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PDTP - The Best of Both FTP and BitTorrent?
ikewillis writes "For awhile I've been following the development of PDTP (Peer Distributed Transfer Protocol), which is trying to merge the concepts of FTP and BitTorrent. This sounds like it could be useful for apt-get repositories or other high demand FTP sites. It's designed to be used as part of scalable networks which could replace manual selection of FTP mirrors. It also supports a number of other nifty features like cryptographic file signatures. Isn't it about time we ditched FTP for something better?"
Next thing it'll be transmitting voice and pictures over radio waves... AS IF!
A feeling of having made the same mistake before: Deja Foobar
I feel sorry for these people. See, this isn't your typical slashdotting... It's a slashdotting that comes after eighteen consecutive nonsense stories being posted over twelve hours on the US April Fool's Day.
So, their chance to build a reputation is going to be damaged by the fact that anybody reading Slashdot today has already given up on finding anything useful, and will be evaluating them as a joke that they're "not getting" rather than as a proposed networking scheme.
Furthermore, the geek world is bored today by Slashdot's denial-of-normal-service throughout the day. So, once word leaks out that this is a real and normal story, they're going to get all of the pent up slashdotting force applied to their server.
Simon, you should have started your set tonight with an NY Times article or two. That would have been a suitable transition between nonsense content and factual content, since NYT operates in that murky space and has a suitable web setup to absorb a larger-than-usual slashdotting. I'm sure the people at PDTP would have not minded at all if their moment in the sun had come an hour later tonight.
BannedMusic.org made a BitTorrent wrapper that installs the application and then automatically launches the download, they call it an "easy downloader" and have instructions and a script for sites that want to make their own. Makes it a *lot* easier for sites to give out big files to non-techy audiences.
Quoth the Debian Troll:
True story.
R.A.I.D. == redundant array of intolerable diversions
or at least on april fool's day....
...mirrors would need to be in sync at all times for this to work. Otherwise your PDTP client is only able to download from the mirrors that are in sync, or worse, will get some chunks from files that aren't up-to-date, causing problems.
Unfortunately, it's (almost) impossible to mirror new files instantaneously, so mirrors are never all in sync, all the time.
Isn't it about time we ditched FTP for something better?
Isn't it about time we ditched floppy disks for something better?
Isn't it about time we ditched IDE drives for something better?
Isn't it about time we ditched x86 for something better?
Isn't it about time we ditched Microsoft Windows for something better?
Isn't it about time we ditched CDs for something better?
Isn't it about time we ditched telnet for something better?
Isn't it about time we ditched CRTs for something better?
Isn't it about time we ditched 20-year-old TV sets for something better?
Isn't it about time we ditched COBOL for something better?
Isn't it about time we ditched BASIC for something better?
Isn't it about time we ditched SCO Unix for something better?
Isn't it about time we ditched DOS for something better?
Isn't it about time we ditched Dubya for something better?
my point is that there is a lot of very old crap out there that should be replaces, but is going to get used and keep getting used for years to come.
Interesting... this could bring piracy back to the ftp world, rather than the emule appz or bittorrent world where it's easier to get caught.
We already have. It is called SCP
"Weapons should be hardy rather than decorative" - Miyamoto Musashi
I think that goes for OS's too
Currently at v0.1.0, awaiting Something Big in Perl 6, it would seem.
You can never go home again... but I guess you can shop there.
There are several P2P research projects that are looking at building reliabale and scalable P2P systems.
Take a look at Tapestry, and Chord (and read some of the papers) to understand the issues involved in providing scalable and high performance P2P services. Not only is scalable search and overlay graph connectivity an issue, but also node failure and short session times of P2P nodes.
Additionally, when you actually handle the issue of downloading data, building application-lvel multicast trees to distribute the data efficiently on a large scale is not easy. Two papers from SOSP '03 SplitStream, and Bullet address that issue.
"...Beer..."
"I am Bittorrentholio...I need PDTP for my Torrenthole!"
"Heh heh heh heh...file transfers RULE!"
There's no problem with that, don't share your bandwith with anyone, noone shares bandwith with you. Then you can only download from one source with limited resources. Other people that share can download from many sources (eventually each one with much less resources) that provide a total bandwith much greater, and more, when there is more people downloading they also download faster, instead of you that don't wanna share and have to slower the download when more people that don't share start to download... And besides, most people's connection limits are dowload limits not uploads :-P
And unfortunately, it's windows only, and still requires installing the software, which is 3MB+.
What is needed is something along the lines of a very small, very simple java client or a browser plugin. Azureus is java, but is huge and has massive feature-bloat for the purposes of just downloading(and sharing back) one file. However, Bram and others don't seem terribly interested in expanding possibilities; a mac developer offered up numerous improvements to the BitTorrent team for the mac client(which among other things is based on 3.3a, not 3.4.1, weeks after 3.4.1 released) and was rewarded with deafening silence.
