| 1 | <?xml version="1.0" encoding="utf-8" ?> |
|---|
| 2 | <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> |
|---|
| 3 | <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> |
|---|
| 4 | <head> |
|---|
| 5 | <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> |
|---|
| 6 | <meta name="generator" content="Docutils 0.5: http://docutils.sourceforge.net/" /> |
|---|
| 7 | <title></title> |
|---|
| 8 | <link rel="stylesheet" href="../css/bep.css" type="text/css" /> |
|---|
| 9 | </head> |
|---|
| 10 | <body> |
|---|
| 11 | <div class="document"> |
|---|
| 12 | |
|---|
| 13 | <div id="upper" class="clear"> |
|---|
| 14 | <div id="wrap"> |
|---|
| 15 | <div id="header"> |
|---|
| 16 | <h1><a href="../index.html">BitTorrent<span>.org</span></a></h1> |
|---|
| 17 | </div> |
|---|
| 18 | <div id="nav"> |
|---|
| 19 | <ul> |
|---|
| 20 | <li><a href="../index.html">Home</a></li> |
|---|
| 21 | <li><a href="../introduction.html">For Users</a></li> |
|---|
| 22 | <li><a href="bep_0000.html"><span>For Developers</span></a></li> |
|---|
| 23 | <!-- <li><a href="./blog">Blog</a></li> --> |
|---|
| 24 | <li><a href="http://forum.bittorrent.org"> Forums </li> |
|---|
| 25 | <li><a href="../donate.html">Donate!</a></li> |
|---|
| 26 | </ul> |
|---|
| 27 | </div> <!-- nav --> |
|---|
| 28 | <!-- ### Begin Content ### --> |
|---|
| 29 | <div id="second"> |
|---|
| 30 | |
|---|
| 31 | |
|---|
| 32 | |
|---|
| 33 | <table class="rfc2822 docutils field-list" frame="void" rules="none"> |
|---|
| 34 | <col class="field-name" /> |
|---|
| 35 | <col class="field-body" /> |
|---|
| 36 | <tbody valign="top"> |
|---|
| 37 | <tr class="field"><th class="field-name">BEP:</th><td class="field-body">12</td> |
|---|
| 38 | </tr> |
|---|
| 39 | <tr class="field"><th class="field-name">Title:</th><td class="field-body">Multitracker Metadata Extension</td> |
|---|
| 40 | </tr> |
|---|
| 41 | <tr class="field"><th class="field-name">Version:</th><td class="field-body">10759</td> |
|---|
| 42 | </tr> |
|---|
| 43 | <tr class="field"><th class="field-name">Last-Modified:</th><td class="field-body"><a class="reference external" href="http://bittorrent.org/trac/browser/dotorg/trunk/html/beps/bep_0012.rst">2008-02-14 12:51:44 -0800 (Thu, 14 Feb 2008)</a></td> |
|---|
| 44 | </tr> |
|---|
| 45 | <tr class="field"><th class="field-name">Author:</th><td class="field-body">John Hoffman <theshadow at degreez.net></td> |
|---|
| 46 | </tr> |
|---|
| 47 | <tr class="field"><th class="field-name">Status:</th><td class="field-body">Draft</td> |
|---|
| 48 | </tr> |
|---|
| 49 | <tr class="field"><th class="field-name">Type:</th><td class="field-body">Standards Track</td> |
|---|
| 50 | </tr> |
|---|
| 51 | <tr class="field"><th class="field-name">Created:</th><td class="field-body">07-Feb-2008</td> |
|---|
| 52 | </tr> |
|---|
| 53 | <tr class="field"><th class="field-name">Post-History:</th><td class="field-body"></td> |
|---|
| 54 | </tr> |
|---|
| 55 | </tbody> |
|---|
| 56 | </table> |
|---|
| 57 | <hr /> |
|---|
| 58 | <div class="contents topic" id="contents"> |
|---|
| 59 | <p class="topic-title first">Contents</p> |
|---|
| 60 | <ul class="simple"> |
|---|
| 61 | <li><a class="reference internal" href="#metadata-extension" id="id2">Metadata Extension</a></li> |
|---|
