Remove non-determinism in tests (undo FAB-839)

The changeset submitted for FAB-839 introduces some non-determinism which
makes the tests in the kafka package block. To test that this is the
case, checkout that changeset [1] and run the tests in the kafka package
with the "-count 50" option. A quick inspection shows we may be dealing
with context leakage, but I'll defer to Luis to investigate this further.
Until then, this changeset disables the new test and restores the old
send-replies logic of the code. It passes all tests.

[1] https://gerrit.hyperledger.org/r/#/c/2043/

Change-Id: Ie29bc38288fad3c893bc332771974ec1f19b7a4b
Signed-off-by: Kostas Christidis <kostas@christidis.io>

Author: Kostas Christidis

orderer/kafka/broadcast.go

@@ -25,7 +25,6 @@ import (
 	"github.com/hyperledger/fabric/orderer/config"
 	cb "github.com/hyperledger/fabric/protos/common"
 	ab "github.com/hyperledger/fabric/protos/orderer"
-	"golang.org/x/net/context"
 
 	"github.com/golang/protobuf/proto"
 )
@@ -142,9 +141,7 @@ func (b *broadcasterImpl) cutBlock(period time.Duration, maxSize uint) {
 }
 
 func (b *broadcasterImpl) recvRequests(stream ab.AtomicBroadcast_BroadcastServer) error {
-	context, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	bsr := newBroadcastSessionResponder(context, stream, b.config.General.QueueSize)
+	reply := new(ab.BroadcastResponse)
 	for {
 		msg, err := stream.Recv()
 		if err != nil {
@@ -153,33 +150,12 @@ func (b *broadcasterImpl) recvRequests(stream ab.AtomicBroadcast_BroadcastServer
 		}
 
 		b.batchChan <- msg
-		bsr.reply(cb.Status_SUCCESS) // TODO This shouldn't always be a success
+		reply.Status = cb.Status_SUCCESS // TODO This shouldn't always be a success
 
-	}
-}
-
-func newBroadcastSessionResponder(context context.Context, stream ab.AtomicBroadcast_BroadcastServer, queueSize uint) *broadcastSessionResponder {
-	bsr := &broadcastSessionResponder{
-		queue: make(chan *ab.BroadcastResponse, queueSize),
-	}
-	go bsr.sendReplies(context, stream)
-	return bsr
-}
-
-func (bsr *broadcastSessionResponder) reply(status cb.Status) {
-	bsr.queue <- &ab.BroadcastResponse{Status: status}
-}
-
-func (bsr *broadcastSessionResponder) sendReplies(context context.Context, stream ab.AtomicBroadcast_BroadcastServer) {
-	for {
-		select {
-		case reply := <-bsr.queue:
-			if err := stream.Send(reply); err != nil {
-				logger.Info("Cannot send broadcast reply to client")
-			}
-			logger.Debugf("Sent broadcast reply %v to client", reply.Status.String())
-		case <-context.Done():
-			return
+		if err := stream.Send(reply); err != nil {
+			logger.Info("Cannot send broadcast reply to client")
 		}
+		logger.Debugf("Sent broadcast reply %s to client", reply.Status.String())
+
 	}
 }

orderer/kafka/broadcast_mock_test.go

@@ -27,7 +27,7 @@ func mockNewBroadcaster(t *testing.T, conf *config.TopLevel, seek int64, disk ch
 	mb := &broadcasterImpl{
 		producer:   mockNewProducer(t, conf, seek, disk),
 		config:     conf,
-		batchChan:  make(chan *cb.Envelope, batchChanSize),
+		batchChan:  make(chan *cb.Envelope, conf.General.BatchSize),
 		messages:   [][]byte{[]byte("checkpoint")},
 		nextNumber: uint64(seek),
 	}

orderer/kafka/broadcast_test.go

@@ -139,7 +139,7 @@ func TestBroadcastBatch(t *testing.T) {
 // then if the response queue overflows, the order should not be able
 // to send back a block to the client. (Sending replies and adding
 // messages to the about-to-be-sent block happens on the same routine.)
-func TestBroadcastResponseQueueOverflow(t *testing.T) {
+/* func TestBroadcastResponseQueueOverflow(t *testing.T) {
 
 	// Make sure that the response queue is less than the batch size
 	originalQueueSize := testConf.General.QueueSize
@@ -180,7 +180,7 @@ loop:
 			break loop // This is the success path
 		}
 	}
-}
+} */
 
 func TestBroadcastIncompleteBatch(t *testing.T) {
 	if testConf.General.BatchSize <= 1 {

orderer/kafka/config_test.go

@@ -24,11 +24,10 @@ import (
 )
 
 var (
-	brokerID      = int32(0)
-	oldestOffset  = int64(100)                            // The oldest block available on the broker
-	newestOffset  = int64(1100)                           // The offset that will be assigned to the next block
-	middleOffset  = (oldestOffset + newestOffset - 1) / 2 // Just an offset in the middle
-	batchChanSize = 1000                                  // Size of batch channel (eventually sync with FAB-821)
+	brokerID     = int32(0)
+	oldestOffset = int64(100)                            // The oldest block available on the broker
+	newestOffset = int64(1100)                           // The offset that will be assigned to the next block
+	middleOffset = (oldestOffset + newestOffset - 1) / 2 // Just an offset in the middle
 
 	// Amount of time to wait for block processing when doing time-based tests
 	// We generally want this value to be as small as possible so as to make tests execute faster

orderer/kafka/orderer_mock_test.go

@@ -53,8 +53,6 @@ func (mbs *mockBroadcastStream) Recv() (*cb.Envelope, error) {
 }
 
 func (mbs *mockBroadcastStream) Send(reply *ab.BroadcastResponse) error {
-	for mbs.closed {
-	}
 	if !mbs.closed {
 		mbs.outgoing <- reply
 	}

orderer/orderer.yaml

@@ -25,6 +25,7 @@ General:
     BatchSize: 10
 
     # Queue Size: The maximum number of messages to allow pending from a gRPC client
+    # This option is currently ignored for the Kafka OrdererType.
     QueueSize: 10
 
     # Max Window Size: The maximum number of messages to for the orderer Deliver