les, light: fix CHT trie retrievals (#16039)

* les, light: fix CHT trie retrievals

* les, light: minor polishes, test remote CHT retrievals

* les, light: deterministic nodeset rlp, bloombits test skeleton

* les: add an event emission to the les bloombits test

* les: drop dead tester code

10 files changed, 210 insertions, 119 deletions

diff --git a/les/handler.go b/les/handler.go
index 5c93133fb..864abe605 100644
--- a/les/handler.go
+++ b/les/handler.go
@@ -790,10 +790,9 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 				break
 			}
 		}
-		proofs := nodes.NodeList()
 		bv, rcost := p.fcClient.RequestProcessed(costs.baseCost + uint64(reqCnt)*costs.reqCost)
 		pm.server.fcCostStats.update(msg.Code, uint64(reqCnt), rcost)
-		return p.SendProofsV2(req.ReqID, bv, proofs)
+		return p.SendProofsV2(req.ReqID, bv, nodes.NodeList())
 
 	case ProofsV1Msg:
 		if pm.odr == nil {
@@ -856,15 +855,12 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 		if reject(uint64(reqCnt), MaxHelperTrieProofsFetch) {
 			return errResp(ErrRequestRejected, "")
 		}
+		trieDb := trie.NewDatabase(ethdb.NewTable(pm.chainDb, light.ChtTablePrefix))
 		for _, req := range req.Reqs {
 			if header := pm.blockchain.GetHeaderByNumber(req.BlockNum); header != nil {
-				sectionHead := core.GetCanonicalHash(pm.chainDb, req.ChtNum*light.ChtV1Frequency-1)
+				sectionHead := core.GetCanonicalHash(pm.chainDb, req.ChtNum*light.CHTFrequencyServer-1)
 				if root := light.GetChtRoot(pm.chainDb, req.ChtNum-1, sectionHead); root != (common.Hash{}) {
-					statedb, err := pm.blockchain.State()
-					if err != nil {
-						continue
-					}
-					trie, err := statedb.Database().OpenTrie(root)
+					trie, err := trie.New(root, trieDb)
 					if err != nil {
 						continue
 					}
@@ -878,7 +874,6 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 					if bytes += proof.DataSize() + estHeaderRlpSize; bytes >= softResponseLimit {
 						break
 					}
-
 				}
 			}
 		}
@@ -910,20 +905,16 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 			lastIdx  uint64
 			lastType uint
 			root     common.Hash
-			statedb  *state.StateDB
-			trie     state.Trie
+			auxTrie  *trie.Trie
 		)
-
 		nodes := light.NewNodeSet()
-
 		for _, req := range req.Reqs {
-			if trie == nil || req.HelperTrieType != lastType || req.TrieIdx != lastIdx {
-				statedb, trie, lastType, lastIdx = nil, nil, req.HelperTrieType, req.TrieIdx
+			if auxTrie == nil || req.Type != lastType || req.TrieIdx != lastIdx {
+				auxTrie, lastType, lastIdx = nil, req.Type, req.TrieIdx
 
-				if root, _ = pm.getHelperTrie(req.HelperTrieType, req.TrieIdx); root != (common.Hash{}) {
-					if statedb, _ = pm.blockchain.State(); statedb != nil {
-						trie, _ = statedb.Database().OpenTrie(root)
-					}
+				var prefix string
+				if root, prefix = pm.getHelperTrie(req.Type, req.TrieIdx); root != (common.Hash{}) {
+					auxTrie, _ = trie.New(root, trie.NewDatabase(ethdb.NewTable(pm.chainDb, prefix)))
 				}
 			}
 			if req.AuxReq == auxRoot {
@@ -934,8 +925,8 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 				auxData = append(auxData, data)
 				auxBytes += len(data)
 			} else {
-				if trie != nil {
-					trie.Prove(req.Key, req.FromLevel, nodes)
+				if auxTrie != nil {
+					auxTrie.Prove(req.Key, req.FromLevel, nodes)
 				}
 				if req.AuxReq != 0 {
 					data := pm.getHelperTrieAuxData(req)
@@ -947,10 +938,9 @@ func (pm *ProtocolManager) handleMsg(p *peer) error {
 				break
 			}
 		}
-		proofs := nodes.NodeList()
 		bv, rcost := p.fcClient.RequestProcessed(costs.baseCost + uint64(reqCnt)*costs.reqCost)
 		pm.server.fcCostStats.update(msg.Code, uint64(reqCnt), rcost)
-		return p.SendHelperTrieProofs(req.ReqID, bv, HelperTrieResps{Proofs: proofs, AuxData: auxData})
+		return p.SendHelperTrieProofs(req.ReqID, bv, HelperTrieResps{Proofs: nodes.NodeList(), AuxData: auxData})
 
