fix sbft hello msg issue

After receiveing a hello message, a replica would not cleanup its sbft
state (checkpointDone and timer cancellation). This would leave a replica
hanging not able to process new requests.

Added a test (TestHelloMsg) to demonstrate this. This required also
enabling sbft TestSystem configuration with disabled Timer interface.

Change-Id: I4f8dc7e57c656a09ad536b229c9709213c5eb6af
Signed-off-by: Marko Vukolic <[email protected]>

Author: Marko Vukolic

orderer/sbft/simplebft/checkpoint.go

@@ -84,7 +84,6 @@ func (s *SBFT) handleCheckpoint(c *Checkpoint, src uint64) {
 		cp := s.cur.checkpoint[r]
 		cpset[r] = cp.Signature
 	}
-	s.cur.checkpointDone = true
 
 	c = s.cur.checkpoint[replicas[0]]
 
@@ -98,10 +97,7 @@ func (s *SBFT) handleCheckpoint(c *Checkpoint, src uint64) {
 	batch := *s.cur.preprep.Batch
 	batch.Signatures = cpset
 	s.deliverBatch(&batch)
-
-	s.cur.timeout.Cancel()
-	log.Infof("replica %d: request %s %s completed on %d", s.id, s.cur.subject.Seq, hash2str(s.cur.subject.Digest), s.id)
-
+	log.Infof("replica %d: request %s %s delivered on %d (completed common case)", s.id, s.cur.subject.Seq, hash2str(s.cur.subject.Digest), s.id)
 	s.maybeSendNextBatch()
 	s.processBacklog()
 }

orderer/sbft/simplebft/connection.go

@@ -66,12 +66,15 @@ func (s *SBFT) Connection(replica uint64) {
 
 func (s *SBFT) handleHello(h *Hello, src uint64) {
 	bh, err := s.checkBatch(h.Batch, false, true)
+	log.Debugf("replica %d: got hello for batch %d from replica %d", s.id, bh.Seq, src)
+
 	if err != nil {
 		log.Warningf("replica %d: invalid hello batch from %d: %s", s.id, src, err)
 		return
 	}
 
 	if s.sys.LastBatch().DecodeHeader().Seq < bh.Seq {
+		log.Debugf("replica %d: delivering batch %d after hello from replica %d", s.id, bh.Seq, src)
 		s.deliverBatch(h.Batch)
 	}
 

orderer/sbft/simplebft/newview.go

@@ -199,7 +199,6 @@ func (s *SBFT) maybeDeliverUsingXset(nv *NewView) {
 			// we just received a signature set for a request which we preprepared, but never delivered.
 			prevBatch.Payloads = s.cur.preprep.Batch.Payloads
 		}
-		s.cur.checkpointDone = true
 		s.deliverBatch(prevBatch)
 	}
 }

orderer/sbft/simplebft/simplebft.go

@@ -230,6 +230,8 @@ func (s *SBFT) handleQueueableMessage(m *Msg, src uint64) {
 }
 
 func (s *SBFT) deliverBatch(batch *Batch) {
+	s.cur.checkpointDone = true
+	s.cur.timeout.Cancel()
 	s.sys.Deliver(batch)
 
