eth/downloader: port over old logs from glog to log15

4 files changed, 137 insertions, 125 deletions

diff --git a/eth/downloader/downloader.go b/eth/downloader/downloader.go
index 1fac6156d..f71ecbb43 100644
--- a/eth/downloader/downloader.go
+++ b/eth/downloader/downloader.go
@@ -23,7 +23,6 @@ import (
 	"fmt"
 	"math"
 	"math/big"
-	"strings"
 	"sync"
 	"sync/atomic"
 	"time"
@@ -248,9 +247,10 @@ func (d *Downloader) RegisterPeer(id string, version int, currentHead currentHea
 	getRelHeaders relativeHeaderFetcherFn, getAbsHeaders absoluteHeaderFetcherFn, getBlockBodies blockBodyFetcherFn,
 	getReceipts receiptFetcherFn, getNodeData stateFetcherFn) error {
 
-	log.Trace(fmt.Sprint("Registering peer", id))
-	if err := d.peers.Register(newPeer(id, version, currentHead, getRelHeaders, getAbsHeaders, getBlockBodies, getReceipts, getNodeData)); err != nil {
-		log.Error(fmt.Sprint("Register failed:", err))
+	logger := log.New("peer", id)
+	logger.Trace("Registering sync peer")
+	if err := d.peers.Register(newPeer(id, version, currentHead, getRelHeaders, getAbsHeaders, getBlockBodies, getReceipts, getNodeData, logger)); err != nil {
+		logger.Error("Failed to register sync peer", "error", err)
 		return err
 	}
 	d.qosReduceConfidence()
@@ -263,9 +263,10 @@ func (d *Downloader) RegisterPeer(id string, version int, currentHead currentHea
 // the queue.
 func (d *Downloader) UnregisterPeer(id string) error {
 	// Unregister the peer from the active peer set and revoke any fetch tasks
-	log.Trace(fmt.Sprint("Unregistering peer", id))
+	logger := log.New("peer", id)
+	logger.Trace("Unregistering sync peer")
 	if err := d.peers.Unregister(id); err != nil {
-		log.Error(fmt.Sprint("Unregister failed:", err))
+		logger.Error("Failed to unregister sync peer", "error", err)
 		return err
 	}
 	d.queue.Revoke(id)
@@ -284,24 +285,19 @@ func (d *Downloader) UnregisterPeer(id string) error {
 // Synchronise tries to sync up our local block chain with a remote peer, both
 // adding various sanity checks as well as wrapping it with various log entries.
 func (d *Downloader) Synchronise(id string, head common.Hash, td *big.Int, mode SyncMode) error {
-	log.Trace(fmt.Sprintf("Attempting synchronisation: %v, head [%x…], TD %v", id, head[:4], td))
-
 	err := d.synchronise(id, head, td, mode)
 	switch err {
 	case nil:
-		log.Trace(fmt.Sprintf("Synchronisation completed"))
-
 	case errBusy:
-		log.Trace(fmt.Sprintf("Synchronisation already in progress"))
 
 	case errTimeout, errBadPeer, errStallingPeer,
 		errEmptyHeaderSet, errPeersUnavailable, errTooOld,
 		errInvalidAncestor, errInvalidChain:
-		log.Debug(fmt.Sprintf("Removing peer %v: %v", id, err))
+		log.Warn("Synchronisation failed, dropping peer", "peer", id, "error", err)
 		d.dropPeer(id)
 
 	default:
-		log.Warn(fmt.Sprintf("Synchronisation failed: %v", err))
+		log.Warn("Synchronisation failed, retrying", "error", err)
 	}
 	return err
 }
@@ -322,7 +318,7 @@ func (d *Downloader) synchronise(id string, hash common.Hash, td *big.Int, mode
 
 	// Post a user notification of the sync (only once per session)
 	if atomic.CompareAndSwapInt32(&d.notified, 0, 1) {
-		log.Info(fmt.Sprint("Block synchronisation started"))
+		log.Info("Block synchronisation started")
 	}
 	// Reset the queue, peer set and wake channels to clean any internal leftover state
 	d.queue.Reset()
@@ -387,9 +383,9 @@ func (d *Downloader) syncWithPeer(p *peer, hash common.Hash, td *big.Int) (err e
 		return errTooOld
 	}
 
-	log.Debug(fmt.Sprintf("Synchronising with the network using: %s [eth/%d]", p.id, p.version))
+	log.Debug("Synchronising with the network", "peer", p.id, "eth", p.version, "head", hash.Hex()[2:10], "td", td, "mode", syncModeLabels[d.mode])
 	defer func(start time.Time) {
-		log.Debug(fmt.Sprintf("Synchronisation terminated after %v", time.Since(start)))
+		log.Debug("Synchronisation terminated", "elapsed", time.Since(start))
 	}(time.Now())
 
 	// Look up the sync boundaries: the common ancestor and the target block
@@ -437,7 +433,7 @@ func (d *Downloader) syncWithPeer(p *peer, hash common.Hash, td *big.Int) (err e
 				origin = 0
 			}
 		}
-		log.Debug(fmt.Sprintf("Fast syncing until pivot block #%d", pivot))
+		log.Debug("Fast syncing until pivot block", "pivot", pivot)
 	}
 	d.queue.Prepare(origin+1, d.mode, pivot, latest)
 	if d.syncInitHook != nil {
@@ -522,13 +518,14 @@ func (d *Downloader) Terminate() {
 // fetchHeight retrieves the head header of the remote peer to aid in estimating
 // the total time a pending synchronisation would take.
 func (d *Downloader) fetchHeight(p *peer) (*types.Header, error) {
-	log.Debug(fmt.Sprintf("%v: retrieving remote chain height", p))
+	p.logger.Debug("Retrieving remote chain height")
 
