Slyck.com
 
Slyck Chatbox - And More

Azureus Introduces DHT Layer

Discuss Slyck's latest news
Forum rules
PLEASE READ BEFORE POSTING: Slyck Forum Rules

Azureus Introduces DHT Layer

Postby SlyckTom » Tue May 03, 2005 6:22 pm

Azureus, a leading java based BitTorrent client, has introduced DHT (Distributed Hash Table) to its client. DHT is a networking protocol that enhances the scalability and efficiency of decentralized networks by creating a virtual index rather than broadcasting search queries. Decentralized networks that utilized DHT technology are able to search and locate files significantly faster than networks that do not use this technology.

You may think to yourself, "So what, Azureus has incorporated DHT, many decentralized networks employ this technology."

The significance of adding this layer to Azureus is that it significantly increases the efficiency of file distribution. With the new version of Azureus, any client can choose to become a tracker or not. This is where DHT comes into play.

With DHT, each node is responsible for indexing a certain percentage of hash files on the network. For example, say there are 50 Azureus users all participating on the DHT portion of the network. If 8 decide to become nodes, each one will work together to become a virtual index (so-called "tracker-less.")

This allows a client to continue downloading a file even if the web-based tracker goes down. In addition, even if a tracker happens to go down, the swarms will continue to be maintained - even finding alternative file sources. Olivier from Azureus explains this new DHT implementation has a familiar origin.

"The technology behind the DHT (Distributed Hash Table = Distributed
Database) is Kademlia, (the "Kad" network in eMule is another Kademlia distributed hash table, Kad is heavily modified from the original specifications for performance reasons). Azureus implementation follows quite a lot the original Kademlia specifications so far."

Keep in mind this is not a "decentralized BitTorrent" network. The BitTorrent network and DHT network operate independently. DHT is a layer added on top of the BitTorrent network to assist in Azureus’ performance. BitTorrent is a distinct networking protocol, of which is specified by creator Bram Cohen. Anything existing outside of those specifications is not BitTorrent. Some articles have attempted to label the new Azureus as a “decentralized BitTorrent”, possibly confusing some with a dubious client named “eXeem.” Olivier makes it quite clear these two clients are not even in the same Universe.

“It has nothing to do with eXeem, and in terms of performance, searching the DHT is a matter of ms (milliseconds) when the content is available (ie, when it has results), and of seconds when it' s not. I don't know for sure how eXeem works, but from the test I did, it's not using a DHT.”
Follow us on Twitter @SlyckDotCom
Join our Facebook Fan page
SlyckTom
 
Posts: 5713
Joined: Fri Jul 26, 2002 7:22 pm
Location: New York City

Postby LxBeast » Tue May 03, 2005 6:36 pm

Informative article ST.

It really is impressive to see the Azureus team keep on improving an already great program.

I just hope DHT get's the attention it deserves.
LxBeast
 

Postby _eAgLe_ » Tue May 03, 2005 6:40 pm

Yer, great article as usual Tom. Also, great to see Azureus continuing to improve. That should take a little heat off trackers... i think lol
User avatar
_eAgLe_
 
Posts: 1190
Joined: Wed Dec 22, 2004 2:06 am

Postby Psycho Ced » Tue May 03, 2005 6:42 pm

Nice article
SlyckTom wrote:Some articles have attempted to label the new Azureus as a “decentralized BitTorrent”, possibly confusing some with a dubious client named “eXeem.” Oliver makes it quite clear these two clients are not even in the same Universe.

Glad that has been cleared up!
User avatar
Psycho Ced
Psycho+
 
Posts: 5892
Joined: Sun Oct 26, 2003 2:52 pm
Location: Relative to where?

Postby Wolfie » Tue May 03, 2005 7:04 pm

Looks interesting and been testing it for the last 3 hours.

I'm hoping this will make overloaded trackers like Pirate Bay run better.


:!: How come I have a leech with the tag "eXeem [optimus" in my client list??? :shock:

edit: and another one called "eXeem [anonymous
both Dutch IPs
User avatar
Wolfie
 
Posts: 93
Joined: Fri Dec 17, 2004 8:20 am

Postby Foreigner999 » Tue May 03, 2005 8:14 pm

Thats really interesting :o
I just read from the exeem website that they are having trouble with people having connection problems. I hope the exeem universe isn't going to start invading the Azureus universe by stapling on thier crappy network.

174k users so far on the DHT layer. How many users do you guys/gals see?
Foreigner999
 
Posts: 58
Joined: Tue Apr 12, 2005 8:50 pm

Postby Psycho Ced » Tue May 03, 2005 8:30 pm

Foreigner999 wrote:

174k users so far on the DHT layer. How many users do you guys/gals see?

201170 users :D
User avatar
Psycho Ced
Psycho+
 
Posts: 5892
Joined: Sun Oct 26, 2003 2:52 pm
Location: Relative to where?