 	case HeaderProofsMsg:
 		if pm.odr == nil {
@@ -1123,7 +1113,7 @@ func (pm *ProtocolManager) getAccount(statedb *state.StateDB, root, hash common.
 func (pm *ProtocolManager) getHelperTrie(id uint, idx uint64) (common.Hash, string) {
 	switch id {
 	case htCanonical:
-		sectionHead := core.GetCanonicalHash(pm.chainDb, (idx+1)*light.ChtFrequency-1)
+		sectionHead := core.GetCanonicalHash(pm.chainDb, (idx+1)*light.CHTFrequencyClient-1)
 		return light.GetChtV2Root(pm.chainDb, idx, sectionHead), light.ChtTablePrefix
 	case htBloomBits:
 		sectionHead := core.GetCanonicalHash(pm.chainDb, (idx+1)*light.BloomTrieFrequency-1)
@@ -1134,10 +1124,8 @@ func (pm *ProtocolManager) getHelperTrie(id uint, idx uint64) (common.Hash, stri
 
 // getHelperTrieAuxData returns requested auxiliary data for the given HelperTrie request
 func (pm *ProtocolManager) getHelperTrieAuxData(req HelperTrieReq) []byte {
-	if req.HelperTrieType == htCanonical && req.AuxReq == auxHeader {
-		if len(req.Key) != 8 {
-			return nil
-		}
+	switch {
+	case req.Type == htCanonical && req.AuxReq == auxHeader && len(req.Key) == 8:
 		blockNum := binary.BigEndian.Uint64(req.Key)
 		hash := core.GetCanonicalHash(pm.chainDb, blockNum)
 		return core.GetHeaderRLP(pm.chainDb, hash, blockNum)
diff --git a/les/handler_test.go b/les/handler_test.go
index e5446c031..9468032f6 100644
--- a/les/handler_test.go
+++ b/les/handler_test.go
@@ -17,7 +17,7 @@
 package les
 
 import (
-	"bytes"
+	"encoding/binary"
 	"math/big"
 	"math/rand"
 	"testing"
@@ -45,27 +45,8 @@ func expectResponse(r p2p.MsgReader, msgcode, reqID, bv uint64, data interface{}
 	return p2p.ExpectMsg(r, msgcode, resp{reqID, bv, data})
 }
 
-func testCheckProof(t *testing.T, exp *light.NodeSet, got light.NodeList) {
-	if exp.KeyCount() > len(got) {
-		t.Errorf("proof has fewer nodes than expected")
-		return
-	}
-	if exp.KeyCount() < len(got) {
-		t.Errorf("proof has more nodes than expected")
-		return
-	}
-	for _, node := range got {
-		n, _ := exp.Get(crypto.Keccak256(node))
-		if !bytes.Equal(n, node) {
-			t.Errorf("proof contents mismatch")
-			return
-		}
-	}
-}
-
 // Tests that block headers can be retrieved from a remote chain based on user queries.
 func TestGetBlockHeadersLes1(t *testing.T) { testGetBlockHeaders(t, 1) }
-
 func TestGetBlockHeadersLes2(t *testing.T) { testGetBlockHeaders(t, 2) }
 
 func testGetBlockHeaders(t *testing.T, protocol int) {
@@ -196,7 +177,6 @@ func testGetBlockHeaders(t *testing.T, protocol int) {
 
 // Tests that block contents can be retrieved from a remote chain based on their hashes.
 func TestGetBlockBodiesLes1(t *testing.T) { testGetBlockBodies(t, 1) }
-
 func TestGetBlockBodiesLes2(t *testing.T) { testGetBlockBodies(t, 2) }
 
 func testGetBlockBodies(t *testing.T, protocol int) {
@@ -274,7 +254,6 @@ func testGetBlockBodies(t *testing.T, protocol int) {
 
 // Tests that the contract codes can be retrieved based on account addresses.
 func TestGetCodeLes1(t *testing.T) { testGetCode(t, 1) }
-
 func TestGetCodeLes2(t *testing.T) { testGetCode(t, 2) }
 
 func testGetCode(t *testing.T, protocol int) {
@@ -309,7 +288,6 @@ func testGetCode(t *testing.T, protocol int) {
 
 // Tests that the transaction receipts can be retrieved based on hashes.
 func TestGetReceiptLes1(t *testing.T) { testGetReceipt(t, 1) }
-
 func TestGetReceiptLes2(t *testing.T) { testGetReceipt(t, 2) }
 
 func testGetReceipt(t *testing.T, protocol int) {
@@ -338,7 +316,6 @@ func testGetReceipt(t *testing.T, protocol int) {
 
