Mailman 3 June 2008 - Twisted

[Twisted-Python] ANNOUNCING Allmydata.org "Tahoe", the Least-Authority Filesystem, v1.1
by zooko 12 Jun '08

12 Jun '08

ANNOUNCING Allmydata.org "Tahoe", the Least-Authority Filesystem, v1.1 We are pleased to announce the release of version 1.1 of the "Tahoe" Least Authority Filesystem. The "Tahoe" Least Authority Filesystem is a secure, decentralized, fault-tolerant filesystem. All of the source code is available under a Free Software, Open Source licence (or two). This filesystem is encrypted and distributed over multiple peers in such a way it continues to function even when some of the peers are unavailable, malfunctioning, or malicious. A one-page explanation of the security and fault-tolerance properties that it offers is visible at: http://allmydata.org/source/tahoe/trunk/docs/about.html This is the successor to Allmydata.org "Tahoe" Least Authority Filesystem v1.0, which was released March 25, 2008 [1]. This release fixes several serious issues in Tahoe v1.0, and improves the user interfaces. See the known_issues.txt file [2] and the NEWS file [3] for details. COMPATIBILITY The version 1 branch of Tahoe is used as the basis of the consumer backup product from Allmydata, Inc. -- http://allmydata.com . Tahoe v1.1 is fully compatible with Tahoe v1.0. v1.1 clients produce files which can be read by v1.0 clients. v1.1 clients can read files produced by clients of all versions >= v0.8. v1.1 servers can serve v1.0 clients and v1.1 clients can use v1.0 servers. This is the second release in the version 1 series. We believe that this version of Tahoe is stable enough to rely on as a permanent store of valuable data. The version 1 branch of Tahoe will be actively supported and maintained for the forseeable future, and future versions of Tahoe will retain the ability to read files and directories produced by Tahoe v1 for the forseeable future. WHAT IS IT GOOD FOR? With Tahoe, you can distribute your filesystem across a set of computers, such that if some of the computers fail or turn out to be malicious, the filesystem continues to work from the remaining computers. You can also share your files with other users, using a cryptographic capability-based access control scheme. Because this software is the product of less than two years of active development, we do not categorically recommend it for the storage of data which is extremely confidential or precious. However, we believe that the combination of erasure coding, strong encryption, and careful engineering makes the use of this software a much safer alternative than common alternatives, such as RAID, or traditional backup onto a remote server, removable drive, or tape. This software comes with extensive unit tests [4], and there are no known security flaws which would compromise confidentiality or data integrity. (For all currently known issues please see the known_issues.txt file [2].) This release of Tahoe is suitable for the "friendnet" use case [5] -- it is easy to create a filesystem spread over the computers of you and your friends so that you can share files and disk space with one another. LICENCE You may use this package under the GNU General Public License, version 2 or, at your option, any later version. See the file "COPYING.GPL" [6] for the terms of the GNU General Public License, version 2. You may use this package under the Transitive Grace Period Public Licence, version 1.0. The Transitive Grace Period Public Licence says that you may distribute proprietary derived works of Tahoe without releasing the source code of that derived work for up to twelve months, after which time you are obligated to release the source code of the derived work under the Transitive Grace Period Public Licence. See the file "COPYING.TGPPL.html" [7] for the terms of the Transitive Grace Period Public Licence, version 1.0. (You may choose to use this package under the terms of either licence, at your option.) INSTALLATION Tahoe works on Linux, Mac OS X, Windows, Cygwin, and Solaris. For installation instructions please see "docs/install.html" [8]. HACKING AND COMMUNITY Please join us on the mailing list [9] to discuss uses of Tahoe. Patches that extend and improve Tahoe are gratefully accepted -- the RoadMap page [10] shows the next improvements that we plan to make and CREDITS [11] lists the names of people who've contributed to the project. The wiki Dev page [12] contains resources for hackers. SPONSORSHIP Tahoe is sponsored by Allmydata, Inc. [13], a provider of consumer backup services. Allmydata, Inc. contributes hardware, software, ideas, bug reports, suggestions, demands, and money (employing several allmydata.org Tahoe hackers and instructing them to spend part of their work time on this free-software project). We are eternally grateful! Zooko O'Whielacronx on behalf of the allmydata.org team June 11, 2008 San Francisco, California, USA [1] http://allmydata.org/trac/tahoe/browser/relnotes.txt?rev=2348 [2] http://allmydata.org/trac/tahoe/browser/docs/known_issues.txt [3] http://allmydata.org/trac/tahoe/browser/docs/NEWS [4] http://allmydata.org/trac/tahoe/wiki/Dev [5] http://allmydata.org/trac/tahoe/wiki/UseCases [6] http://allmydata.org/trac/tahoe/browser/COPYING.GPL [7] http://allmydata.org/source/tahoe/trunk/COPYING.TGPPL.html [8] http://allmydata.org/source/tahoe/trunk/docs/install.html [9] http://allmydata.org/cgi-bin/mailman/listinfo/tahoe-dev [10] http://allmydata.org/trac/tahoe/roadmap [11] http://allmydata.org/trac/tahoe/browser/CREDITS?rev=2677 [12] http://allmydata.org/trac/tahoe/wiki/Dev [13] http://allmydata.com

