📅 Original date posted:2019-04-01
📝 Original message:
Good morning Rene,
>
> Maybe I oversee something - in that case sorry for spamming the list - but I don't understand how you could know the distance from yourself if you don't know the entire topology? (unless u use it on the pruned view as you suggested)
That is correct, and the reason that it would still lose determinism (and thus be hard to test anyway), as I lamented.
At least for a pruning heuristic like you proposed (i.e. probabilistically prune channels) it is possible to make deterministic with a fixed RNG seed.
For instance a node might concatenate its own public key with the short-channel-id (in some fixed byte order) of the channel, hash the concatenation, then use the hash as the seed of an RNG that gives 1 bit, and prune the channel if the bit is cleared (to remove half the channels in the routemap).
>
> On the other hand querying for a certain depth would be possible with the suggested `query ask egonetwork` in case for depth 3 one would have to peer with the nodes from the friend of a friend network.
But for this, you would require that every node also keep every channel with depth less than your maximum query amount.
Perhaps for friend-of-friend, it might be sufficient to just query a peer to give its own direct public channels, which it needs to remember anyway.
But that is basically only a depth of 2 (if we count depth of 1 as your direct channels).
Regards,
ZmnSCPxj
ZmnSCPxj [ARCHIVE] /
npub1g5…3ms3l
2023-06-09 12:54:42
in reply to nevent1q…sncl
Author Public Key
npub1g5zswf6y48f7fy90jf3tlcuwdmjn8znhzaa4vkmtxaeskca8hpss23ms3lPublished at
2023-06-09 12:54:42Event JSON
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"content": "📅 Original date posted:2019-04-01\n📝 Original message:\nGood morning Rene,\n\n\u003e\n\u003e Maybe I oversee something - in that case sorry for spamming the list - but I don't understand how you could know the distance from yourself if you don't know the entire topology? (unless u use it on the pruned view as you suggested) \n\nThat is correct, and the reason that it would still lose determinism (and thus be hard to test anyway), as I lamented.\nAt least for a pruning heuristic like you proposed (i.e. probabilistically prune channels) it is possible to make deterministic with a fixed RNG seed.\n\nFor instance a node might concatenate its own public key with the short-channel-id (in some fixed byte order) of the channel, hash the concatenation, then use the hash as the seed of an RNG that gives 1 bit, and prune the channel if the bit is cleared (to remove half the channels in the routemap).\n\n\u003e\n\u003e On the other hand querying for a certain depth would be possible with the suggested `query ask egonetwork` in case for depth 3 one would have to peer with the nodes from the friend of a friend network. \n\nBut for this, you would require that every node also keep every channel with depth less than your maximum query amount.\n\nPerhaps for friend-of-friend, it might be sufficient to just query a peer to give its own direct public channels, which it needs to remember anyway.\nBut that is basically only a depth of 2 (if we count depth of 1 as your direct channels).\n\nRegards,\nZmnSCPxj",
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