config: add channel commit batch size parameter

config.go

@@ -145,6 +145,11 @@ const (
 	// defaultChannelCommitInterval is the default maximum time between receiving a
 	// channel state update and signing a new commitment.
 	defaultChannelCommitInterval = 50 * time.Millisecond
+
+	// defaultChannelCommitBatchSize is the default maximum number of
+	// channel state updates that is accumulated before signing a new
+	// commitment.
+	defaultChannelCommitBatchSize = 10
 )
 
 var (
@@ -294,6 +299,7 @@ type Config struct {
 	CoopCloseTargetConfs          uint32        `long:"coop-close-target-confs" description:"The target number of blocks that a cooperative channel close transaction should confirm in. This is used to estimate the fee to use as the lower bound during fee negotiation for the channel closure."`
 
 	ChannelCommitInterval  time.Duration `long:"channel-commit-interval" description:"The maximum time that is allowed to pass between receiving a channel state update and signing the next commitment. Setting this to a longer duration allows for more efficient channel operations at the cost of latency."`
+	ChannelCommitBatchSize uint32        `long:"channel-commit-batch-size" description:"The maximum number of channel state updates that is accumulated before signing a new commitment."`
 
 	DefaultRemoteMaxHtlcs uint16 `long:"default-remote-max-htlcs" description:"The default max_htlc applied when opening or accepting channels. This value limits the number of concurrent HTLCs that the remote party can add to the commitment. The maximum possible value is 483."`
 
@@ -514,6 +520,7 @@ func DefaultConfig() Config {
 		registeredChains:        chainreg.NewChainRegistry(),
 		ActiveNetParams:         chainreg.BitcoinTestNetParams,
 		ChannelCommitInterval:   defaultChannelCommitInterval,
+		ChannelCommitBatchSize:  defaultChannelCommitBatchSize,
 	}
 }
 

peer/brontide.go

@@ -314,6 +314,10 @@ type Config struct {
 	// operations at the cost of latency.
 	ChannelCommitInterval time.Duration
 
+	// ChannelCommitBatchSize is the maximum number of channel state updates
+	// that is accumulated before signing a new commitment.
+	ChannelCommitBatchSize uint32
+
 	// Quit is the server's quit channel. If this is closed, we halt operation.
 	Quit chan struct{}
 }
@@ -822,7 +826,7 @@ func (p *Brontide) addLink(chanPoint *wire.OutPoint,
 		BatchTicker:             ticker.New(p.cfg.ChannelCommitInterval),
 		FwdPkgGCTicker:          ticker.New(time.Hour),
 		PendingCommitTicker:     ticker.New(time.Minute),
-		BatchSize:               10,
+		BatchSize:               p.cfg.ChannelCommitBatchSize,
 		UnsafeReplay:            p.cfg.UnsafeReplay,
 		MinFeeUpdateTimeout:     htlcswitch.DefaultMinLinkFeeUpdateTimeout,
 		MaxFeeUpdateTimeout:     htlcswitch.DefaultMaxLinkFeeUpdateTimeout,

sample-lnd.conf

@@ -269,6 +269,10 @@
 ; allows for more efficient channel operations at the cost of latency.
 ; channel-commit-interval=50ms
 
+; The maximum number of channel state updates that is accumulated before signing
+; a new commitment.
+; channel-commit-batch-size=10
+
 ; The default max_htlc applied when opening or accepting channels. This value
 ; limits the number of concurrent HTLCs that the remote party can add to the
 ; commitment. The maximum possible value is 483.

server.go

@@ -3138,6 +3138,7 @@ func (s *server) peerConnected(conn net.Conn, connReq *connmgr.ConnReq,
 		MaxAnchorsCommitFeeRate: chainfee.SatPerKVByte(
 			s.cfg.MaxCommitFeeRateAnchors * 1000).FeePerKWeight(),
 		ChannelCommitInterval:  s.cfg.ChannelCommitInterval,
+		ChannelCommitBatchSize: s.cfg.ChannelCommitBatchSize,
 		Quit:                   s.quit,
 	}