Mailman 3 February 2006 - Twisted-web

Test
by Philippe Lafoucrière 05 Aug '21

05 Aug '21

Hi all just a test

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remote admin app, ssh connection costs
by Gustavo Rahal 03 Mar '06

03 Mar '06

Hi All I did a small xmlrpc webservice that basicly expose some methods to interact (run commands, for example) with a lists of UNIX servers. At startup, the webservice connects via ssh to all the UNIX servers (currently 16) and leave the connections open waiting for requests from clients. The app was designed mostly as a way of learninig how to use twisted ssh modules, deferreds etc... Some questions (I'll try to be brief): 1) At startup, the ssh connections to the UNIX servers goes as far as the client connection step (connection.SSHConnection) and are kept open. So, each time a client requests (via xmlrpc) a shell command to run, the webservice opens a channel to this server (channel.SSHChannel) runs the command, gets the output and closes the channel. Would it be better to leave a channel open so there is no overhead of openning a channel each time there is a command to run? What are the pros and cons? 2) Supposing that the number of servers grow, how many simultaneous ssh connections is a reasonable amount? Let's say a Pentium III 500MHz with 1 GB RAM and a 4 Mbits link. What is a reasonable amont? 0-50, 50-100, 100-150? I know it depends on the internet link and server specs but is there a math that calculate a reasonable amount of tcp/ssh connections? I guess that's it for now... Thanks Gustavo

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Fwd: [Twisted-Python] Twisted & SOAP
by Charlie Moad 28 Feb '06

28 Feb '06

SOAPpy is a very primitive soap implementation compared to ZSI, but it works for the simple cases. However, focus is being directed to ZSI primarily now. If you check out ZSI from cvs you can build it with, "python setup.py build --twisted", and this will include twisted resources that can be used like any other twisted.web resource. This work migrated from pygridware to ZSI recently, so it is not trivial to use yet. Pygridware also includes a web2 resource, but this has not been moved to ZSI yet. Maybe once these classes mature they will be donated for twisted to include. I am not a twisted developer so I can't speak for them, but this is the current status of the pywebsvcs group. I cc'd the twisted-web mailing list, because that is probably where this thread belongs, hence the general list should not be included in future replies. - Charlie On 2/28/06, Richard Townsend <richard(a)reticulatus.plus.com> wrote: > I've been experimenting with the Twisted web/soap.py integration with > SOAPpy which appears to do the sort of I stuff I need at the moment. > > However, a recent message on the Pywebsvcs-talk mailing list said: > > "Any objection to our diabolical plan to integrate > wstools into ZSI and shove SOAPpy to a second class status? We'd like to > converge on a single python web services solution, but we're working hard to > make sure SOAPpy users can do in ZSI what they can do in SOAPpy..." > > What effect will this development have on support for SOAP in Twisted? > > regards > Richard > > > > > _______________________________________________ > Twisted-Python mailing list > Twisted-Python(a)twistedmatrix.com > http://twistedmatrix.com/cgi-bin/mailman/listinfo/twisted-python >

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Some help with Nevow and databse I/O
by Eric Gaumer 25 Feb '06

