multi: make SubBatchDelay configurable

This commit adds a new config option `--gossip.sub-batch-delay` so we
can speed up our itest.

config.go

@@ -629,6 +629,7 @@ func DefaultConfig() Config {
 		Gossip: &lncfg.Gossip{
 			MaxChannelUpdateBurst: discovery.DefaultMaxChannelUpdateBurst,
 			ChannelUpdateInterval: discovery.DefaultChannelUpdateInterval,
+			SubBatchDelay:         discovery.DefaultSubBatchDelay,
 		},
 		Invoices: &lncfg.Invoices{
 			HoldExpiryDelta: lncfg.DefaultHoldInvoiceExpiryDelta,

discovery/gossiper.go

@@ -47,6 +47,10 @@ const (
 	// updates that we'll hold onto.
 	maxPrematureUpdates = 100
 
+	// DefaultSubBatchDelay is the default delay we'll use when
+	// broadcasting the next announcement batch.
+	DefaultSubBatchDelay = 5 * time.Second
+
 	// maxRejectedUpdates tracks the max amount of rejected channel updates
 	// we'll maintain. This is the global size across all peers. We'll
 	// allocate ~3 MB max to the cache.

lncfg/gossip.go

@@ -16,6 +16,8 @@ type Gossip struct {
 	MaxChannelUpdateBurst int `long:"max-channel-update-burst" description:"The maximum number of updates for a specific channel and direction that lnd will accept over the channel update interval."`
 
 	ChannelUpdateInterval time.Duration `long:"channel-update-interval" description:"The interval used to determine how often lnd should allow a burst of new updates for a specific channel and direction."`
+
+	SubBatchDelay time.Duration `long:"sub-batch-delay" description:"The duration to wait before sending the next announcement batch if there are multiple. Use a small value if there are a lot announcements and they need to be broadcast quickly."`
 }
 
 // Parse the pubkeys for the pinned syncers.

lntemp/node/config.go

@@ -187,6 +187,10 @@ func (cfg *BaseNodeConfig) GenArgs() []string {
 		// Use a small batch window so we can broadcast our sweep
 		// transactions faster.
 		"--sweeper.batchwindowduration=5s",
+
+		// Use a small batch delay so we can broadcast the
+		// announcements quickly in the tests.
+		"--gossip.sub-batch-delay=5ms",
 	}
 	args = append(args, nodeArgs...)
 

sample-lnd.conf

@@ -1423,6 +1423,10 @@ litecoin.node=ltcd
 ; gossip.max-channel-update-burst=10
 ; gossip.channel-update-interval=1m
 
+; The duration to wait before sending the next announcement batch if there are
+; multiple. Use a small value if there are a lot announcements and they need to
+; be broadcast quickly.
+; gossip.sub-batch-delay=5s
 
 [invoices]
 

server.go

@@ -1013,7 +1013,7 @@ func newServer(cfg *Config, listenAddrs []net.Addr,
 		HistoricalSyncTicker:    ticker.New(cfg.HistoricalSyncInterval),
 		NumActiveSyncers:        cfg.NumGraphSyncPeers,
 		MinimumBatchSize:        10,
-		SubBatchDelay:           time.Second * 5,
+		SubBatchDelay:           cfg.Gossip.SubBatchDelay,
 		IgnoreHistoricalFilters: cfg.IgnoreHistoricalGossipFilters,
 		PinnedSyncers:           cfg.Gossip.PinnedSyncers,
 		MaxChannelUpdateBurst:   cfg.Gossip.MaxChannelUpdateBurst,