Merge pull request #579 from libp2p/feat/fix-peer-pinging

Fix bug in periodic peer pinging

Author: Stebalien

dht.go

@@ -110,10 +110,10 @@ type IpfsDHT struct {
 	// networks).
 	enableProviders, enableValues bool
 
-	// maxLastSuccessfulOutboundThreshold is the max threshold/upper limit for the value of "lastSuccessfulOutboundQuery"
-	// of the peer in the bucket above which we will evict it to make place for a new peer if the bucket
-	// is full
-	maxLastSuccessfulOutboundThreshold time.Duration
+	// successfulOutboundQueryGracePeriod is the maximum grace period we will give to a peer
+	// to between two successful query responses from it, failing which,
+	// we will ping it to see if it's alive.
+	successfulOutboundQueryGracePeriod time.Duration
 
 	fixLowPeersChan chan struct{}
 }
@@ -287,11 +287,12 @@ func makeRoutingTable(dht *IpfsDHT, cfg config) (*kb.RoutingTable, error) {
 	// be published soon.
 	l1 := math.Log(float64(1) / float64(defaultBucketSize))                              //(Log(1/K))
 	l2 := math.Log(float64(1) - (float64(cfg.concurrency) / float64(defaultBucketSize))) // Log(1 - (alpha / K))
-	maxLastSuccessfulOutboundThreshold := l1 / l2 * float64(cfg.routingTable.refreshInterval)
+	maxLastSuccessfulOutboundThreshold := time.Duration(l1 / l2 * float64(cfg.routingTable.refreshInterval))
 
 	self := kb.ConvertPeerID(dht.host.ID())
 
 	rt, err := kb.NewRoutingTable(cfg.bucketSize, self, time.Minute, dht.host.Peerstore(), maxLastSuccessfulOutboundThreshold)
+	dht.successfulOutboundQueryGracePeriod = maxLastSuccessfulOutboundThreshold
 	cmgr := dht.host.ConnManager()
 
 	rt.PeerAdded = func(p peer.ID) {
@@ -451,22 +452,37 @@ func (dht *IpfsDHT) putLocal(key string, rec *recpb.Record) error {
 
 // peerFound signals the routingTable that we've found a peer that
 // might support the DHT protocol.
+// If we have a connection a peer but no exchange of a query RPC ->
+//    LastQueriedAt=time.Now (so we don't ping it for some time for a liveliness check)
+//    LastUsefulAt=N/A
+// If we connect to a peer and exchange a query RPC ->
+//    LastQueriedAt=time.Now (same reason as above)
+//    LastUsefulAt=time.Now (so we give it some life in the RT without immediately evicting it)
+// If we query a peer we already have in our Routing Table ->
+//    LastQueriedAt=time.Now()
+//    LastUsefulAt remains unchanged
+// If we connect to a peer we already have in the RT but do not exchange a query (rare)
+//    Do Nothing.
 func (dht *IpfsDHT) peerFound(ctx context.Context, p peer.ID, queryPeer bool) {
 	logger.Debugw("peer found", "peer", p)
 	b, err := dht.validRTPeer(p)
 	if err != nil {
 		logger.Errorw("failed to validate if peer is a DHT peer", "peer", p, "error", err)
 	} else if b {
-		_, err := dht.routingTable.TryAddPeer(p, queryPeer)
+		newlyAdded, err := dht.routingTable.TryAddPeer(p, queryPeer)
 		if err != nil {
 			// peer not added.
 			return
 		}
 
-		// If we discovered the peer because of a query, we need to ensure we override the "zero" lastSuccessfulOutboundQuery
+		// If we freshly added the peer because of a query, we need to ensure we override the "zero" lastUsefulAt
 		// value that must have been set in the Routing Table for this peer when it was first added during a connection.
-		if queryPeer {
-			dht.routingTable.UpdateLastSuccessfulOutboundQuery(p, time.Now())
+		if newlyAdded && queryPeer {
+			dht.routingTable.UpdateLastUsefulAt(p, time.Now())
+		} else if queryPeer {
+			// the peer is already in our RT, but we just successfully queried it and so let's give it a
+			// bump on the query time so we don't ping it too soon for a liveliness check.
+			dht.routingTable.UpdateLastSuccessfulOutboundQueryAt(p, time.Now())
 		}
 	}
 }