 	// Request the advertised remote head block and wait for the response
 	head, _ := p.currentHead()
 	go p.getRelHeaders(head, 1, 0, false)
 
-	timeout := time.After(d.requestTTL())
+	ttl := d.requestTTL()
+	timeout := time.After(ttl)
 	for {
 		select {
 		case <-d.cancelCh:
@@ -537,19 +534,21 @@ func (d *Downloader) fetchHeight(p *peer) (*types.Header, error) {
 		case packet := <-d.headerCh:
 			// Discard anything not from the origin peer
 			if packet.PeerId() != p.id {
-				log.Debug(fmt.Sprintf("Received headers from incorrect peer(%s)", packet.PeerId()))
+				log.Debug("Received headers from incorrect peer", "peer", packet.PeerId())
 				break
 			}
 			// Make sure the peer actually gave something valid
 			headers := packet.(*headerPack).headers
 			if len(headers) != 1 {
-				log.Debug(fmt.Sprintf("%v: invalid number of head headers: %d != 1", p, len(headers)))
+				p.logger.Debug("Multiple headers for single request", "headers", len(headers))
 				return nil, errBadPeer
 			}
-			return headers[0], nil
+			head := headers[0]
+			p.logger.Debug("Remote head header identified", "number", head.Number, "hash", head.Hash().Hex()[2:10])
+			return head, nil
 
 		case <-timeout:
-			log.Debug(fmt.Sprintf("%v: head header timeout", p))
+			p.logger.Debug("Waiting for head header timed out", "elapsed", ttl)
 			return nil, errTimeout
 
 		case <-d.bodyCh:
@@ -566,10 +565,10 @@ func (d *Downloader) fetchHeight(p *peer) (*types.Header, error) {
 // In the rare scenario when we ended up on a long reorganisation (i.e. none of
 // the head links match), we do a binary search to find the common ancestor.
 func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
-	log.Debug(fmt.Sprintf("%v: looking for common ancestor (remote height %d)", p, height))
-
 	// Figure out the valid ancestor range to prevent rewrite attacks
 	floor, ceil := int64(-1), d.headHeader().Number.Uint64()
+
+	p.logger.Debug("Looking for common ancestor", "local", ceil, "remote", height)
 	if d.mode == FullSync {
 		ceil = d.headBlock().NumberU64()
 	} else if d.mode == FastSync {
@@ -597,7 +596,9 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
 
 	// Wait for the remote response to the head fetch
 	number, hash := uint64(0), common.Hash{}
-	timeout := time.After(d.requestTTL())
+
+	ttl := d.requestTTL()
+	timeout := time.After(ttl)
 
 	for finished := false; !finished; {
 		select {
@@ -607,19 +608,19 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
 		case packet := <-d.headerCh:
 			// Discard anything not from the origin peer
 			if packet.PeerId() != p.id {
-				log.Debug(fmt.Sprintf("Received headers from incorrect peer(%s)", packet.PeerId()))
+				log.Debug("Received headers from incorrect peer", "peer", packet.PeerId())
 				break
 			}
 			// Make sure the peer actually gave something valid
 			headers := packet.(*headerPack).headers
 			if len(headers) == 0 {
-				log.Warn(fmt.Sprintf("%v: empty head header set", p))
+				p.logger.Warn("Empty head header set")
 				return 0, errEmptyHeaderSet
 			}
 			// Make sure the peer's reply conforms to the request
 			for i := 0; i < len(headers); i++ {
 				if number := headers[i].Number.Int64(); number != from+int64(i)*16 {
-					log.Warn(fmt.Sprintf("%v: head header set (item %d) broke chain ordering: requested %d, got %d", p, i, from+int64(i)*16, number))
+					p.logger.Warn("Head headers broke chain ordering", "index", i, "requested", from+int64(i)*16, "received", number)
 					return 0, errInvalidChain
 				}
 			}
@@ -636,7 +637,7 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
 
 					// If every header is known, even future ones, the peer straight out lied about its head
 					if number > height && i == limit-1 {
-						log.Warn(fmt.Sprintf("%v: lied about chain head: reported %d, found above %d", p, height, number))
+						p.logger.Warn("Lied about chain head", "reported", height, "found", number)
 						return 0, errStallingPeer
 					}
 					break
@@ -644,7 +645,7 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
 			}
 
 		case <-timeout:
-			log.Debug(fmt.Sprintf("%v: head header timeout", p))
+			p.logger.Debug("Waiting for head header timed out", "elapsed", ttl)
 			return 0, errTimeout
 
 		case <-d.bodyCh:
@@ -656,10 +657,10 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
 	// If the head fetch already found an ancestor, return
 	if !common.EmptyHash(hash) {
 		if int64(number) <= floor {
-			log.Warn(fmt.Sprintf("%v: potential rewrite attack: #%d [%x…] <= #%d limit", p, number, hash[:4], floor))
+			p.logger.Warn("Ancestor below allowance", "number", number, "hash", hash.Hex()[2:10], "allowance", floor)
 			return 0, errInvalidAncestor
 		}
-		log.Debug(fmt.Sprintf("%v: common ancestor: #%d [%x…]", p, number, hash[:4]))
+		p.logger.Debug("Found common ancestor", "number", number, "hash", hash.Hex()[2:10])
 		return number, nil
 	}
 	// Ancestor not found, we need to binary search over our chain
@@ -671,7 +672,9 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
 		// Split our chain interval in two, and request the hash to cross check
 		check := (start + end) / 2
 
-		timeout := time.After(d.requestTTL())
+		ttl := d.requestTTL()
+		timeout := time.After(ttl)
+
 		go p.getAbsHeaders(uint64(check), 1, 0, false)
 
