingTransactions(ctx context.Context) (*rpc.Su
 	rpcSub := notifier.CreateSubscription()
 
 	go func() {
-		txHashes := make(chan common.Hash)
-		pendingTxSub := api.events.SubscribePendingTxEvents(txHashes)
+		txHashes := make(chan []common.Hash, 128)
+		pendingTxSub := api.events.SubscribePendingTxs(txHashes)
 
 		for {
 			select {
-			case h := <-txHashes:
-				notifier.Notify(rpcSub.ID, h)
+			case hashes := <-txHashes:
+				// To keep the original behaviour, send a single tx hash in one notification.
+				// TODO(rjl493456442) Send a batch of tx hashes in one notification
+				for _, h := range hashes {
+					notifier.Notify(rpcSub.ID, h)
+				}
 			case <-rpcSub.Err():
 				pendingTxSub.Unsubscribe()
 				return
diff --git a/eth/filters/filter.go b/eth/filters/filter.go
index 5dfe60e772..67b4612ae4 100644
--- a/eth/filters/filter.go
+++ b/eth/filters/filter.go
@@ -36,7 +36,7 @@ type Backend interface {
 	GetReceipts(ctx context.Context, blockHash common.Hash) (types.Receipts, error)
 	GetLogs(ctx context.Context, blockHash common.Hash) ([][]*types.Log, error)
 
-	SubscribeTxPreEvent(chan<- core.TxPreEvent) event.Subscription
+	SubscribeNewTxsEvent(chan<- core.NewTxsEvent) event.Subscription
 	SubscribeChainEvent(ch chan<- core.ChainEvent) event.Subscription
 	SubscribeRemovedLogsEvent(ch chan<- core.RemovedLogsEvent) event.Subscription
 	SubscribeLogsEvent(ch chan<- []*types.Log) event.Subscription
diff --git a/eth/filters/filter_system.go b/eth/filters/filter_system.go
index bb11734a76..4e999cda85 100644
--- a/eth/filters/filter_system.go
+++ b/eth/filters/filter_system.go
@@ -59,7 +59,7 @@ const (
 
 const (
 
-	// txChanSize is the size of channel listening to TxPreEvent.
+	// txChanSize is the size of channel listening to NewTxsEvent.
 	// The number is referenced from the size of tx pool.
 	txChanSize = 4096
 	// rmLogsChanSize is the size of channel listening to RemovedLogsEvent.
@@ -80,7 +80,7 @@ type subscription struct {
 	created   time.Time
 	logsCrit  ethereum.FilterQuery
 	logs      chan []*types.Log
-	hashes    chan common.Hash
+	hashes    chan []common.Hash
 	headers   chan *types.Header
 	installed chan struct{} // closed when the filter is installed
 	err       chan error    // closed when the filter is uninstalled
@@ -95,7 +95,7 @@ type EventSystem struct {
 	lastHead  *types.Header
 
 	// Subscriptions
-	txSub         event.Subscription         // Subscription for new transaction event
+	txsSub        event.Subscription         // Subscription for new transaction event
 	logsSub       event.Subscription         // Subscription for new log event
 	rmLogsSub     event.Subscription         // Subscription for removed log event
 	chainSub      event.Subscription         // Subscription for new chain event
@@ -104,7 +104,7 @@ type EventSystem struct {
 	// Channels
 	install   chan *subscription         // install filter for event notification
 	uninstall chan *subscription         // remove filter for event notification
-	txCh      chan core.TxPreEvent       // Channel to receive new transaction event
+	txsCh     chan core.NewTxsEvent      // Channel to receive new transactions event
 	logsCh    chan []*types.Log          // Channel to receive new log event
 	rmLogsCh  chan core.RemovedLogsEvent // Channel to receive removed log event
 	chainCh   chan core.ChainEvent       // Channel to receive new chain event
@@ -123,14 +123,14 @@ func NewEventSystem(mux *event.TypeMux, backend Backend, lightMode bool) *EventS
 		lightMode: lightMode,
 		install:   make(chan *subscription),
 		uninstall: make(chan *subscription),
-		txCh:      make(chan core.TxPreEvent, txChanSize),
+		txsCh:     make(chan core.NewTxsEvent, txChanSize),
 		logsCh:    make(chan []*types.Log, logsChanSize),
 		rmLogsCh:  make(chan core.RemovedLogsEvent, rmLogsChanSize),
 		chainCh:   make(chan core.ChainEvent, chainEvChanSize),
 	}
 
 	// Subscribe events
-	m.txSub = m.backend.SubscribeTxPreEvent(m.txCh)
+	m.txsSub = m.backend.SubscribeNewTxsEvent(m.txsCh)
 	m.logsSub = m.backend.SubscribeLogsEvent(m.logsCh)
 	m.rmLogsSub = m.backend.SubscribeRemovedLogsEvent(m.rmLogsCh)
 	m.chainSub = m.backend.SubscribeChainEvent(m.chainCh)
@@ -138,7 +138,7 @@ func NewEventSystem(mux *event.TypeMux, backend Backend, lightMode bool) *EventS
 	m.pendingLogSub = m.mux.Subscribe(core.PendingLogsEvent{})
 
 	// Make sure none of the subscriptions are empty
-	if m.txSub == nil || m.logsSub == nil || m.rmLogsSub == nil || m.chainSub == nil ||
+	if m.txsSub == nil || m.logsSub == nil || m.rmLogsSub == nil || m.chainSub == nil ||
 		m.pendingLogSub.Closed() {
 		log.Crit("Subscribe for event system failed")
 	}
@@ -240,7 +240,7 @@ func (es *EventSystem) subscribeMinedPendingLogs(crit ethereum.FilterQuery, logs
 		logsCrit:  crit,
 		created:   time.Now(),
 		logs:      logs,
-		hashes:    make(chan common.Hash),
+		hashes:    make(chan []common.Hash),
 		headers:   make(chan *types.Header),
 		installed: make(chan struct{}),
 		err:       make(chan error),
@@ -257,7 +257,7 @@ func (es *EventSystem) subscribeLogs(crit ethereum.FilterQuery, logs chan []*typ
 		logsCrit:  crit,
 		created:   time.Now(),
 		logs:      logs,
-		hashes:    make(chan common.Hash),
+		hashes:    make(chan []common.Hash),
 		headers:   make(chan *types.Header),
 		installed: make(chan struct{}),
 		err:       make(chan error),
@@ -274,7 +274,7 @@ func (es *EventSystem) subscribePendingLogs(crit ethereum.FilterQuery, logs chan
 		logsCrit:  crit,
 		created:   time.Now(),
 		logs:      logs,
-		hashes:    make(chan common.Hash),
+		hashes:    make(chan []common.Hash),
 		headers:   make(chan *types.Header),
 		installed: make(chan struct{}),
 		err:       make(chan error),
@@ -290,7 +290,7 @@ func (es *EventSystem) SubscribeNewHeads(headers chan *types.Header) *Subscripti
 		typ:       BlocksSubscription,
 		created:   time.Now(),
 		logs:      make(chan []*types.Log),
-		hashes:    make(chan common.Hash),
+		hashes:    make(chan []common.Hash),
 		headers:   headers,
 		installed: make(chan struct{}),
 		err:       make(chan error),
@@ -298,9 +298,9 @@ func (es *EventSystem) SubscribeNewHeads(headers chan *types.Header) *Subscripti
 	return es.subscribe(sub)
 }
 
-// SubscribePendingTxEvents creates a subscription that writes transaction hashes for
+// SubscribePendingTxs creates a subscription that writes transaction hashes for
 // transactions that enter the transaction pool.
-func (es *EventSystem) SubscribePendingTxEvents(hashes chan common.Hash) *Subscription {
+func (es *EventSystem) SubscribePendingTxs(hashes chan []common.Hash) *Subscription {
 	sub := &subscription{
 		id:        rpc.NewID(),
 		typ:       PendingTransactionsSubscription,
@@ -348,9 +348,13 @@ func (es *EventSystem) broadcast(filters filterIndex, ev interface{}) {
 				}
 			}
 		}
-	case core.TxPreEvent:
+	case core.NewTxsEvent:
+		hashes := make([]common.Hash, 0, len(e.Txs))
+		for _, tx := range e.Txs {
+			hashes = append(hashes, tx.Hash())
+		}
 		for _, f := range filters[PendingTransactionsSubscription] {
-			f.hashes <- e.Tx.Hash()
+			f.hashes <- hashes
 		}
 	case core.ChainEvent:
 		for _, f := range filters[BlocksSubscription] {
@@ -446,7 +450,7 @@ func (es *EventSystem) eventLoop() {
 	// Ensure all subscriptions get cleaned up
 	defer func() {
 		es.pendingLogSub.Unsubscribe()
-		es.txSub.Unsubscribe()
+		es.txsSub.Unsubscribe()
 		es.logsSub.Unsubscribe()
 		es.rmLogsSub.Unsubscribe()
 		es.chainSub.Unsubscribe()
@@ -460,7 +464,7 @@ func (es *EventSystem) eventLoop() {
 	for {
 		select {
 		// Handle subscribed events
-		case ev := <-es.txCh:
+		case ev := <-es.txsCh:
 			es.broadcast(index, ev)
 		case ev := <-es.logsCh:
 			es.broadcast(index, ev)
@@ -495,7 +499,7 @@ func (es *EventSystem) eventLoop() {
 			close(f.err)
 
 		// System stopped
-		case <-es.txSub.Err():
+		case <-es.txsSub.Err():
 			return
 		case <-es.logsSub.Err():
 			return
diff --git a/eth/filters/filter_system_test.go b/eth/filters/filter_system_test.go
index b4df24b471..ff1af85a80 100644
--- a/eth/filters/filter_system_test.go
+++ b/eth/filters/filter_system_test.go
@@ -96,7 +96,7 @@ func (b *testBackend) GetLogs(ctx context.Context, hash common.Hash) ([][]*types
 	return logs, nil
 }
 
-func (b *testBackend) SubscribeTxPreEvent(ch chan<- core.TxPreEvent) event.Subscription {
+func (b *testBackend) SubscribeNewTxsEvent(ch chan<- core.NewTxsEvent) event.Subscription {
 	return b.txFeed.Subscribe(ch)
 }
 
@@ -232,10 +232,7 @@ func TestPendingTxFilter(t *testing.T) {
 	fid0 := api.NewPendingTransactionFilter()
 
 	time.Sleep(1 * time.Second)
-	for _, tx := range transactions {
-		ev := core.TxPreEvent{Tx: tx}
-		txFeed.Send(ev)
-	}
+	txFeed.Send(core.NewTxsEvent{Txs: transactions})
 
 	timeout := time.Now().Add(1 * time.Second)
 	for {
diff --git a/eth/handler.go b/eth/handler.go
index c8f7e13f16..918d71088d 100644
--- a/eth/handler.go
+++ b/eth/handler.go
@@ -46,7 +46,7 @@ const (
 	softResponseLimit = 2 * 1024 * 1024 // Target maximum size of returned blocks, headers or node data.
 	estHeaderRlpSize  = 500             // Approximate size of an RLP encoded block header
 
-	// txChanSize is the size of channel listening to TxPreEvent.
+	// txChanSize is the size of channel listening to NewTxsEvent.
 	// The number is referenced from the size of tx pool.
 	txChanSize = 4096
 )
@@ -81,8 +81,8 @@ type ProtocolManager struct {
 	SubProtocols []p2p.Protocol
 
 	eventMux      *event.TypeMux
-	txCh          chan core.TxPreEvent
-	txSub         event.Subscription
+	txsCh         chan core.NewTxsEvent
+	txsSub        event.Subscription
 	minedBlockSub *event.TypeMuxSubscription
 
