feature: Prune should include an optional reason

[MarcoPolo]

It would be very helpful for debugging and health monitoring of the network to know why a peer pruned us. Even if they only tell we were pruned because our score became negative that would be helpful.

I don't think there's a security issue here since a node can essentially infer it is misbehaving if many peers prune at once. This just makes that explicit.

[vyzo]

I dont think this adds anything to the protocol, other than increasing bandwisth use.

[vyzo]

Also, that would require a spec change, this is not the place to directly implement without discussion in the specs with community.

[MarcoPolo]

We can have a single bit for “because your score is negative”

[vyzo]

Maybe, but again this should be discussed with the community. I still think it is of marginal utily, if any.

[MarcoPolo]

Also, that would require a spec change, this is not the place to directly implement without discussion in the specs with community.

Thanks, good point.

[MarcoPolo]

https://github.com/libp2p/specs/issues/555