p2p, p2p/discover: add dial metrics (ethereum#27621)

This PR adds metrics for p2p dialing, which gives us visibility into the quality of the dial 
candidates  returned by our discovery methods.

eth/handler.go

@@ -38,6 +38,7 @@ import (
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/p2p"
 )
 
@@ -424,6 +425,13 @@ func (h *handler) runSnapExtension(peer *snap.Peer, handler snap.Handler) error
 	defer h.peerWG.Done()
 
 	if err := h.peers.registerSnapExtension(peer); err != nil {
+		if metrics.Enabled {
+			if peer.Inbound() {
+				snap.IngressRegistrationErrorMeter.Mark(1)
+			} else {
+				snap.EgressRegistrationErrorMeter.Mark(1)
+			}
+		}
 		peer.Log().Warn("Snapshot extension registration failed", "err", err)
 		return err
 	}

eth/protocols/eth/handshake.go

@@ -17,12 +17,14 @@
 package eth
 
 import (
+	"errors"
 	"fmt"
 	"math/big"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/forkid"
+	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/p2p"
 )
 
@@ -59,9 +61,11 @@ func (p *Peer) Handshake(network uint64, td *big.Int, head common.Hash, genesis
 		select {
 		case err := <-errc:
 			if err != nil {
+				markError(p, err)
 				return err
 			}
 		case <-timeout.C:
+			markError(p, p2p.DiscReadTimeout)
 			return p2p.DiscReadTimeout
 		}
 	}
@@ -105,3 +109,25 @@ func (p *Peer) readStatus(network uint64, status *StatusPacket, genesis common.H
 	}
 	return nil
 }
+
+// markError registers the error with the corresponding metric.
+func markError(p *Peer, err error) {
+	if !metrics.Enabled {
+		return
+	}
+	m := meters.get(p.Inbound())
+	switch errors.Unwrap(err) {
+	case errNetworkIDMismatch:
+		m.networkIDMismatch.Mark(1)
+	case errProtocolVersionMismatch:
+		m.protocolVersionMismatch.Mark(1)
+	case errGenesisMismatch:
+		m.genesisMismatch.Mark(1)
+	case errForkIDRejected:
+		m.forkidRejected.Mark(1)
+	case p2p.DiscReadTimeout:
+		m.timeoutError.Mark(1)
+	default:
+		m.peerError.Mark(1)
+	}
+}

eth/protocols/eth/metrics.go

@@ -0,0 +1,81 @@
+// Copyright 2023 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package eth
+
+import "github.com/ethereum/go-ethereum/metrics"
+
+// meters stores ingress and egress handshake meters.
+var meters bidirectionalMeters
+
+// bidirectionalMeters stores ingress and egress handshake meters.
+type bidirectionalMeters struct {
+	ingress *hsMeters
+	egress  *hsMeters
+}
+
+// get returns the corresponding meter depending if ingress or egress is
+// desired.
+func (h *bidirectionalMeters) get(ingress bool) *hsMeters {
+	if ingress {
+		return h.ingress
+	}
+	return h.egress
+}
+
+// hsMeters is a collection of meters which track metrics related to the
+// eth subprotocol handshake.
+type hsMeters struct {
+	// peerError measures the number of errors related to incorrect peer
+	// behaviour, such as invalid message code, size, encoding, etc.
+	peerError metrics.Meter
+
+	// timeoutError measures the number of timeouts.
+	timeoutError metrics.Meter
+
+	// networkIDMismatch measures the number of network id mismatch errors.
+	networkIDMismatch metrics.Meter
+
+	// protocolVersionMismatch measures the number of differing protocol
+	// versions.
+	protocolVersionMismatch metrics.Meter
+
+	// genesisMismatch measures the number of differing genesises.
+	genesisMismatch metrics.Meter
+
+	// forkidRejected measures the number of differing forkids.
+	forkidRejected metrics.Meter
+}
+
+// newHandshakeMeters registers and returns handshake meters for the given
+// base.
+func newHandshakeMeters(base string) *hsMeters {
+	return &hsMeters{
+		peerError:               metrics.NewRegisteredMeter(base+"error/peer", nil),
+		timeoutError:            metrics.NewRegisteredMeter(base+"error/timeout", nil),
+		networkIDMismatch:       metrics.NewRegisteredMeter(base+"error/network", nil),
+		protocolVersionMismatch: metrics.NewRegisteredMeter(base+"error/version", nil),
+		genesisMismatch:         metrics.NewRegisteredMeter(base+"error/genesis", nil),
+		forkidRejected:          metrics.NewRegisteredMeter(base+"error/forkid", nil),
+	}
+}
+
+func init() {
+	meters = bidirectionalMeters{
+		ingress: newHandshakeMeters("eth/protocols/eth/ingress/handshake/"),
+		egress:  newHandshakeMeters("eth/protocols/eth/egress/handshake/"),
+	}
+}