 	// channels for fetcher, syncer, txsyncLoop
@@ -204,8 +204,8 @@ func (pm *ProtocolManager) Start(maxPeers int) {
 	pm.maxPeers = maxPeers
 
 	// broadcast transactions
-	pm.txCh = make(chan core.TxPreEvent, txChanSize)
-	pm.txSub = pm.txpool.SubscribeTxPreEvent(pm.txCh)
+	pm.txsCh = make(chan core.NewTxsEvent, txChanSize)
+	pm.txsSub = pm.txpool.SubscribeNewTxsEvent(pm.txsCh)
 	go pm.txBroadcastLoop()
 
 	// broadcast mined blocks
@@ -220,7 +220,7 @@ func (pm *ProtocolManager) Start(maxPeers int) {
 func (pm *ProtocolManager) Stop() {
 	log.Info("Stopping Ethereum protocol")
 
-	pm.txSub.Unsubscribe()         // quits txBroadcastLoop
+	pm.txsSub.Unsubscribe()        // quits txBroadcastLoop
 	pm.minedBlockSub.Unsubscribe() // quits blockBroadcastLoop
 
 	// Quit the sync loop.
@@ -698,7 +698,7 @@ func (pm *ProtocolManager) BroadcastBlock(block *types.Block, propagate bool) {
 		// Send the block to a subset of our peers
 		transfer := peers[:int(math.Sqrt(float64(len(peers))))]
 		for _, peer := range transfer {
-			peer.SendNewBlock(block, td)
+			peer.AsyncSendNewBlock(block, td)
 		}
 		log.Trace("Propagated block", "hash", hash, "recipients", len(transfer), "duration", common.PrettyDuration(time.Since(block.ReceivedAt)))
 		return
@@ -706,22 +706,29 @@ func (pm *ProtocolManager) BroadcastBlock(block *types.Block, propagate bool) {
 	// Otherwise if the block is indeed in out own chain, announce it
 	if pm.blockchain.HasBlock(hash, block.NumberU64()) {
 		for _, peer := range peers {
-			peer.SendNewBlockHashes([]common.Hash{hash}, []uint64{block.NumberU64()})
+			peer.AsyncSendNewBlockHash(block)
 		}
 		log.Trace("Announced block", "hash", hash, "recipients", len(peers), "duration", common.PrettyDuration(time.Since(block.ReceivedAt)))
 	}
 }
 
-// BroadcastTx will propagate a transaction to all peers which are not known to
+// BroadcastTxs will propagate a batch of transactions to all peers which are not known to
 // already have the given transaction.
-func (pm *ProtocolManager) BroadcastTx(hash common.Hash, tx *types.Transaction) {
-	// Broadcast transaction to a batch of peers not knowing about it
-	peers := pm.peers.PeersWithoutTx(hash)
-	//FIXME include this again: peers = peers[:int(math.Sqrt(float64(len(peers))))]
-	for _, peer := range peers {
-		peer.SendTransactions(types.Transactions{tx})
+func (pm *ProtocolManager) BroadcastTxs(txs types.Transactions) {
+	var txset = make(map[*peer]types.Transactions)
+
+	// Broadcast transactions to a batch of peers not knowing about it
+	for _, tx := range txs {
+		peers := pm.peers.PeersWithoutTx(tx.Hash())
+		for _, peer := range peers {
+			txset[peer] = append(txset[peer], tx)
+		}
+		log.Trace("Broadcast transaction", "hash", tx.Hash(), "recipients", len(peers))
+	}
+	// FIXME include this again: peers = peers[:int(math.Sqrt(float64(len(peers))))]
+	for peer, txs := range txset {
+		peer.AsyncSendTransactions(txs)
 	}
-	log.Trace("Broadcast transaction", "hash", hash, "recipients", len(peers))
 }
 
 // Mined broadcast loop
@@ -739,11 +746,11 @@ func (pm *ProtocolManager) minedBroadcastLoop() {
 func (pm *ProtocolManager) txBroadcastLoop() {
 	for {
 		select {
-		case event := <-pm.txCh:
-			pm.BroadcastTx(event.Tx.Hash(), event.Tx)
+		case event := <-pm.txsCh:
+			pm.BroadcastTxs(event.Txs)
 
 		// Err() channel will be closed when unsubscribing.
-		case <-pm.txSub.Err():
+		case <-pm.txsSub.Err():
 			return
 		}
 	}
diff --git a/eth/helper_test.go b/eth/helper_test.go
index 8a0260fc95..3d2ab0aba1 100644
--- a/eth/helper_test.go
+++ b/eth/helper_test.go
@@ -124,7 +124,7 @@ func (p *testTxPool) Pending() (map[common.Address]types.Transactions, error) {
 	return batches, nil
 }
 
-func (p *testTxPool) SubscribeTxPreEvent(ch chan<- core.TxPreEvent) event.Subscription {
+func (p *testTxPool) SubscribeNewTxsEvent(ch chan<- core.NewTxsEvent) event.Subscription {
 	return p.txFeed.Subscribe(ch)
 }
 
diff --git a/eth/peer.go b/eth/peer.go
index 42ead53965..953aca17b9 100644
--- a/eth/peer.go
+++ b/eth/peer.go
@@ -37,8 +37,24 @@ var (
 )
 
 const (
-	maxKnownTxs      = 32768 // Maximum transactions hashes to keep in the known list (prevent DOS)
-	maxKnownBlocks   = 1024  // Maximum block hashes to keep in the known list (prevent DOS)
+	maxKnownTxs    = 32768 // Maximum transactions hashes to keep in the known list (prevent DOS)
+	maxKnownBlocks = 1024  // Maximum block hashes to keep in the known list (prevent DOS)
+
+	// maxQueuedTxs is the maximum number of transaction lists to queue up before
+	// dropping broadcasts. This is a sensitive number as a transaction list might
+	// contain a single transaction, or thousands.
+	maxQueuedTxs = 128
+
+	// maxQueuedProps is the maximum number of block propagations to queue up before
+	// dropping broadcasts. There's not much point in queueing stale blocks, so a few
+	// that might cover uncles should be enough.
+	maxQueuedProps = 4
+
+	// maxQueuedAnns is the maximum number of block announcements to queue up before
+	// dropping broadcasts. Similarly to block propagations, there's no point to queue
+	// above some healthy uncle limit, so use that.
+	maxQueuedAnns = 4
+
 	handshakeTimeout = 5 * time.Second
 )
 
@@ -50,6 +66,12 @@ type PeerInfo struct {
 	Head       string   `json:"head"`       // SHA3 hash of the peer's best owned block
 }
 
+// propEvent is a block propagation, waiting for its turn in the broadcast queue.
+type propEvent struct {
+	block *types.Block
+	td    *big.Int
+}
+
 type peer struct {
 	id string
 
@@ -63,23 +85,64 @@ type peer struct {
 	td   *big.Int
 	lock sync.RWMutex
 
-	knownTxs    *set.Set // Set of transaction hashes known to be known by this peer
-	knownBlocks *set.Set // Set of block hashes known to be known by this peer
+	knownTxs    *set.Set                  // Set of transaction hashes known to be known by this peer
+	knownBlocks *set.Set                  // Set of block hashes known to be known by this peer
+	queuedTxs   chan []*types.Transaction // Queue of transactions to broadcast to the peer
+	queuedProps chan *propEvent           // Queue of blocks to broadcast to the peer
+	queuedAnns  chan *types.Block         // Queue of blocks to announce to the peer
+	term        chan struct{}             // Termination channel to stop the broadcaster
 }
 
 func newPeer(version int, p *p2p.Peer, rw p2p.MsgReadWriter) *peer {
-	id := p.ID()
-
 	return &peer{
 		Peer:        p,
 		rw:          rw,
 		version:     version,
-		id:          fmt.Sprintf("%x", id[:8]),
+		id:          fmt.Sprintf("%x", p.ID().Bytes()[:8]),
 		knownTxs:    set.New(),
 		knownBlocks: set.New(),
+		queuedTxs:   make(chan []*types.Transaction, maxQueuedTxs),
+		queuedProps: make(chan *propEvent, maxQueuedProps),
+		queuedAnns:  make(chan *types.Block, maxQueuedAnns),
+		term:        make(chan struct{}),
 	}
 }
 
+// broadcast is a write loop that multiplexes block propagations, announcements
+// and transaction broadcasts into the remote peer. The goal is to have an async
+// writer that does not lock up node internals.
+func (p *peer) broadcast() {
+	for {
+		select {
+		case txs := <-p.queuedTxs:
+			if err := p.SendTransactions(txs); err != nil {
+				return
+			}
+			p.Log().Trace("Broadcast transactions", "count", len(txs))
+
+		case prop := <-p.queuedProps:
+			if err := p.SendNewBlock(prop.block, prop.td); err != nil {
+				return
+			}
+			p.Log().Trace("Propagated block", "number", prop.block.Number(), "hash", prop.block.Hash(), "td", prop.td)
+
+		case block := <-p.queuedAnns:
+			if err := p.SendNewBlockHashes([]common.Hash{block.Hash()}, []uint64{block.NumberU64()}); err != nil {
+				return
+			}
+			p.Log().Trace("Announced block", "number", block.Number(), "hash", block.Hash())
+
+		case <-p.term:
+			return
+		}
+	}
+}
+
+// close signals the broadcast goroutine to terminate.
+func (p *peer) close() {
+	close(p.term)
+}
+
 // Info gathers and returns a collection of metadata known about a peer.
 func (p *peer) Info() *PeerInfo {
 	hash, td := p.Head()
@@ -139,6 +202,19 @@ func (p *peer) SendTransactions(txs types.Transactions) error {
 	return p2p.Send(p.rw, TxMsg, txs)
 }
 
+// AsyncSendTransactions queues list of transactions propagation to a remote
+// peer. If the peer's broadcast queue is full, the event is silently dropped.
+func (p *peer) AsyncSendTransactions(txs []*types.Transaction) {
+	select {
+	case p.queuedTxs <- txs:
+		for _, tx := range txs {
+			p.knownTxs.Add(tx.Hash())
+		}
+	default:
+		p.Log().Debug("Dropping transaction propagation", "count", len(txs))
+	}
+}
+
 // SendNewBlockHashes announces the availability of a number of blocks through
 // a hash notification.
 func (p *peer) SendNewBlockHashes(hashes []common.Hash, numbers []uint64) error {
@@ -153,12 +229,35 @@ func (p *peer) SendNewBlockHashes(hashes []common.Hash, numbers []uint64) error
 	return p2p.Send(p.rw, NewBlockHashesMsg, request)
 }
 
+// AsyncSendNewBlockHash queues the availability of a block for propagation to a
+// remote peer. If the peer's broadcast queue is full, the event is silently
+// dropped.
+func (p *peer) AsyncSendNewBlockHash(block *types.Block) {
+	select {
+	case p.queuedAnns <- block:
+		p.knownBlocks.Add(block.Hash())
+	default:
+		p.Log().Debug("Dropping block announcement", "number", block.NumberU64(), "hash", block.Hash())
+	}
+}
+
 // SendNewBlock propagates an entire block to a remote peer.
 func (p *peer) SendNewBlock(block *types.Block, td *big.Int) error {
 	p.knownBlocks.Add(block.Hash())
 	return p2p.Send(p.rw, NewBlockMsg, []interface{}{block, td})
 }
 