 		// Wait until a reply arrives to this request
@@ -683,13 +686,13 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
 			case packer := <-d.headerCh:
 				// Discard anything not from the origin peer
 				if packer.PeerId() != p.id {
-					log.Debug(fmt.Sprintf("Received headers from incorrect peer(%s)", packer.PeerId()))
+					log.Debug("Received headers from incorrect peer", "peer", packer.PeerId())
 					break
 				}
 				// Make sure the peer actually gave something valid
 				headers := packer.(*headerPack).headers
 				if len(headers) != 1 {
-					log.Debug(fmt.Sprintf("%v: invalid search header set (%d)", p, len(headers)))
+					p.logger.Debug("Multiple headers for single request", "headers", len(headers))
 					return 0, errBadPeer
 				}
 				arrived = true
@@ -701,13 +704,13 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
 				}
 				header := d.getHeader(headers[0].Hash()) // Independent of sync mode, header surely exists
 				if header.Number.Uint64() != check {
-					log.Debug(fmt.Sprintf("%v: non requested header #%d [%x…], instead of #%d", p, header.Number, header.Hash().Bytes()[:4], check))
+					p.logger.Debug("Received non requested header", "number", header.Number, "hash", header.Hash().Hex()[2:10], "request", check)
 					return 0, errBadPeer
 				}
 				start = check
 
 			case <-timeout:
-				log.Debug(fmt.Sprintf("%v: search header timeout", p))
+				p.logger.Debug("Waiting for search header timed out", "elapsed", ttl)
 				return 0, errTimeout
 
 			case <-d.bodyCh:
@@ -719,10 +722,10 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
 	}
 	// Ensure valid ancestry and return
 	if int64(start) <= floor {
-		log.Warn(fmt.Sprintf("%v: potential rewrite attack: #%d [%x…] <= #%d limit", p, start, hash[:4], floor))
+		p.logger.Warn("Ancestor below allowance", "number", start, "hash", hash.Hex()[2:10], "allowance", floor)
 		return 0, errInvalidAncestor
 	}
-	log.Debug(fmt.Sprintf("%v: common ancestor: #%d [%x…]", p, start, hash[:4]))
+	p.logger.Debug("Found common ancestor", "number", start, "hash", hash.Hex()[2:10])
 	return start, nil
 }
 
@@ -735,8 +738,8 @@ func (d *Downloader) findAncestor(p *peer, height uint64) (uint64, error) {
 // can fill in the skeleton - not even the origin peer - it's assumed invalid and
 // the origin is dropped.
 func (d *Downloader) fetchHeaders(p *peer, from uint64) error {
-	log.Debug(fmt.Sprintf("%v: directing header downloads from #%d", p, from))
-	defer log.Debug(fmt.Sprintf("%v: header download terminated", p))
+	p.logger.Debug("Directing header downloads", "origin", from)
+	defer p.logger.Debug("Header download terminated")
 
 	// Create a timeout timer, and the associated header fetcher
 	skeleton := true            // Skeleton assembly phase or finishing up
@@ -745,15 +748,18 @@ func (d *Downloader) fetchHeaders(p *peer, from uint64) error {
 	<-timeout.C                 // timeout channel should be initially empty
 	defer timeout.Stop()
 
+	var ttl time.Duration
 	getHeaders := func(from uint64) {
 		request = time.Now()
-		timeout.Reset(d.requestTTL())
+
+		ttl = d.requestTTL()
+		timeout.Reset(ttl)
 
 		if skeleton {
-			log.Trace(fmt.Sprintf("%v: fetching %d skeleton headers from #%d", p, MaxHeaderFetch, from))
+			p.logger.Trace("Fetching skeleton headers", "count", MaxHeaderFetch, "from", from)
 			go p.getAbsHeaders(from+uint64(MaxHeaderFetch)-1, MaxSkeletonSize, MaxHeaderFetch-1, false)
 		} else {
-			log.Trace(fmt.Sprintf("%v: fetching %d full headers from #%d", p, MaxHeaderFetch, from))
+			p.logger.Trace("Fetching full headers", "count", MaxHeaderFetch, "from", from)
 			go p.getAbsHeaders(from, MaxHeaderFetch, 0, false)
 		}
 	}
@@ -768,7 +774,7 @@ func (d *Downloader) fetchHeaders(p *peer, from uint64) error {
 		case packet := <-d.headerCh:
 			// Make sure the active peer is giving us the skeleton headers
 			if packet.PeerId() != p.id {
-				log.Debug(fmt.Sprintf("Received skeleton headers from incorrect peer (%s)", packet.PeerId()))
+				log.Debug("Received skeleton from incorrect peer", "peer", packet.PeerId())
 				break
 			}
 			headerReqTimer.UpdateSince(request)
@@ -782,7 +788,7 @@ func (d *Downloader) fetchHeaders(p *peer, from uint64) error {
 			}
 			// If no more headers are inbound, notify the content fetchers and return
 			if packet.Items() == 0 {
-				log.Debug(fmt.Sprintf("%v: no available headers", p))
+				p.logger.Debug("No more headers available")
 				select {
 				case d.headerProcCh <- nil:
 					return nil
@@ -796,7 +802,7 @@ func (d *Downloader) fetchHeaders(p *peer, from uint64) error {
 			if skeleton {
 				filled, proced, err := d.fillHeaderSkeleton(from, headers)
 				if err != nil {
-					log.Debug(fmt.Sprintf("%v: skeleton chain invalid: %v", p, err))
+					p.logger.Debug("Skeleton chain invalid", "error", err)
 					return errInvalidChain
 				}
 				headers = filled[proced:]
@@ -804,7 +810,7 @@ func (d *Downloader) fetchHeaders(p *peer, from uint64) error {
 			}
 			// Insert all the new headers and fetch the next batch
 			if len(headers) > 0 {
-				log.Trace(fmt.Sprintf("%v: schedule %d headers from #%d", p, len(headers), from))
+				p.logger.Trace("Scheduling new headers", "count", len(headers), "from", from)
 				select {
 				case d.headerProcCh <- headers:
 				case <-d.cancelCh:
@@ -816,7 +822,7 @@ func (d *Downloader) fetchHeaders(p *peer, from uint64) error {
 
 		case <-timeout.C:
 			// Header retrieval timed out, consider the peer bad and drop
-			log.Debug(fmt.Sprintf("%v: header request timed out", p))
+			p.logger.Debug("Header request timed out", "elapsed", ttl)
 			headerTimeoutMeter.Mark(1)
 			d.dropPeer(p.id)
 
