Fix Mesh Size in libp2p-pubsub

[zhaochonghe]

Describe the bug

prysm/beacon-chain/p2p/pubsub.go

Lines 180 to 189 in cfbfccb

	// creates a custom gossipsub parameter set.
	func pubsubGossipParam() pubsub.GossipSubParams {
	gParams := pubsub.DefaultGossipSubParams()
	gParams.Dlo = gossipSubDlo
	gParams.D = gossipSubD
	gParams.HeartbeatInterval = gossipSubHeartbeatInterval
	gParams.HistoryLength = gossipSubMcacheLen
	gParams.HistoryGossip = gossipSubMcacheGossip
	return gParams
	}

This is the function that sets the mesh size in the underlying LibP2P network. However, the setting for parameter “gParams.Dhi” is missing in this function, and the following line should be added:

"gParams.Dhi=gossipSubDhi"

The reason and the bug are as follows:

"gParams.Dlo", "gParams.D", and "gParams.Dhi" are used to maintain the mesh size for libP2P network: when the mesh size is smaller than "gParams.Dlo" or larger than "gParams.Dhi", the mesh size will be adjusted to "gParams.D". In current libP2P, the default values for these three parameters are 5, 6, and 12, respectively (details can be found in the following link).

https://github.com/libp2p/go-libp2p-pubsub/blob/f71345c1ec0ee4b30cd702bb605927f788ff9f36/gossipsub.go#L45-L47

In the current version of prysm, if we want to enlarge the mesh size so that our nodes can collect data in time, and then try to modify "gossipSubD=16", "gossipSubDlo = 14" and "gossipSubDhi = 20" by modifying the following codes.

prysm/beacon-chain/p2p/pubsub.go

Lines 22 to 24 in cfbfccb

	gossipSubD = 8 // topic stable mesh target count
	gossipSubDlo = 6 // topic stable mesh low watermark
	gossipSubDhi = 12 // topic stable mesh high watermark

Through the above function of "pubsubGossipParam()", the parameter "gParams.Dlo" in libP2P will be modified to "14", and the parameter in lib P2P "gParams.D" will be modified to "16". But due to the miss of "gParams.Dhi=gossipSubDhi" in the function of
"pubsubGossipParam()", the parameter "gParams.Dhi" is still 12. Because "gParams.Dlo=14" and "gParams.D=16" are larger than "gParams.Dhi", and the following problem will occur:

Fix the bug:

Based on the above discussion, I think "gParams.Dhi=gossipSubDhi" should be added in the function of "pubsubGossipParam()".

Has this worked before in a previous version?

No response

🔬 Minimal Reproduction

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Error

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Platform(s)

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What version of Prysm are you running? (Which release)

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Anything else relevant (validator index / public key)?

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[james-prysm]

fixed with #14521