dht_bootstrap.go

@@ -128,7 +128,7 @@ func (dht *IpfsDHT) startRefreshing() {
 			// ping Routing Table peers that haven't been hear of/from in the interval they should have been.
 			for _, ps := range dht.routingTable.GetPeerInfos() {
 				// ping the peer if it's due for a ping and evict it if the ping fails
-				if time.Since(ps.LastSuccessfulOutboundQuery) > dht.maxLastSuccessfulOutboundThreshold {
+				if time.Since(ps.LastSuccessfulOutboundQueryAt) > dht.successfulOutboundQueryGracePeriod {
 					livelinessCtx, cancel := context.WithTimeout(ctx, peerPingTimeout)
 					if err := dht.host.Connect(livelinessCtx, peer.AddrInfo{ID: ps.Id}); err != nil {
 						logger.Debugw("evicting peer after failed ping", "peer", ps.Id, "error", err)

go.mod

@@ -18,8 +18,8 @@ require (
 	github.com/libp2p/go-eventbus v0.1.0
 	github.com/libp2p/go-libp2p v0.7.4
 	github.com/libp2p/go-libp2p-core v0.5.1
-	github.com/libp2p/go-libp2p-kbucket v0.3.3
-	github.com/libp2p/go-libp2p-peerstore v0.2.2
+	github.com/libp2p/go-libp2p-kbucket v0.4.1
+	github.com/libp2p/go-libp2p-peerstore v0.2.3
 	github.com/libp2p/go-libp2p-record v0.1.2
 	github.com/libp2p/go-libp2p-routing-helpers v0.2.0
 	github.com/libp2p/go-libp2p-swarm v0.2.3