eth/protocols/snap/metrics.go

@@ -0,0 +1,29 @@
+// Copyright 2023 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package snap
+
+import (
+	metrics "github.com/ethereum/go-ethereum/metrics"
+)
+
+var (
+	ingressRegistrationErrorName = "eth/protocols/snap/ingress/registration/error"
+	egressRegistrationErrorName  = "eth/protocols/snap/egress/registration/error"
+
+	IngressRegistrationErrorMeter = metrics.NewRegisteredMeter(ingressRegistrationErrorName, nil)
+	EgressRegistrationErrorMeter  = metrics.NewRegisteredMeter(egressRegistrationErrorName, nil)
+)

p2p/dial.go

@@ -521,13 +521,14 @@ func (t *dialTask) resolve(d *dialScheduler) bool {
 
 // dial performs the actual connection attempt.
 func (t *dialTask) dial(d *dialScheduler, dest *enode.Node) error {
+	dialMeter.Mark(1)
 	fd, err := d.dialer.Dial(d.ctx, t.dest)
 	if err != nil {
 		d.log.Trace("Dial error", "id", t.dest.ID(), "addr", nodeAddr(t.dest), "conn", t.flags, "err", cleanupDialErr(err))
+		dialConnectionError.Mark(1)
 		return &dialError{err}
 	}
-	mfd := newMeteredConn(fd, false, &net.TCPAddr{IP: dest.IP(), Port: dest.TCP()})
-	return d.setupFunc(mfd, t.flags, dest)
+	return d.setupFunc(newMeteredConn(fd), t.flags, dest)
 }
 
 func (t *dialTask) String() string {

p2p/discover/metrics.go

@@ -17,6 +17,7 @@
 package discover
 
 import (
+	"fmt"
 	"net"
 
 	"github.com/ethereum/go-ethereum/metrics"
@@ -32,10 +33,17 @@ const (
 )
 
 var (
+	bucketsCounter      []metrics.Counter
 	ingressTrafficMeter = metrics.NewRegisteredMeter(ingressMeterName, nil)
 	egressTrafficMeter  = metrics.NewRegisteredMeter(egressMeterName, nil)
 )
 
+func init() {
+	for i := 0; i < nBuckets; i++ {
+		bucketsCounter = append(bucketsCounter, metrics.NewRegisteredCounter(fmt.Sprintf("%s/bucket/%d/count", moduleName, i), nil))
+	}
+}
+
 // meteredConn is a wrapper around a net.UDPConn that meters both the
 // inbound and outbound network traffic.
 type meteredUdpConn struct {

p2p/discover/table.go

@@ -34,6 +34,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/metrics"
 	"github.com/ethereum/go-ethereum/p2p/enode"
 	"github.com/ethereum/go-ethereum/p2p/netutil"
 )
@@ -80,7 +81,8 @@ type Table struct {
 	closeReq   chan struct{}
 	closed     chan struct{}
 
-	nodeAddedHook func(*node) // for testing
+	nodeAddedHook   func(*bucket, *node)
+	nodeRemovedHook func(*bucket, *node)
 }
 