 // Tests that trie merkle proofs can be retrieved
 func TestGetProofsLes1(t *testing.T) { testGetProofs(t, 1) }
-
 func TestGetProofsLes2(t *testing.T) { testGetProofs(t, 2) }
 
 func testGetProofs(t *testing.T, protocol int) {
@@ -389,27 +366,126 @@ func testGetProofs(t *testing.T, protocol int) {
 	case 2:
 		cost := peer.GetRequestCost(GetProofsV2Msg, len(proofreqs))
 		sendRequest(peer.app, GetProofsV2Msg, 42, cost, proofreqs)
-		msg, err := peer.app.ReadMsg()
-		if err != nil {
-			t.Errorf("Message read error: %v", err)
-		}
-		var resp struct {
-			ReqID, BV uint64
-			Data      light.NodeList
-		}
-		if err := msg.Decode(&resp); err != nil {
-			t.Errorf("reply decode error: %v", err)
+		if err := expectResponse(peer.app, ProofsV2Msg, 42, testBufLimit, proofsV2.NodeList()); err != nil {
+			t.Errorf("proofs mismatch: %v", err)
 		}
-		if msg.Code != ProofsV2Msg {
-			t.Errorf("Message code mismatch")
+	}
+}
+
+// Tests that CHT proofs can be correctly retrieved.
+func TestGetCHTProofsLes1(t *testing.T) { testGetCHTProofs(t, 1) }
+func TestGetCHTProofsLes2(t *testing.T) { testGetCHTProofs(t, 2) }
+
+func testGetCHTProofs(t *testing.T, protocol int) {
+	// Figure out the client's CHT frequency
+	frequency := uint64(light.CHTFrequencyClient)
+	if protocol == 1 {
+		frequency = uint64(light.CHTFrequencyServer)
+	}
+	// Assemble the test environment
+	db, _ := ethdb.NewMemDatabase()
+	pm := newTestProtocolManagerMust(t, false, int(frequency)+light.HelperTrieProcessConfirmations, testChainGen, nil, nil, db)
+	bc := pm.blockchain.(*core.BlockChain)
+	peer, _ := newTestPeer(t, "peer", protocol, pm, true)
+	defer peer.close()
+
+	// Wait a while for the CHT indexer to process the new headers
+	time.Sleep(100 * time.Millisecond * time.Duration(frequency/light.CHTFrequencyServer)) // Chain indexer throttling
+	time.Sleep(250 * time.Millisecond)                                                     // CI tester slack
+
+	// Assemble the proofs from the different protocols
+	header := bc.GetHeaderByNumber(frequency)
+	rlp, _ := rlp.EncodeToBytes(header)
+
+	key := make([]byte, 8)
+	binary.BigEndian.PutUint64(key, frequency)
+
+	proofsV1 := []ChtResp{{
+		Header: header,
+	}}
+	proofsV2 := HelperTrieResps{
+		AuxData: [][]byte{rlp},
+	}
+	switch protocol {
+	case 1:
+		root := light.GetChtRoot(db, 0, bc.GetHeaderByNumber(frequency-1).Hash())
+		trie, _ := trie.New(root, trie.NewDatabase(ethdb.NewTable(db, light.ChtTablePrefix)))
+
+		var proof light.NodeList
+		trie.Prove(key, 0, &proof)
+		proofsV1[0].Proof = proof
+
+	case 2:
+		root := light.GetChtV2Root(db, 0, bc.GetHeaderByNumber(frequency-1).Hash())
+		trie, _ := trie.New(root, trie.NewDatabase(ethdb.NewTable(db, light.ChtTablePrefix)))
+		trie.Prove(key, 0, &proofsV2.Proofs)
+	}
