Mailman 3 November 2014 - Twisted

[Twisted-Python] Importing/Exporting Putty and SSH.com keys
by Adi Roiban 30 Nov '14

30 Nov '14

Hi, I just want to let you know about a piece of code I was working on. I wanted to import and export Putty and SSH.com (Tectia) SSH keys in Python and I could not find any existing code for that... my final goal is to replicate the puttygen functionality. I have extended the current twisted.conch.ssh.key.Key class to import/export Putty and SSH.com keys Code is here: https://github.com/chevah/chevah-keycert Not sure if it make sense to have it integrated in Twisted. If there is someone willing to review (part of) and merge this code I am happy to send patches. Right now it depend on Twisted but only because of the original Key and packing/unpacking MP/NS values... Have a nice day! -- Adi Roiban

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[Twisted-Python] Weekly Bug Summary
by trac＠twistedmatrix.com 30 Nov '14

30 Nov '14

1 0

[Twisted-Python] I would like to port twisted to c++(14)
by Danny Shemesh 29 Nov '14

29 Nov '14

Hello everyone, I am Danny, a C++ dev, I'm familiar with twisted from past projects and by this day I am enchanted with its magic. I would like to port twisted to c++ (or at least the base ot it) and have couple of questions - 1. Is it legally ok to port it and open source it at github ? 2. Would anyone consider helping to this cause ? 3. Would you know of a code base that would benefit from such port ? Thanks!

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[Twisted-Python] Weekly Bug Summary
by trac＠twistedmatrix.com 23 Nov '14

23 Nov '14

1 0

[Twisted-Python] How do I debug this network problem?
by Peter Westlake 22 Nov '14

22 Nov '14

TL;DR - how do I debug the sequence of events between an AMP answer box arriving at a NIC, and AMP firing the callRemote Deferred? I have an application with two processes, on separate machines, communicating using AMP. One process does a callRemote, which returns a Deferred, which is never fired. I know from tcpdump that the AMP answer box arrives safely at the network interface card. This isn't something which can easily be reproduced. Instead, I want to ask the specific question: how do I debug the data path from the NIC to AMP firing its Deferred? I've had a look at the code, and got rather lost amongst the interfaces and inheritance and protocols and transports. If someone can help me narrow down the relevant bits of code, I can put in some Python tracing. FWIW, this is happening on Debian Squeeze and Wheezy, on VMs hosted on Xen 6.5. It only happens on some specific machines, and only sometimes. The same code has run flawlessly for many years elsewhere, though this same bug did happen there too some years ago. That time, it went away after most of the software in the system was upgraded. I tried that this time - Debian Squeeze to Wheezy, with associated kernel, Python and Twisted versions - but the problem persists. Anyway, I don't want to make the problem go away without understanding it, for fear that it will come back a third time. Peter.

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[Twisted-Python] Twisted 14.0.2 & edns client subnet
by Jason J. W. Williams 22 Nov '14

22 Nov '14

Has anyone used the support for EDNS option information in the 14.0.2 twisted.names client to transmit EDNS client subnet information in upstream DNS queries? Any advice/pointers would be greatly appreciated. -J

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[Twisted-Python] Weekly Bug Summary
by trac＠twistedmatrix.com 16 Nov '14

16 Nov '14

1 0

[Twisted-Python] Sending longer messages in AMP
by Gavin Panella 14 Nov '14

14 Nov '14

Hi, We're using AMP and are starting to hit TooLong errors when scaling our application. In one respect it's a sign that we should do something like paging large requests and responses, but that's a lot more work, and comes with its own problems. We also don't need particularly large payloads: right now, a limit of ~500kiB would allow us to scale as far as we need and beyond. I've put together a fork of Twisted's AMP implementation that uses 32-bit length prefixes everywhere, though it limits the maximum message size to 2MiB. Every other aspect of it is the same so it's a drop-in replacement, as long as both ends of a connection use it. However, there's no negotiation phase so it's completely incompatible on the wire. The overhead of a few extra bytes is negligible for our use cases, where the networks are all assumed to be low-latency high-bandwidth LANs. Are there any reasons that we shouldn't be doing this? Was there a good reason for 16-bit length prefixes that still holds? Should we be doing something else? If I assume that the answers are all no, would someone find this protocol useful if we submitted it for inclusion in Twisted itself? The code right now is a straight copy of amp.py and test_amp.py with changes to 32-bit length prefixes everywhere, but for upstreaming we'd probably propose instead to modify the original to have an optional negotiation phase, and to make the maximum message size a parameter. Thanks! Gavin.

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[Twisted-Python] is it possible to change the isolation level of a psycopg2 connection under enterprise.adbapi ?
by Jonathan Vanasco 13 Nov '14

13 Nov '14

there doesn't seem to be a way to access the connection objects within the pool ( psycopg2 manages this via `connection.set_isolation_level(X)` the only workaround I can think of seems to be emitting raw sql when I first start the transaction - but this doesn't seem right. am i missing anything?

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[Twisted-Python] Manhole info needed
by Vikas Kumar 10 Nov '14

10 Nov '14

Hi, Can somebody tell me what is the need of manhole in twisted? Specially I've seen them in files like tap.py (twisted application process). One usecase I've seen them is wrt ShellFactory classes: manhole = ShellFactory() manhole.setService(self) internet.TCPServer(<someservice_name>.config.dget('jsonapi.port') + 10000, manhole, interface='127.0.0.1').setServiceParent(self) Could somebody please tell me what is being tried to achieve over here in the above code?

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