the forums at degreez.net

I have a program called torrentsniff (torrentutils) that grabs information about a torrent from the file and the tracker, like the number of seeds and peers.

Now, I've got a bunch of torrents that bittornado reports have very few or no peers/seeds, but torrentsniff reports 5-10 of each.

The connection attempt to the trackers takes a while, but I've set the http timeout to 180, which should cover just about any network problems I can think of.

I don't know enough about how torrentsniff and bittornado compile their list of peers/seeds, but something is funny. If bittornado said I had no peers, I would just think the connection timed out, but having only a few of them doesn't make much sense.


Any idea why this inconsistency?

Your tool lists all peers and seeds connected to the tracker, but bittornado and any other client only ask for a small list of peers out of this pool. The peers/seeds bittornado shows, are those which he currently knows of and could try to connect to.

I'm thinking that the difference might be accounted for by hosts that are a) invalid or b) unreachable. That means that my client tests every ip in the pool somehow, whether an active connection attempt or by running some filter over them.

Still, when you say a small list of peers, why would it only only get one-two peers when there are only a total of 5-10? Why not grab all of them? The overhead of tcp and the protocol amount for more than 5-10 ips. That would easily fit in a tcp packet.

A tracker knows all connected peers and seeds and torrentsniff only asks for that number of peers/seeds.
If a bittorrent client connects to a tracker it gets a random list of peers, the client can ask for more peers after some time if he needs more. If you have a torrent with many peers/seeds you never get to know them all, because you can't connect and you don't need to connect to all of them. If you have a torrent with only a few peers/seeds you should "see" all other peers/seeds. But there are other problems, peers could still be listed on the tracker if they don't close the client properly and another issue is with firewalled peers: you can't connect to firewalled peers, you have to wait until they connect to you.