Exactly-once message propagation.

[iwasaki-kenta]

Not mandatory for release.

Syntax:

• 0<2 implies that Node 2 bootstrapped with Node 0.
• 0<=2 implies that Node 2 sent a message to Node 0.

Say we have a setup 0<1 + 1<2. Proxying means: 0=>1 + 1=>2. Node 0 sends a message to Node 1 who notices the request to have the message proxied/propagated to Node 2.

To do this, some requirements need to be done:

• If we have 1000 nodes, we don't want to redundantly keep having nodes proxy a single particular message multiple times. To do this, our message keeps track of nodes that have already been proxied through via. a space-efficient data structure (Bloom/Cuckoo Filter).
• We have a routing table from Kademlia. We can use this to our advantage, as XOR'ing the proxy target node ID with our own node ID will give us the bucket ID filled with nodes most likely closest to the target node. Hence, if the target node is not in our list of nodes, we broadcast and have the closest nodes proxy the message forward. If the target node is in our list of nodes, just send the message directly to it.

[iwasaki-kenta]

Update: findNode in network/discovery/rpc.go can be made public s.t. we can find the most probable closest nodes to the target and have a few of the closest nodes proxy the message over to the target.

If no nodes appear to be close to the target, we can consider the proxying to have failed.

[samsends]

Perhaps FindNode + a hop counter in the msg for tuning spread

[tongxin97]

Hi! Has anyone implemented this yet? We are using Noise for our network, and it'd be helpful to have this feature.
Also, I noticed the given Broadcast(Async) method broadcasts to peers closest to the node itself only, does that mean Noise does not support global broadcasting (gossiping) right now?

[creamwhip]

I am curious about how this is done in modern Wavelet. When Transactions are gossiped through the network, is it possible for a node to receive the same data several times?