go.sum

@@ -3,6 +3,7 @@ github.com/AndreasBriese/bbloom v0.0.0-20180913140656-343706a395b7/go.mod h1:bOv
 github.com/AndreasBriese/bbloom v0.0.0-20190306092124-e2d15f34fcf9/go.mod h1:bOvUY6CB00SOBii9/FifXqc0awNKxLFCL/+pkDPuyl8=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/Kubuxu/go-os-helper v0.0.1/go.mod h1:N8B+I7vPCT80IcP58r50u4+gEEcsZETFUpAzWW2ep1Y=
+github.com/OneOfOne/xxhash v1.2.2/go.mod h1:HSdplMjZKSmBqAxg5vPj2TmRDmfkzw+cTzAElWljhcU=
 github.com/aead/siphash v1.0.1/go.mod h1:Nywa3cDsYNNK3gaciGTWPwHt0wlpNV15vwmswBAUSII=
 github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6/go.mod h1:grANhF5doyWs3UAsr3K4I6qtAmlQcZDesFNEHPZAzj8=
 github.com/btcsuite/btcd v0.0.0-20190213025234-306aecffea32 h1:qkOC5Gd33k54tobS36cXdAzJbeHaduLtnLQQwNoIi78=
@@ -21,6 +22,7 @@ github.com/btcsuite/goleveldb v0.0.0-20160330041536-7834afc9e8cd/go.mod h1:F+uVa
 github.com/btcsuite/snappy-go v0.0.0-20151229074030-0bdef8d06723/go.mod h1:8woku9dyThutzjeg+3xrA5iCpBRH8XEEg3lh6TiUghc=
 github.com/btcsuite/websocket v0.0.0-20150119174127-31079b680792/go.mod h1:ghJtEyQwv5/p4Mg4C0fgbePVuGr935/5ddU9Z3TmDRY=
 github.com/btcsuite/winsvc v1.0.0/go.mod h1:jsenWakMcC0zFBFurPLEAyrnc/teJEM1O46fmI40EZs=
+github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/coreos/etcd v3.3.10+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
 github.com/coreos/go-etcd v2.0.0+incompatible/go.mod h1:Jez6KQU2B/sWsbdaef3ED8NzMklzPG4d5KIOhIy30Tk=
@@ -38,6 +40,8 @@ github.com/davidlazar/go-crypto v0.0.0-20170701192655-dcfb0a7ac018/go.mod h1:rQY
 github.com/dgraph-io/badger v1.5.5-0.20190226225317-8115aed38f8f/go.mod h1:VZxzAIRPHRVNRKRo6AXrX9BJegn6il06VMTZVJYCIjQ=
 github.com/dgraph-io/badger v1.6.0-rc1/go.mod h1:zwt7syl517jmP8s94KqSxTlM6IMsdhYy6psNgSztDR4=
 github.com/dgraph-io/badger v1.6.0/go.mod h1:zwt7syl517jmP8s94KqSxTlM6IMsdhYy6psNgSztDR4=
+github.com/dgraph-io/badger v1.6.1/go.mod h1:FRmFw3uxvcpa8zG3Rxs0th+hCLIuaQg8HlNV5bjgnuU=
+github.com/dgraph-io/ristretto v0.0.2/go.mod h1:KPxhHT9ZxKefz+PCeOGsrHpl1qZ7i70dGTu2u+Ahh6E=
 github.com/dgryski/go-farm v0.0.0-20190104051053-3adb47b1fb0f/go.mod h1:SqUrOPUnsFjfmXRMNPybcSiG0BgUW2AuFH8PAnS2iTw=
 github.com/dgryski/go-farm v0.0.0-20190423205320-6a90982ecee2/go.mod h1:SqUrOPUnsFjfmXRMNPybcSiG0BgUW2AuFH8PAnS2iTw=
 github.com/dustin/go-humanize v1.0.0/go.mod h1:HtrtbFcZ19U5GC7JDqmcUSB87Iq5E25KnS6fMYU6eOk=
@@ -119,9 +123,11 @@ github.com/ipfs/go-ds-badger v0.0.2/go.mod h1:Y3QpeSFWQf6MopLTiZD+VT6IC1yZqaGmjv
 github.com/ipfs/go-ds-badger v0.0.5/go.mod h1:g5AuuCGmr7efyzQhLL8MzwqcauPojGPUaHzfGTzuE3s=
 github.com/ipfs/go-ds-badger v0.0.7/go.mod h1:qt0/fWzZDoPW6jpQeqUjR5kBfhDNB65jd9YlmAvpQBk=
 github.com/ipfs/go-ds-badger v0.2.1/go.mod h1:Tx7l3aTph3FMFrRS838dcSJh+jjA7cX9DrGVwx/NOwE=
+github.com/ipfs/go-ds-badger v0.2.3/go.mod h1:pEYw0rgg3FIrywKKnL+Snr+w/LjJZVMTBRn4FS6UHUk=
 github.com/ipfs/go-ds-leveldb v0.0.1/go.mod h1:feO8V3kubwsEF22n0YRQCffeb79OOYIykR4L04tMOYc=
 github.com/ipfs/go-ds-leveldb v0.1.0/go.mod h1:hqAW8y4bwX5LWcCtku2rFNX3vjDZCy5LZCg+cSZvYb8=
 github.com/ipfs/go-ds-leveldb v0.4.1/go.mod h1:jpbku/YqBSsBc1qgME8BkWS4AxzF2cEu1Ii2r79Hh9s=
+github.com/ipfs/go-ds-leveldb v0.4.2/go.mod h1:jpbku/YqBSsBc1qgME8BkWS4AxzF2cEu1Ii2r79Hh9s=
 github.com/ipfs/go-ipfs-delay v0.0.0-20181109222059-70721b86a9a8/go.mod h1:8SP1YXK1M1kXuc4KJZINY3TQQ03J2rwBG9QfXmbRPrw=
 github.com/ipfs/go-ipfs-util v0.0.1 h1:Wz9bL2wB2YBJqggkA4dD7oSmqB4cAnpNbGrlHJulv50=
 github.com/ipfs/go-ipfs-util v0.0.1/go.mod h1:spsl5z8KUnrve+73pOhSVZND1SIxPW5RyBCNzQxlJBc=
