[bittorrent] Questions related to mainline DHT specs...

NewMedia42 newmedia42 at excite.com
Sat Aug 19 17:46:23 EDT 2006

>I send find_node requests to my closest neighbours in the
>outing table as well as to a couple of random peers every once
>in a while. The peer_id I'm querying them for is my own ID with
>the last bit flipped, i.e. a node very very close to me.

Is there any particular reason you pick this (couldn't you just user your id)?  Since it returns the K closest nodes, does it really matter if you flipped the bit - it never should return a values type of exact match, correct?

Also, at one point do you decide to add someone to your routing table?  I was attempting to do it on every transaction, but it looks like one of the clients is using different ports and NodeID's for each query, which breaks things.  Not quite sure why it would be doing that, or what the developer was trying to accomplish - boy, it sure makes the 'v' field that uTorrent added make a whole lot of sense - I have no clue what clients is generating the message to be able to troubleshoot with a locally running one.

How large do you typically let your DHT table grow, in number of peers and routes?  In fiddling around with it, I've seen it grow to about 11k nodes and 6k routes after a few hours - but the caveat to that is I'm not being very aggressive expiring nodes yet, and I'm not recombining routes (not sure if I will bother) - thoughts?

Have you ever seen a node return more than 8 values/nodes for either a get_peers or get_node query?  Right now I support any arbitrary number of returns, but I wasn't sure if it was worth much.  I can obviously return less (such as if I didn't have anything), but have you seen in practice anyone sending more?

Finally, on announce, when are you typically sending that?  Would it be fine immediately after the get_peers, so I wouldn't necessarily have to track the token (since I already have to track the token I give them)?

Thanks again for your insight, it's helped me more than the docs!  :)

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