feat: quick prune failed peers with no history (#1730)

pkg/topology/kademlia/internal/metrics/metrics.go

@@ -7,6 +7,7 @@
 package metrics
 
 import (
+	"errors"
 	"fmt"
 	"sync"
 	"time"
@@ -16,6 +17,8 @@ import (
 	"github.com/hashicorp/go-multierror"
 )
 
+var ErrPeerNotFound = errors.New("peer no found")
+
 const (
 	peerLastSeenTimestamp       string = "peer-last-seen-timestamp"
 	peerTotalConnectionDuration string = "peer-total-connection-duration"
@@ -208,16 +211,46 @@ func (c *Collector) Record(addr swarm.Address, rop ...RecordOp) error {
 // error, it rather continues and all the execution errors are returned together
 // with the successful metrics snapshots.
 func (c *Collector) Snapshot(t time.Time, addresses ...swarm.Address) (map[string]*Snapshot, error) {
-	c.mu.RLock()
-	defer c.mu.RUnlock()
 
 	var mErr error
 	snapshot := make(map[string]*Snapshot)
 
 	take := func(addr string) {
+		peerSnapshot, err := c.peer(t, addr)
+		if err != nil {
+			mErr = multierror.Append(err)
+		} else {
+			snapshot[addr] = peerSnapshot
+		}
+	}
+
+	for _, addr := range addresses {
+		take(addr.String())
+	}
+	if len(addresses) == 0 {
+		c.mu.RLock()
+		for addr := range c.counters {
+			take(addr)
+		}
+		c.mu.RUnlock()
+	}
+
+	return snapshot, mErr
+}
+
+func (c *Collector) Peer(t time.Time, addr swarm.Address) (*Snapshot, error) {
+	return c.peer(t, addr.String())
+}
+
+func (c *Collector) peer(t time.Time, addr string) (*Snapshot, error) {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	var mErr error
+
 	cs := c.counters[addr]
 	if cs == nil {
-			return
+		return nil, ErrPeerNotFound
 	}
 
 	ls, err := cs.lastSeenTimestamp.Get()
@@ -238,25 +271,13 @@ func (c *Collector) Snapshot(t time.Time, addresses ...swarm.Address) (map[strin
 		connTotalDuration += sessionConnDuration
 	}
 
-		snapshot[addr] = &Snapshot{
+	return &Snapshot{
 		LastSeenTimestamp:          lastSeenTimestamp,
-			SessionConnectionRetry:     cs.sessionConnRetry,
 		ConnectionTotalDuration:    connTotalDuration,
+		SessionConnectionRetry:     cs.sessionConnRetry,
 		SessionConnectionDuration:  sessionConnDuration,
 		SessionConnectionDirection: cs.sessionConnDirection,
-		}
-	}
-
-	for _, addr := range addresses {
-		take(addr.String())
-	}
-	if len(addresses) == 0 {
-		for addr := range c.counters {
-			take(addr)
-		}
-	}
-
-	return snapshot, mErr
+	}, mErr
 }
 
 // Finalize logs out all ongoing peer sessions

pkg/topology/kademlia/internal/metrics/metrics_test.go

@@ -5,6 +5,7 @@
 package metrics_test
 
 import (
+	"errors"
 	"testing"
 	"time"
 
@@ -137,7 +138,7 @@ func TestPeerMetricsCollector(t *testing.T) {
 		t.Fatalf("Finalize(%s): unexpected error: %v", t3, err)
 	}
 	sss, err := mc.Snapshot(t2, addr)
-	if err != nil {
+	if !errors.Is(err, metrics.ErrPeerNotFound) {
 		t.Fatalf("Snapshot(%q, ...): unexpected error: %v", addr, err)
 	}
 	if have, want := len(sss), 0; have != want {

pkg/topology/kademlia/kademlia.go

@@ -689,7 +689,7 @@ func (k *Kad) connect(ctx context.Context, peer swarm.Address, ma ma.Multiaddr)
 			k.logger.Debugf("kademlia: unable to record session connection retry metrics for %q: %v", peer, err)
 		}
 