@@ -168,6 +174,8 @@ github.com/koron/go-ssdp v0.0.0-20191105050749-2e1c40ed0b5d h1:68u9r4wEvL3gYg2jv
 github.com/koron/go-ssdp v0.0.0-20191105050749-2e1c40ed0b5d/go.mod h1:5Ky9EC2xfoUKUor0Hjgi2BJhCSXJfMOFlmyYrVKGQMk=
 github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
+github.com/kr/pretty v0.2.0 h1:s5hAObm+yFO5uHYt5dYjxi2rXrsnmRpJx4OYvIWUaQs=
+github.com/kr/pretty v0.2.0/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
@@ -231,8 +239,8 @@ github.com/libp2p/go-libp2p-discovery v0.2.0 h1:1p3YSOq7VsgaL+xVHPi8XAmtGyas6D2J
 github.com/libp2p/go-libp2p-discovery v0.2.0/go.mod h1:s4VGaxYMbw4+4+tsoQTqh7wfxg97AEdo4GYBt6BadWg=
 github.com/libp2p/go-libp2p-discovery v0.3.0 h1:+JnYBRLzZQtRq0mK3xhyjBwHytLmJXMTZkQfbw+UrGA=
 github.com/libp2p/go-libp2p-discovery v0.3.0/go.mod h1:o03drFnz9BVAZdzC/QUQ+NeQOu38Fu7LJGEOK2gQltw=
-github.com/libp2p/go-libp2p-kbucket v0.3.3 h1:V2Zwv6QnCK6Who0iiJW2eUKwdlTYGJ2HnLViaolDOcs=
-github.com/libp2p/go-libp2p-kbucket v0.3.3/go.mod h1:IWFdYRBOYzaLEHnvrfzEkr+UcuveCXIoeO8QeFZSI6A=
+github.com/libp2p/go-libp2p-kbucket v0.4.1 h1:6FyzbQuGLPzbMv3HiD232zqscIz5iB8ppJwb380+OGI=
+github.com/libp2p/go-libp2p-kbucket v0.4.1/go.mod h1:7sCeZx2GkNK1S6lQnGUW5JYZCFPnXzAZCCBBS70lytY=
 github.com/libp2p/go-libp2p-loggables v0.1.0 h1:h3w8QFfCt2UJl/0/NW4K829HX/0S4KD31PQ7m8UXXO8=
 github.com/libp2p/go-libp2p-loggables v0.1.0/go.mod h1:EyumB2Y6PrYjr55Q3/tiJ/o3xoDasoRYM7nOzEpoa90=
 github.com/libp2p/go-libp2p-mplex v0.2.0/go.mod h1:Ejl9IyjvXJ0T9iqUTE1jpYATQ9NM3g+OtR+EMMODbKo=
@@ -261,6 +269,8 @@ github.com/libp2p/go-libp2p-peerstore v0.2.1 h1:u+gOfsKgu73ZkGWhvckRm03z9C+iS9Tr
 github.com/libp2p/go-libp2p-peerstore v0.2.1/go.mod h1:NQxhNjWxf1d4w6PihR8btWIRjwRLBr4TYKfNgrUkOPA=
 github.com/libp2p/go-libp2p-peerstore v0.2.2 h1:iqc/m03jHn5doXN3+kS6JKvqQRHEltiXljQB85iVHWE=
 github.com/libp2p/go-libp2p-peerstore v0.2.2/go.mod h1:NQxhNjWxf1d4w6PihR8btWIRjwRLBr4TYKfNgrUkOPA=
+github.com/libp2p/go-libp2p-peerstore v0.2.3 h1:MofRq2l3c15vQpEygTetV+zRRrncz+ktiXW7H2EKoEQ=
+github.com/libp2p/go-libp2p-peerstore v0.2.3/go.mod h1:K8ljLdFn590GMttg/luh4caB/3g0vKuY01psze0upRw=
 github.com/libp2p/go-libp2p-pnet v0.2.0 h1:J6htxttBipJujEjz1y0a5+eYoiPcFHhSYHH6na5f0/k=
 github.com/libp2p/go-libp2p-pnet v0.2.0/go.mod h1:Qqvq6JH/oMZGwqs3N1Fqhv8NVhrdYcO0BW4wssv21LA=
 github.com/libp2p/go-libp2p-record v0.1.2 h1:M50VKzWnmUrk/M5/Dz99qO9Xh4vs8ijsK+7HkJvRP+0=
@@ -475,6 +485,7 @@ github.com/spacemonkeygo/openssl v0.0.0-20181017203307-c2dcc5cca94a h1:/eS3yfGjQ
 github.com/spacemonkeygo/openssl v0.0.0-20181017203307-c2dcc5cca94a/go.mod h1:7AyxJNCJ7SBZ1MfVQCWD6Uqo2oubI2Eq2y2eqf+A5r0=
 github.com/spacemonkeygo/spacelog v0.0.0-20180420211403-2296661a0572 h1:RC6RW7j+1+HkWaX/Yh71Ee5ZHaHYt7ZP4sQgUrm6cDU=
 github.com/spacemonkeygo/spacelog v0.0.0-20180420211403-2296661a0572/go.mod h1:w0SWMsp6j9O/dk4/ZpIhL+3CkG8ofA2vuv7k+ltqUMc=
+github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/spaolacci/murmur3 v1.1.0 h1:7c1g84S4BPRrfL5Xrdp6fOJ206sU9y293DDHaoy0bLI=
 github.com/spaolacci/murmur3 v1.1.0/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/spf13/afero v1.1.2/go.mod h1:j4pytiNVoe2o6bmDsKpLACNPDBIoEAkihy7loJ1B0CQ=

query.go

@@ -174,7 +174,7 @@ func (dht *IpfsDHT) runQuery(ctx context.Context, target string, queryFn queryFn
 }
 
 func (q *query) recordPeerIsValuable(p peer.ID) {
-	q.dht.routingTable.UpdateLastSuccessfulOutboundQuery(p, time.Now())
+	q.dht.routingTable.UpdateLastUsefulAt(p, time.Now())
 }
 
 func (q *query) recordValuablePeers() {