+// AsyncSendNewBlock queues an entire block for propagation to a remote peer. If
+// the peer's broadcast queue is full, the event is silently dropped.
+func (p *peer) AsyncSendNewBlock(block *types.Block, td *big.Int) {
+	select {
+	case p.queuedProps <- &propEvent{block: block, td: td}:
+		p.knownBlocks.Add(block.Hash())
+	default:
+		p.Log().Debug("Dropping block propagation", "number", block.NumberU64(), "hash", block.Hash())
+	}
+}
+
 // SendBlockHeaders sends a batch of block headers to the remote peer.
 func (p *peer) SendBlockHeaders(headers []*types.Header) error {
 	return p2p.Send(p.rw, BlockHeadersMsg, headers)
@@ -313,7 +412,8 @@ func newPeerSet() *peerSet {
 }
 
 // Register injects a new peer into the working set, or returns an error if the
-// peer is already known.
+// peer is already known. If a new peer it registered, its broadcast loop is also
+// started.
 func (ps *peerSet) Register(p *peer) error {
 	ps.lock.Lock()
 	defer ps.lock.Unlock()
@@ -325,6 +425,8 @@ func (ps *peerSet) Register(p *peer) error {
 		return errAlreadyRegistered
 	}
 	ps.peers[p.id] = p
+	go p.broadcast()
+
 	return nil
 }
 
@@ -334,10 +436,13 @@ func (ps *peerSet) Unregister(id string) error {
 	ps.lock.Lock()
 	defer ps.lock.Unlock()
 
-	if _, ok := ps.peers[id]; !ok {
+	p, ok := ps.peers[id]
+	if !ok {
 		return errNotRegistered
 	}
 	delete(ps.peers, id)
+	p.close()
+
 	return nil
 }
 
diff --git a/eth/protocol.go b/eth/protocol.go
index 328d5b9939..0e90e6a2ef 100644
--- a/eth/protocol.go
+++ b/eth/protocol.go
@@ -103,9 +103,9 @@ type txPool interface {
 	// The slice should be modifiable by the caller.
 	Pending() (map[common.Address]types.Transactions, error)
 
-	// SubscribeTxPreEvent should return an event subscription of
-	// TxPreEvent and send events to the given channel.
-	SubscribeTxPreEvent(chan<- core.TxPreEvent) event.Subscription
+	// SubscribeNewTxsEvent should return an event subscription of
+	// NewTxsEvent and send events to the given channel.
+	SubscribeNewTxsEvent(chan<- core.NewTxsEvent) event.Subscription
 }
 
 // statusData is the network packet for the status message.
diff --git a/eth/protocol_test.go b/eth/protocol_test.go
index b2f93d8dd1..aa43dfa920 100644
--- a/eth/protocol_test.go
+++ b/eth/protocol_test.go
@@ -116,7 +116,7 @@ func testRecvTransactions(t *testing.T, protocol int) {
 			t.Errorf("added wrong tx hash: got %v, want %v", added[0].Hash(), tx.Hash())
 		}
 	case <-time.After(2 * time.Second):
-		t.Errorf("no TxPreEvent received within 2 seconds")
+		t.Errorf("no NewTxsEvent received within 2 seconds")
 	}
 }
 
diff --git a/ethdb/database.go b/ethdb/database.go
index 001d8f0bb9..86dd210762 100644
--- a/ethdb/database.go
+++ b/ethdb/database.go
@@ -207,6 +207,7 @@ func (db *LDBDatabase) meter(refresh time.Duration) {
 		delaystats      [2]int64
 		lastWriteDelay  time.Time
 		lastWriteDelayN time.Time
+		lastWritePaused time.Time
 	)
 
 	// Iterate ad infinitum and collect the stats
@@ -267,8 +268,9 @@ func (db *LDBDatabase) meter(refresh time.Duration) {
 			delayN        int64
 			delayDuration string
 			duration      time.Duration
+			paused        bool
 		)
-		if n, err := fmt.Sscanf(writedelay, "DelayN:%d Delay:%s", &delayN, &delayDuration); n != 2 || err != nil {
+		if n, err := fmt.Sscanf(writedelay, "DelayN:%d Delay:%s Paused:%t", &delayN, &delayDuration, &paused); n != 3 || err != nil {
 			db.log.Error("Write delay statistic not found")
 			return
 		}
@@ -301,6 +303,14 @@ func (db *LDBDatabase) meter(refresh time.Duration) {
 				lastWriteDelay = time.Now()
 			}
 		}
+		// If a warning that db is performing compaction has been displayed, any subsequent
+		// warnings will be withheld for one minute not to overwhelm the user.
+		if paused && delayN-delaystats[0] == 0 && duration.Nanoseconds()-delaystats[1] == 0 &&
+			time.Now().After(lastWritePaused.Add(writeDelayWarningThrottler)) {
+			db.log.Warn("Database compacting, degraded performance")
+			lastWritePaused = time.Now()
+		}
+
 		delaystats[0], delaystats[1] = delayN, duration.Nanoseconds()
 
 		// Retrieve the database iostats.
diff --git a/ethstats/ethstats.go b/ethstats/ethstats.go
index a15d846150..c116014351 100644
--- a/ethstats/ethstats.go
+++ b/ethstats/ethstats.go
@@ -49,7 +49,7 @@ const (
 	// history request.
 	historyUpdateRange = 50
 
-	// txChanSize is the size of channel listening to TxPreEvent.
+	// txChanSize is the size of channel listening to NewTxsEvent.
 	// The number is referenced from the size of tx pool.
 	txChanSize = 4096
 	// chainHeadChanSize is the size of channel listening to ChainHeadEvent.
@@ -57,9 +57,9 @@ const (
 )
 
 type txPool interface {
-	// SubscribeTxPreEvent should return an event subscription of
-	// TxPreEvent and send events to the given channel.
-	SubscribeTxPreEvent(chan<- core.TxPreEvent) event.Subscription
+	// SubscribeNewTxsEvent should return an event subscription of
+	// NewTxsEvent and send events to the given channel.
+	SubscribeNewTxsEvent(chan<- core.NewTxsEvent) event.Subscription
 }
 
 type blockChain interface {
@@ -150,8 +150,8 @@ func (s *Service) loop() {
 	headSub := blockchain.SubscribeChainHeadEvent(chainHeadCh)
 	defer headSub.Unsubscribe()
 
-	txEventCh := make(chan core.TxPreEvent, txChanSize)
-	txSub := txpool.SubscribeTxPreEvent(txEventCh)
+	txEventCh := make(chan core.NewTxsEvent, txChanSize)
+	txSub := txpool.SubscribeNewTxsEvent(txEventCh)
 	defer txSub.Unsubscribe()
 
 	// Start a goroutine that exhausts the subsciptions to avoid events piling up
diff --git a/interfaces.go b/interfaces.go
index 1ae1eba48a..a8b48c93d7 100644
--- a/interfaces.go
+++ b/interfaces.go
@@ -144,7 +144,7 @@ type FilterQuery struct {
 	// {} or nil          matches any topic list
 	// {{A}}              matches topic A in first position
 	// {{}, {B}}          matches any topic in first position, B in second position
-	// {{A}}, {B}}        matches topic A in first position, B in second position
+	// {{A}, {B}}         matches topic A in first position, B in second position
 	// {{A, B}}, {C, D}}  matches topic (A OR B) in first position, (C OR D) in second position
 	Topics [][]common.Hash
 }
diff --git a/internal/ethapi/backend.go b/internal/ethapi/backend.go
index af95d7906f..c9ffe230c6 100644
--- a/internal/ethapi/backend.go
+++ b/internal/ethapi/backend.go
@@ -65,7 +65,7 @@ type Backend interface {
 	GetPoolNonce(ctx context.Context, addr common.Address) (uint64, error)
 	Stats() (pending int, queued int)
 	TxPoolContent() (map[common.Address]types.Transactions, map[common.Address]types.Transactions)
-	SubscribeTxPreEvent(chan<- core.TxPreEvent) event.Subscription
+	SubscribeNewTxsEvent(chan<- core.NewTxsEvent) event.Subscription
 
 	ChainConfig() *params.ChainConfig
 	CurrentBlock() *types.Block
diff --git a/les/api_backend.go b/les/api_backend.go
index 1d3c995134..dea33c4702 100644
--- a/les/api_backend.go
+++ b/les/api_backend.go
@@ -136,8 +136,8 @@ func (b *LesApiBackend) TxPoolContent() (map[common.Address]types.Transactions,
 	return b.eth.txPool.Content()
 }
 
-func (b *LesApiBackend) SubscribeTxPreEvent(ch chan<- core.TxPreEvent) event.Subscription {
-	return b.eth.txPool.SubscribeTxPreEvent(ch)
+func (b *LesApiBackend) SubscribeNewTxsEvent(ch chan<- core.NewTxsEvent) event.Subscription {
+	return b.eth.txPool.SubscribeNewTxsEvent(ch)
 }
 
 func (b *LesApiBackend) SubscribeChainEvent(ch chan<- core.ChainEvent) event.Subscription {
diff --git a/les/odr_requests.go b/les/odr_requests.go
index c7f06df94d..075fcd92ca 100644
--- a/les/odr_requests.go
+++ b/les/odr_requests.go
@@ -230,7 +230,7 @@ func (r *TrieRequest) Validate(db ethdb.Database, msg *Msg) error {
 		}
 		nodeSet := proofs[0].NodeSet()
 		// Verify the proof and store if checks out
-		if _, err, _ := trie.VerifyProof(r.Id.Root, r.Key, nodeSet); err != nil {
+		if _, _, err := trie.VerifyProof(r.Id.Root, r.Key, nodeSet); err != nil {
 			return fmt.Errorf("merkle proof verification failed: %v", err)
 		}
 		r.Proof = nodeSet
@@ -241,7 +241,7 @@ func (r *TrieRequest) Validate(db ethdb.Database, msg *Msg) error {
 		// Verify the proof and store if checks out
 		nodeSet := proofs.NodeSet()
 		reads := &readTraceDB{db: nodeSet}
-		if _, err, _ := trie.VerifyProof(r.Id.Root, r.Key, reads); err != nil {
+		if _, _, err := trie.VerifyProof(r.Id.Root, r.Key, reads); err != nil {
 			return fmt.Errorf("merkle proof verification failed: %v", err)
 		}
 		// check if all nodes have been read by VerifyProof
@@ -400,7 +400,7 @@ func (r *ChtRequest) Validate(db ethdb.Database, msg *Msg) error {
 		var encNumber [8]byte
 		binary.BigEndian.PutUint64(encNumber[:], r.BlockNum)
 
-		value, err, _ := trie.VerifyProof(r.ChtRoot, encNumber[:], light.NodeList(proof.Proof).NodeSet())
+		value, _, err := trie.VerifyProof(r.ChtRoot, encNumber[:], light.NodeList(proof.Proof).NodeSet())
 		if err != nil {
 			return err
 		}
@@ -435,7 +435,7 @@ func (r *ChtRequest) Validate(db ethdb.Database, msg *Msg) error {
 		binary.BigEndian.PutUint64(encNumber[:], r.BlockNum)
 
 		reads := &readTraceDB{db: nodeSet}
-		value, err, _ := trie.VerifyProof(r.ChtRoot, encNumber[:], reads)
+		value, _, err := trie.VerifyProof(r.ChtRoot, encNumber[:], reads)
 		if err != nil {
 			return fmt.Errorf("merkle proof verification failed: %v", err)
 		}
@@ -529,7 +529,7 @@ func (r *BloomRequest) Validate(db ethdb.Database, msg *Msg) error {
 
 	for i, idx := range r.SectionIdxList {
 		binary.BigEndian.PutUint64(encNumber[2:], idx)
-		value, err, _ := trie.VerifyProof(r.BloomTrieRoot, encNumber[:], reads)
+		value, _, err := trie.VerifyProof(r.BloomTrieRoot, encNumber[:], reads)
 		if err != nil {
 			return err
 		}
diff --git a/light/txpool.go b/light/txpool.go
index 94c8139cbd..1fabc3dc5a 100644
--- a/light/txpool.go
+++ b/light/txpool.go
@@ -321,9 +321,9 @@ func (pool *TxPool) Stop() {
 	log.Info("Transaction pool stopped")
 }
 