+	// Assemble the requests for the different protocols
+	requestsV1 := []ChtReq{{
+		ChtNum:   1,
+		BlockNum: frequency,
+	}}
+	requestsV2 := []HelperTrieReq{{
+		Type:    htCanonical,
+		TrieIdx: 0,
+		Key:     key,
+		AuxReq:  auxHeader,
+	}}
+	// Send the proof request and verify the response
+	switch protocol {
+	case 1:
+		cost := peer.GetRequestCost(GetHeaderProofsMsg, len(requestsV1))
+		sendRequest(peer.app, GetHeaderProofsMsg, 42, cost, requestsV1)
+		if err := expectResponse(peer.app, HeaderProofsMsg, 42, testBufLimit, proofsV1); err != nil {
+			t.Errorf("proofs mismatch: %v", err)
 		}
-		if resp.ReqID != 42 {
-			t.Errorf("ReqID mismatch")
+	case 2:
+		cost := peer.GetRequestCost(GetHelperTrieProofsMsg, len(requestsV2))
+		sendRequest(peer.app, GetHelperTrieProofsMsg, 42, cost, requestsV2)
+		if err := expectResponse(peer.app, HelperTrieProofsMsg, 42, testBufLimit, proofsV2); err != nil {
+			t.Errorf("proofs mismatch: %v", err)
 		}
-		if resp.BV != testBufLimit {
-			t.Errorf("BV mismatch")
+	}
+}
+
+// Tests that bloombits proofs can be correctly retrieved.
+func TestGetBloombitsProofs(t *testing.T) {
+	// Assemble the test environment
+	db, _ := ethdb.NewMemDatabase()
+	pm := newTestProtocolManagerMust(t, false, light.BloomTrieFrequency+256, testChainGen, nil, nil, db)
+	bc := pm.blockchain.(*core.BlockChain)
+	peer, _ := newTestPeer(t, "peer", 2, pm, true)
+	defer peer.close()
+
+	// Wait a while for the bloombits indexer to process the new headers
+	time.Sleep(100 * time.Millisecond * time.Duration(light.BloomTrieFrequency/4096)) // Chain indexer throttling
+	time.Sleep(250 * time.Millisecond)                                                // CI tester slack
+
+	// Request and verify each bit of the bloom bits proofs
+	for bit := 0; bit < 2048; bit++ {
+		// Assemble therequest and proofs for the bloombits
+		key := make([]byte, 10)
+
+		binary.BigEndian.PutUint16(key[:2], uint16(bit))
+		binary.BigEndian.PutUint64(key[2:], uint64(light.BloomTrieFrequency))
+
+		requests := []HelperTrieReq{{
+			Type:    htBloomBits,
+			TrieIdx: 0,
+			Key:     key,
+		}}
+		var proofs HelperTrieResps
+
+		root := light.GetBloomTrieRoot(db, 0, bc.GetHeaderByNumber(light.BloomTrieFrequency-1).Hash())
+		trie, _ := trie.New(root, trie.NewDatabase(ethdb.NewTable(db, light.BloomTrieTablePrefix)))
+		trie.Prove(key, 0, &proofs.Proofs)
+
+		// Send the proof request and verify the response
+		cost := peer.GetRequestCost(GetHelperTrieProofsMsg, len(requests))
+		sendRequest(peer.app, GetHelperTrieProofsMsg, 42, cost, requests)
+		if err := expectResponse(peer.app, HelperTrieProofsMsg, 42, testBufLimit, proofs); err != nil {
+			t.Errorf("bit %d: proofs mismatch: %v", bit, err)
 		}
-		testCheckProof(t, proofsV2, resp.Data)
 	}
 }
 