Postby torentfiend » Tue May 03, 2005 8:34 pm

Foreigner999 wrote:174k users so far on the DHT layer. How many users do you guys/gals see?


I'm seeing about 150k here and now.

I'd sure be curious to know how the DHT interacts with trackers and with the clients for that matter.

For instance, when you join the distributed tracker, do you track everything anyone connected to the DT is sharing or is it only what you are hosting?

But anything to reduce reliance on the vulnerable trackers....

I also see that they've added support for anonymous trackers/clients with tor and I2P...
torentfiend
 
Posts: 3
Joined: Tue May 03, 2005 8:27 pm

Postby zab » Tue May 03, 2005 8:56 pm

Just for the record, the guy's name is Olivier, not Oliver. He's French.
User avatar
zab
 
Posts: 114
Joined: Fri Sep 24, 2004 10:20 pm

Postby Assyrian » Tue May 03, 2005 9:24 pm

as a bittornado user, its good to see the azureus team doing so well. well done to them, but ill stick to bittornado :)

btw, great article ST.
away.
User avatar
Assyrian
The King
 
Posts: 4822
Joined: Wed Aug 25, 2004 4:00 am
Location: Sydney, OZ

Re: Azureus Introduces DHT Layer

Postby bkman » Tue May 03, 2005 11:47 pm

Informative article as usual (I didn't know that they used a Kad based DHT!), but I have some comments:
SlyckTom wrote:You may think to yourself, "So what, Azureus has incorporated DHT, many decentralized networks employ this technology."

Yes, because everyone is just pumping out DHT's these days.. :lol:
SlyckTom wrote:This allows a client to continue downloading a file even if the web-based tracker goes down. In addition, even if a tracker happens to go down, the swarms will continue to be maintained - even finding alternative file sources.

SlyckTom wrote:Keep in mind this is not a "decentralized BitTorrent" network.


There is some contradiction between these two paragraphs. What is "decentralized Bittorrent" but Bittorrent that doesn't rely on centralized trackers? Theoretically, all the Azurues 2.3 users could ostracize themselves from using trackers all together and use magnet links, and they would still be using the BT transfer protocol.

Olivier makes it quite clear these two clients are not even in the same Universe.

Actually, he makes clear that they are implemented in completely different ways. It doesn't take a leap of deduction, however, to realize that the two very different implementations have some of the same goals, like distributing the load of BT.
User avatar
bkman
 
Posts: 338
Joined: Sun Jan 23, 2005 1:24 am

Postby Allied » Wed May 04, 2005 12:30 am

Assyrian wrote:as a bittornado user, its good to see the azureus team doing so well. well done to them, but ill stick to bittornado :)

btw, great article ST.

Ditto.
It makes Azureus seem alot more reliable than any other client. If the tracker goes down, the Azureus users work together to form a backup network.

I rarely see a tracker go down anymore.Unless its a really old torrent.
I agree its not decentralized BitTorrent. More like less centralized BitTorrent.
Allied's Review:
Recommended: LimeWire | Ares | Shareaza | eMule | KCeasy
Not Recommended: Morpheus | Kazaa | eDonkey2000 | Manolito | iMesh
User avatar
Allied
Mostly Harmless
 
Posts: 2170
Joined: Sat Aug 14, 2004 11:23 pm
Location: Behind You Shoe Size: 11.008 BitTorrent: µTorrent Nationality: Canuckian Newsgroups: GrabIt

Postby JunqueMan » Wed May 04, 2005 1:29 am

Good article SlyckTom

I d/l'ed and installed Azureus but could not get it to connect (red not so friendly Smileys under Health). Tried port forwarding, changing ports, changing different settings, exited ZA Pro v5.5 and rebooted, disabled Norton's AV, tried just about everything in Azureus' troubleshooting FAQ, nothing worked. It would show quite a few numbers of peers but just wouldn't connect and d/l the torrents. :shock:

-EDIT- Ooops, got it working. Thought I already had the latest version of Java, I didn't. :oops:

Otherwise this client looks really good with some really nice features. :)

Junque Man

btw - does any know of another BT client that has roughly the same look/features?
User avatar
JunqueMan
 
Posts: 2727
Joined: Fri Feb 18, 2005 4:27 pm
Location: The Drunken Clam

Postby no_dammagE » Wed May 04, 2005 3:29 am

btw - does any know of another BT client that has roughly the same look/features?


You could use Shareaza as a pure BT client with G2 backbone in case a tracker goes down. In this case G2 will work between Shareaza users the same was as DHT among Azureus ones, but additionally IIRC Raza has alt-src-meshes for BT sources, too, so that you'll exchange with non-shareaza sources, too, if a node is aware of any.
Windows? Blah. Linux? Blah. BSD? Blah.
Just make sure you have a computer licence and I can open your fsckin files.
Vorbis | Theora | LaTeX | OpenDocument
User avatar
no_dammagE
 
Posts: 652
Joined: Sat Jul 05, 2003 9:37 am

Honoured to read it!

