Will the new GossipSub router allow topic agnostic message dissemination?

In a P2P network where not all nodes subscribe to the same topic, if a message reaches a node and the node is not subscribed to the topic the message is intended for, it drops the message when using GossipSub. This means that to ensure 100% message dissemination, all nodes subscribed to a particular topic must be eventually connected to all other nodes on the same topic. If there are several different topics dividing the nodes in disjoint sets, this results a large fanout (a very dense network).

This severely reduces how well we can scale since if there are more than 1000s of nodes we end up with each node having several hundred direct connections to ensure full connectivity for each topic. (I had asked this question earlier as well - Gossip sub IWANT issued only for local topics?)

In the new GossipSub spec v1.1. there is this new concept of Explicit Peering Arrangements. With explicit peering arrangements, in a gossipsub setup, will the intermediate nodes propagate messages for topics they are not subscribed to?


CC: @vyzo @raul

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No, we will not allow message dissemination if the peer has not joined the topic; that’s a DoS attack waiting to happen.
You can use the new Relay only option, which joins the topic (explicit) and forwards messages without the need for a goroutine to consume messages.


thanks for the reply!

Would you be able to link documentation for this? I tried searching the repo, but didn’t come up with anything for “relay only”