Slashdot Mirror
Stanford P2P Group Releases Software and Analysis
Bert690 writes "Apropos of yesterday's Slashdot story on BitTorrent: Some folks at Stanford have released a paper on P2P "bucket brigade"-like streaming that contains *an actual analysis* and a downloadable implementation."
Could this be considered actual research on the subject of p2p networks and
scalability?
My name's Eric and I'm addicted to Slashdot.
(FP)
- AIX is dying.
- AmigaOS is dying.
- BSD is dying.
- BeOS is dying.
- CPM is dying.
- DOS is dying.
- FreeBSD is dying.
- GNU Hurd is dying.
- HP-UX is dying.
- IRIX is dying.
- Inferno is dying.
- Linux is dying.
- LynxOS is dying.
- MINIX is dying.
- MacOS is dying.
- Mach is dying.
- MicroC/OS is dying.
- NachOS is dying.
- NeXT is dying.
- Nemesis is dying.
- NetBSD is dying.
- NetWare is dying.
- OS-400 is dying.
- OS-9 is dying.
- OS/2 is dying.
- Oberon is dying.
- OpenBSD is dying.
- Palm OS is dying.
- Plan 9 is dying.
- pSOS is dying.
- QNX is dying.
- RTEMS is dying.
- SCO is dying.
- Solaris is dying.
- SunOS is dying.
- TRON is dying.
- ThreadX is dying.
- TinyOS is dying.
- Unix is dying.
- VMS is dying.
- VxWorks is dying.
- Windows 2000 is dying.
- Windows 3.11 is dying.
- Windows 95 is dying.
- Windows 98 is dying.
- Windows CE is dying.
- Windows ME is dying.
- Windows NT is dying.
- Windows XP is dying.
The Free On-Line Dictionary of Computing defines an operating system as: "The low-level software which handles the interface to peripheral hardware, schedules tasks, allocates storage, and presents a default interface to the user when no application program is running. The OS may be split into a kernel which is always present and various system programs which use facilities provided by the kernel to perform higher-level house-keeping tasks, often acting as servers in a client-server relationship. Some would include a graphical user interface and window system as part of the OS, others would not.The operating system loader, BIOS, or other firmware required at boot time or when installing the operating system would generally not be considered part of the operating system, though this distinction is unclear in the case of a rommable operating system such as RISC OS. The facilities an operating system provides and its general design philosophy exert an extremely strong influence on programming style and on the technical cultures that grow up around the machines on which it runs.
The comp.os.research FAQ makes the following distinction between micro- and macrokernels:
"A recurrent topic of discussion in this newsgroup has been the comparison between microkernel (for example Mach and QNX) and `macrokernel' (traditional Unix) operating systems. The basic notion of a microkernel consists of devolving as much functionality as possible into processes rather than the kernel itself; different systems take different approaches to implementing this.
For example, some systems (such as Mach) leave device drivers in the kernel, and place higher-level services (such as file systems) outside; others (such as QNX) move device drivers outside of the kernel.
However, anecdotal evidence [93-03-03-07-56.52] suggests that the distinction between microkernel and monolithic architectures is becoming more blurred as time goes on, as the two advance. For example, most modern monolithic kernels now implement multiple threads of execution and fine-grained parallelism. Architecturally, this approach begins to appear similar to a microkernel with several kernel-space processes working from shared memory.
As an aside, people often complain that the Mach system can't be a `real' microkernel, because it is so large (at least, this is the argument most frequently cited). However, I have been told that automatically-generated code stubs contribute very significantly to the size of the kernel, and that some size reduction would be likely if MIG (the stub generator) produced better code. [Can someone from CMU comment on this?] As mentioned above, the leaving of device drivers in the kernel also contributes to Mach's size.
Debating microkernels versus monolithic kernels on the basis of kernel size misses the central, architectural point. In the same way as the point of a RISC processor is not to minimise the instruction count, but rather to make a different tradeoff between what is implemented in the processor instruction set and what is implemented in other ways, the microkernel architectural issue is to determine which services are implemented in the microkernel, and which services are implemented external to that microkernel. By making appropriate choices here, the goal is to enhance various OS attributes in a manner that might not be addressable with a monolithic kernel OS. System attributes such as performance, flexibility, realtime, etc. are all variables which are taken into account.
Lately I have discovered that women are what's wrong with society. Yes that's right, the world would be a better place without women.
Nag, bitch, bitch, whine, nag. All the bloody time. But alas women are here to stay.
Hell, I'd turn gay so I'd never need them again, that is if it wasn't so condemned.
mmmm... tasty!
mod this mofo parent up, god damnit. or i'll eat you.