diff --git a/les/helper_test.go b/les/helper_test.go
index bf08e1e2f..6d997a1a3 100644
--- a/les/helper_test.go
+++ b/les/helper_test.go
@@ -31,6 +31,7 @@ import (
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/eth"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/les/flowcontrol"
@@ -55,6 +56,9 @@ var (
 	testContractCodeDeployed = testContractCode[16:]
 	testContractDeployed     = uint64(2)
 
+	testEventEmitterCode = common.Hex2Bytes("60606040523415600e57600080fd5b7f57050ab73f6b9ebdd9f76b8d4997793f48cf956e965ee070551b9ca0bb71584e60405160405180910390a160358060476000396000f3006060604052600080fd00a165627a7a723058203f727efcad8b5811f8cb1fc2620ce5e8c63570d697aef968172de296ea3994140029")
+	testEventEmitterAddr common.Address
+
 	testBufLimit = uint64(100)
 )
 
@@ -85,15 +89,19 @@ func testChainGen(i int, block *core.BlockGen) {
 		// In block 2, the test bank sends some more ether to account #1.
 		// acc1Addr passes it on to account #2.
 		// acc1Addr creates a test contract.
-		tx1, _ := types.SignTx(types.NewTransaction(block.TxNonce(testBankAddress), acc1Addr, big.NewInt(1000), params.TxGas, nil, nil), signer, testBankKey)
+		// acc1Addr creates a test event.
 		nonce := block.TxNonce(acc1Addr)
+
+		tx1, _ := types.SignTx(types.NewTransaction(block.TxNonce(testBankAddress), acc1Addr, big.NewInt(1000), params.TxGas, nil, nil), signer, testBankKey)
 		tx2, _ := types.SignTx(types.NewTransaction(nonce, acc2Addr, big.NewInt(1000), params.TxGas, nil, nil), signer, acc1Key)
-		nonce++
-		tx3, _ := types.SignTx(types.NewContractCreation(nonce, big.NewInt(0), 200000, big.NewInt(0), testContractCode), signer, acc1Key)
-		testContractAddr = crypto.CreateAddress(acc1Addr, nonce)
+		tx3, _ := types.SignTx(types.NewContractCreation(nonce+1, big.NewInt(0), 200000, big.NewInt(0), testContractCode), signer, acc1Key)
+		testContractAddr = crypto.CreateAddress(acc1Addr, nonce+1)
+		tx4, _ := types.SignTx(types.NewContractCreation(nonce+2, big.NewInt(0), 200000, big.NewInt(0), testEventEmitterCode), signer, acc1Key)
+		testEventEmitterAddr = crypto.CreateAddress(acc1Addr, nonce+2)
 		block.AddTx(tx1)
 		block.AddTx(tx2)
 		block.AddTx(tx3)
+		block.AddTx(tx4)
 	case 2:
 		// Block 3 is empty but was mined by account #2.
 		block.SetCoinbase(acc2Addr)
@@ -147,6 +155,16 @@ func newTestProtocolManager(lightSync bool, blocks int, generator func(int, *cor
 		chain, _ = light.NewLightChain(odr, gspec.Config, engine)
 	} else {
 		blockchain, _ := core.NewBlockChain(db, nil, gspec.Config, engine, vm.Config{})
+
+		chtIndexer := light.NewChtIndexer(db, false)
+		chtIndexer.Start(blockchain)
+
+		bbtIndexer := light.NewBloomTrieIndexer(db, false)
+
+		bloomIndexer := eth.NewBloomIndexer(db, params.BloomBitsBlocks)
+		bloomIndexer.AddChildIndexer(bbtIndexer)
+		bloomIndexer.Start(blockchain)
+
 		gchain, _ := core.GenerateChain(gspec.Config, genesis, ethash.NewFaker(), db, blocks, generator)
 		if _, err := blockchain.InsertChain(gchain); err != nil {
 			panic(err)
diff --git a/les/odr_requests.go b/les/odr_requests.go
index 937a4f1d9..34d759dd2 100644
--- a/les/odr_requests.go
+++ b/les/odr_requests.go
@@ -321,7 +321,7 @@ const (
 )
 
 type HelperTrieReq struct {
-	HelperTrieType    uint
+	Type              uint
 	TrieIdx           uint64
 	Key               []byte
 	FromLevel, AuxReq uint
@@ -365,7 +365,7 @@ func (r *ChtRequest) CanSend(peer *peer) bool {
 	peer.lock.RLock()
 	defer peer.lock.RUnlock()
 
-	return peer.headInfo.Number >= light.HelperTrieConfirmations && r.ChtNum <= (peer.headInfo.Number-light.HelperTrieConfirmations)/light.ChtFrequency
+	return peer.headInfo.Number >= light.HelperTrieConfirmations && r.ChtNum <= (peer.headInfo.Number-light.HelperTrieConfirmations)/light.CHTFrequencyClient
 }
 
 // Request sends an ODR request to the LES network (implementation of LesOdrRequest)
@@ -374,10 +374,10 @@ func (r *ChtRequest) Request(reqID uint64, peer *peer) error {
 	var encNum [8]byte
 	binary.BigEndian.PutUint64(encNum[:], r.BlockNum)
 	req := HelperTrieReq{
-		HelperTrieType: htCanonical,
-		TrieIdx:        r.ChtNum,
-		Key:            encNum[:],
-		AuxReq:         auxHeader,
+		Type:    htCanonical,
+		TrieIdx: r.ChtNum,
+		Key:     encNum[:],
+		AuxReq:  auxHeader,
 	}
 	return peer.RequestHelperTrieProofs(reqID, r.GetCost(peer), []HelperTrieReq{req})
 }
@@ -493,14 +493,14 @@ func (r *BloomRequest) Request(reqID uint64, peer *peer) error {
 	reqs := make([]HelperTrieReq, len(r.SectionIdxList))
 
 	var encNumber [10]byte
-	binary.BigEndian.PutUint16(encNumber[0:2], uint16(r.BitIdx))
+	binary.BigEndian.PutUint16(encNumber[:2], uint16(r.BitIdx))
 
 	for i, sectionIdx := range r.SectionIdxList {
-		binary.BigEndian.PutUint64(encNumber[2:10], sectionIdx)
+		binary.BigEndian.PutUint64(encNumber[2:], sectionIdx)
 		reqs[i] = HelperTrieReq{
-			HelperTrieType: htBloomBits,
-			TrieIdx:        r.BloomTrieNum,
-			Key:            common.CopyBytes(encNumber[:]),
+			Type:    htBloomBits,
+			TrieIdx: r.BloomTrieNum,
+			Key:     common.CopyBytes(encNumber[:]),
 		}
 	}
 	return peer.RequestHelperTrieProofs(reqID, r.GetCost(peer), reqs)
@@ -525,10 +525,10 @@ func (r *BloomRequest) Validate(db ethdb.Database, msg *Msg) error {
 