25 Feb '06

Hello everyone, Twisted is relatively new to me but I've become fascinated by the idea of asynchronous network programming and I generally enjoy the feel of the twisted framework. I'm developing a web application with a limited set of pages that will eventually serve as a bandwidth statistics application (uses SNMP to poll switch counters). I'm using newvow to render some simple XML pages which basically take the form of: def data_listCusotmers(self, context, data): args = inevow.IRequest(context).args db = shelve.open('authdb') return db docFactory = loaders.xmlfile('templates/ListCustomers.html') I have two questions that are somewhat interrelated. In my test cases I have authentication (using nevow session guard) setup using a SHA stored via the shelve module. The true customer info is stored in a MySQL database. I can pull that data doing the following: def data_query(self, context, data): return self.dbpool.runQuery('SELECT name, email, id, TransferType, basic_charge, over_charge, permitted_transfer FROM Customers') I've read Abe's book on twisted and on page 54 he states "Nevow is designed from the ground up for Twisted, which means you can use Deferreds everywhere" My question is do I have to use the adbapi module or can I use deferreds to handle database queries? I've read the docs on deferreds but I'd be lying if I said I can fully wrap my brain around all aspects of the concept or how it's implemented. I don't understand why I would need separate threads in the first place. I know that the query would block but isn't that transaction being done via sockets anyway? Why can't I use the same mechanism (deferred) I would use, to say, defer work waiting on a response from a mail server? Can't I submit a query, have the reactor go do something else, and have a callback run when the data becomes available? Why do I need to spawn threads to avoid blocking? It should be pretty obvious that I don't fully grasp the concept of asynchronous socket programming. Can somebody provide insight that may help me to better understand things. I can live with using the adbapi but wonder if it's possible to simply defer that work and use a callback mechanism (I'm using the original twisted.web not twisted.web2). I've also read Glyf's post where he states "The documentation is really poor, and never says this, but using Twisted, or rather ADBAPI, to convert every single SQL statement into a separate transaction and handle its results separately, has a whole slew of problems". http://glyf.livejournal.com/2005/09/24/ I was pretty much heading down this road but I don't really understand how else to do it. I've browsed many examples and have never really come across one that involves session.guard, newvow, and db access all in the same application. Anyone have any experience they could share? Thanks, -- Eric Gaumer Debian GNU/Linux PPC egaumer(a)pagecache.org http://egaumer.pagecache.org PGP/GPG Key 0xF15D41E9

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Re: [Twisted-web] Using Cheetah with twisted.web
by Matt Helm 23 Feb '06

23 Feb '06

On 2/21/06, Graeme Glass wrote: > Would you mind posting some sample code, for refrence? > Many thanks. class Resource(resource.Resource): def render(self, request): def cheeto(r): request.write(r.__str__()) request.finish() def cherr(r): request.write("Bang!") request.write(str(r)) request.finish() d_cheeto = threads.deferToThread(Template, file="alf.tmpl", searchList = slist) d_cheeto.addCallback(cheeto) d_cheeto.addErrback(cherr) return server.NOT_DONE_YET resource = Resource()

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SOAP over SSL connection
by Derek Horton 22 Feb '06

22 Feb '06

Hello, I'm new to python, soap, and twisted. Forgive my ignorance please. I was wondering if its currently possible to use SOAP over an SSL connection. Is there some documentation that explains how to set this up? I'd be glad to RTFM if you could point me to the doc. Any help is appreciated! Thanks, trohed

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help needed for httpserver
by piton miton 22 Feb '06

22 Feb '06

Hi, Could some of you lease help me about creating an httpserver behind twisted server? Where can I find any documentation about this? I dont have much experience so I really need a guide! Thanks in advance, Burge __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Status of forms, potential debianization
by Tommi Virtanen 21 Feb '06

21 Feb '06

Hi. I'm starting to use forms for real, and anything I do in production needs a deb ;) Is forms stable (=unchanging) enough to give to the masses? I'm a bit worried that some may complain that forms (well, pythonX.Y-forms) is a bit too generic as a name, but we'll see..

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But doesn't twcgi run cgi?
by Jonathan Mark 20 Feb '06

20 Feb '06

Christopher Armstrong wrote: """RPY? If you mean RPY as in the thing that ResourceScript handles, that doesn't have anything at all to do with CGI...""" I am new, and do not question the correctness of this statement. I don't understand how it could be so, however. My working .rpy file says class RubyScript(twcgi.FilteredScript): (1) Is the name "twcgi" a misnomer? (2) A second question. Is there some way to get my postings to this list to thread? Simply emailing to twisted-web(a)twistedmatrix.com would put each email as its own thread, it seems to me. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Using Cheetah with twisted.web
by Matt Helm 20 Feb '06

20 Feb '06

Hello all, I have just recently started working with twisted.web and think is great. I would like to use Cheetah templates with it - should I be doing something more complicated than the following? ################# # alf.rpy from twisted.web import resource from Cheetah.Template import Template f = "foo" b = ["bar", "baz"] class Resource(resource.Resource): def render(self, request): return Template(file="alf.tmpl", searchList = [{'f': f, 'b': b}]).__str__() resource = Resource() ################# Thanks, Matt

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