chore(shwap/discovery): prefix -> suffix (#3778)

Fixes #3777

nodebuilder/share/p2p_constructors.go

@@ -26,9 +26,9 @@ const (
 	// discovery service.
 	archivalNodesTag = "archival"
 
-	// discovery version is a prefix for all tags used in discovery. It is bumped when
-	// there are protocol breaking changes.
-	version = "v0.1.0"
+	// protocolVersion is a prefix for all tags used in discovery. It is bumped when
+	// there are protocol breaking changes to prevent new software version to discover older versions.
+	protocolVersion = "v0.1.0"
 )
 
 // TODO @renaynay: rename
@@ -85,8 +85,8 @@ func fullDiscoveryAndPeerManager(tp node.Type, cfg *Config) fx.Option {
 				cfg.Discovery,
 				host,
 				disc,
-				version,
 				fullNodesTag,
+				protocolVersion,
 				discOpts...,
 			)
 			if err != nil {
@@ -133,7 +133,7 @@ func archivalDiscoveryAndPeerManager(tp node.Type, cfg *Config) fx.Option {
 				cfg.Discovery,
 				h,
 				disc,
-				version,
+				protocolVersion,
 				archivalNodesTag,
 				discOpts...,
 			)

share/shwap/p2p/discovery/discovery.go

@@ -77,12 +77,15 @@ func (f OnUpdatedPeers) add(next OnUpdatedPeers) OnUpdatedPeers {
 }
 
 // NewDiscovery constructs a new discovery.
+// It accepts tag which is a rendezvous point/topic for peers
+// to advertise and discover each other. Tag suffix is used to create
+// subnetworks within a tag, e.g. for different protocol versions yet running
+// over the same p2p network.
 func NewDiscovery(
 	params *Parameters,
 	h host.Host,
 	d discovery.Discovery,
-	prefix string,
-	tag string,
+	tag, tagSuffix string,
 	opts ...Option,
 ) (*Discovery, error) {
 	if err := params.Validate(); err != nil {
@@ -95,7 +98,7 @@ func NewDiscovery(
 	o := newOptions(opts...)
 	return &Discovery{
 		tag:            tag,
-		topic:          fmt.Sprintf("/%s/%s", prefix, tag),
+		topic:          fmt.Sprintf("/%s/%s", tag, tagSuffix),
 		set:            newLimitedSet(params.PeersLimit),
 		host:           h,
 		disc:           d,