@@ -846,7 +852,7 @@ func (d *Downloader) fetchHeaders(p *peer, from uint64) error {
 // The method returs the entire filled skeleton and also the number of headers
 // already forwarded for processing.
 func (d *Downloader) fillHeaderSkeleton(from uint64, skeleton []*types.Header) ([]*types.Header, int, error) {
-	log.Debug(fmt.Sprintf("Filling up skeleton from #%d", from))
+	log.Debug("Filling up skeleton", "from", from)
 	d.queue.ScheduleSkeleton(from, skeleton)
 
 	var (
@@ -865,9 +871,9 @@ func (d *Downloader) fillHeaderSkeleton(from uint64, skeleton []*types.Header) (
 	)
 	err := d.fetchParts(errCancelHeaderFetch, d.headerCh, deliver, d.queue.headerContCh, expire,
 		d.queue.PendingHeaders, d.queue.InFlightHeaders, throttle, reserve,
-		nil, fetch, d.queue.CancelHeaders, capacity, d.peers.HeaderIdlePeers, setIdle, "Header")
+		nil, fetch, d.queue.CancelHeaders, capacity, d.peers.HeaderIdlePeers, setIdle, "headers")
 
-	log.Debug(fmt.Sprintf("Skeleton fill terminated: %v", err))
+	log.Debug("Skeleton fill terminated", "error", err)
 
 	filled, proced := d.queue.RetrieveHeaders()
 	return filled, proced, err
@@ -877,7 +883,7 @@ func (d *Downloader) fillHeaderSkeleton(from uint64, skeleton []*types.Header) (
 // available peers, reserving a chunk of blocks for each, waiting for delivery
 // and also periodically checking for timeouts.
 func (d *Downloader) fetchBodies(from uint64) error {
-	log.Debug(fmt.Sprintf("Downloading block bodies from #%d", from))
+	log.Debug("Downloading block bodies", "origin", from)
 
 	var (
 		deliver = func(packet dataPack) (int, error) {
@@ -891,9 +897,9 @@ func (d *Downloader) fetchBodies(from uint64) error {
 	)
 	err := d.fetchParts(errCancelBodyFetch, d.bodyCh, deliver, d.bodyWakeCh, expire,
 		d.queue.PendingBlocks, d.queue.InFlightBlocks, d.queue.ShouldThrottleBlocks, d.queue.ReserveBodies,
-		d.bodyFetchHook, fetch, d.queue.CancelBodies, capacity, d.peers.BodyIdlePeers, setIdle, "Body")
+		d.bodyFetchHook, fetch, d.queue.CancelBodies, capacity, d.peers.BodyIdlePeers, setIdle, "bodies")
 
-	log.Debug(fmt.Sprintf("Block body download terminated: %v", err))
+	log.Debug("Block body download terminated", "error", err)
 	return err
 }
 
@@ -901,7 +907,7 @@ func (d *Downloader) fetchBodies(from uint64) error {
 // available peers, reserving a chunk of receipts for each, waiting for delivery
 // and also periodically checking for timeouts.
 func (d *Downloader) fetchReceipts(from uint64) error {
-	log.Debug(fmt.Sprintf("Downloading receipts from #%d", from))
+	log.Debug("Downloading transaction receipts", "origin", from)
 
 	var (
 		deliver = func(packet dataPack) (int, error) {
@@ -915,9 +921,9 @@ func (d *Downloader) fetchReceipts(from uint64) error {
 	)
 	err := d.fetchParts(errCancelReceiptFetch, d.receiptCh, deliver, d.receiptWakeCh, expire,
 		d.queue.PendingReceipts, d.queue.InFlightReceipts, d.queue.ShouldThrottleReceipts, d.queue.ReserveReceipts,
-		d.receiptFetchHook, fetch, d.queue.CancelReceipts, capacity, d.peers.ReceiptIdlePeers, setIdle, "Receipt")
+		d.receiptFetchHook, fetch, d.queue.CancelReceipts, capacity, d.peers.ReceiptIdlePeers, setIdle, "receipts")
 
-	log.Debug(fmt.Sprintf("Receipt download terminated: %v", err))
+	log.Debug("Transaction receipt download terminated", "error", err)
 	return err
 }
 
@@ -925,7 +931,7 @@ func (d *Downloader) fetchReceipts(from uint64) error {
 // available peers, reserving a chunk of nodes for each, waiting for delivery and
 // also periodically checking for timeouts.
 func (d *Downloader) fetchNodeData() error {
-	log.Debug(fmt.Sprintf("Downloading node state data"))
+	log.Debug("Downloading node state data")
 
 	var (
 		deliver = func(packet dataPack) (int, error) {
@@ -933,12 +939,12 @@ func (d *Downloader) fetchNodeData() error {
 			return d.queue.DeliverNodeData(packet.PeerId(), packet.(*statePack).states, func(delivered int, progressed bool, err error) {
 				// If the peer returned old-requested data, forgive
 				if err == trie.ErrNotRequested {
-					log.Debug(fmt.Sprintf("peer %s: replied to stale state request, forgiving", packet.PeerId()))
+					log.Debug("Forgiving reply to stale state request", "peer", packet.PeerId())
 					return
 				}
 				if err != nil {
 					// If the node data processing failed, the root hash is very wrong, abort
-					log.Error(fmt.Sprintf("peer %s: state processing failed: %v", packet.PeerId(), err))
+					log.Error("State processing failed", "peer", packet.PeerId(), "error", err)
 					d.cancel()
 					return
 				}
@@ -957,12 +963,12 @@ func (d *Downloader) fetchNodeData() error {
 