-// SubscribeTxPreEvent registers a subscription of core.TxPreEvent and
+// SubscribeNewTxsEvent registers a subscription of core.NewTxsEvent and
 // starts sending event to the given channel.
-func (pool *TxPool) SubscribeTxPreEvent(ch chan<- core.TxPreEvent) event.Subscription {
+func (pool *TxPool) SubscribeNewTxsEvent(ch chan<- core.NewTxsEvent) event.Subscription {
 	return pool.scope.Track(pool.txFeed.Subscribe(ch))
 }
 
@@ -412,7 +412,7 @@ func (self *TxPool) add(ctx context.Context, tx *types.Transaction) error {
 		// Notify the subscribers. This event is posted in a goroutine
 		// because it's possible that somewhere during the post "Remove transaction"
 		// gets called which will then wait for the global tx pool lock and deadlock.
-		go self.txFeed.Send(core.TxPreEvent{Tx: tx})
+		go self.txFeed.Send(core.NewTxsEvent{Txs: types.Transactions{tx}})
 	}
 
 	// Print a log message if low enough level is set
diff --git a/log/README.md b/log/README.md
index 0951b21cb5..b4476577b6 100644
--- a/log/README.md
+++ b/log/README.md
@@ -45,7 +45,7 @@ srvlog.SetHandler(log.MultiHandler(
     log.StreamHandler(os.Stderr, log.LogfmtFormat()),
     log.LvlFilterHandler(
         log.LvlError,
-        log.Must.FileHandler("errors.json", log.JsonFormat()))))
+        log.Must.FileHandler("errors.json", log.JSONFormat()))))
 ```
 
 Will result in output that looks like this:
diff --git a/log/doc.go b/log/doc.go
index 83ad8c54f6..bff2f4966a 100644
--- a/log/doc.go
+++ b/log/doc.go
@@ -86,7 +86,7 @@ from the rpc package in logfmt to standard out. The other prints records at Erro
 or above in JSON formatted output to the file /var/log/service.json
 
     handler := log.MultiHandler(
-        log.LvlFilterHandler(log.LvlError, log.Must.FileHandler("/var/log/service.json", log.JsonFormat())),
+        log.LvlFilterHandler(log.LvlError, log.Must.FileHandler("/var/log/service.json", log.JSONFormat())),
         log.MatchFilterHandler("pkg", "app/rpc" log.StdoutHandler())
     )
 
@@ -304,8 +304,8 @@ For all Handler functions which can return an error, there is a version of that
 function which will return no error but panics on failure. They are all available
 on the Must object. For example:
 
-    log.Must.FileHandler("/path", log.JsonFormat)
-    log.Must.NetHandler("tcp", ":1234", log.JsonFormat)
+    log.Must.FileHandler("/path", log.JSONFormat)
+    log.Must.NetHandler("tcp", ":1234", log.JSONFormat)
 
 Inspiration and Credit
 
diff --git a/log/format.go b/log/format.go
index 0b07abb2ac..fb1ea1a7b4 100644
--- a/log/format.go
+++ b/log/format.go
@@ -196,16 +196,16 @@ func logfmt(buf *bytes.Buffer, ctx []interface{}, color int, term bool) {
 	buf.WriteByte('\n')
 }
 
-// JsonFormat formats log records as JSON objects separated by newlines.
-// It is the equivalent of JsonFormatEx(false, true).
-func JsonFormat() Format {
-	return JsonFormatEx(false, true)
+// JSONFormat formats log records as JSON objects separated by newlines.
+// It is the equivalent of JSONFormatEx(false, true).
+func JSONFormat() Format {
+	return JSONFormatEx(false, true)
 }
 
-// JsonFormatEx formats log records as JSON objects. If pretty is true,
+// JSONFormatEx formats log records as JSON objects. If pretty is true,
 // records will be pretty-printed. If lineSeparated is true, records
 // will be logged with a new line between each record.
-func JsonFormatEx(pretty, lineSeparated bool) Format {
+func JSONFormatEx(pretty, lineSeparated bool) Format {
 	jsonMarshal := json.Marshal
 	if pretty {
 		jsonMarshal = func(v interface{}) ([]byte, error) {
@@ -225,7 +225,7 @@ func JsonFormatEx(pretty, lineSeparated bool) Format {
 			if !ok {
 				props[errorKey] = fmt.Sprintf("%+v is not a string key", r.Ctx[i])
 			}
-			props[k] = formatJsonValue(r.Ctx[i+1])
+			props[k] = formatJSONValue(r.Ctx[i+1])
 		}
 
 		b, err := jsonMarshal(props)
@@ -270,7 +270,7 @@ func formatShared(value interface{}) (result interface{}) {
 	}
 }
 
-func formatJsonValue(value interface{}) interface{} {
+func formatJSONValue(value interface{}) interface{} {
 	value = formatShared(value)
 	switch value.(type) {
 	case int, int8, int16, int32, int64, float32, float64, uint, uint8, uint16, uint32, uint64, string:
diff --git a/log/handler.go b/log/handler.go
index 41d5718ddb..3c99114dcb 100644
--- a/log/handler.go
+++ b/log/handler.go
@@ -11,8 +11,8 @@ import (
 	"github.com/go-stack/stack"
 )
 
+// Handler defines where and how log records are written.
 // A Logger prints its log records by writing to a Handler.
-// The Handler interface defines where and how log records are written.
 // Handlers are composable, providing you great flexibility in combining
 // them to achieve the logging structure that suits your applications.
 type Handler interface {
@@ -193,7 +193,7 @@ func LvlFilterHandler(maxLvl Lvl, h Handler) Handler {
 	}, h)
 }
 
-// A MultiHandler dispatches any write to each of its handlers.
+// MultiHandler dispatches any write to each of its handlers.
 // This is useful for writing different types of log information
 // to different locations. For example, to log to a file and
 // standard error:
@@ -212,7 +212,7 @@ func MultiHandler(hs ...Handler) Handler {
 	})
 }
 
-// A FailoverHandler writes all log records to the first handler
+// FailoverHandler writes all log records to the first handler
 // specified, but will failover and write to the second handler if
 // the first handler has failed, and so on for all handlers specified.
 // For example you might want to log to a network socket, but failover
@@ -220,7 +220,7 @@ func MultiHandler(hs ...Handler) Handler {
 // standard out if the file write fails:
 //
 //     log.FailoverHandler(
-//         log.Must.NetHandler("tcp", ":9090", log.JsonFormat()),
+//         log.Must.NetHandler("tcp", ":9090", log.JSONFormat()),
 //         log.Must.FileHandler("/var/log/app.log", log.LogfmtFormat()),
 //         log.StdoutHandler)
 //
@@ -336,7 +336,7 @@ func DiscardHandler() Handler {
 	})
 }
 
-// The Must object provides the following Handler creation functions
+// Must provides the following Handler creation functions
 // which instead of returning an error parameter only return a Handler
 // and panic on failure: FileHandler, NetHandler, SyslogHandler, SyslogNetHandler
 var Must muster
diff --git a/log/logger.go b/log/logger.go
index 15c83a9b25..a2fe6dc580 100644
--- a/log/logger.go
+++ b/log/logger.go
@@ -24,7 +24,7 @@ const (
 	LvlTrace
 )
 
-// Aligned returns a 5-character string containing the name of a Lvl.
+// AlignedString returns a 5-character string containing the name of a Lvl.
 func (l Lvl) AlignedString() string {
 	switch l {
 	case LvlTrace:
@@ -64,7 +64,7 @@ func (l Lvl) String() string {
 	}
 }
 
-// Returns the appropriate Lvl from a string name.
+// LvlFromString returns the appropriate Lvl from a string name.
 // Useful for parsing command line args and configuration files.
 func LvlFromString(lvlString string) (Lvl, error) {
 	switch lvlString {
@@ -95,6 +95,7 @@ type Record struct {
 	KeyNames RecordKeyNames
 }
 
+// RecordKeyNames gets stored in a Record when the write function is executed.
 type RecordKeyNames struct {
 	Time string
 	Msg  string
diff --git a/miner/worker.go b/miner/worker.go
index 48b0b27652..640e9032e7 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -42,7 +42,7 @@ const (
 	resultQueueSize  = 10
 	miningLogAtDepth = 5
 
-	// txChanSize is the size of channel listening to TxPreEvent.
+	// txChanSize is the size of channel listening to NewTxsEvent.
 	// The number is referenced from the size of tx pool.
 	txChanSize = 4096
 	// chainHeadChanSize is the size of channel listening to ChainHeadEvent.
@@ -71,6 +71,7 @@ type Work struct {
 	family    *set.Set       // family set (used for checking uncle invalidity)
 	uncles    *set.Set       // uncle set
 	tcount    int            // tx count in cycle
+	gasPool   *core.GasPool  // available gas used to pack transactions
 
 	Block *types.Block // the new block
 
@@ -95,8 +96,8 @@ type worker struct {
 
 	// update loop
 	mux          *event.TypeMux
-	txCh         chan core.TxPreEvent
-	txSub        event.Subscription
+	txsCh        chan core.NewTxsEvent
+	txsSub       event.Subscription
 	chainHeadCh  chan core.ChainHeadEvent
 	chainHeadSub event.Subscription
 	chainSideCh  chan core.ChainSideEvent
@@ -137,7 +138,7 @@ func newWorker(config *params.ChainConfig, engine consensus.Engine, coinbase com
 		engine:         engine,
 		eth:            eth,
 		mux:            mux,
-		txCh:           make(chan core.TxPreEvent, txChanSize),
+		txsCh:          make(chan core.NewTxsEvent, txChanSize),
 		chainHeadCh:    make(chan core.ChainHeadEvent, chainHeadChanSize),
 		chainSideCh:    make(chan core.ChainSideEvent, chainSideChanSize),
 		chainDb:        eth.ChainDb(),
@@ -149,8 +150,8 @@ func newWorker(config *params.ChainConfig, engine consensus.Engine, coinbase com
 		agents:         make(map[Agent]struct{}),
 		unconfirmed:    newUnconfirmedBlocks(eth.BlockChain(), miningLogAtDepth),
 	}
-	// Subscribe TxPreEvent for tx pool
-	worker.txSub = eth.TxPool().SubscribeTxPreEvent(worker.txCh)
+	// Subscribe NewTxsEvent for tx pool
+	worker.txsSub = eth.TxPool().SubscribeNewTxsEvent(worker.txsCh)
 	// Subscribe events for blockchain
 	worker.chainHeadSub = eth.BlockChain().SubscribeChainHeadEvent(worker.chainHeadCh)
 	worker.chainSideSub = eth.BlockChain().SubscribeChainSideEvent(worker.chainSideCh)
@@ -241,7 +242,7 @@ func (self *worker) unregister(agent Agent) {
 }
 
 func (self *worker) update() {
-	defer self.txSub.Unsubscribe()
+	defer self.txsSub.Unsubscribe()
 	defer self.chainHeadSub.Unsubscribe()
 	defer self.chainSideSub.Unsubscribe()
 
@@ -258,15 +259,21 @@ func (self *worker) update() {
 			self.possibleUncles[ev.Block.Hash()] = ev.Block
 			self.uncleMu.Unlock()
 
-		// Handle TxPreEvent