| 62 | <li><a class="reference internal" href="#order-of-processing" id="id3">Order of Processing</a></li> |
|---|
| 63 | </ul> |
|---|
| 64 | </div> |
|---|
| 65 | <div class="section" id="metadata-extension"> |
|---|
| 66 | <h1>Metadata Extension</h1> |
|---|
| 67 | <p>In addition to the standard "announce" key, in the main area of the |
|---|
| 68 | metadata file and not part of the "info" section, will be a new key, |
|---|
| 69 | "announce-list". This key will refer to a list of lists of URLs, and |
|---|
| 70 | will contain a list of tiers of announces. If the client is compatible |
|---|
| 71 | with the multitracker specification, and if the "announce-list" key is |
|---|
| 72 | present, the client will ignore the "announce" key and only use the |
|---|
| 73 | URLs in "announce-list".</p> |
|---|
| 74 | </div> |
|---|
| 75 | <div class="section" id="order-of-processing"> |
|---|
| 76 | <h1>Order of Processing</h1> |
|---|
| 77 | <p>The tiers of announces will be processed sequentially; all URLs in each |
|---|
| 78 | tier must be checked before the client goes on to the next tier. URLs |
|---|
| 79 | within each tier will be processed in a randomly chosen order; in other |
|---|
| 80 | words, the list will be shuffled when first read, and then parsed in |
|---|
| 81 | order. In addition, if a connection with a tracker is successful, it |
|---|
| 82 | will be moved to the front of the tier.</p> |
|---|
| 83 | <p>Examples:</p> |
|---|
| 84 | <pre class="literal-block"> |
|---|
| 85 | d['announce-list'] = [ [tracker1], [backup1], [backup2] ] |
|---|
| 86 | </pre> |
|---|
| 87 | <p>On each announce, first try tracker1, then if that cannot be reached, |
|---|
| 88 | try backup1 and backup2 respectively. On the next announce, repeat |
|---|
| 89 | in the same order. This is meant for when the trackers are standard |
|---|
| 90 | and can not share information.</p> |
|---|
| 91 | <blockquote> |
|---|
| 92 | d['announce-list'] = [[ tracker1, tracker2, tracker3 ]]</blockquote> |
|---|
| 93 | <p>First, shuffle the list. (For argument's sake, we'll say the list |
|---|
| 94 | has already been shuffled.) Then, if tracker1 cannot be reached, try |
|---|
| 95 | tracker2. If tracker2 can be reached, the list is now: |
|---|
| 96 | tracker2,tracker1,tracker3. From then on, this will be the order the |
|---|
| 97 | client tries. If later neither tracker2 nor tracker1 can be reached, |
|---|
| 98 | but tracker3 responds, then the list will be changed to: |
|---|
| 99 | tracker3,tracker2,tracker1, and will be tried in that order in the |
|---|
| 100 | future. This form is meant for trackers which can trade peer |
|---|
| 101 | information and will cause the clients to help balance the load |
|---|
| 102 | between the trackers.</p> |
|---|
| 103 | <blockquote> |
|---|
| 104 | d['announce-list'] = [ [ tracker1, tracker2 ], [backup1] ]</blockquote> |
|---|
| 105 | <p>The first tier, consisting of tracker1 and tracker2, is shuffled. |
|---|
| 106 | Both trackers 1 and 2 will be tried on each announce (though perhaps |
|---|
| 107 | in varying order) before the client tries to reach backup1.</p> |
|---|
| 108 | </div> |
|---|
| 109 | |
|---|
| 110 | |
|---|
| 111 | </div> |
|---|
| 112 | <div id="footer"> |
|---|
| 113 | <hr/> |
|---|
| 114 | </div> |
|---|
| 115 | |
|---|
| 116 | </div> |
|---|
| 117 | </body> |
|---|
| 118 | </html> |
|---|