 	// Verify the proofs
 	var encNumber [10]byte
-	binary.BigEndian.PutUint16(encNumber[0:2], uint16(r.BitIdx))
+	binary.BigEndian.PutUint16(encNumber[:2], uint16(r.BitIdx))
 
 	for i, idx := range r.SectionIdxList {
-		binary.BigEndian.PutUint64(encNumber[2:10], idx)
+		binary.BigEndian.PutUint64(encNumber[2:], idx)
 		value, err, _ := trie.VerifyProof(r.BloomTrieRoot, encNumber[:], reads)
 		if err != nil {
 			return err
diff --git a/les/peer.go b/les/peer.go
index b72c80d35..caf568077 100644
--- a/les/peer.go
+++ b/les/peer.go
@@ -281,7 +281,6 @@ func (p *peer) RequestProofs(reqID, cost uint64, reqs []ProofReq) error {
 	default:
 		panic(nil)
 	}
-
 }
 
 // RequestHelperTrieProofs fetches a batch of HelperTrie merkle proofs from a remote node.
@@ -291,12 +290,12 @@ func (p *peer) RequestHelperTrieProofs(reqID, cost uint64, reqs []HelperTrieReq)
 	case lpv1:
 		reqsV1 := make([]ChtReq, len(reqs))
 		for i, req := range reqs {
-			if req.HelperTrieType != htCanonical || req.AuxReq != auxHeader || len(req.Key) != 8 {
+			if req.Type != htCanonical || req.AuxReq != auxHeader || len(req.Key) != 8 {
 				return fmt.Errorf("Request invalid in LES/1 mode")
 			}
 			blockNum := binary.BigEndian.Uint64(req.Key)
 			// convert HelperTrie request to old CHT request
-			reqsV1[i] = ChtReq{ChtNum: (req.TrieIdx + 1) * (light.ChtFrequency / light.ChtV1Frequency), BlockNum: blockNum, FromLevel: req.FromLevel}
+			reqsV1[i] = ChtReq{ChtNum: (req.TrieIdx + 1) * (light.CHTFrequencyClient / light.CHTFrequencyServer), BlockNum: blockNum, FromLevel: req.FromLevel}
 		}
 		return sendRequest(p.rw, GetHeaderProofsMsg, reqID, cost, reqsV1)
 	case lpv2:
diff --git a/les/server.go b/les/server.go
index 65b8c357d..28b87008a 100644
--- a/les/server.go
+++ b/les/server.go
@@ -20,7 +20,6 @@ package les
 import (
 	"crypto/ecdsa"
 	"encoding/binary"
-	"fmt"
 	"math"
 	"sync"
 
@@ -73,23 +72,22 @@ func NewLesServer(eth *eth.Ethereum, config *eth.Config) (*LesServer, error) {
 	logger := log.New()
 
 	chtV1SectionCount, _, _ := srv.chtIndexer.Sections() // indexer still uses LES/1 4k section size for backwards server compatibility
-	chtV2SectionCount := chtV1SectionCount / (light.ChtFrequency / light.ChtV1Frequency)
+	chtV2SectionCount := chtV1SectionCount / (light.CHTFrequencyClient / light.CHTFrequencyServer)
 	if chtV2SectionCount != 0 {
 		// convert to LES/2 section
 		chtLastSection := chtV2SectionCount - 1
 		// convert last LES/2 section index back to LES/1 index for chtIndexer.SectionHead
-		chtLastSectionV1 := (chtLastSection+1)*(light.ChtFrequency/light.ChtV1Frequency) - 1
+		chtLastSectionV1 := (chtLastSection+1)*(light.CHTFrequencyClient/light.CHTFrequencyServer) - 1
 		chtSectionHead := srv.chtIndexer.SectionHead(chtLastSectionV1)
 		chtRoot := light.GetChtV2Root(pm.chainDb, chtLastSection, chtSectionHead)
-		logger.Info("CHT", "section", chtLastSection, "sectionHead", fmt.Sprintf("%064x", chtSectionHead), "root", fmt.Sprintf("%064x", chtRoot))
+		logger.Info("Loaded CHT", "section", chtLastSection, "head", chtSectionHead, "root", chtRoot)
 	}
-
 	bloomTrieSectionCount, _, _ := srv.bloomTrieIndexer.Sections()
 	if bloomTrieSectionCount != 0 {
 		bloomTrieLastSection := bloomTrieSectionCount - 1
 		bloomTrieSectionHead := srv.bloomTrieIndexer.SectionHead(bloomTrieLastSection)
 		bloomTrieRoot := light.GetBloomTrieRoot(pm.chainDb, bloomTrieLastSection, bloomTrieSectionHead)
-		logger.Info("BloomTrie", "section", bloomTrieLastSection, "sectionHead", fmt.Sprintf("%064x", bloomTrieSectionHead), "root", fmt.Sprintf("%064x", bloomTrieRoot))
+		logger.Info("Loaded bloom trie", "section", bloomTrieLastSection, "head", bloomTrieSectionHead, "root", bloomTrieRoot)
 	}
 
