Optionally disable gossip block forwarding (#2606)

This commit adds a new configuration option to the peer which makes peers
not forward blocks that they pull from the ordering service.

If all peers in an organization explicitly set "peer.deliveryclient.blockGossipEnabled" to false,
no peer in the organization gossips blocks to any other peer in that organization.

Change-Id: I5d9b278ae72f239129827c044fa78179f6ba87ab
Signed-off-by: Yacov Manevich <yacovm@il.ibm.com>
(cherry picked from commit 4e201af)

core/deliverservice/config.go

@@ -29,6 +29,8 @@ const (
 type DeliverServiceConfig struct {
 	// PeerTLSEnabled enables/disables Peer TLS.
 	PeerTLSEnabled bool
+	// BlockGossipEnabled enables block forwarding via gossip
+	BlockGossipEnabled bool
 	// ReConnectBackoffThreshold sets the delivery service maximal delay between consencutive retries.
 	ReConnectBackoffThreshold time.Duration
 	// ReconnectTotalTimeThreshold sets the total time the delivery service may spend in reconnection attempts
@@ -95,6 +97,13 @@ func LoadOverridesMap() (map[string]*orderers.Endpoint, error) {
 }
 
 func (c *DeliverServiceConfig) loadDeliverServiceConfig() {
+	enabledKey := "peer.deliveryclient.blockGossipEnabled"
+	enabledConfigOptionMissing := !viper.IsSet(enabledKey)
+	if enabledConfigOptionMissing {
+		logger.Infof("peer.deliveryclient.blockGossipEnabled is not set, defaulting to true.")
+	}
+	c.BlockGossipEnabled = enabledConfigOptionMissing || viper.GetBool(enabledKey)
+
 	c.PeerTLSEnabled = viper.GetBool("peer.tls.enabled")
 
 	c.ReConnectBackoffThreshold = viper.GetDuration("peer.deliveryclient.reConnectBackoffThreshold")

core/deliverservice/config_test.go

@@ -93,6 +93,7 @@ func TestGlobalConfig(t *testing.T) {
 	coreConfig := deliverservice.GlobalConfig()
 
 	expectedConfig := &deliverservice.DeliverServiceConfig{
+		BlockGossipEnabled:          true,
 		PeerTLSEnabled:              true,
 		ReConnectBackoffThreshold:   25 * time.Second,
 		ReconnectTotalTimeThreshold: 20 * time.Second,
@@ -119,6 +120,7 @@ func TestGlobalConfigDefault(t *testing.T) {
 	coreConfig := deliverservice.GlobalConfig()
 
 	expectedConfig := &deliverservice.DeliverServiceConfig{
+		BlockGossipEnabled:          true,
 		PeerTLSEnabled:              false,
 		ReConnectBackoffThreshold:   deliverservice.DefaultReConnectBackoffThreshold,
 		ReconnectTotalTimeThreshold: deliverservice.DefaultReConnectTotalTimeThreshold,

core/deliverservice/deliveryclient.go

@@ -128,15 +128,16 @@ func (d *deliverServiceImpl) StartDeliverForChannel(chainID string, ledgerInfo b
 		Dialer: DialerAdapter{
 			Client: d.conf.DeliverGRPCClient,
 		},
-		Orderers:          d.conf.OrdererSource,
-		DoneC:             make(chan struct{}),
-		Signer:            d.conf.Signer,
-		DeliverStreamer:   DeliverAdapter{},
-		Logger:            flogging.MustGetLogger("peer.blocksprovider").With("channel", chainID),
-		MaxRetryDelay:     d.conf.DeliverServiceConfig.ReConnectBackoffThreshold,
-		MaxRetryDuration:  d.conf.DeliverServiceConfig.ReconnectTotalTimeThreshold,
-		InitialRetryDelay: 100 * time.Millisecond,
-		YieldLeadership:   !d.conf.IsStaticLeader,
+		Orderers:            d.conf.OrdererSource,
+		DoneC:               make(chan struct{}),
+		Signer:              d.conf.Signer,
+		DeliverStreamer:     DeliverAdapter{},
+		Logger:              flogging.MustGetLogger("peer.blocksprovider").With("channel", chainID),
+		MaxRetryDelay:       d.conf.DeliverServiceConfig.ReConnectBackoffThreshold,
+		MaxRetryDuration:    d.conf.DeliverServiceConfig.ReconnectTotalTimeThreshold,
+		BlockGossipDisabled: !d.conf.DeliverServiceConfig.BlockGossipEnabled,
+		InitialRetryDelay:   100 * time.Millisecond,
+		YieldLeadership:     !d.conf.IsStaticLeader,
 	}
 