-		case ev := <-self.txCh:
-			// Apply transaction to the pending state if we're not mining
+		// Handle NewTxsEvent
+		case ev := <-self.txsCh:
+			// Apply transactions to the pending state if we're not mining.
+			//
+			// Note all transactions received may not be continuous with transactions
+			// already included in the current mining block. These transactions will
+			// be automatically eliminated.
 			if atomic.LoadInt32(&self.mining) == 0 {
 				self.currentMu.Lock()
-				acc, _ := types.Sender(self.current.signer, ev.Tx)
-				txs := map[common.Address]types.Transactions{acc: {ev.Tx}}
+				txs := make(map[common.Address]types.Transactions)
+				for _, tx := range ev.Txs {
+					acc, _ := types.Sender(self.current.signer, tx)
+					txs[acc] = append(txs[acc], tx)
+				}
 				txset := types.NewTransactionsByPriceAndNonce(self.current.signer, txs)
-
 				self.current.commitTransactions(self.mux, txset, self.chain, self.coinbase)
 				self.updateSnapshot()
 				self.currentMu.Unlock()
@@ -278,7 +285,7 @@ func (self *worker) update() {
 			}
 
 		// System stopped
-		case <-self.txSub.Err():
+		case <-self.txsSub.Err():
 			return
 		case <-self.chainHeadSub.Err():
 			return
@@ -522,14 +529,16 @@ func (self *worker) updateSnapshot() {
 }
 
 func (env *Work) commitTransactions(mux *event.TypeMux, txs *types.TransactionsByPriceAndNonce, bc *core.BlockChain, coinbase common.Address) {
-	gp := new(core.GasPool).AddGas(env.header.GasLimit)
+	if env.gasPool == nil {
+		env.gasPool = new(core.GasPool).AddGas(env.header.GasLimit)
+	}
 
 	var coalescedLogs []*types.Log
 
 	for {
 		// If we don't have enough gas for any further transactions then we're done
-		if gp.Gas() < params.TxGas {
-			log.Trace("Not enough gas for further transactions", "gp", gp)
+		if env.gasPool.Gas() < params.TxGas {
+			log.Trace("Not enough gas for further transactions", "have", env.gasPool, "want", params.TxGas)
 			break
 		}
 		// Retrieve the next transaction and abort if all done
@@ -553,7 +562,7 @@ func (env *Work) commitTransactions(mux *event.TypeMux, txs *types.TransactionsB
 		// Start executing the transaction
 		env.state.Prepare(tx.Hash(), common.Hash{}, env.tcount)
 
-		err, logs := env.commitTransaction(tx, bc, coinbase, gp)
+		err, logs := env.commitTransaction(tx, bc, coinbase, env.gasPool)
 		switch err {
 		case core.ErrGasLimitReached:
 			// Pop the current out-of-gas transaction without shifting in the next from the account
diff --git a/node/api.go b/node/api.go
index a3b8bc0bb5..da9da5bd72 100644
--- a/node/api.go
+++ b/node/api.go
@@ -217,7 +217,7 @@ func (api *PrivateAdminAPI) StartWS(host *string, port *int, allowedOrigins *str
 	return true, nil
 }
 
-// StopRPC terminates an already running websocket RPC API endpoint.
+// StopWS terminates an already running websocket RPC API endpoint.
 func (api *PrivateAdminAPI) StopWS() (bool, error) {
 	api.node.lock.Lock()
 	defer api.node.lock.Unlock()
diff --git a/node/doc.go b/node/doc.go
index d9688e0a12..41a88c19a1 100644
--- a/node/doc.go
+++ b/node/doc.go
@@ -59,7 +59,7 @@ using the same data directory will store this information in different subdirect
 the data directory.
 
 LevelDB databases are also stored within the instance subdirectory. If multiple node
-instances use the same data directory, openening the databases with identical names will
+instances use the same data directory, opening the databases with identical names will
 create one database for each instance.
 
 The account key store is shared among all node instances using the same data directory
@@ -84,7 +84,7 @@ directory. Mode instance A opens the database "db", node instance B opens the da
             static-nodes.json  -- devp2p static node list of instance B
             db/                -- LevelDB content for "db"
             db-2/              -- LevelDB content for "db-2"
-        B.ipc                  -- JSON-RPC UNIX domain socket endpoint of instance A
+        B.ipc                  -- JSON-RPC UNIX domain socket endpoint of instance B
         keystore/              -- account key store, used by both instances
 */
 package node
diff --git a/node/node_test.go b/node/node_test.go
index 2880efa619..e51900bd1e 100644
--- a/node/node_test.go
+++ b/node/node_test.go
@@ -507,8 +507,8 @@ func TestAPIGather(t *testing.T) {
 	}
 	// Register a batch of services with some configured APIs
 	calls := make(chan string, 1)
-	makeAPI := func(result string) *OneMethodApi {
-		return &OneMethodApi{fun: func() { calls <- result }}
+	makeAPI := func(result string) *OneMethodAPI {
+		return &OneMethodAPI{fun: func() { calls <- result }}
 	}
 	services := map[string]struct {
 		APIs  []rpc.API
diff --git a/node/utils_test.go b/node/utils_test.go
index 8eddce3ed7..9801b1ed45 100644
--- a/node/utils_test.go
+++ b/node/utils_test.go
@@ -121,12 +121,12 @@ func InstrumentedServiceMakerC(base ServiceConstructor) ServiceConstructor {
 	return InstrumentingWrapperMaker(base, reflect.TypeOf(InstrumentedServiceC{}))
 }
 
-// OneMethodApi is a single-method API handler to be returned by test services.
-type OneMethodApi struct {
+// OneMethodAPI is a single-method API handler to be returned by test services.
+type OneMethodAPI struct {
 	fun func()
 }
 
-func (api *OneMethodApi) TheOneMethod() {
+func (api *OneMethodAPI) TheOneMethod() {
 	if api.fun != nil {
 		api.fun()
 	}
diff --git a/p2p/discv5/metrics.go b/p2p/discv5/metrics.go
new file mode 100644
index 0000000000..cb11d7eacf
--- /dev/null
+++ b/p2p/discv5/metrics.go
@@ -0,0 +1,8 @@
+package discv5
+
+import "github.com/ethereum/go-ethereum/metrics"
+
+var (
+	ingressTrafficMeter = metrics.NewRegisteredMeter("discv5/InboundTraffic", nil)
+	egressTrafficMeter  = metrics.NewRegisteredMeter("discv5/OutboundTraffic", nil)
+)
diff --git a/p2p/discv5/udp.go b/p2p/discv5/udp.go
index 09e5f8b374..49e1cb811a 100644
--- a/p2p/discv5/udp.go
+++ b/p2p/discv5/udp.go
@@ -334,8 +334,10 @@ func (t *udp) sendPacket(toid NodeID, toaddr *net.UDPAddr, ptype byte, req inter
 		return hash, err
 	}
 	log.Trace(fmt.Sprintf(">>> %v to %x@%v", nodeEvent(ptype), toid[:8], toaddr))
-	if _, err = t.conn.WriteToUDP(packet, toaddr); err != nil {
+	if nbytes, err := t.conn.WriteToUDP(packet, toaddr); err != nil {
 		log.Trace(fmt.Sprint("UDP send failed:", err))
+	} else {
+		egressTrafficMeter.Mark(int64(nbytes))
 	}
 	//fmt.Println(err)
 	return hash, err
@@ -374,6 +376,7 @@ func (t *udp) readLoop() {
 	buf := make([]byte, 1280)
 	for {
 		nbytes, from, err := t.conn.ReadFromUDP(buf)
+		ingressTrafficMeter.Mark(int64(nbytes))
 		if netutil.IsTemporaryError(err) {
 			// Ignore temporary read errors.
 			log.Debug(fmt.Sprintf("Temporary read error: %v", err))
diff --git a/params/version.go b/params/version.go
index 1e8c43bf81..e38c23293a 100644
--- a/params/version.go
+++ b/params/version.go
@@ -21,10 +21,10 @@ import (
 )
 
 const (
-	VersionMajor = 1          // Major version component of the current release
-	VersionMinor = 8          // Minor version component of the current release
-	VersionPatch = 9          // Patch version component of the current release
-	VersionMeta  = "unstable" // Version metadata to append to the version string
+	VersionMajor = 1        // Major version component of the current release
+	VersionMinor = 8        // Minor version component of the current release
+	VersionPatch = 10       // Patch version component of the current release
+	VersionMeta  = "stable" // Version metadata to append to the version string
 )
 
 // Version holds the textual version string.
diff --git a/trie/encoding.go b/trie/encoding.go
index e96a786e40..221fa6d3aa 100644
--- a/trie/encoding.go
+++ b/trie/encoding.go
@@ -83,7 +83,7 @@ func hexToKeybytes(hex []byte) []byte {
 	if len(hex)&1 != 0 {
 		panic("can't convert hex key of odd length")
 	}
-	key := make([]byte, (len(hex)+1)/2)
+	key := make([]byte, len(hex)/2)
 	decodeNibbles(hex, key)
 	return key
 }
diff --git a/trie/hasher.go b/trie/hasher.go
index 2fc44787ac..ff61e70922 100644
--- a/trie/hasher.go
+++ b/trie/hasher.go
@@ -196,12 +196,12 @@ func (h *hasher) store(n node, db *Database, force bool) (node, error) {
 		if h.onleaf != nil {
 			switch n := n.(type) {
 			case *shortNode:
-				if child, ok := n.Val.(valueNode); ok {
+				if child, ok := n.Val.(valueNode); ok && child != nil {
 					h.onleaf(child, hash)
 				}
 			case *fullNode:
 				for i := 0; i < 16; i++ {
-					if child, ok := n.Children[i].(valueNode); ok {
+					if child, ok := n.Children[i].(valueNode); ok && child != nil {
 						h.onleaf(child, hash)
 					}
 				}
diff --git a/trie/iterator.go b/trie/iterator.go
index 3bae8e186b..00b890eb89 100644
--- a/trie/iterator.go
+++ b/trie/iterator.go
@@ -22,6 +22,7 @@ import (
 	"errors"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/rlp"
 )
 
 // Iterator is a key-value trie iterator that traverses a Trie.
@@ -55,31 +56,50 @@ func (it *Iterator) Next() bool {
 	return false
 }
 
+// Prove generates the Merkle proof for the leaf node the iterator is currently
+// positioned on.
+func (it *Iterator) Prove() [][]byte {
+	return it.nodeIt.LeafProof()
+}
+
 // NodeIterator is an iterator to traverse the trie pre-order.
 type NodeIterator interface {
 	// Next moves the iterator to the next node. If the parameter is false, any child
 	// nodes will be skipped.
 	Next(bool) bool
+
 	// Error returns the error status of the iterator.
 	Error() error
 
 	// Hash returns the hash of the current node.
 	Hash() common.Hash
+
 	// Parent returns the hash of the parent of the current node. The hash may be the one
 	// grandparent if the immediate parent is an internal node with no hash.
 	Parent() common.Hash
+
 	// Path returns the hex-encoded path to the current node.
 	// Callers must not retain references to the return value after calling Next.