 				// If real database progress was made, reset any fast-sync pivot failure
 				if progressed && atomic.LoadUint32(&d.fsPivotFails) > 1 {
-					log.Debug(fmt.Sprintf("fast-sync progressed, resetting fail counter from %d", atomic.LoadUint32(&d.fsPivotFails)))
+					log.Debug("Fast-sync progressed, resetting fail counter", "previous", atomic.LoadUint32(&d.fsPivotFails))
 					atomic.StoreUint32(&d.fsPivotFails, 1) // Don't ever reset to 0, as that will unlock the pivot block
 				}
 				// Log a message to the user and return
 				if delivered > 0 {
-					log.Info(fmt.Sprintf("imported %3d state entries in %9v: processed %d, pending at least %d", delivered, common.PrettyDuration(time.Since(start)), syncStatsStateDone, pending))
+					log.Info("Imported new state entries", "count", delivered, "elapsed", common.PrettyDuration(time.Since(start)), "processed", syncStatsStateDone, "pending", pending)
 				}
 			})
 		}
@@ -977,9 +983,9 @@ func (d *Downloader) fetchNodeData() error {
 	)
 	err := d.fetchParts(errCancelStateFetch, d.stateCh, deliver, d.stateWakeCh, expire,
 		d.queue.PendingNodeData, d.queue.InFlightNodeData, throttle, reserve, nil, fetch,
-		d.queue.CancelNodeData, capacity, d.peers.NodeDataIdlePeers, setIdle, "State")
+		d.queue.CancelNodeData, capacity, d.peers.NodeDataIdlePeers, setIdle, "states")
 
-	log.Debug(fmt.Sprintf("Node state data download terminated: %v", err))
+	log.Debug("Node state data download terminated", "error", err)
 	return err
 }
 
@@ -1044,11 +1050,11 @@ func (d *Downloader) fetchParts(errCancel error, deliveryCh chan dataPack, deliv
 				// Issue a log to the user to see what's going on
 				switch {
 				case err == nil && packet.Items() == 0:
-					log.Trace(fmt.Sprintf("%s: no %s delivered", peer, strings.ToLower(kind)))
+					peer.logger.Trace("Requested data not delivered", "type", kind)
 				case err == nil:
-					log.Trace(fmt.Sprintf("%s: delivered %s %s(s)", peer, packet.Stats(), strings.ToLower(kind)))
+					peer.logger.Trace("Delivered new batch of data", "type", kind, "count", packet.Stats())
 				default:
-					log.Trace(fmt.Sprintf("%s: %s delivery failed: %v", peer, strings.ToLower(kind), err))
+					peer.logger.Trace("Failed to deliver retrieved data", "type", kind, "error", err)
 				}
 			}
 			// Blocks assembled, try to update the progress
@@ -1091,10 +1097,10 @@ func (d *Downloader) fetchParts(errCancel error, deliveryCh chan dataPack, deliv
 					// and latency of a peer separately, which requires pushing the measures capacity a bit and seeing
 					// how response times reacts, to it always requests one more than the minimum (i.e. min 2).
 					if fails > 2 {
-						log.Trace(fmt.Sprintf("%s: %s delivery timeout", peer, strings.ToLower(kind)))
+						peer.logger.Trace("Data delivery timed out", "type", kind)
 						setIdle(peer, 0)
 					} else {
-						log.Debug(fmt.Sprintf("%s: stalling %s delivery, dropping", peer, strings.ToLower(kind)))
+						peer.logger.Debug("Stalling delivery, dropping", "type", kind)
 						d.dropPeer(pid)
 					}
 				}
@@ -1102,7 +1108,7 @@ func (d *Downloader) fetchParts(errCancel error, deliveryCh chan dataPack, deliv
 			// If there's nothing more to fetch, wait or terminate
 			if pending() == 0 {
 				if !inFlight() && finished {
-					log.Debug(fmt.Sprintf("%s fetching completed", kind))
+					log.Debug("Data fetching completed", "type", kind)
 					return nil
 				}
 				break
@@ -1130,15 +1136,13 @@ func (d *Downloader) fetchParts(errCancel error, deliveryCh chan dataPack, deliv
 				if request == nil {
 					continue
 				}
-				log.Trace("", "msg", log.Lazy{Fn: func() string {
-					if request.From > 0 {
-						return fmt.Sprintf("%s: requesting %s(s) from #%d", peer, strings.ToLower(kind), request.From)
-					} else if len(request.Headers) > 0 {
-						return fmt.Sprintf("%s: requesting %d %s(s), first at #%d", peer, len(request.Headers), strings.ToLower(kind), request.Headers[0].Number)
-					} else {
-						return fmt.Sprintf("%s: requesting %d %s(s)", peer, len(request.Hashes), strings.ToLower(kind))
-					}
-				}})
+				if request.From > 0 {
+					peer.logger.Trace("Requesting new batch of data", "type", kind, "from", request.From)
+				} else if len(request.Headers) > 0 {
+					peer.logger.Trace("Requesting new batch of data", "type", kind, "count", len(request.Headers), "from", request.Headers[0].Number)
+				} else {
+					peer.logger.Trace("Requesting new batch of data", "type", kind, "count", len(request.Hashes))
+				}
 				// Fetch the chunk and make sure any errors return the hashes to the queue
 				if fetchHook != nil {
 					fetchHook(request.Headers)
@@ -1149,7 +1153,7 @@ func (d *Downloader) fetchParts(errCancel error, deliveryCh chan dataPack, deliv
 					// case, the internal state of the downloader and the queue is very wrong so
 					// better hard crash and note the error instead of silently accumulating into
 					// a much bigger issue.
-					panic(fmt.Sprintf("%v: %s fetch assignment failed", peer, strings.ToLower(kind)))
+					panic(fmt.Sprintf("%v: %s fetch assignment failed", peer, kind))
 				}
 				running = true
 			}
@@ -1193,8 +1197,10 @@ func (d *Downloader) processHeaders(origin uint64, td *big.Int) error {
 			if d.headBlock != nil {
 				curBlock = d.headBlock().Number()
 			}
-			log.Warn(fmt.Sprintf("Rolled back %d headers (LH: %d->%d, FB: %d->%d, LB: %d->%d)",
-				len(hashes), lastHeader, d.headHeader().Number, lastFastBlock, curFastBlock, lastBlock, curBlock))
+			log.Warn("Rolled back headers", "count", len(hashes),
+				"header", fmt.Sprintf("%d->%d", lastHeader, d.headHeader().Number),
+				"fast", fmt.Sprintf("%d->%d", lastFastBlock, curFastBlock),
+				"block", fmt.Sprintf("%d->%d", lastBlock, curBlock))
 