 	srv.chtIndexer.Start(eth.BlockChain())
diff --git a/light/lightchain.go b/light/lightchain.go
index bc88aeb48..181a1c2a6 100644
--- a/light/lightchain.go
+++ b/light/lightchain.go
@@ -127,7 +127,7 @@ func (self *LightChain) addTrustedCheckpoint(cp trustedCheckpoint) {
 	if self.odr.BloomIndexer() != nil {
 		self.odr.BloomIndexer().AddKnownSectionHead(cp.sectionIdx, cp.sectionHead)
 	}
-	log.Info("Added trusted checkpoint", "chain", cp.name, "block", (cp.sectionIdx+1)*ChtFrequency-1, "hash", cp.sectionHead)
+	log.Info("Added trusted checkpoint", "chain", cp.name, "block", (cp.sectionIdx+1)*CHTFrequencyClient-1, "hash", cp.sectionHead)
 }
 
 func (self *LightChain) getProcInterrupt() bool {
@@ -453,8 +453,8 @@ func (self *LightChain) SyncCht(ctx context.Context) bool {
 	}
 	headNum := self.CurrentHeader().Number.Uint64()
 	chtCount, _, _ := self.odr.ChtIndexer().Sections()
-	if headNum+1 < chtCount*ChtFrequency {
-		num := chtCount*ChtFrequency - 1
+	if headNum+1 < chtCount*CHTFrequencyClient {
+		num := chtCount*CHTFrequencyClient - 1
 		header, err := GetHeaderByNumber(ctx, self.odr, num)
 		if header != nil && err == nil {
 			self.mu.Lock()
diff --git a/light/nodeset.go b/light/nodeset.go
index ffdb71bb7..245b5eb76 100644
--- a/light/nodeset.go
+++ b/light/nodeset.go
@@ -29,7 +29,9 @@ import (
 // NodeSet stores a set of trie nodes. It implements trie.Database and can also
 // act as a cache for another trie.Database.
 type NodeSet struct {
-	db       map[string][]byte
+	nodes map[string][]byte
+	order []string
+
 	dataSize int
 	lock     sync.RWMutex
 }
@@ -37,7 +39,7 @@ type NodeSet struct {
 // NewNodeSet creates an empty node set
 func NewNodeSet() *NodeSet {
 	return &NodeSet{
-		db: make(map[string][]byte),
+		nodes: make(map[string][]byte),
 	}
 }
 
@@ -46,10 +48,15 @@ func (db *NodeSet) Put(key []byte, value []byte) error {
 	db.lock.Lock()
 	defer db.lock.Unlock()
 
-	if _, ok := db.db[string(key)]; !ok {
-		db.db[string(key)] = common.CopyBytes(value)
-		db.dataSize += len(value)
+	if _, ok := db.nodes[string(key)]; ok {
+		return nil
 	}
+	keystr := string(key)
+
+	db.nodes[keystr] = common.CopyBytes(value)
+	db.order = append(db.order, keystr)
+	db.dataSize += len(value)
+
 	return nil
 }
 
@@ -58,7 +65,7 @@ func (db *NodeSet) Get(key []byte) ([]byte, error) {
 	db.lock.RLock()
 	defer db.lock.RUnlock()
 
-	if entry, ok := db.db[string(key)]; ok {
+	if entry, ok := db.nodes[string(key)]; ok {
 		return entry, nil
 	}
 	return nil, errors.New("not found")
@@ -75,7 +82,7 @@ func (db *NodeSet) KeyCount() int {
 	db.lock.RLock()
 	defer db.lock.RUnlock()
 
-	return len(db.db)
+	return len(db.nodes)
 }
 
 // DataSize returns the aggregated data size of nodes in the set
@@ -92,8 +99,8 @@ func (db *NodeSet) NodeList() NodeList {
 	defer db.lock.RUnlock()
 
 	var values NodeList
-	for _, value := range db.db {
-		values = append(values, value)
+	for _, key := range db.order {
+		values = append(values, db.nodes[key])
 	}
 	return values
 }
@@ -103,7 +110,7 @@ func (db *NodeSet) Store(target ethdb.Putter) {
 	db.lock.RLock()
 	defer db.lock.RUnlock()
 