 	// For leaf nodes, the last element of the path is the 'terminator symbol' 0x10.
 	Path() []byte
 
 	// Leaf returns true iff the current node is a leaf node.
-	// LeafBlob, LeafKey return the contents and key of the leaf node. These
-	// method panic if the iterator is not positioned at a leaf.
-	// Callers must not retain references to their return value after calling Next
 	Leaf() bool
-	LeafBlob() []byte
+
+	// LeafKey returns the key of the leaf. The method panics if the iterator is not
+	// positioned at a leaf. Callers must not retain references to the value after
+	// calling Next.
 	LeafKey() []byte
+
+	// LeafBlob returns the content of the leaf. The method panics if the iterator
+	// is not positioned at a leaf. Callers must not retain references to the value
+	// after calling Next.
+	LeafBlob() []byte
+
+	// LeafProof returns the Merkle proof of the leaf. The method panics if the
+	// iterator is not positioned at a leaf. Callers must not retain references
+	// to the value after calling Next.
+	LeafProof() [][]byte
 }
 
 // nodeIteratorState represents the iteration state at one particular node of the
@@ -99,8 +119,8 @@ type nodeIterator struct {
 	err   error                // Failure set in case of an internal error in the iterator
 }
 
-// iteratorEnd is stored in nodeIterator.err when iteration is done.
-var iteratorEnd = errors.New("end of iteration")
+// errIteratorEnd is stored in nodeIterator.err when iteration is done.
+var errIteratorEnd = errors.New("end of iteration")
 
 // seekError is stored in nodeIterator.err if the initial seek has failed.
 type seekError struct {
@@ -139,6 +159,15 @@ func (it *nodeIterator) Leaf() bool {
 	return hasTerm(it.path)
 }
 
+func (it *nodeIterator) LeafKey() []byte {
+	if len(it.stack) > 0 {
+		if _, ok := it.stack[len(it.stack)-1].node.(valueNode); ok {
+			return hexToKeybytes(it.path)
+		}
+	}
+	panic("not at leaf")
+}
+
 func (it *nodeIterator) LeafBlob() []byte {
 	if len(it.stack) > 0 {
 		if node, ok := it.stack[len(it.stack)-1].node.(valueNode); ok {
@@ -148,10 +177,22 @@ func (it *nodeIterator) LeafBlob() []byte {
 	panic("not at leaf")
 }
 
-func (it *nodeIterator) LeafKey() []byte {
+func (it *nodeIterator) LeafProof() [][]byte {
 	if len(it.stack) > 0 {
 		if _, ok := it.stack[len(it.stack)-1].node.(valueNode); ok {
-			return hexToKeybytes(it.path)
+			hasher := newHasher(0, 0, nil)
+			proofs := make([][]byte, 0, len(it.stack))
+
+			for i, item := range it.stack[:len(it.stack)-1] {
+				// Gather nodes that end up as hash nodes (or the root)
+				node, _, _ := hasher.hashChildren(item.node, nil)
+				hashed, _ := hasher.store(node, nil, false)
+				if _, ok := hashed.(hashNode); ok || i == 0 {
+					enc, _ := rlp.EncodeToBytes(node)
+					proofs = append(proofs, enc)
+				}
+			}
+			return proofs
 		}
 	}
 	panic("not at leaf")
@@ -162,7 +203,7 @@ func (it *nodeIterator) Path() []byte {
 }
 
 func (it *nodeIterator) Error() error {
-	if it.err == iteratorEnd {
+	if it.err == errIteratorEnd {
 		return nil
 	}
 	if seek, ok := it.err.(seekError); ok {
@@ -176,7 +217,7 @@ func (it *nodeIterator) Error() error {
 // sets the Error field to the encountered failure. If `descend` is false,
 // skips iterating over any subnodes of the current node.
 func (it *nodeIterator) Next(descend bool) bool {
-	if it.err == iteratorEnd {
+	if it.err == errIteratorEnd {
 		return false
 	}
 	if seek, ok := it.err.(seekError); ok {
@@ -201,8 +242,8 @@ func (it *nodeIterator) seek(prefix []byte) error {
 	// Move forward until we're just before the closest match to key.
 	for {
 		state, parentIndex, path, err := it.peek(bytes.HasPrefix(key, it.path))
-		if err == iteratorEnd {
-			return iteratorEnd
+		if err == errIteratorEnd {
+			return errIteratorEnd
 		} else if err != nil {
 			return seekError{prefix, err}
 		} else if bytes.Compare(path, key) >= 0 {
@@ -246,7 +287,7 @@ func (it *nodeIterator) peek(descend bool) (*nodeIteratorState, *int, []byte, er
 		// No more child nodes, move back up.
 		it.pop()
 	}
-	return nil, nil, nil, iteratorEnd
+	return nil, nil, nil, errIteratorEnd
 }
 
 func (st *nodeIteratorState) resolve(tr *Trie, path []byte) error {
@@ -361,12 +402,16 @@ func (it *differenceIterator) Leaf() bool {
 	return it.b.Leaf()
 }
 
+func (it *differenceIterator) LeafKey() []byte {
+	return it.b.LeafKey()
+}
+
 func (it *differenceIterator) LeafBlob() []byte {
 	return it.b.LeafBlob()
 }
 
-func (it *differenceIterator) LeafKey() []byte {
-	return it.b.LeafKey()
+func (it *differenceIterator) LeafProof() [][]byte {
+	return it.b.LeafProof()
 }
 
 func (it *differenceIterator) Path() []byte {
@@ -464,12 +509,16 @@ func (it *unionIterator) Leaf() bool {
 	return (*it.items)[0].Leaf()
 }
 
+func (it *unionIterator) LeafKey() []byte {
+	return (*it.items)[0].LeafKey()
+}
+
 func (it *unionIterator) LeafBlob() []byte {
 	return (*it.items)[0].LeafBlob()
 }
 
-func (it *unionIterator) LeafKey() []byte {
-	return (*it.items)[0].LeafKey()
+func (it *unionIterator) LeafProof() [][]byte {
+	return (*it.items)[0].LeafProof()
 }
 
 func (it *unionIterator) Path() []byte {
@@ -509,12 +558,10 @@ func (it *unionIterator) Next(descend bool) bool {
 			heap.Push(it.items, skipped)
 		}
 	}
-
 	if least.Next(descend) {
 		it.count++
 		heap.Push(it.items, least)
 	}
-
 	return len(*it.items) > 0
 }
 
diff --git a/trie/proof.go b/trie/proof.go
index 508e4a6cf4..6cb8f4d5f7 100644
--- a/trie/proof.go
+++ b/trie/proof.go
@@ -102,28 +102,28 @@ func (t *SecureTrie) Prove(key []byte, fromLevel uint, proofDb ethdb.Putter) err
 // VerifyProof checks merkle proofs. The given proof must contain the value for
 // key in a trie with the given root hash. VerifyProof returns an error if the
 // proof contains invalid trie nodes or the wrong value.
-func VerifyProof(rootHash common.Hash, key []byte, proofDb DatabaseReader) (value []byte, err error, nodes int) {
+func VerifyProof(rootHash common.Hash, key []byte, proofDb DatabaseReader) (value []byte, nodes int, err error) {
 	key = keybytesToHex(key)
 	wantHash := rootHash
 	for i := 0; ; i++ {
 		buf, _ := proofDb.Get(wantHash[:])
 		if buf == nil {
-			return nil, fmt.Errorf("proof node %d (hash %064x) missing", i, wantHash), i
+			return nil, i, fmt.Errorf("proof node %d (hash %064x) missing", i, wantHash)
 		}
 		n, err := decodeNode(wantHash[:], buf, 0)
 		if err != nil {
-			return nil, fmt.Errorf("bad proof node %d: %v", i, err), i
+			return nil, i, fmt.Errorf("bad proof node %d: %v", i, err)
 		}
 		keyrest, cld := get(n, key)
 		switch cld := cld.(type) {
 		case nil:
 			// The trie doesn't contain the key.
-			return nil, nil, i
+			return nil, i, nil
 		case hashNode:
 			key = keyrest
 			copy(wantHash[:], cld)
 		case valueNode:
-			return cld, nil, i + 1
+			return cld, i + 1, nil
 		}
 	}
 }
diff --git a/trie/proof_test.go b/trie/proof_test.go
index a3537787cc..996f874781 100644
--- a/trie/proof_test.go
+++ b/trie/proof_test.go
@@ -32,20 +32,46 @@ func init() {
 	mrand.Seed(time.Now().Unix())
 }
 
+// makeProvers creates Merkle trie provers based on different implementations to
+// test all variations.
+func makeProvers(trie *Trie) []func(key []byte) *ethdb.MemDatabase {
+	var provers []func(key []byte) *ethdb.MemDatabase
+
+	// Create a direct trie based Merkle prover
+	provers = append(provers, func(key []byte) *ethdb.MemDatabase {
+		proof := ethdb.NewMemDatabase()
+		trie.Prove(key, 0, proof)
+		return proof
+	})
+	// Create a leaf iterator based Merkle prover
+	provers = append(provers, func(key []byte) *ethdb.MemDatabase {
+		proof := ethdb.NewMemDatabase()
+		if it := NewIterator(trie.NodeIterator(key)); it.Next() && bytes.Equal(key, it.Key) {
+			for _, p := range it.Prove() {
+				proof.Put(crypto.Keccak256(p), p)
+			}
+		}
+		return proof
+	})
+	return provers
+}
+
 func TestProof(t *testing.T) {
 	trie, vals := randomTrie(500)
 	root := trie.Hash()
-	for _, kv := range vals {
-		proofs := ethdb.NewMemDatabase()
-		if trie.Prove(kv.k, 0, proofs) != nil {
-			t.Fatalf("missing key %x while constructing proof", kv.k)
-		}
-		val, err, _ := VerifyProof(root, kv.k, proofs)
-		if err != nil {
-			t.Fatalf("VerifyProof error for key %x: %v\nraw proof: %v", kv.k, err, proofs)
-		}
-		if !bytes.Equal(val, kv.v) {
-			t.Fatalf("VerifyProof returned wrong value for key %x: got %x, want %x", kv.k, val, kv.v)
+	for i, prover := range makeProvers(trie) {
+		for _, kv := range vals {
+			proof := prover(kv.k)
+			if proof == nil {
+				t.Fatalf("prover %d: missing key %x while constructing proof", i, kv.k)
+			}
+			val, _, err := VerifyProof(root, kv.k, proof)
+			if err != nil {
+				t.Fatalf("prover %d: failed to verify proof for key %x: %v\nraw proof: %x", i, kv.k, err, proof)
+			}
+			if !bytes.Equal(val, kv.v) {
+				t.Fatalf("prover %d: verified value mismatch for key %x: have %x, want %x", i, kv.k, val, kv.v)
+			}
 		}
 	}
 }
@@ -53,37 +79,66 @@ func TestProof(t *testing.T) {
 func TestOneElementProof(t *testing.T) {
 	trie := new(Trie)
 	updateString(trie, "k", "v")
-	proofs := ethdb.NewMemDatabase()
-	trie.Prove([]byte("k"), 0, proofs)
-	if len(proofs.Keys()) != 1 {
-		t.Error("proof should have one element")
-	}
-	val, err, _ := VerifyProof(trie.Hash(), []byte("k"), proofs)
-	if err != nil {
-		t.Fatalf("VerifyProof error: %v\nproof hashes: %v", err, proofs.Keys())
-	}
-	if !bytes.Equal(val, []byte("v")) {
-		t.Fatalf("VerifyProof returned wrong value: got %x, want 'k'", val)
+	for i, prover := range makeProvers(trie) {
+		proof := prover([]byte("k"))
+		if proof == nil {
+			t.Fatalf("prover %d: nil proof", i)
+		}
+		if proof.Len() != 1 {
+			t.Errorf("prover %d: proof should have one element", i)
+		}
+		val, _, err := VerifyProof(trie.Hash(), []byte("k"), proof)
+		if err != nil {
+			t.Fatalf("prover %d: failed to verify proof: %v\nraw proof: %x", i, err, proof)
+		}