 			// If we're already past the pivot point, this could be an attack, thread carefully
 			if rollback[len(rollback)-1].Number.Uint64() > pivot {
@@ -1202,7 +1208,7 @@ func (d *Downloader) processHeaders(origin uint64, td *big.Int) error {
 				if atomic.LoadUint32(&d.fsPivotFails) == 0 {
 					for _, header := range rollback {
 						if header.Number.Uint64() == pivot {
-							log.Warn(fmt.Sprintf("Fast-sync critical section failure, locked pivot to header #%d [%x…]", pivot, header.Hash().Bytes()[:4]))
+							log.Warn("Fast-sync critical section failure, locked pivot to header", "number", pivot, "hash", header.Hash().Hex()[2:10])
 							d.fsPivotLock = header
 						}
 					}
@@ -1298,7 +1304,7 @@ func (d *Downloader) processHeaders(origin uint64, td *big.Int) error {
 						if n > 0 {
 							rollback = append(rollback, chunk[:n]...)
 						}
-						log.Debug(fmt.Sprintf("invalid header #%d [%x…]: %v", chunk[n].Number, chunk[n].Hash().Bytes()[:4], err))
+						log.Debug("Invalid header encountered", "number", chunk[n].Number, "hash", chunk[n].Hash().Hex()[2:10], "error", err)
 						return errInvalidChain
 					}
 					// All verifications passed, store newly found uncertain headers
@@ -1310,7 +1316,7 @@ func (d *Downloader) processHeaders(origin uint64, td *big.Int) error {
 				// If we're fast syncing and just pulled in the pivot, make sure it's the one locked in
 				if d.mode == FastSync && d.fsPivotLock != nil && chunk[0].Number.Uint64() <= pivot && chunk[len(chunk)-1].Number.Uint64() >= pivot {
 					if pivot := chunk[int(pivot-chunk[0].Number.Uint64())]; pivot.Hash() != d.fsPivotLock.Hash() {
-						log.Warn(fmt.Sprintf("Pivot doesn't match locked in version: have #%v [%x…], want #%v [%x…]", pivot.Number, pivot.Hash().Bytes()[:4], d.fsPivotLock.Number, d.fsPivotLock.Hash().Bytes()[:4]))
+						log.Warn("Pivot doesn't match locked in one", "remoteNumber", pivot.Number, "remoteHash", pivot.Hash().Hex()[2:10], "localNumber", d.fsPivotLock.Number, "localHash", d.fsPivotLock.Hash().Hex()[2:10])
 						return errInvalidChain
 					}
 				}
@@ -1327,7 +1333,7 @@ func (d *Downloader) processHeaders(origin uint64, td *big.Int) error {
 					// Otherwise insert the headers for content retrieval
 					inserts := d.queue.Schedule(chunk, origin)
 					if len(inserts) != len(chunk) {
-						log.Debug(fmt.Sprintf("stale headers"))
+						log.Debug("Stale headers")
 						return errBadPeer
 					}
 				}
@@ -1358,10 +1364,15 @@ func (d *Downloader) processContent() error {
 			d.chainInsertHook(results)
 		}
 		// Actually import the blocks
-		log.Debug("", "msg", log.Lazy{Fn: func() string {
-			first, last := results[0].Header, results[len(results)-1].Header
-			return fmt.Sprintf("Inserting chain with %d items (#%d [%x…] - #%d [%x…])", len(results), first.Number, first.Hash().Bytes()[:4], last.Number, last.Hash().Bytes()[:4])
-		}})
+		first, last := results[0].Header, results[len(results)-1].Header
+		log.Debug("Inserting downloaded chain", "items", len(results),
+			"from", log.Lazy{Fn: func() string {
+				return fmt.Sprintf("#%d [%x…]", first.Number, first.Hash().Bytes()[:4])
+			}},
+			"till", log.Lazy{Fn: func() string {
+				return fmt.Sprintf("#%d [%x…]", last.Number, last.Hash().Bytes()[:4])
+			}})
+
 		for len(results) != 0 {
 			// Check for any termination requests
 			select {
@@ -1395,14 +1406,14 @@ func (d *Downloader) processContent() error {
 			case len(receipts) > 0:
 				index, err = d.insertReceipts(blocks, receipts)
 				if err == nil && blocks[len(blocks)-1].NumberU64() == pivot {
-					log.Debug(fmt.Sprintf("Committing block #%d [%x…] as the new head", blocks[len(blocks)-1].Number(), blocks[len(blocks)-1].Hash().Bytes()[:4]))
+					log.Debug("Committing block as new head", "number", blocks[len(blocks)-1].Number(), "hash", blocks[len(blocks)-1].Hash().Hex()[2:10])
 					index, err = len(blocks)-1, d.commitHeadBlock(blocks[len(blocks)-1].Hash())
 				}
 			default:
 				index, err = d.insertBlocks(blocks)
 			}
 			if err != nil {
-				log.Debug(fmt.Sprintf("Result #%d [%x…] processing failed: %v", results[index].Header.Number, results[index].Header.Hash().Bytes()[:4], err))
+				log.Debug("Downloaded item processing failed", "number", results[index].Header.Number, "hash", results[index].Header.Hash().Hex()[2:10], "error", err)
 				return errInvalidChain
 			}
 			// Shift the results to the next batch
@@ -1470,7 +1481,7 @@ func (d *Downloader) qosTuner() {
 		atomic.StoreUint64(&d.rttConfidence, conf)
 