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[Twisted-Python] Asynqueue 101 (Help)
by Mustafa Sakalsiz 11 Jun '08

11 Jun '08

Hi, I want to develop a server that has a dispatcher and worker processes. Asynqueue seems to be a perfect choice for my intention. However, I couldn't understand what I should do first and next. The workers will be processes and tasks will be queued and assigned to the child processes. There are many classes but I couldn't understand their interaction. For example what is the difference between a job and a task. How will I use TaskQueue with child processes or process workers. I need some examples, asynqueue has some test codes but they don't give enough clue to me. I need the general idea and the use of asynqueue. Thanks in advance.

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[Twisted-Python] suggestions for naming to help us preserve a Twisted trademark
by glyph＠divmod.com 10 Jun '08

10 Jun '08

Hello, Twisted community: I'd really like "twisted" (and our various "dot product" subprojects) to be a trademark that the software freedom conservancy can protect and defend. For similar reasons, I'd like to have an unambiguous naming convention for projects which are *part* of Twisted versus those which are built on it or are compatible with it. There are a few projects out there that just call themselves "py- whatever" but use Twisted (for some reason, none come to mind at the moment); that's fine, of course. The jabber transports which use Twisted are pyMSNt, pyICQt; I'm not sure if the "t" stands for "transport" or "twisted" :). There are also a few projects out there called "Twisted Whatever" which aren't part of Twisted; I can only hope that more projects will want to advertise their association with Twisted in this way. I'd like to suggest, however, that new projects use the word "Twisty" in this context rather than the hopefully trademarked "Twisted". i.e. if you are making an implementation of the protocol Bloobloo and want to give it a name associated with Twisted, please describe it as "Twisty Bloobloo: an implementation of bloobloo for Twisted", and name your packages similarly (twistybloobloo.stuff). Sun has a great webpage about how to use their trademarks in this capacity: http://www.sun.com/policies/trademarks/. I'm aware of 3 projects which are currently called "Twisted X" but are not actually a part of Twisted. The first is Twisted Goodies, which was named with our explicit permission. I appreciate that Ed asked first, and so he is welcome to continue using that name. (I'd still prefer that it be changed to "Twisty Goodies" just to help establish the convention and reduce potential user confusion, but realistically there has not been any actual user confusion about that package, and packages with our explicit permission I don't believe weaken our copyright claim.) Two other things that I'm aware of using names like this, however, do not have our permission, and if those authors are listening here (or if someone who knows the authors here could get in touch with them) I'd really like their names to be changed: Twisted SNMP and Twisted Storage. Most of all though I hope that all 1000-odd subscribers to this list have their own soon-to-be-released project which can make use of this new convention ;). Also, if a graphic designer out there could help with a modified version of the logo that could be used in the way that the Debian "open use" images, that would be helpful: http://www.debian.org/logos/#open-use