-		if failedAttempts > maxConnAttempts {
+		if k.quickPrune(peer) || failedAttempts > maxConnAttempts {
 			delete(k.waitNext, peer.String())
 			if err := k.addressBook.Remove(peer); err != nil {
 				k.logger.Debugf("could not remove peer from addressbook: %s", peer.String())
@@ -700,6 +700,7 @@ func (k *Kad) connect(ctx context.Context, peer swarm.Address, ma ma.Multiaddr)
 		}
 
 		k.waitNextMu.Unlock()
+
 		return err
 	}
 
@@ -712,6 +713,22 @@ func (k *Kad) connect(ctx context.Context, peer swarm.Address, ma ma.Multiaddr)
 	return k.Announce(ctx, peer)
 }
 
+// quickPrune will return true for cases where:
+//  there are other connected peers, the addr has never been seen before, AND it's the first failed attempt
+func (k *Kad) quickPrune(addr swarm.Address) bool {
+
+	if k.connectedPeers.Length() == 0 {
+		return false
+	}
+
+	snapshot, _ := k.collector.Peer(time.Now(), addr)
+	if snapshot == nil || (snapshot.LastSeenTimestamp == 0 && snapshot.SessionConnectionRetry <= 1) {
+		return true
+	}
+
+	return false
+}
+
 // announce a newly connected peer to our connected peers, but also
 // notify the peer about our already connected peers
 func (k *Kad) Announce(ctx context.Context, peer swarm.Address) error {

pkg/topology/kademlia/kademlia_test.go

@@ -735,20 +735,18 @@ func TestAddressBookPrune(t *testing.T) {
 	waitCounter(t, &conns, 0)
 	waitCounter(t, &failedConns, 1)
 
-	addr := test.RandomAddressAt(base, 1)
-	addr1 := test.RandomAddressAt(base, 1)
-	addr2 := test.RandomAddressAt(base, 1)
-
 	p, err := ab.Get(nonConnPeer.Overlay)
 	if err != nil {
 		t.Fatal(err)
 	}
-
 	if !nonConnPeer.Equal(p) {
 		t.Fatalf("expected %+v, got %+v", nonConnPeer, p)
 	}
 
-	time.Sleep(50 * time.Millisecond)
+	addr := test.RandomAddressAt(base, 1)
+	addr1 := test.RandomAddressAt(base, 1)
+	addr2 := test.RandomAddressAt(base, 1)
+
 	// add one valid peer to initiate the retry, check connection and failed connection counters
 	addOne(t, signer, kad, ab, addr)
 	waitCounter(t, &conns, 1)
@@ -790,6 +788,50 @@ func TestAddressBookPrune(t *testing.T) {
 	}
 }
 
+func TestAddressBookQuickPrune(t *testing.T) {
+	// test pruning addressbook after successive failed connect attempts
+	// cheat and decrease the timer
+	defer func(t time.Duration) {
+		*kademlia.TimeToRetry = t
+	}(*kademlia.TimeToRetry)
+
+	*kademlia.TimeToRetry = 50 * time.Millisecond
+
+	var (
+		conns, failedConns       int32 // how many connect calls were made to the p2p mock
+		base, kad, ab, _, signer = newTestKademlia(t, &conns, &failedConns, kademlia.Options{})
+	)
+
+	if err := kad.Start(context.Background()); err != nil {
+		t.Fatal(err)
+	}
+	defer kad.Close()
+
+	nonConnPeer, err := bzz.NewAddress(signer, nonConnectableAddress, test.RandomAddressAt(base, 1), 0)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := ab.Put(nonConnPeer.Overlay, *nonConnPeer); err != nil {
+		t.Fatal(err)
+	}
+
+	addr := test.RandomAddressAt(base, 1)
+	// add one valid peer
+	addOne(t, signer, kad, ab, addr)
+	waitCounter(t, &conns, 1)
+	waitCounter(t, &failedConns, 0)
+
+	// add non connectable peer, check connection and failed connection counters
+	_ = kad.AddPeers(context.Background(), nonConnPeer.Overlay)
+	waitCounter(t, &conns, 0)
+	waitCounter(t, &failedConns, 1)
+
+	_, err = ab.Get(nonConnPeer.Overlay)
+	if !errors.Is(err, addressbook.ErrNotFound) {
+		t.Fatal(err)
+	}
+}
+
 // TestClosestPeer tests that ClosestPeer method returns closest connected peer to a given address.
 func TestClosestPeer(t *testing.T) {
 	metricsDB, err := shed.NewDB("", nil)