Postby Anonymous » Wed May 04, 2005 4:09 am

A Fine Article Tom. Thank You For Writing Such Quality Articles.
Anonymous
 

Postby poles_apart » Wed May 04, 2005 4:20 am

Thanks for the tip Junque Man; I had made the same mistake myself.

Will DHT cause problems for private trackers by allowing peers to download a torrent without registering? I know of certain clients being banned by trackers because they share peer information directly with other peers. I think the reason usually given is that the unregistered users don't contribute to the share ratio of the registered ones.
poles_apart
 
Posts: 13
Joined: Thu Jan 20, 2005 7:24 am

Postby eAi » Wed May 04, 2005 11:44 am

If you look on the Azureus site theres a link on the right hand side (I think, the site is blocked from work) that tells you how to disable DHT for a torrent.
eAi
 
Posts: 79
Joined: Mon Jan 03, 2005 11:44 am

Postby Wolffi » Wed May 04, 2005 1:23 pm

Too bad the new version eats resources like there's no tomorrow. I had no problems with the previous version, but when I upgraded I started seeing Azureus use up 30-40% of prosessor time and eat up memory to a hundred mb..that's simply not acceptable so I switched to another client.
Wolffi
 
Posts: 41
Joined: Wed May 04, 2005 1:19 pm

Postby ilbozo » Wed May 04, 2005 2:32 pm

Great article Tom. Thanks man
May venture back into the world of BT to try this out.
ilbozo
 
Posts: 326
Joined: Thu Apr 07, 2005 5:01 am

Postby Nick » Wed May 04, 2005 4:06 pm

Great article

Now upgraded to "new improved" Azureus (irony), although to be fair, it doesn't seem that bad. At least this release seems to have resolved some of the probs that kept my pc crashing on average 3 times daily! Time will of course tell

I note that it constantly seems to be uploading, even if all transfers are stopped. This seems to suggest it is a bit heavier on resources, but if it works, then what the heck?
Nick
 
Posts: 3840
Joined: Sun Jan 30, 2005 7:38 am

Postby Trev0r269 » Wed May 04, 2005 4:21 pm

For me the new Azureus just freezes up and stops responding...

Although I am still very exciting about this adavance. Adding the DHT layer is a nice improvement. This is the first version with the "new stuff" in it and of course it'll be the most buggy.
Trev0r269
 
Posts: 584
Joined: Mon Feb 23, 2004 7:53 pm
Location: Slow - hio

Postby jaleal » Wed May 04, 2005 4:45 pm

^^
That happen to me too as soon as i updated. I had to download the latest version of Java and it started working great again :)
jaleal
 
Posts: 86
Joined: Tue Feb 08, 2005 6:16 pm

Postby ejonesss » Wed May 04, 2005 5:00 pm

how does the dht hold up against the spies mentioned

http://www.technewsworld.com/story/40247.html p2p users cant hide story
ejonesss
 
Posts: 2970
Joined: Thu Feb 06, 2003 5:43 pm

Postby jimilarue » Thu May 05, 2005 10:47 pm

Wolffi wrote:Too bad the new version eats resources like there's no tomorrow. I had no problems with the previous version, but when I upgraded I started seeing Azureus use up 30-40% of prosessor time and eat up memory to a hundred mb..that's simply not acceptable so I switched to another client.


Why people don't have atleast a gig of memory in this day in age baffles me.

Stop complaining bitch
jimilarue
 
Posts: 119
Joined: Sun Jan 23, 2005 7:39 pm

Postby poullos » Fri May 06, 2005 4:53 am

We had a similar topic about a month ago about bitcomet being banned from private trackers because of the request of peers beyond the tracker's swarm.

This a document from azureus official site on how to create torrents and add a value that disables DHT for the specific torrent:

Secure Azureus Torrents

Tracker sites wanting to ensure that Azureus only obtains peers directly from the tracker itself (i.e. no DHT or peer exchange usage) should embed the key "private" with the value "1" inside the "info" dict of the .torrent file:

infod6:lengthi136547e4:name6:a............7:privatei1ee

Azureus clients, upon seeing this flag set, will disable any sort of external peer exchange for that torrent; meaning only peers given out by the tracker will be used, even if that tracker goes down, as it is normally today.

This new field will be ignored by other BT clients, so it does not break compatibility as long as they've properly implemented the BT spec. Also, this new field WILL change the torrent's infohash, which means that torrents made without the secure flag aren't compatible with torrents made with it. If you update all the torrents on your web site, you will have to ask users to re-download the torrent files in order to let them connect to your tracker.

The Azureus Team recommends only using this flag for new torrents, as it'll provide a smooth transition for your users.


Source
¯\(º_o)/¯
User avatar
poullos
 
Posts: 1087
Joined: Fri Mar 19, 2004 9:29 am
Location: Mobile Server

Next

Return to Slyck News

Who is online

Users browsing this forum: No registered users and 3 guests

© 2001-2008 Slyck.com