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[Twisted-Python] twisted.protocols.telnet is deprecated. But how should I migrate?
by Marcin Kasperski 08 Jun '08

08 Jun '08

Long time ago I wrote some code using twisted.protocols.telnet.Telnet. Now I get: DeprecationWarning: As of Twisted 2.1, twisted.protocols.telnet is deprecated. See twisted.conch.telnet for the current, supported API. The problem is ... I do not know how to migrate. Bare substitution of twisted.conch.telnet instead of twisted.protocols.telnet does not work (my code, which subclassed Telnet and provided welcomeMessage, checkUserAndPass, and loggedIn, simply is not called). I checked for docs, but twisted.conch has only some docs about SSH clients, and by looking only at the code I can't figure what should I do. I suspect that I should use AuthenticatingTelnetProtocol but I do not understand how should I do it (what is this portal, why should I return some other protocol). I grepped through all examples for this class, but found nothing. So: how should one migrate twisted.telnet.Telnet to twisted.conch.telnet? Does there exist any example of simple telnet server?

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[Twisted-Python] Weekly Bug Summary
by exarkun＠twistedmatrix.com 08 Jun '08

08 Jun '08

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[Twisted-Python] "core docs" pdf --> 404
by Peter Sabaini 07 Jun '08

07 Jun '08

Just FYI -- the "Core Documentation" PDF gives me a 404 http://twistedmatrix.com/projects/core/documentation/howto/book.pdf

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[Twisted-Python] pyprocessing in twisted
by Peter Sabaini 06 Jun '08

06 Jun '08

Hello list, probably a dumb question, but is it possible / a good idea to use pyProcessing[1] in a Twisted application? More specifically, I'd like to run a Twisted process A that accepts data from the network and sends it down to a process B through a processing.Queue(). Is that wise? Or should I just stick with reactor.spawnProcess() and communicate with ProcessProtocol? Sorry for the newb-ness, peter. [1] http://pyprocessing.berlios.de/

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Re: [Twisted-Python] Re: How to detect dead client
by big_tyo＠inf.its-sby.edu 06 Jun '08

06 Jun '08

where is this tcp_keepalive_time located? is it on twisted source code or python library?

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[Twisted-Python] DeferredList + LoopingCall
by J Davis 05 Jun '08

05 Jun '08

Hello, I want to group several calls to a function() that returns a deferred into a DeferredList so that I can add callbacks that will fire once each call to function() has returned. Furthermore, I want to arrange it so that this process repeats every X seconds. The problem I'm having is understanding how I can combine the concept of a DeferredList with task.LoopingCall in this scenario. Or is that even the right approach to take? Thanks, -Jake

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[Twisted-Python] CLOSE_WAIT (debian)
by Josef Novak 05 Jun '08

05 Jun '08

Hi, I have a fairly simple twisted daemon based on the starpy protocol, which I am running in combination with the asterisk pbx. I sometimes this daemon accumulates CLOSE_WAIT connections in a rather unpredictable fashion, which when stacked up eventually cause the daemon to stop responding to new connections. My understanding is that there is no default timeout for the CLOSE_WAIT socket state, as per the relevant rfc standard, and that in any netstat declares that CLOSE_WAIT indicates that the remote end of the connection has shut down, and that it is now up to the local application to finish closing the socket. The implication is that there is something wrong with my application code, however before posting the whole thing I'd like to know if there are any cannonical reasons for this kind of issue being raised in twisted applications. For instance is this likely to occur when one uses defertothread for blocking third party code, and the child process spawned to handle this returns to find the parent process already gone? ( e.g. my twisted app spawns for a new call from asterisk, but the call instance is destroyed for some reason before the defertothread that it executes returns?) I'm having trouble reliably causing the issue, but it continues to pop up, so any general information about regarding debugging twisted applications would be of help. Thanks!

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