Why is WakuRelay a protocol different from GossipSub?

[richard-ramos]

While attempting to implement WakuRelay in go-waku, i noticed that go's libp2p-pubsub implementation does not support extending the list of protocols (see discussion here: libp2p/go-libp2p-pubsub#408), which increased the difficulty of implementing this spec in go.

Is there a reason why is WakuRelay defined as a new protocol (/vac/waku/relay/2.0.0-beta2) instead of using GossipSub directly (with /meshsub/1.1.0 and 1.0.0) + StrictNoSign? From reading the spec, the intention behind WakuRelay being a new protocol is not clear to me.

[D4nte]

This indeed creates some issues when trying to use js-libp2p-gossipsub. For example, as per gossipsub behaviour, when a peer subscribe to a topic, it adds know peers that are already subscribed to the topic to a mesh. This does not happen because a check on whether these peers use gossipsub is done:

https://github.com/ChainSafe/js-libp2p-gossipsub/blob/12626e863075d5fb1ef88cfed36b72c3b70cdf0f/ts/index.ts#L977

https://github.com/ChainSafe/js-libp2p-gossipsub/blob/12626e863075d5fb1ef88cfed36b72c3b70cdf0f/ts/get-gossip-peers.ts#L35

hasGossipProtocol checks gossip protocols only.

Which means waku peers are not added to the mesh and down the line, no messages are sent to those waku peers.

I can workaround it but I just want to highlight that this choice does create some obstacles.

[oskarth]

Copy-paste from chat:

the use of gossipsub is an implementation detail and it could change in the future; waku relay is concerned with different properties such as privacy etc, spec different focus; gossipsub is more a description of how it is done, previously this was done with floodsub, and in the future this could use kademlia, etc

[oskarth]

Additionally, the goal with semantics is also to capture these notions #87

[oskarth]

@richard-ramos has this been answered?

[oskarth]

Generic message follows

I'm going to go ahead and close this discussion as:

1. It is quite old and we are moving away from GH discussions (in favor of either forum.vac.dev or normal issues)

2. Existing discussion has evolved and is captured in more targeted issues already

If you feel like this is in error, please create a thread on Vac forum or a new issue.