Fluffy: Make number of nodes to gossip content to configurable (#2653)

fluffy/conf.nim

@@ -45,6 +45,7 @@ const
   defaultTableIpLimitDesc* = $defaultPortalProtocolConfig.tableIpLimits.tableIpLimit
   defaultBucketIpLimitDesc* = $defaultPortalProtocolConfig.tableIpLimits.bucketIpLimit
   defaultBitsPerHopDesc* = $defaultPortalProtocolConfig.bitsPerHop
+  defaultMaxGossipNodesDesc* = $defaultPortalProtocolConfig.maxGossipNodes
 
 type
   TrustedDigest* = MDigest[32 * 8]
@@ -235,6 +236,14 @@ type
       name: "bits-per-hop"
     .}: int
 
+    maxGossipNodes* {.
+      hidden,
+      desc: "The maximum number of nodes to send content to during gossip",
+      defaultValue: defaultPortalProtocolConfig.maxGossipNodes,
+      defaultValueDesc: $defaultMaxGossipNodesDesc,
+      name: "max-gossip-nodes"
+    .}: int
+
     radiusConfig* {.
       desc:
         "Radius configuration for a fluffy node. Radius can be either `dynamic` " &

fluffy/fluffy.nim

@@ -159,7 +159,7 @@ proc run(
   let
     portalProtocolConfig = PortalProtocolConfig.init(
       config.tableIpLimit, config.bucketIpLimit, config.bitsPerHop, config.radiusConfig,
-      config.disablePoke,
+      config.disablePoke, config.maxGossipNodes,
     )
 
     portalNodeConfig = PortalNodeConfig(

fluffy/network/wire/portal_protocol.nim

@@ -182,6 +182,7 @@ type
     offerWorkers: seq[Future[void]]
     disablePoke: bool
     pingTimings: Table[NodeId, chronos.Moment]
+    maxGossipNodes: int
 
   PortalResult*[T] = Result[T, string]
 
@@ -573,6 +574,7 @@ proc new*(
     offerQueue: newAsyncQueue[OfferRequest](concurrentOffers),
     disablePoke: config.disablePoke,
     pingTimings: Table[NodeId, chronos.Moment](),
+    maxGossipNodes: config.maxGossipNodes,
   )
 
   proto.baseProtocol.registerTalkProtocol(@(proto.protocolId), proto).expect(
@@ -1503,7 +1505,6 @@ proc neighborhoodGossip*(
   # in its propagation than when looking only for nodes in the own routing
   # table, but at the same time avoid unnecessary node lookups.
   # It might still cause issues in data getting propagated in a wider id range.
-  const maxGossipNodes = 8
 
   let closestLocalNodes =
     p.routingTable.neighbours(NodeId(contentId), k = 16, seenOnly = true)
@@ -1518,9 +1519,9 @@ proc neighborhoodGossip*(
         elif node.id != srcNodeId.get():
           gossipNodes.add(node)
 
-  if gossipNodes.len >= 8: # use local nodes for gossip
+  if gossipNodes.len >= p.maxGossipNodes: # use local nodes for gossip
     portal_gossip_without_lookup.inc(labelValues = [$p.protocolId])
-    let numberOfGossipedNodes = min(gossipNodes.len, maxGossipNodes)
+    let numberOfGossipedNodes = min(gossipNodes.len, p.maxGossipNodes)
     for node in gossipNodes[0 ..< numberOfGossipedNodes]:
       let req = OfferRequest(dst: node, kind: Direct, contentList: contentList)
       await p.offerQueue.addLast(req)
@@ -1528,7 +1529,7 @@ proc neighborhoodGossip*(
   else: # use looked up nodes for gossip
     portal_gossip_with_lookup.inc(labelValues = [$p.protocolId])
     let closestNodes = await p.lookup(NodeId(contentId))
-    let numberOfGossipedNodes = min(closestNodes.len, maxGossipNodes)
+    let numberOfGossipedNodes = min(closestNodes.len, p.maxGossipNodes)
     for node in closestNodes[0 ..< numberOfGossipedNodes]:
       # Note: opportunistically not checking if the radius of the node is known
       # and thus if the node is in radius with the content. Reason is, these

fluffy/network/wire/portal_protocol_config.nim

@@ -40,17 +40,21 @@ type
     bitsPerHop*: int
     radiusConfig*: RadiusConfig
     disablePoke*: bool
+    maxGossipNodes*: int
 
 const
   defaultRadiusConfig* = RadiusConfig(kind: Dynamic)
   defaultRadiusConfigDesc* = $defaultRadiusConfig.kind
   defaultDisablePoke* = false
+  defaultMaxGossipNodes = 8
   revalidationTimeout* = chronos.seconds(30)
 
   defaultPortalProtocolConfig* = PortalProtocolConfig(
     tableIpLimits: DefaultTableIpLimits,
     bitsPerHop: DefaultBitsPerHop,
     radiusConfig: defaultRadiusConfig,
+    disablePoke: defaultDisablePoke,
+    maxGossipNodes: defaultMaxGossipNodes,
   )
 
 proc init*(
@@ -60,6 +64,7 @@ proc init*(
     bitsPerHop: int,
     radiusConfig: RadiusConfig,
     disablePoke: bool,
+    maxGossipNodes: int,
 ): T =
   PortalProtocolConfig(
     tableIpLimits:
@@ -67,6 +72,7 @@ proc init*(
     bitsPerHop: bitsPerHop,
     radiusConfig: radiusConfig,
     disablePoke: disablePoke,
+    maxGossipNodes: maxGossipNodes,
   )
 
 func fromLogRadius*(T: type UInt256, logRadius: uint16): T =