 // transport is implemented by the UDP transports.
@@ -98,6 +100,7 @@ type bucket struct {
 	entries      []*node // live entries, sorted by time of last contact
 	replacements []*node // recently seen nodes to be used if revalidation fails
 	ips          netutil.DistinctNetSet
+	index        int
 }
 
 func newTable(t transport, db *enode.DB, cfg Config) (*Table, error) {
@@ -119,7 +122,8 @@ func newTable(t transport, db *enode.DB, cfg Config) (*Table, error) {
 	}
 	for i := range tab.buckets {
 		tab.buckets[i] = &bucket{
-			ips: netutil.DistinctNetSet{Subnet: bucketSubnet, Limit: bucketIPLimit},
+			index: i,
+			ips:   netutil.DistinctNetSet{Subnet: bucketSubnet, Limit: bucketIPLimit},
 		}
 	}
 	tab.seedRand()
@@ -128,6 +132,22 @@ func newTable(t transport, db *enode.DB, cfg Config) (*Table, error) {
 	return tab, nil
 }
 
+func newMeteredTable(t transport, db *enode.DB, cfg Config) (*Table, error) {
+	tab, err := newTable(t, db, cfg)
+	if err != nil {
+		return nil, err
+	}
+	if metrics.Enabled {
+		tab.nodeAddedHook = func(b *bucket, n *node) {
+			bucketsCounter[b.index].Inc(1)
+		}
+		tab.nodeRemovedHook = func(b *bucket, n *node) {
+			bucketsCounter[b.index].Dec(1)
+		}
+	}
+	return tab, nil
+}
+
 // Nodes returns all nodes contained in the table.
 func (tab *Table) Nodes() []*enode.Node {
 	if !tab.isInitDone() {
@@ -495,7 +515,7 @@ func (tab *Table) addSeenNode(n *node) {
 	n.addedAt = time.Now()
 
 	if tab.nodeAddedHook != nil {
-		tab.nodeAddedHook(n)
+		tab.nodeAddedHook(b, n)
 	}
 }
 
@@ -539,7 +559,7 @@ func (tab *Table) addVerifiedNode(n *node) {
 	n.addedAt = time.Now()
 
 	if tab.nodeAddedHook != nil {
-		tab.nodeAddedHook(n)
+		tab.nodeAddedHook(b, n)
 	}
 }
 
@@ -638,8 +658,16 @@ func (tab *Table) bumpInBucket(b *bucket, n *node) bool {
 }
 
 func (tab *Table) deleteInBucket(b *bucket, n *node) {
+	// Check if the node is actually in the bucket so the removed hook
+	// isn't called multiple times for the same node.
+	if !contains(b.entries, n.ID()) {
+		return
+	}
 	b.entries = deleteNode(b.entries, n)
 	tab.removeIP(b, n.IP())
+	if tab.nodeRemovedHook != nil {
+		tab.nodeRemovedHook(b, n)
+	}
 }
 
 func contains(ns []*node, id enode.ID) bool {

p2p/discover/v4_udp.go

@@ -142,7 +142,7 @@ func ListenV4(c UDPConn, ln *enode.LocalNode, cfg Config) (*UDPv4, error) {
 		log:             cfg.Log,
 	}
 
-	tab, err := newTable(t, ln.Database(), cfg)
+	tab, err := newMeteredTable(t, ln.Database(), cfg)
 	if err != nil {
 		return nil, err
 	}

p2p/discover/v4_udp_test.go

@@ -394,7 +394,7 @@ func TestUDPv4_pingMatchIP(t *testing.T) {
 func TestUDPv4_successfulPing(t *testing.T) {
 	test := newUDPTest(t)
 	added := make(chan *node, 1)
-	test.table.nodeAddedHook = func(n *node) { added <- n }
+	test.table.nodeAddedHook = func(b *bucket, n *node) { added <- n }
 	defer test.close()
 
 	// The remote side sends a ping packet to initiate the exchange.

p2p/discover/v5_udp.go

@@ -174,7 +174,7 @@ func newUDPv5(conn UDPConn, ln *enode.LocalNode, cfg Config) (*UDPv5, error) {
 		cancelCloseCtx: cancelCloseCtx,
 	}
 	t.talk = newTalkSystem(t)
-	tab, err := newTable(t, t.db, cfg)
+	tab, err := newMeteredTable(t, t.db, cfg)
 	if err != nil {
 		return nil, err
 	}