Restrict Dials From Discovery (#14052)

* Fix Excessive Subnet Dials

* Handle backoff in Iterator

* Slow Down Lookups

* Add Flag To Configure Dials

* Preston's Review

* Update cmd/beacon-chain/flags/base.go

Co-authored-by: Preston Van Loon <pvanloon@offchainlabs.com>

* Reduce polling period

* Manu's Review

---------

Co-authored-by: Preston Van Loon <pvanloon@offchainlabs.com>

cmd/beacon-chain/flags/base.go

@@ -227,6 +227,12 @@ var (
 		Usage: "Sets the minimum number of peers that a node will attempt to peer with that are subscribed to a subnet.",
 		Value: 6,
 	}
+	// MaxConcurrentDials defines a flag to set the maximum number of peers that a node will attempt to dial with from discovery.
+	MaxConcurrentDials = &cli.Uint64Flag{
+		Name: "max-concurrent-dials",
+		Usage: "Sets the maximum number of peers that a node will attempt to dial with from discovery. By default we will dials as " +
+			"many peers as possible.",
+	}
 	// SuggestedFeeRecipient specifies the fee recipient for the transaction fees.
 	SuggestedFeeRecipient = &cli.StringFlag{
 		Name:  "suggested-fee-recipient",

cmd/beacon-chain/flags/config.go

@@ -11,6 +11,7 @@ type GlobalFlags struct {
 	SubscribeToAllSubnets      bool
 	MinimumSyncPeers           int
 	MinimumPeersPerSubnet      int
+	MaxConcurrentDials         int
 	BlockBatchLimit            int
 	BlockBatchLimitBurstFactor int
 	BlobBatchLimit             int
@@ -45,11 +46,17 @@ func ConfigureGlobalFlags(ctx *cli.Context) {
 	cfg.BlobBatchLimit = ctx.Int(BlobBatchLimit.Name)
 	cfg.BlobBatchLimitBurstFactor = ctx.Int(BlobBatchLimitBurstFactor.Name)
 	cfg.MinimumPeersPerSubnet = ctx.Int(MinPeersPerSubnet.Name)
+	cfg.MaxConcurrentDials = ctx.Int(MaxConcurrentDials.Name)
 	configureMinimumPeers(ctx, cfg)
 
 	Init(cfg)
 }
 
+// MaxDialIsActive checks if the user has enabled the max dial flag.
+func MaxDialIsActive() bool {
+	return Get().MaxConcurrentDials > 0
+}
+
 func configureMinimumPeers(ctx *cli.Context, cfg *GlobalFlags) {
 	cfg.MinimumSyncPeers = ctx.Int(MinSyncPeers.Name)
 	maxPeers := ctx.Int(cmd.P2PMaxPeers.Name)

cmd/beacon-chain/main.go

@@ -72,6 +72,7 @@ var appFlags = []cli.Flag{
 	flags.WeakSubjectivityCheckpoint,
 	flags.Eth1HeaderReqLimit,
 	flags.MinPeersPerSubnet,
+	flags.MaxConcurrentDials,
 	flags.SuggestedFeeRecipient,
 	flags.TerminalTotalDifficultyOverride,
 	flags.TerminalBlockHashOverride,

cmd/beacon-chain/usage.go

@@ -124,6 +124,7 @@ var appHelpFlagGroups = []flagGroup{
 			flags.WeakSubjectivityCheckpoint,
 			flags.Eth1HeaderReqLimit,
 			flags.MinPeersPerSubnet,
+			flags.MaxConcurrentDials,
 			flags.MevRelayEndpoint,
 			flags.MaxBuilderEpochMissedSlots,
 			flags.MaxBuilderConsecutiveMissedSlots,