 	if d.conf.DeliverGRPCClient.MutualTLSRequired() {

internal/pkg/peer/blocksprovider/blocksprovider.go

@@ -96,9 +96,10 @@ type Deliverer struct {
 	Logger          *flogging.FabricLogger
 	YieldLeadership bool
 
-	MaxRetryDelay     time.Duration
-	InitialRetryDelay time.Duration
-	MaxRetryDuration  time.Duration
+	BlockGossipDisabled bool
+	MaxRetryDelay       time.Duration
+	InitialRetryDelay   time.Duration
+	MaxRetryDuration    time.Duration
 
 	// TLSCertHash should be nil when TLS is not enabled
 	TLSCertHash []byte // util.ComputeSHA256(b.credSupport.GetClientCertificate().Certificate[0])
@@ -111,6 +112,9 @@ const backoffExponentBase = 1.2
 // DeliverBlocks used to pull out blocks from the ordering service to
 // distributed them across peers
 func (d *Deliverer) DeliverBlocks() {
+	if d.BlockGossipDisabled {
+		d.Logger.Infof("Will pull blocks without forwarding them to remote peers via gossip")
+	}
 	failureCounter := 0
 	totalDuration := time.Duration(0)
 
@@ -256,7 +260,9 @@ func (d *Deliverer) processMsg(msg *orderer.DeliverResponse) error {
 			d.Logger.Warningf("Block [%d] received from ordering service wasn't added to payload buffer: %v", blockNum, err)
 			return errors.WithMessage(err, "could not add block as payload")
 		}
-
+		if d.BlockGossipDisabled {
+			return nil
+		}
 		// Gossip messages with other nodes
 		d.Logger.Debugf("Gossiping block [%d]", blockNum)
 		d.Gossip.Gossip(gossipMsg)

internal/pkg/peer/blocksprovider/blocksprovider_test.go

@@ -533,6 +533,28 @@ var _ = Describe("Blocksprovider", func() {
 				},
 			}))
 		})
+
+		When("gossip dissemination is disabled", func() {
+			BeforeEach(func() {
+				d.BlockGossipDisabled = true
+			})
+
+			It("doesn't gossip, only adds to the payload buffer", func() {
+				Eventually(fakeGossipServiceAdapter.AddPayloadCallCount).Should(Equal(1))
+				channelID, payload := fakeGossipServiceAdapter.AddPayloadArgsForCall(0)
+				Expect(channelID).To(Equal("channel-id"))
+				Expect(payload).To(Equal(&gossip.Payload{
+					Data: protoutil.MarshalOrPanic(&common.Block{
+						Header: &common.BlockHeader{
+							Number: 8,
+						},
+					}),
+					SeqNum: 8,
+				}))
+
+				Consistently(fakeGossipServiceAdapter.GossipCallCount).Should(Equal(0))
+			})
+		})
 	})
 
 	When("the deliver client returns a status", func() {

sampleconfig/core.yaml

@@ -343,6 +343,11 @@ peer:
 
     # Delivery service related config
     deliveryclient:
+        # Enables this peer to disseminate blocks it pulled from the ordering service
+        # via gossip.
+        # Note that 'gossip.state.enabled' controls point to point block replication
+        # of blocks committed in the past.
+        blockGossipEnabled: true
         # It sets the total time the delivery service may spend in reconnection
         # attempts until its retry logic gives up and returns an error
         reconnectTotalTimeThreshold: 3600s