+		if !bytes.Equal(val, []byte("v")) {
+			t.Fatalf("prover %d: verified value mismatch: have %x, want 'k'", i, val)
+		}
 	}
 }
 
-func TestVerifyBadProof(t *testing.T) {
+func TestBadProof(t *testing.T) {
 	trie, vals := randomTrie(800)
 	root := trie.Hash()
-	for _, kv := range vals {
-		proofs := ethdb.NewMemDatabase()
-		trie.Prove(kv.k, 0, proofs)
-		if len(proofs.Keys()) == 0 {
-			t.Fatal("zero length proof")
+	for i, prover := range makeProvers(trie) {
+		for _, kv := range vals {
+			proof := prover(kv.k)
+			if proof == nil {
+				t.Fatalf("prover %d: nil proof", i)
+			}
+			key := proof.Keys()[mrand.Intn(proof.Len())]
+			val, _ := proof.Get(key)
+			proof.Delete(key)
+
+			mutateByte(val)
+			proof.Put(crypto.Keccak256(val), val)
+
+			if _, _, err := VerifyProof(root, kv.k, proof); err == nil {
+				t.Fatalf("prover %d: expected proof to fail for key %x", i, kv.k)
+			}
 		}
-		keys := proofs.Keys()
-		key := keys[mrand.Intn(len(keys))]
-		node, _ := proofs.Get(key)
-		proofs.Delete(key)
-		mutateByte(node)
-		proofs.Put(crypto.Keccak256(node), node)
-		if _, err, _ := VerifyProof(root, kv.k, proofs); err == nil {
-			t.Fatalf("expected proof to fail for key %x", kv.k)
+	}
+}
+
+// Tests that missing keys can also be proven. The test explicitly uses a single
+// entry trie and checks for missing keys both before and after the single entry.
+func TestMissingKeyProof(t *testing.T) {
+	trie := new(Trie)
+	updateString(trie, "k", "v")
+
+	for i, key := range []string{"a", "j", "l", "z"} {
+		proof := ethdb.NewMemDatabase()
+		trie.Prove([]byte(key), 0, proof)
+
+		if proof.Len() != 1 {
+			t.Errorf("test %d: proof should have one element", i)
+		}
+		val, _, err := VerifyProof(trie.Hash(), []byte(key), proof)
+		if err != nil {
+			t.Fatalf("test %d: failed to verify proof: %v\nraw proof: %x", i, err, proof)
+		}
+		if val != nil {
+			t.Fatalf("test %d: verified value mismatch: have %x, want nil", i, val)
 		}
 	}
 }
@@ -131,7 +186,7 @@ func BenchmarkVerifyProof(b *testing.B) {
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
 		im := i % len(keys)
-		if _, err, _ := VerifyProof(root, []byte(keys[im]), proofs[im]); err != nil {
+		if _, _, err := VerifyProof(root, []byte(keys[im]), proofs[im]); err != nil {
 			b.Fatalf("key %x: %v", keys[im], err)
 		}
 	}
diff --git a/trie/secure_trie.go b/trie/secure_trie.go
index 3881ee18a0..6a50cfd5a6 100644
--- a/trie/secure_trie.go
+++ b/trie/secure_trie.go
@@ -155,14 +155,19 @@ func (t *SecureTrie) Commit(onleaf LeafCallback) (root common.Hash, err error) {
 	return t.trie.Commit(onleaf)
 }
 
+// Hash returns the root hash of SecureTrie. It does not write to the
+// database and can be used even if the trie doesn't have one.
 func (t *SecureTrie) Hash() common.Hash {
 	return t.trie.Hash()
 }
 
+// Root returns the root hash of SecureTrie.
+// Deprecated: use Hash instead.
 func (t *SecureTrie) Root() []byte {
 	return t.trie.Root()
 }
 
+// Copy returns a copy of SecureTrie.
 func (t *SecureTrie) Copy() *SecureTrie {
 	cpy := *t
 	return &cpy
diff --git a/trie/sync.go b/trie/sync.go
index 4ae975d042..ccec80c9e3 100644
--- a/trie/sync.go
+++ b/trie/sync.go
@@ -68,19 +68,19 @@ func newSyncMemBatch() *syncMemBatch {
 	}
 }
 
-// TrieSync is the main state trie synchronisation scheduler, which provides yet
+// Sync is the main state trie synchronisation scheduler, which provides yet
 // unknown trie hashes to retrieve, accepts node data associated with said hashes
 // and reconstructs the trie step by step until all is done.
-type TrieSync struct {
+type Sync struct {
 	database DatabaseReader           // Persistent database to check for existing entries
 	membatch *syncMemBatch            // Memory buffer to avoid frequest database writes
 	requests map[common.Hash]*request // Pending requests pertaining to a key hash
 	queue    *prque.Prque             // Priority queue with the pending requests
 }
 
-// NewTrieSync creates a new trie data download scheduler.
-func NewTrieSync(root common.Hash, database DatabaseReader, callback LeafCallback) *TrieSync {
-	ts := &TrieSync{
+// NewSync creates a new trie data download scheduler.
+func NewSync(root common.Hash, database DatabaseReader, callback LeafCallback) *Sync {
+	ts := &Sync{
 		database: database,
 		membatch: newSyncMemBatch(),
 		requests: make(map[common.Hash]*request),
@@ -91,7 +91,7 @@ func NewTrieSync(root common.Hash, database DatabaseReader, callback LeafCallbac
 }
 
 // AddSubTrie registers a new trie to the sync code, rooted at the designated parent.
-func (s *TrieSync) AddSubTrie(root common.Hash, depth int, parent common.Hash, callback LeafCallback) {
+func (s *Sync) AddSubTrie(root common.Hash, depth int, parent common.Hash, callback LeafCallback) {
 	// Short circuit if the trie is empty or already known
 	if root == emptyRoot {
 		return
@@ -126,7 +126,7 @@ func (s *TrieSync) AddSubTrie(root common.Hash, depth int, parent common.Hash, c
 // interpreted as a trie node, but rather accepted and stored into the database
 // as is. This method's goal is to support misc state metadata retrievals (e.g.
 // contract code).
-func (s *TrieSync) AddRawEntry(hash common.Hash, depth int, parent common.Hash) {
+func (s *Sync) AddRawEntry(hash common.Hash, depth int, parent common.Hash) {
 	// Short circuit if the entry is empty or already known
 	if hash == emptyState {
 		return
@@ -156,7 +156,7 @@ func (s *TrieSync) AddRawEntry(hash common.Hash, depth int, parent common.Hash)
 }
 
 // Missing retrieves the known missing nodes from the trie for retrieval.
-func (s *TrieSync) Missing(max int) []common.Hash {
+func (s *Sync) Missing(max int) []common.Hash {
 	requests := []common.Hash{}
 	for !s.queue.Empty() && (max == 0 || len(requests) < max) {
 		requests = append(requests, s.queue.PopItem().(common.Hash))
@@ -167,7 +167,7 @@ func (s *TrieSync) Missing(max int) []common.Hash {
 // Process injects a batch of retrieved trie nodes data, returning if something
 // was committed to the database and also the index of an entry if processing of
 // it failed.
-func (s *TrieSync) Process(results []SyncResult) (bool, int, error) {
+func (s *Sync) Process(results []SyncResult) (bool, int, error) {
 	committed := false
 
 	for i, item := range results {
@@ -213,7 +213,7 @@ func (s *TrieSync) Process(results []SyncResult) (bool, int, error) {
 
 // Commit flushes the data stored in the internal membatch out to persistent
 // storage, returning the number of items written and any occurred error.
-func (s *TrieSync) Commit(dbw ethdb.Putter) (int, error) {
+func (s *Sync) Commit(dbw ethdb.Putter) (int, error) {
 	// Dump the membatch into a database dbw
 	for i, key := range s.membatch.order {
 		if err := dbw.Put(key[:], s.membatch.batch[key]); err != nil {
@@ -228,14 +228,14 @@ func (s *TrieSync) Commit(dbw ethdb.Putter) (int, error) {
 }
 
 // Pending returns the number of state entries currently pending for download.
-func (s *TrieSync) Pending() int {
+func (s *Sync) Pending() int {
 	return len(s.requests)
 }
 
 // schedule inserts a new state retrieval request into the fetch queue. If there
 // is already a pending request for this node, the new request will be discarded
 // and only a parent reference added to the old one.
-func (s *TrieSync) schedule(req *request) {
+func (s *Sync) schedule(req *request) {
 	// If we're already requesting this node, add a new reference and stop
 	if old, ok := s.requests[req.hash]; ok {
 		old.parents = append(old.parents, req.parents...)
@@ -248,7 +248,7 @@ func (s *TrieSync) schedule(req *request) {
 
 // children retrieves all the missing children of a state trie entry for future
 // retrieval scheduling.
-func (s *TrieSync) children(req *request, object node) ([]*request, error) {
+func (s *Sync) children(req *request, object node) ([]*request, error) {
 	// Gather all the children of the node, irrelevant whether known or not
 	type child struct {
 		node  node
@@ -310,7 +310,7 @@ func (s *TrieSync) children(req *request, object node) ([]*request, error) {
 // commit finalizes a retrieval request and stores it into the membatch. If any
 // of the referencing parent requests complete due to this commit, they are also
 // committed themselves.
-func (s *TrieSync) commit(req *request) (err error) {
+func (s *Sync) commit(req *request) (err error) {
 	// Write the node content to the membatch
 	s.membatch.batch[req.hash] = req.data
 	s.membatch.order = append(s.membatch.order, req.hash)
diff --git a/trie/sync_test.go b/trie/sync_test.go
index 142a6f5b1a..c76779e5c7 100644
--- a/trie/sync_test.go
+++ b/trie/sync_test.go
@@ -87,14 +87,14 @@ func checkTrieConsistency(db *Database, root common.Hash) error {
 }
 
 // Tests that an empty trie is not scheduled for syncing.
-func TestEmptyTrieSync(t *testing.T) {
+func TestEmptySync(t *testing.T) {
 	dbA := NewDatabase(ethdb.NewMemDatabase())
 	dbB := NewDatabase(ethdb.NewMemDatabase())
 	emptyA, _ := New(common.Hash{}, dbA)
 	emptyB, _ := New(emptyRoot, dbB)
 
 	for i, trie := range []*Trie{emptyA, emptyB} {
-		if req := NewTrieSync(trie.Hash(), ethdb.NewMemDatabase(), nil).Missing(1); len(req) != 0 {
+		if req := NewSync(trie.Hash(), ethdb.NewMemDatabase(), nil).Missing(1); len(req) != 0 {
 			t.Errorf("test %d: content requested for empty trie: %v", i, req)
 		}
 	}
@@ -102,17 +102,17 @@ func TestEmptyTrieSync(t *testing.T) {
 
 // Tests that given a root hash, a trie can sync iteratively on a single thread,
 // requesting retrieval tasks and returning all of them in one go.
-func TestIterativeTrieSyncIndividual(t *testing.T) { testIterativeTrieSync(t, 1) }
-func TestIterativeTrieSyncBatched(t *testing.T)    { testIterativeTrieSync(t, 100) }
+func TestIterativeSyncIndividual(t *testing.T) { testIterativeSync(t, 1) }
+func TestIterativeSyncBatched(t *testing.T)    { testIterativeSync(t, 100) }
 