 		// Log the new QoS values and sleep until the next RTT
-		log.Debug(fmt.Sprintf("Quality of service: rtt %v, conf %.3f, ttl %v", rtt, float64(conf)/1000000.0, d.requestTTL()))
+		log.Debug("Recalculated downloader QoS values", "rtt", rtt, "confidence", float64(conf)/1000000.0, "ttl", d.requestTTL())
 		select {
 		case <-d.quitCh:
 			return
@@ -1500,7 +1511,7 @@ func (d *Downloader) qosReduceConfidence() {
 	atomic.StoreUint64(&d.rttConfidence, conf)
 
 	rtt := time.Duration(atomic.LoadUint64(&d.rttEstimate))
-	log.Debug(fmt.Sprintf("Quality of service: rtt %v, conf %.3f, ttl %v", rtt, float64(conf)/1000000.0, d.requestTTL()))
+	log.Debug("Relaxed downloader QoS values", "rtt", rtt, "confidence", float64(conf)/1000000.0, "ttl", d.requestTTL())
 }
 
 // requestRTT returns the current target round trip time for a download request
diff --git a/eth/downloader/modes.go b/eth/downloader/modes.go
index ec339c074..c2ce0cfef 100644
--- a/eth/downloader/modes.go
+++ b/eth/downloader/modes.go
@@ -24,3 +24,11 @@ const (
 	FastSync                  // Quickly download the headers, full sync only at the chain head
 	LightSync                 // Download only the headers and terminate afterwards
 )
+
+// syncModeLabels contains a mapping of sync modes to textual label used by the
+// logging system.
+var syncModeLabels = map[SyncMode]string{
+	FullSync:  "full",
+	FastSync:  "fast",
+	LightSync: "light",
+}
diff --git a/eth/downloader/peer.go b/eth/downloader/peer.go
index ea4b6a6f2..c1a9b859d 100644
--- a/eth/downloader/peer.go
+++ b/eth/downloader/peer.go
@@ -25,12 +25,12 @@ import (
 	"math"
 	"math/big"
 	"sort"
-	"strings"
 	"sync"
 	"sync/atomic"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/log"
 )
 
 const (
@@ -86,7 +86,8 @@ type peer struct {
 	getReceipts receiptFetcherFn // [eth/63] Method to retrieve a batch of block transaction receipts
 	getNodeData stateFetcherFn   // [eth/63] Method to retrieve a batch of state trie data
 
-	version int // Eth protocol version number to switch strategies
+	version int        // Eth protocol version number to switch strategies
+	logger  log.Logger // Contextual logger to add extra infos to peer logs
 	lock    sync.RWMutex
 }
 
@@ -94,7 +95,8 @@ type peer struct {
 // mechanisms.
 func newPeer(id string, version int, currentHead currentHeadRetrievalFn,
 	getRelHeaders relativeHeaderFetcherFn, getAbsHeaders absoluteHeaderFetcherFn, getBlockBodies blockBodyFetcherFn,
-	getReceipts receiptFetcherFn, getNodeData stateFetcherFn) *peer {
+	getReceipts receiptFetcherFn, getNodeData stateFetcherFn, logger log.Logger) *peer {
+
 	return &peer{
 		id:      id,
 		lacking: make(map[common.Hash]struct{}),
@@ -108,6 +110,7 @@ func newPeer(id string, version int, currentHead currentHeadRetrievalFn,
 		getNodeData: getNodeData,
 
 		version: version,
+		logger:  logger,
 	}
 }
 
@@ -268,6 +271,11 @@ func (p *peer) setIdle(started time.Time, delivered int, throughput *float64, id
 
 	*throughput = (1-measurementImpact)*(*throughput) + measurementImpact*measured
 	p.rtt = time.Duration((1-measurementImpact)*float64(p.rtt) + measurementImpact*float64(elapsed))
+
+	p.logger.Trace("Peer throughput measurements updated",
+		"hps", p.headerThroughput, "bps", p.blockThroughput,
+		"rps", p.receiptThroughput, "sps", p.stateThroughput,
+		"miss", len(p.lacking), "rtt", p.rtt)
 }
 
 // HeaderCapacity retrieves the peers header download allowance based on its
@@ -332,21 +340,6 @@ func (p *peer) Lacks(hash common.Hash) bool {
 	return ok
 }
 