-	for key, value := range db.db {
+	for key, value := range db.nodes {
 		target.Put([]byte(key), value)
 	}
 }
diff --git a/light/odr_util.go b/light/odr_util.go
index 33a8e80ce..8f92d6442 100644
--- a/light/odr_util.go
+++ b/light/odr_util.go
@@ -52,13 +52,13 @@ func GetHeaderByNumber(ctx context.Context, odr OdrBackend, number uint64) (*typ
 		for chtCount > 0 && canonicalHash != sectionHead && canonicalHash != (common.Hash{}) {
 			chtCount--
 			if chtCount > 0 {
-				sectionHeadNum = chtCount*ChtFrequency - 1
+				sectionHeadNum = chtCount*CHTFrequencyClient - 1
 				sectionHead = odr.ChtIndexer().SectionHead(chtCount - 1)
 				canonicalHash = core.GetCanonicalHash(db, sectionHeadNum)
 			}
 		}
 	}
-	if number >= chtCount*ChtFrequency {
+	if number >= chtCount*CHTFrequencyClient {
 		return nil, ErrNoTrustedCht
 	}
 	r := &ChtRequest{ChtRoot: GetChtRoot(db, chtCount-1, sectionHead), ChtNum: chtCount - 1, BlockNum: number}
diff --git a/light/postprocess.go b/light/postprocess.go
index 160d07b17..b6756de51 100644
--- a/light/postprocess.go
+++ b/light/postprocess.go
@@ -19,7 +19,6 @@ package light
 import (
 	"encoding/binary"
 	"errors"
-	"fmt"
 	"math/big"
 	"time"
 
@@ -35,8 +34,14 @@ import (
 )
 
 const (
-	ChtFrequency                   = 32768
-	ChtV1Frequency                 = 4096 // as long as we want to retain LES/1 compatibility, servers generate CHTs with the old, higher frequency
+	// CHTFrequencyClient is the block frequency for creating CHTs on the client side.
+	CHTFrequencyClient = 32768
+
+	// CHTFrequencyServer is the block frequency for creating CHTs on the server side.
+	// Eventually this can be merged back with the client version, but that requires a
+	// full database upgrade, so that should be left for a suitable moment.
+	CHTFrequencyServer = 4096
+
 	HelperTrieConfirmations        = 2048 // number of confirmations before a server is expected to have the given HelperTrie available
 	HelperTrieProcessConfirmations = 256  // number of confirmations before a HelperTrie is generated
 )
@@ -100,7 +105,7 @@ func GetChtRoot(db ethdb.Database, sectionIdx uint64, sectionHead common.Hash) c
 // GetChtV2Root reads the CHT root assoctiated to the given section from the database
 // Note that sectionIdx is specified according to LES/2 CHT section size
 func GetChtV2Root(db ethdb.Database, sectionIdx uint64, sectionHead common.Hash) common.Hash {
-	return GetChtRoot(db, (sectionIdx+1)*(ChtFrequency/ChtV1Frequency)-1, sectionHead)
+	return GetChtRoot(db, (sectionIdx+1)*(CHTFrequencyClient/CHTFrequencyServer)-1, sectionHead)
 }
 
 // StoreChtRoot writes the CHT root assoctiated to the given section into the database
@@ -124,10 +129,10 @@ type ChtIndexerBackend struct {
 func NewChtIndexer(db ethdb.Database, clientMode bool) *core.ChainIndexer {
 	var sectionSize, confirmReq uint64
 	if clientMode {
-		sectionSize = ChtFrequency
+		sectionSize = CHTFrequencyClient
 		confirmReq = HelperTrieConfirmations
 	} else {
-		sectionSize = ChtV1Frequency
+		sectionSize = CHTFrequencyServer
 		confirmReq = HelperTrieProcessConfirmations
 	}
 	idb := ethdb.NewTable(db, "chtIndex-")
@@ -174,8 +179,8 @@ func (c *ChtIndexerBackend) Commit() error {
 	}
 	c.triedb.Commit(root, false)
 
-	if ((c.section+1)*c.sectionSize)%ChtFrequency == 0 {
-		log.Info("Storing CHT", "idx", c.section*c.sectionSize/ChtFrequency, "sectionHead", fmt.Sprintf("%064x", c.lastHash), "root", fmt.Sprintf("%064x", root))
+	if ((c.section+1)*c.sectionSize)%CHTFrequencyClient == 0 {
+		log.Info("Storing CHT", "section", c.section*c.sectionSize/CHTFrequencyClient, "head", c.lastHash, "root", root)
 	}
 	StoreChtRoot(c.diskdb, c.section, c.lastHash, root)
 	return nil
@@ -294,7 +299,7 @@ func (b *BloomTrieIndexerBackend) Commit() error {
 	b.triedb.Commit(root, false)
 
 	sectionHead := b.sectionHeads[b.bloomTrieRatio-1]
-	log.Info("Storing BloomTrie", "section", b.section, "sectionHead", fmt.Sprintf("%064x", sectionHead), "root", fmt.Sprintf("%064x", root), "compression ratio", float64(compSize)/float64(decompSize))
+	log.Info("Storing bloom trie", "section", b.section, "head", sectionHead, "root", root, "compression", float64(compSize)/float64(decompSize))
 	StoreBloomTrieRoot(b.diskdb, b.section, sectionHead, root)
 
 	return nil