 	for _, req := range batch.Payloads {

orderer/sbft/simplebft/simplebft_test.go

@@ -940,6 +940,72 @@ func TestFullBacklog(t *testing.T) {
 	}
 }
 
+func TestHelloMsg(t *testing.T) {
+	N := uint64(4)
+	sys := newTestSystemWOTimers(N)
+	var repls []*SBFT
+	var adapters []*testSystemAdapter
+	for i := uint64(0); i < N; i++ {
+		a := sys.NewAdapter(i)
+		s, err := New(i, &Config{N: N, F: 1, BatchDurationNsec: 2000000000, BatchSizeBytes: 1, RequestTimeoutNsec: 20000000000}, a)
+		if err != nil {
+			t.Fatal(err)
+		}
+		repls = append(repls, s)
+		adapters = append(adapters, a)
+	}
+
+	phase := 1
+
+	// We are going to deliver only pre-prepare of the first request to replica 1
+	// other messages pertaining to first request, destined to 1 will be dropped
+	sys.filterFn = func(e testElem) (testElem, bool) {
+		if msg, ok := e.ev.(*testMsgEvent); ok {
+			if msg.dst == 1 {
+				c := msg.msg.GetPreprepare()
+				if c != nil && c.Seq.View == 0 && phase == 1 {
+					return e, true // letting the first pre-prepare be delivered to 1
+				}
+				if phase > 1 {
+					return e, true //letting msgs outside phase 1 through
+				}
+				return e, false //dropping other phase 1 msgs
+			}
+		}
+		return e, true
+	}
+
+	connectAll(sys)
+	r1 := []byte{1, 2, 3}
+	repls[0].Request(r1)
+	sys.Run()
+
+	phase = 2 //start delivering msgs to replica 1
+
+	testLog.Notice("restarting replica 1")
+	repls[1], _ = New(1, &Config{N: N, F: 1, BatchDurationNsec: 2000000000, BatchSizeBytes: 10, RequestTimeoutNsec: 20000000000}, adapters[1])
+	for _, a := range adapters {
+		if a.id != 1 {
+			a.receiver.Connection(1)
+			adapters[1].receiver.Connection(a.id)
+		}
+	}
+
+	sys.Run()
+
+	phase = 3
+
+	r3 := []byte{3, 5, 2}
+	repls[1].Request(r3)
+	sys.Run()
+
+	for _, a := range adapters {
+		if len(a.batches) != 2 {
+			t.Fatal("expected execution of 2 batches")
+		}
+	}
+}
+
 func TestViewChangeTimer(t *testing.T) {
 	N := uint64(4)
 	sys := newTestSystem(N)

orderer/sbft/simplebft/testsys_test.go

@@ -139,7 +139,9 @@ func (t *testTimer) String() string {
 
 func (t *testSystemAdapter) Timer(d time.Duration, tf func()) Canceller {
 	tt := &testTimer{id: t.id, tf: tf}
-	t.sys.enqueue(d, tt)
+	if !t.sys.disableTimers {
+		t.sys.enqueue(d, tt)
+	}
 	return tt
 }
 
@@ -171,9 +173,8 @@ func (t *testSystemAdapter) Restore(key string, out proto.Message) bool {
 func (t *testSystemAdapter) LastBatch() *Batch {
 	if len(t.batches) == 0 {
 		return t.receiver.(*SBFT).makeBatch(0, nil, nil)
-	} else {
-		return t.batches[len(t.batches)-1]
 	}
+	return t.batches[len(t.batches)-1]
 }
 
 func (t *testSystemAdapter) Sign(data []byte) []byte {
@@ -233,11 +234,12 @@ type testEvent interface {
 // ==============================================
 
 type testSystem struct {
-	rand     *rand.Rand
-	now      time.Duration
-	queue    *calendarQueue
-	adapters map[uint64]*testSystemAdapter
-	filterFn func(testElem) (testElem, bool)
+	rand          *rand.Rand
+	now           time.Duration
+	queue         *calendarQueue
+	adapters      map[uint64]*testSystemAdapter
+	filterFn      func(testElem) (testElem, bool)
+	disableTimers bool
 }
 
 type testElem struct {
@@ -257,6 +259,15 @@ func newTestSystem(n uint64) *testSystem {
 	}
 }
 
+func newTestSystemWOTimers(n uint64) *testSystem {
+	return &testSystem{
+		rand:          rand.New(rand.NewSource(0)),
+		adapters:      make(map[uint64]*testSystemAdapter),
+		queue:         newCalendarQueue(time.Millisecond/time.Duration(n*n), int(n*n)),
+		disableTimers: true,
+	}
+}
+
 func (t *testSystem) NewAdapter(id uint64) *testSystemAdapter {
 	key, err := ecdsa.GenerateKey(elliptic.P256(), crand.Reader)
 	if err != nil {