I can't download torrent from public tracker libtorrent

Question

I'm using libtorrent module in python to download torrent. I can download torrent from a private tracker but not from a public one. I tried using various torrents, which I can download using "transmission". I checked it against 4 different connections, all the same.

def downloadTorrent(torrent):
    """
    Download torrent using libtorrent library.
    Torrent will be stored at the current directory.
    """
    ses = lt.session()
    ses.listen_on(6881, 6891)

    info = lt.torrent_info(torrent)
    h = ses.add_torrent({'ti': info, 'save_path': './'})
    ses.start_dht()
    print 'starting', h.name()

    while (not h.is_seed()):
        s = h.status()

        state_str = ['queued', 'checking', 'downloading metadata', \
          'downloading', 'finished', 'seeding', 'allocating', 'checking fastresume']
        print '\r%.2f%% complete (down: %.1f kb/s up: %.1f kB/s peers: %d) %s' % \
          (s.progress * 100, s.download_rate / 1000, s.upload_rate / 1000, \
          s.num_peers, state_str[s.state]),
        sys.stdout.flush()

        time.sleep(1)

    print h.name(), 'complete'

When I try I get:

0.00% complete (down: 0.0 kb/s up: 0.0 kB/s peers: 0) downloading 

And it stop there.

I don't know if it help, but the private tracker is using http and not udp, and it doesn't allow DHT.

Ergot

What happens when you try? Do you get an error that you could include in your question? – Bedaub

It doesn't connect to any peers. – Ergot

Does the tracker(s) really work?! Try the trackers you can find on the list here: coppersurfer.tk Many of the older public trackers doesn't work any more. – Mendie

I can download the same torrent file using transmission, So trackers are working. – Ergot

That doesn't prove that the tracker(s) is working. – Mendie

perhaps you need to bootstrap the DHT. There is no way of knowing without you printing the alerts produced by libtorrent, looking at them to figure out which ones may be relevant. if you can't figure that out, update your question with more information – Sundry

@Sundry The problem that I don't get any alerts from libtorrent. It only stop at 0% with no peers. – Ergot

the code you posted does not ask libtorrent for alerts. are you sure you're just not asking for them? If you ask and literally get 0 alerts back, make sure you set all bits in the alert mask in the session_settings. – Sundry

Can you tell us precisely which public torrent address you're trying to use. – Circumscribe

@Circumscribe it's doesn't work with any tracker. For example here this torrent chaker.tn/big_buck_bunny.torrent which I test with rtorrent and it works perfectly. – Ergot

Answer 1

You don't really explain how you provide the torrent file in your downloadTorrent function. Your function works if you have already downloaded the torrent file on your computer.

If you want to provide a torrent url as an argument for this function, you need to read the http response as bytes like this torrent = lt.bdecode(urllib2.urlopen(torrent_url, 'rb').read())

Here's the full code that works with python 2.7:

import libtorrent as lt
import urllib2

public_torrent = 'http://releases.ubuntu.com/14.04.3/ubuntu-14.04.3-desktop-amd64.iso.torrent'

def downloadTorrent(torrent_url):
    """
    Download torrent using libtorrent library.
    Torrent will be stored at the current directory.
    """
    ses = lt.session()
    ses.listen_on(6881, 6891)

    # read torrent file as bytes
    torrent = lt.bdecode(urllib2.urlopen(torrent_url, 'rb').read())

    info = lt.torrent_info(torrent)
    h = ses.add_torrent({'ti': info, 'save_path': './'})
    ses.start_dht()
    print 'starting', h.name()

    while (not h.is_seed()):
        s = h.status()

        state_str = ['queued', 'checking', 'downloading metadata', \
          'downloading', 'finished', 'seeding', 'allocating', 'checking fastresume']
        print '\r%.2f%% complete (down: %.1f kb/s up: %.1f kB/s peers: %d) %s' % \
          (s.progress * 100, s.download_rate / 1000, s.upload_rate / 1000, \
          s.num_peers, state_str[s.state]),
        sys.stdout.flush()

        time.sleep(1)

    print h.name(), 'complete'

downloadTorrent(public_torrent)

Circumscribe