The bittorrent protocol is http based. It's extensively documented on the bitconjurer website. Cmon folks, let's at least see a mozilla plugin or something! :-)
Please help metamoderate.
am sick of trying to determine the april fool day jokes from the real stories.
So, if for example, I write this need little GPL'd app that everyone loves, and release it as opensource, I should be responsible for hosting the file server for everyone? What if hundreds of thousands of people use it everyday, and a new patch comes out. Should I have to buy a T-1 (or something bigger) that costs an arm and a leg, to provide the file patch for a free program to others with no income for me? Or should I ask others to help out with their extra bandwith, and get a few seeders out there with bittorrent and run the tracker with the DSL line i have. I could pay $20 a month for a metered tiered connection in my town, but I pay $50 for an "unlimited" (notice the quotes). I know that not everywhere has these kinds of services, but you don't have to leave the torrent open forever either, or just leave the upload at 1k/s or something. It might slow down your download, but your still going to get access to the file..
What are we going to do tonight Brain?
I thought something better was sftp. As for distributions.. why not HTTP? Setup one reflector that dynamically kicks outs redirects as new mirrors come online. This is mutch better as we have a ton of clients already installed (curl,wget,..etc) We also have load balancing, dns round robin, authorzation, security(read: SSL) well defined in the protocol. All we need is a cgi script to kick out the redirects, and another that will make signature files based on the publically available SSL cert. Whamo all the same features.. and we didnt have to reinvent the wheel.
Question:
"Skyfire is using a derivative of the Apache License. Doesn't that preclude linking with Qt as the Apache License is incompatible with the GPL?"
Answer:
The FAQ page"Qt/X11 is dual licensed under both the GPL and the QPL. The Apache License, while incompatible with the GPL, is not incompatible with the QPL, so when Skyfire is linked with Qt/X11 the terms of the QPL apply. Qt Non-Commercial Edition for Windows has a separate set of license terms which apply to all Windows builds of Skyfire." (emphasis added)
Isn't this license a poor one? Aren't they breaking sourceforge.net rules by using a OSI unapproved license?
Or maybe I don't know what I am talking about. PLEASE Correct me if I am wrong.It's virtually trivial to mirror subparts of an FTP site, it's much harder to do that on a Website if it has any links to the parent. Especially because websites specifically aren't a filesystem. So you can't make the same heirical assumptions that you would about an FTP site. It's why I always use rsync mirrors to grab files instead of FTP or HTTP. I hate FTP, it's a stupid protocol. HTTP is nice, but there is always extra crapola that I don't want that is a part of the system (index files, icon images, other gunk). HTTP isn't a filesystem. Now, WebDAV from what I have seen, looks like it could be a real filesystem. HTTP straight up isn't.
Kirby
BitTorrent suffers another problem in that the only usable implementations are currently only available in Python. The primary problem with Python is its excessive resource usage
Really? I'm currently running four throttled BT downloads on a PII-350 w/64MB. Max CPU usage is 8%, load average 0.25. If you're really that bothered see here for an alternative.
but other problems arise such as integration of the Python implementation into a native GUI frontend for a given platform
Ever heard of WxGtk? RPMs for most distros, if it wasn't part of your default install.
as well as the need to bundle the Python runtime with the BitTorrent client on most platforms as few deployed systems have a Python runtime available
Now this is just silly. I dont think there is a linux distro which doesn't include Python libraries and even for Windows it's a single small executable. Besides (correct me if I'm wrong) but isn't one of the reasons for using Python that it has bounds-checking on arrays and is therefore proof against the cause of most exploits - the buffer overrun?
Hello. I'm the project manager for PDTP, and author of Skyfire. There's nothing wrong with the QPL whatsoever, unless you mind the fact that it's GPL incompatible (but then again, so is the Apache license). The QPL is an OSI Approved license, so there's nothing to worry about.
Please don't use straight SHA1 - it requires downloading the entire file to verify.
.torrent files relatively big).
Bittorrent and some other file sharing networks split the file into chunks and keep metadata with the hashes of chunks. The problem with this idea is how big to make the chunks: too big and you need to download a big chunk before you can verify. Too small and the list of hashes itself takes too long to download (the hashes are what makes
I think the solution should be to use hash trees. Split the file into relatively small chunks (1k?) and calculate their hashes. Now take every two consecutive hashes and hash them. Repeat with the hash results from the previous step until you have a tree with a single hash at its root. The root hash represents the entire file just like an MD5 of SHA1 sum. The difference is that with a small amount of metadata as hints you can verify any part of the file without downloading the entire file. All you need is a short (log n) chain of hashes leading down to the root hash. The server will trickle the hash information interleaved with the download and the client will verify it on the fly and never need to write a single byte to the disk before it's cryptographically verified.
Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.