At least I think it was a couple of years ago. I was with some people in a McDonald's on a school trip. There was an old man who brought one with him and was going around showing it to people. When I first saw it I thought it was pretty dopey, but when he came and showed it to us, though I hate to admit it, it made me laugh a bit. I'm not the type who usually laughs at this kind of thing. Once when required to write a story or essay with the title "Anything Can Happen" I wrote a story in which ended with the protagonist being killed by a falling bullet which was fired at the beginning of the story. From that you should be able to see how far talking fish are from my notion of what is funny. I think this shows that such a gadget can be somewhat amusing if used in moderation.
I'm kind of tired of hearing about the terrorist attack at this point, and surely the rest of you are as well, but could BitTorrent be used in the event of another attack? Is BitTorrent better than an old standby, like IRC?
First: The Internet news sites were all inaccessible. They were overloaded with requests. For many people who wanted to get online for info, those were their only sources. I was able to get onto some smaller news sites though. For most of my info, I was on IRC as I always am. A very old chat system on the Internet, it lets many different interest groups share info instantly. I'm in something like 7 channels, 3 of them daytrader channels, so I had access to real-time newswire headlines as well as all the sites going up about the incidents. IRC really is a great tool. Nothing else comes close to comparing. It's distributed and not used by the mainstream, so it's always accessible and full of important info when big things happen. It also has decentralized server systems, although not quite P2P. But P2P would be absurd and insecure for IRC anyway. It's a living definition of what ARPA was intented to be.
Not like this would make a difference in privacy. Our privacy is already gone. Well, security also applies. More specifically privacy and security are just not 100% assured. We have to allow for the fact that we can't stop everything. But we can raise the barriers so high that a very small number of people are then capable of committing illegal acts like terrorism/cracking/whatever. I'm talking to a bunch of people who say, for instance, that passengers should've tried to attack the hijackers and shit like that. Well! Isn't everyone a fucking hero. Everyone's an action movie aficionado. Right. They're actually the guy who gets knifed at the beginning of the movie. There's a fine line between courage and stupidity, and usually that line's determined by how knowledgeable you are about the situation. And assuming that most passengers aren't fucking Navy SEALs, Black Ops, or counterterrorists, that means NOT MANY PEOPLE ARE FIT TO ATTACK HIJACKERS. Yay, let me jump on an anxious hijacker who was going to land at an airport in Mexico and let us go. Oh wait, he's strapped with C4 and he's so scared he's going to detonate it! YAY I'm a hero! On the other hand, if you're in a position to retain control of the cockpit, then by all means try. If you're in a position to stop the government from reading your mail, then do your best to stop it. If you're in a position to stop hackers from infiltrating a network, then go ahead. But come on, mindless heroics hurts more than helps. The passengers really didn't know that they would be used as a bomb. I mean, come on. When has that happened in America, or to Americans? Of course, in saying that, it sounds like the fourth plane was steered into the ground, perhaps by heroic passengers/pilots. If so, then wonderful.
Since I talk to traders, most of them are right wingers who love to trash liberals. As soon as shit like the terrorist attack happens, the conservatives seem so ready to turn in all our rights that make America so great, just for the appearance of safety. I was talking to some guys who thought that making public crypto illegal as well as restricting free press and giving away some of our rights to privacy was okay, for national security. They said that citizens have too many rights right now and not enough responsibilities. One guy was like, oh maybe now schools will allow public prayer, funny how it works!!!
For crying out loud.
Okay, for the most part, it's all been pretty good. I mean, watching NYC handle this has impressed me. I thought rabid New Yorkers would just turn into a crazy mob, but they were pretty calm and civilized about the whole thing. Casualties have been limited because of some luck and because of hard working rescuers. It's all gone smoothly.
But these other people, people who didn't have to deal with it directly, sat there spouting off shit about how we need to basically tear up the Constitution. What it indicates to me is that a lot of people don't truly understand and believe in the values and freedoms of the Constitution, they've just been taught to say so. Not much different from how many people are taught religion. It's the equivalent of brainwashing.
There's no excuse for wanting to sacrifice civil liberties. It indicates a profound misunderstanding of how the US works. Doing shit like limiting free press makes us no better than any other country. These people think that normal people having access to all this information is BAD, when in fact, it's the best thing to happen to us. It shows us how worse things were in the past, and how bad they are now. We don't have to rely on the government telling us how good a job it's doing. We just haven't quite learned to assimilate an information culture with our morals and values yet.
The theory of relativity doesn't work right in Arkansas.