-// String implements fmt.Stringer.
-func (p *peer) String() string {
-	p.lock.RLock()
-	defer p.lock.RUnlock()
-
-	return fmt.Sprintf("Peer %s [%s]", p.id, strings.Join([]string{
-		fmt.Sprintf("hs %3.2f/s", p.headerThroughput),
-		fmt.Sprintf("bs %3.2f/s", p.blockThroughput),
-		fmt.Sprintf("rs %3.2f/s", p.receiptThroughput),
-		fmt.Sprintf("ss %3.2f/s", p.stateThroughput),
-		fmt.Sprintf("miss %4d", len(p.lacking)),
-		fmt.Sprintf("rtt %v", p.rtt),
-	}, ", "))
-}
-
 // peerSet represents the collection of active peer participating in the chain
 // download procedure.
 type peerSet struct {
diff --git a/eth/downloader/queue.go b/eth/downloader/queue.go
index fa04e0d23..9530e15be 100644
--- a/eth/downloader/queue.go
+++ b/eth/downloader/queue.go
@@ -364,20 +364,20 @@ func (q *queue) Schedule(headers []*types.Header, from uint64) []*types.Header {
 		// Make sure chain order is honoured and preserved throughout
 		hash := header.Hash()
 		if header.Number == nil || header.Number.Uint64() != from {
-			log.Warn(fmt.Sprintf("Header #%v [%x…] broke chain ordering, expected %d", header.Number, hash[:4], from))
+			log.Warn("Header broke chain ordering", "number", header.Number, "hash", hash.Hex()[2:10], "expected", from)
 			break
 		}
 		if q.headerHead != (common.Hash{}) && q.headerHead != header.ParentHash {
-			log.Warn(fmt.Sprintf("Header #%v [%x…] broke chain ancestry", header.Number, hash[:4]))
+			log.Warn("Header broke chain ancestry", "number", header.Number, "hash", hash.Hex()[2:10])
 			break
 		}
 		// Make sure no duplicate requests are executed
 		if _, ok := q.blockTaskPool[hash]; ok {
-			log.Warn(fmt.Sprintf("Header #%d [%x…] already scheduled for block fetch", header.Number.Uint64(), hash[:4]))
+			log.Warn("Header  already scheduled for block fetch", "number", header.Number, "hash", hash.Hex()[2:10])
 			continue
 		}
 		if _, ok := q.receiptTaskPool[hash]; ok {
-			log.Warn(fmt.Sprintf("Header #%d [%x…] already scheduled for receipt fetch", header.Number.Uint64(), hash[:4]))
+			log.Warn("Header already scheduled for receipt fetch", "number", header.Number, "hash", hash.Hex()[2:10])
 			continue
 		}
 		// Queue the header for content retrieval
@@ -391,7 +391,7 @@ func (q *queue) Schedule(headers []*types.Header, from uint64) []*types.Header {
 		}
 		if q.mode == FastSync && header.Number.Uint64() == q.fastSyncPivot {
 			// Pivoting point of the fast sync, switch the state retrieval to this
-			log.Debug(fmt.Sprintf("Switching state downloads to %d [%x…]", header.Number.Uint64(), header.Hash().Bytes()[:4]))
+			log.Debug("Switching state downloads to new block", "number", header.Number, "hash", hash.Hex()[2:10])
 
 			q.stateTaskIndex = 0
 			q.stateTaskPool = make(map[common.Hash]int)
@@ -872,10 +872,10 @@ func (q *queue) DeliverHeaders(id string, headers []*types.Header, headerProcCh
 	accepted := len(headers) == MaxHeaderFetch
 	if accepted {
 		if headers[0].Number.Uint64() != request.From {
-			log.Trace(fmt.Sprintf("Peer %s: first header #%v [%x…] broke chain ordering, expected %d", id, headers[0].Number, headers[0].Hash().Bytes()[:4], request.From))
+			log.Trace("First header broke chain ordering", "peer", id, "number", headers[0].Number, "hash", headers[0].Hash().Hex()[2:10], request.From)
 			accepted = false
 		} else if headers[len(headers)-1].Hash() != target {
-			log.Trace(fmt.Sprintf("Peer %s: last header #%v [%x…] broke skeleton structure, expected %x", id, headers[len(headers)-1].Number, headers[len(headers)-1].Hash().Bytes()[:4], target[:4]))
+			log.Trace("Last header broke skeleton structure ", "peer", id, "number", headers[len(headers)-1].Number, "hash", headers[len(headers)-1].Hash().Hex()[2:10], "expected", target.Hex()[2:10])
 			accepted = false
 		}
 	}
@@ -883,12 +883,12 @@ func (q *queue) DeliverHeaders(id string, headers []*types.Header, headerProcCh
 		for i, header := range headers[1:] {
 			hash := header.Hash()
 			if want := request.From + 1 + uint64(i); header.Number.Uint64() != want {
-				log.Warn(fmt.Sprintf("Peer %s: header #%v [%x…] broke chain ordering, expected %d", id, header.Number, hash[:4], want))
+				log.Warn("Header broke chain ordering", "peer", id, "number", header.Number, "hash", hash.Hex()[2:10], "expected", want)
 				accepted = false
 				break
 			}
 			if headers[i].Hash() != header.ParentHash {
-				log.Warn(fmt.Sprintf("Peer %s: header #%v [%x…] broke chain ancestry", id, header.Number, hash[:4]))
+				log.Warn("Header broke chain ancestry", "peer", id, "number", header.Number, "hash", hash.Hex()[2:10])
 				accepted = false
 				break
 			}
@@ -896,7 +896,7 @@ func (q *queue) DeliverHeaders(id string, headers []*types.Header, headerProcCh
 	}
 	// If the batch of headers wasn't accepted, mark as unavailable
 	if !accepted {
-		log.Trace(fmt.Sprintf("Peer %s: skeleton filling from header #%d not accepted", id, request.From))
+		log.Trace("Skeleton filling not accepted", "peer", id, "from", request.From)
 
 		miss := q.headerPeerMiss[id]
 		if miss == nil {
@@ -923,7 +923,7 @@ func (q *queue) DeliverHeaders(id string, headers []*types.Header, headerProcCh
 
 		select {
 		case headerProcCh <- process:
-			log.Trace(fmt.Sprintf("%s: pre-scheduled %d headers from #%v", id, len(process), process[0].Number))
+			log.Trace("Pre-scheduled new headers", "peer", id, "count", len(process), "from", process[0].Number)
 			q.headerProced += len(process)
 		default:
 		}