-func testIterativeTrieSync(t *testing.T, batch int) {
+func testIterativeSync(t *testing.T, batch int) {
 	// Create a random trie to copy
 	srcDb, srcTrie, srcData := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
-	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
+	sched := NewSync(srcTrie.Hash(), diskdb, nil)
 
 	queue := append([]common.Hash{}, sched.Missing(batch)...)
 	for len(queue) > 0 {
@@ -138,14 +138,14 @@ func testIterativeTrieSync(t *testing.T, batch int) {
 
 // Tests that the trie scheduler can correctly reconstruct the state even if only
 // partial results are returned, and the others sent only later.
-func TestIterativeDelayedTrieSync(t *testing.T) {
+func TestIterativeDelayedSync(t *testing.T) {
 	// Create a random trie to copy
 	srcDb, srcTrie, srcData := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
-	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
+	sched := NewSync(srcTrie.Hash(), diskdb, nil)
 
 	queue := append([]common.Hash{}, sched.Missing(10000)...)
 	for len(queue) > 0 {
@@ -173,17 +173,17 @@ func TestIterativeDelayedTrieSync(t *testing.T) {
 // Tests that given a root hash, a trie can sync iteratively on a single thread,
 // requesting retrieval tasks and returning all of them in one go, however in a
 // random order.
-func TestIterativeRandomTrieSyncIndividual(t *testing.T) { testIterativeRandomTrieSync(t, 1) }
-func TestIterativeRandomTrieSyncBatched(t *testing.T)    { testIterativeRandomTrieSync(t, 100) }
+func TestIterativeRandomSyncIndividual(t *testing.T) { testIterativeRandomSync(t, 1) }
+func TestIterativeRandomSyncBatched(t *testing.T)    { testIterativeRandomSync(t, 100) }
 
-func testIterativeRandomTrieSync(t *testing.T, batch int) {
+func testIterativeRandomSync(t *testing.T, batch int) {
 	// Create a random trie to copy
 	srcDb, srcTrie, srcData := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
-	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
+	sched := NewSync(srcTrie.Hash(), diskdb, nil)
 
 	queue := make(map[common.Hash]struct{})
 	for _, hash := range sched.Missing(batch) {
@@ -217,14 +217,14 @@ func testIterativeRandomTrieSync(t *testing.T, batch int) {
 
 // Tests that the trie scheduler can correctly reconstruct the state even if only
 // partial results are returned (Even those randomly), others sent only later.
-func TestIterativeRandomDelayedTrieSync(t *testing.T) {
+func TestIterativeRandomDelayedSync(t *testing.T) {
 	// Create a random trie to copy
 	srcDb, srcTrie, srcData := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
-	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
+	sched := NewSync(srcTrie.Hash(), diskdb, nil)
 
 	queue := make(map[common.Hash]struct{})
 	for _, hash := range sched.Missing(10000) {
@@ -264,14 +264,14 @@ func TestIterativeRandomDelayedTrieSync(t *testing.T) {
 
 // Tests that a trie sync will not request nodes multiple times, even if they
 // have such references.
-func TestDuplicateAvoidanceTrieSync(t *testing.T) {
+func TestDuplicateAvoidanceSync(t *testing.T) {
 	// Create a random trie to copy
 	srcDb, srcTrie, srcData := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
-	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
+	sched := NewSync(srcTrie.Hash(), diskdb, nil)
 
 	queue := append([]common.Hash{}, sched.Missing(0)...)
 	requested := make(map[common.Hash]struct{})
@@ -304,14 +304,14 @@ func TestDuplicateAvoidanceTrieSync(t *testing.T) {
 
 // Tests that at any point in time during a sync, only complete sub-tries are in
 // the database.
-func TestIncompleteTrieSync(t *testing.T) {
+func TestIncompleteSync(t *testing.T) {
 	// Create a random trie to copy
 	srcDb, srcTrie, _ := makeTestTrie()
 
 	// Create a destination trie and sync with the scheduler
 	diskdb := ethdb.NewMemDatabase()
 	triedb := NewDatabase(diskdb)
-	sched := NewTrieSync(srcTrie.Hash(), diskdb, nil)
+	sched := NewSync(srcTrie.Hash(), diskdb, nil)
 
 	added := []common.Hash{}
 	queue := append([]common.Hash{}, sched.Missing(1)...)
diff --git a/trie/trie.go b/trie/trie.go
index 31a404e3a0..30543c5496 100644
--- a/trie/trie.go
+++ b/trie/trie.go
@@ -101,7 +101,7 @@ func New(root common.Hash, db *Database) (*Trie, error) {
 		db:           db,
 		originalRoot: root,
 	}
-	if (root != common.Hash{}) && root != emptyRoot {
+	if root != (common.Hash{}) && root != emptyRoot {
 		rootnode, err := trie.resolveHash(root[:], nil)
 		if err != nil {
 			return nil, err
diff --git a/vendor/github.com/syndtr/goleveldb/leveldb/db.go b/vendor/github.com/syndtr/goleveldb/leveldb/db.go
index 3655418ad3..e7ac065418 100644
--- a/vendor/github.com/syndtr/goleveldb/leveldb/db.go
+++ b/vendor/github.com/syndtr/goleveldb/leveldb/db.go
@@ -35,6 +35,7 @@ type DB struct {
 	// Stats. Need 64-bit alignment.
 	cWriteDelay            int64 // The cumulative duration of write delays
 	cWriteDelayN           int32 // The cumulative number of write delays
+	inWritePaused          int32 // The indicator whether write operation is paused by compaction
 	aliveSnaps, aliveIters int32
 
 	// Session.
@@ -967,7 +968,8 @@ func (db *DB) GetProperty(name string) (value string, err error) {
 			float64(db.s.stor.writes())/1048576.0)
 	case p == "writedelay":
 		writeDelayN, writeDelay := atomic.LoadInt32(&db.cWriteDelayN), time.Duration(atomic.LoadInt64(&db.cWriteDelay))
-		value = fmt.Sprintf("DelayN:%d Delay:%s", writeDelayN, writeDelay)
+		paused := atomic.LoadInt32(&db.inWritePaused) == 1
+		value = fmt.Sprintf("DelayN:%d Delay:%s Paused:%t", writeDelayN, writeDelay, paused)
 	case p == "sstables":
 		for level, tables := range v.levels {
 			value += fmt.Sprintf("--- level %d ---\n", level)
@@ -996,6 +998,75 @@ func (db *DB) GetProperty(name string) (value string, err error) {
 	return
 }
 
+// DBStats is database statistics.
+type DBStats struct {
+	WriteDelayCount    int32
+	WriteDelayDuration time.Duration
+	WritePaused        bool
+
+	AliveSnapshots int32
+	AliveIterators int32
+
+	IOWrite uint64
+	IORead  uint64
+
+	BlockCacheSize    int
+	OpenedTablesCount int
+
+	LevelSizes        []int64
+	LevelTablesCounts []int
+	LevelRead         []int64
+	LevelWrite        []int64
+	LevelDurations    []time.Duration
+}
+
+// Stats populates s with database statistics.
+func (db *DB) Stats(s *DBStats) error {
+	err := db.ok()
+	if err != nil {
+		return err
+	}
+
+	s.IORead = db.s.stor.reads()
+	s.IOWrite = db.s.stor.writes()
+	s.WriteDelayCount = atomic.LoadInt32(&db.cWriteDelayN)
+	s.WriteDelayDuration = time.Duration(atomic.LoadInt64(&db.cWriteDelay))
+	s.WritePaused = atomic.LoadInt32(&db.inWritePaused) == 1
+
+	s.OpenedTablesCount = db.s.tops.cache.Size()
+	if db.s.tops.bcache != nil {
+		s.BlockCacheSize = db.s.tops.bcache.Size()
+	} else {
+		s.BlockCacheSize = 0
+	}
+
+	s.AliveIterators = atomic.LoadInt32(&db.aliveIters)
+	s.AliveSnapshots = atomic.LoadInt32(&db.aliveSnaps)
+
+	s.LevelDurations = s.LevelDurations[:0]
+	s.LevelRead = s.LevelRead[:0]
+	s.LevelWrite = s.LevelWrite[:0]
+	s.LevelSizes = s.LevelSizes[:0]
+	s.LevelTablesCounts = s.LevelTablesCounts[:0]
+
+	v := db.s.version()
+	defer v.release()
+
+	for level, tables := range v.levels {
+		duration, read, write := db.compStats.getStat(level)
+		if len(tables) == 0 && duration == 0 {
+			continue
+		}
+		s.LevelDurations = append(s.LevelDurations, duration)
+		s.LevelRead = append(s.LevelRead, read)
+		s.LevelWrite = append(s.LevelWrite, write)
+		s.LevelSizes = append(s.LevelSizes, tables.size())
+		s.LevelTablesCounts = append(s.LevelTablesCounts, len(tables))
+	}
+
+	return nil
+}
+
 // SizeOf calculates approximate sizes of the given key ranges.
 // The length of the returned sizes are equal with the length of the given
 // ranges. The returned sizes measure storage space usage, so if the user
diff --git a/vendor/github.com/syndtr/goleveldb/leveldb/db_write.go b/vendor/github.com/syndtr/goleveldb/leveldb/db_write.go
index 31f4bc5efc..db0c1bece1 100644
--- a/vendor/github.com/syndtr/goleveldb/leveldb/db_write.go
+++ b/vendor/github.com/syndtr/goleveldb/leveldb/db_write.go
@@ -89,7 +89,11 @@ func (db *DB) flush(n int) (mdb *memDB, mdbFree int, err error) {
 			return false
 		case tLen >= pauseTrigger:
 			delayed = true
+			// Set the write paused flag explicitly.
+			atomic.StoreInt32(&db.inWritePaused, 1)
 			err = db.compTriggerWait(db.tcompCmdC)
+			// Unset the write paused flag.
+			atomic.StoreInt32(&db.inWritePaused, 0)
 			if err != nil {
 				return false
 			}
diff --git a/vendor/vendor.json b/vendor/vendor.json
index fdc7789364..dc46b182a9 100644
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -418,10 +418,10 @@
 			"revisionTime": "2017-07-05T02:17:15Z"
 		},
 		{
-			"checksumSHA1": "k13cCuMJO7+KhR8ZXx5oUqDKGQA=",
+			"checksumSHA1": "TJV50D0q8E3vtc90ibC+qOYdjrw=",
 			"path": "github.com/syndtr/goleveldb/leveldb",
-			"revision": "ae970a0732be3a1f5311da86118d37b9f4bd2a5a",
-			"revisionTime": "2018-05-02T07:23:49Z"
+			"revision": "59047f74db0d042c8d8dd8e30bb030bc774a7d7a",
+			"revisionTime": "2018-05-21T04:45:49Z"
 		},
 		{
 			"checksumSHA1": "EKIow7XkgNdWvR/982ffIZxKG8Y=",
diff --git a/whisper/shhclient/client.go b/whisper/shhclient/client.go
index 8e7085a0a6..a814154e47 100644
--- a/whisper/shhclient/client.go
+++ b/whisper/shhclient/client.go
@@ -159,9 +159,9 @@ func (sc *Client) DeleteSymmetricKey(ctx context.Context, id string) error {
 }
 
 // Post a message onto the network.
-func (sc *Client) Post(ctx context.Context, message whisper.NewMessage) error {
-	var ignored bool
-	return sc.c.CallContext(ctx, &ignored, "shh_post", message)
+func (sc *Client) Post(ctx context.Context, message whisper.NewMessage) (string, error) {
+	var hash string
+	return hash, sc.c.CallContext(ctx, &hash, "shh_post", message)
 }
 
 // SubscribeMessages subscribes to messages that match the given criteria. This method