Mailman 3 March 2008 - Twisted

Re: [Twisted-Python] Re: Teach Me Twisted Redux
by Andrew Francis March 20, 2008

March 20, 2008

Hi Folks: > Clearly, the issues Twisted addresses are non->trivial requiring an appreciation of the problem >space before considering Twisted as a solution (you >gotta know there's a question before someone tells you > the answer)... unfortunately, the barrier to >Twisted entry at that point makes most walk away. >I've seen lots of threads concluding, simply, >that twisted looked interesting but was simply too >dense to even get started with... so, they go ahead >and roll their own solution, inevitably identifying >the issues which form heart of the twisted >architecture, but being too far along to refactor. >And away we go. I have barely scratched the surface of Twisted - some of my experiences and suggestions: 1) I found that Abe Fettig's book was a set of good training wheels. Not as good as say, Richard Steven's "UNIX Network Programming" that really saved my bacon when I was first learning socket programming. However Fettig's book is good in the sense that I can find a concrete example (HTTP RequestHandler), modify it a bit and it does something useful. Gets me going while I learn. Newbies need to build confidence with quick successes. Now I go to Twisted documentation that makes far more sense as I need much more technical detail about what Twisted is doing. If I had to alter Twisted documentation, I would make much of the stuff do concrete things, like get a web page. Perhaps I would, through surveys, pick the ten most common things new developers want to do, and show examples. 2) Pictures. Both Twisted documentation and Fettig's book lack pictures. When I was looking for a bug involving a Twisted call that never fired the callback, I took notes, peppered Twisted with logging statements, used a debugger and asked questions, lots of questions. The resulting control flow picture was sufficiently different from what I had in mind. That said, I would be tempted to do a simple client example and server example and illustrate the control flow, carefully matching the drawings with the illustrations. I know this is tough. Idioms: Perhaps this is closely related with common examples, but show common idioms. For example, how to call a database or a web server from a request handler. Or scheduling work with reactor.callLater or Tasks. Cheers, Andrew ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

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[Twisted-Python] Re: [Stackless] Stackless / Twisted Integration Paper
by Andrew Francis March 19, 2008

March 19, 2008

Hello Guy: --- Guy Hulbert <gwhulbert(a)eol.ca> wrote: > Some of the fonts don't render in gpdf on a bare > sarge workstation (just > gnome and basic fonts -- debian release 3.1r7) ... > in case you care. I > will probably try to find the right fonts and > install them. Yes I do care! I have to admit I am a dunce when it comes to preparing slides - I would rather design and write code. Unfortunately I did the slides in Power Point but a colleague did the diagrammes in Illustrator - worse the colleague wasn't around when I detected problems - all this caused immense headaches. I apologize. > In some slides it is just the caps in the titles. > Any hint about the font would be useful ;-) If you have Acrobat, look at Document properties. On mine I get: The fonts are TrueType Arial, Calibri, and Courier New (Embeded subset). When I have time, I will download OpenOffice and take a look. That said, thanks for looking at my paper. Cheers, Andrew ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs

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[Twisted-Python] Stackless / Twisted Integration Paper
by Andrew Francis March 19, 2008

March 19, 2008

Hi Folks: I have uploaded a copy of "Adventures in Stackless Python/Twisted Integration." http://us.pycon.org/common/2008/talkdata/PyCon2008/066/PostAdventures.pdf In the days and weeks to come I will make minor corrections. Although most of the arguments and code actually appear peppered throughout the Stackless and Twisted mailing list (too many people to thank for their help), I will be re-writing some of the examples to make them clearer. I also plan to expand the slides to cover stuff like pickling which I touch on but didn't have time to cover. If anyone attended the talks, I would love to hear, for better or worse, feedback. And once again, I thank everyone that helped me. Thank you, Andrew Francis ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

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[Twisted-Python] Twisted 8.0.0pre1
by Christopher Armstrong March 19, 2008

March 19, 2008

There is a pre-release of Twisted 8.0 available at http://twistedmatrix.com/users/radix/DIST/ Please test and provide feedback. -- Christopher Armstrong International Man of Twistery http://radix.twistedmatrix.com/ http://twistedmatrix.com/ http://canonical.com/

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[Twisted-Python] helping out
by Dave Peticolas March 19, 2008

March 19, 2008

Hello all, it was great to meet so many of you in person at Pycon, I only wish I had come to an earlier one! I'm glad I was able to plug Twisted at Pycon. I do need to set the record straight, as I only realized today that I got a bit confused in my numbers. During my plug, I mentioned one of our twisted servers had served 100 billion queries. I'm afraid it was actually 1 billion, not one hundred. I think I was conflating it with another metric we were touting from our booth for recruiting purposes. Either that, or I'm just a nitwit :) Sorry for the mistake, once they get past a certain number of zeroes, I kind of lose track. The bottom line was, we were really impressed with Twisted's ability to make making robust servers easy. I'm going to try to help out with twisted.enterprise some more. I think the most pressing issue there is the need to deprecate most everything outside of adbapi? Anyway, I'll start reading up on the new development model and hop on irc pretty soon. later, dave

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Re: [Twisted-Python] Teach Me Twisted Redux
by Andrew Francis March 19, 2008

March 19, 2008

Hi Steve and Folks: >I'd just like to thank the Twisted community for their >support in yesterday's "Teach Me Twisted" Open Space >session. To see the room still half-full of people >talking animatedly about Python twenty minutes >after the session ended was a great tribute to how >interested people are in making Twisted work for them, >and a reminder of what PyCon is all >about. I haven't ever enjoyed any PyCon activity so >much. >Couldn't have done it without you,guys, thanks a >million. Here, here. I thought the "Teach Me Twisted" talk was a scream. I never touched building a protocol so that was ultra-useful. Twisted is a truly wonderful product and I think, as corny as it sounds, all that is needed is to lead newbies by the hand for a little while before they get the swing of it. But when people get the swing of Twisted, watch out! Cheers, Andrew P.S: The only downside was I realised I didn't get a t-shirt!!! ____________________________________________________________________________________ Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ

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[Twisted-Python] pyactivemq interfering with Twisted?
by Brian Baquiran March 19, 2008

March 19, 2008

Hi, I'm writing what seems to me to be a trivial Twisted client application using a proprietary protocol, and I'm having problems with integrating it to ActiveMQ using pyactivemq (which is a Boost.Python wrapper around the ActiveMQ-CPP library). What I'm observing is that calling my client protocol's transport.write() doesn't seem to send data to the server. The server, also implemented using Twisted but without using pyactivemq, does not seem to have this problem. Could the part of pyactivemq (or ActiveMQ-CPP) that handles asynchronous consumption of messages be interfering somehow with Twisted's event loop and causing this problem? Brian

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[Twisted-Python] My project is using Twisted
by Martin Geisler March 18, 2008

March 18, 2008

Hi, I would like to ask if a link could be added to my VIFF project on the Projects Using Twisted page: http://twistedmatrix.com/trac/wiki/ProjectsUsingTwisted It could be listed under research projects: [http://viff.dk/ VIFF @ University of Aarhus, Denmark] is an open source Python library for implementing secure multi-party computation. -- Martin Geisler VIFF (Virtual Ideal Functionality Framework) brings easy and efficient SMPC (Secure Multi-Party Computation) to Python. See: http://viff.dk/.

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[Twisted-Python] transport.loseConnection problems
by Alvin Delagon March 18, 2008

March 18, 2008

I have a server application that do forced disconnects to clients on certain conditions by using self.transport.loseConnection() method. On random cases the method that I'm using fails to disconnect the client on the fly. The socket connection that is supposed to be disconnected immediately get disconnected at random times (10-30mins) with an error of: *Connection closed: [Failure instance: Traceback (failure with no frames): twisted.internet.error.ConnectionLost: Connection to the other side was lost in a non-clean fashion. * Can anyone explain why is this happening? I checked the API docs of the loseConnection() and it says there that: *"**Note that if there is a registered producer on a transport it will not be closed until the producer has been unregistered."* I have no idea what is a producer. By the way I'm using twisted.words.xmlstream that implements Protocol and epoll as my reactor. Thanks in advance. :) ---- Alvin

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[Twisted-Python] xmpp_client X-GOOGLE-TOKEN and mechanism
by James Pettit March 18, 2008

March 18, 2008

I'm trying to use the xmpp_client example in twisted.words, and it looks like google is requesting the X-GOOGLE-TOKEN auth mechanism... anyone know how I can specify/force it to use PLAIN? Specifically, the command '> python xmpp_client.py myname(a)gmail.commypassword' gives this output ( http://pastebin.com/m47f6002a). - James

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