[Twisted-Python] any progress for Ticket #6346, #6378?

Tue May 28 18:31:55 MDT 2013

>   By reading these comments, It looks like recent version of twisted
>may
>suffer from this problem. So what version of twisted should  I use? Do
>I
>need to keep using 10.1?

This problem is very frequent on Linux with Python 2.7 / Twisted 12
combination (we had to quickly roll back- cannot operate with that combo).

It never happened with Python 2.6 / Twisted 10 (as in years).

It happens very infrequently with Python 2.7 / Twisted 10.1 (as 1x in weeks)

Right now I have a server in this state on Python 2.7 / Twisted 10.1. It
refuses 30% of new connections, spewing this error:

2013-05-28 17:28:25-0700 [twisted.internet.protocol.ServerFactory] Unhandled
Error
        Traceback (most recent call last):
          File
"/usr/local/encap/Python-2.7.3/lib/python2.7/site-packages/Twisted-10.2.0-py
2.7-linux-x86_64.egg/twisted/python/log.py", line 69, in callWithContext
            return context.call({ILogContext: newCtx}, func, *args, **kw)
          File
"/usr/local/encap/Python-2.7.3/lib/python2.7/site-packages/Twisted-10.2.0-py
2.7-linux-x86_64.egg/twisted/python/context.py", line 59, in callWithContext
            return self.currentContext().callWithContext(ctx, func, *args,
**kw)
          File
"/usr/local/encap/Python-2.7.3/lib/python2.7/site-packages/Twisted-10.2.0-py
2.7-linux-x86_64.egg/twisted/python/context.py", line 37, in callWithContext
            return func(*args,**kw)
          File
"/usr/local/encap/Python-2.7.3/lib/python2.7/site-packages/Twisted-10.2.0-py
2.7-linux-x86_64.egg/twisted/internet/epollreactor.py", line 217, in
_doReadOrWrite
            why = selectable.doRead()
        --- <exception caught here> ---
          File
"/usr/local/encap/Python-2.7.3/lib/python2.7/site-packages/Twisted-10.2.0-py
2.7-linux-x86_64.egg/twisted/internet/tcp.py", line 938, in doRead
            transport = self.transport(skt, protocol, addr, self, s,
self.reactor)
          File
"/usr/local/encap/Python-2.7.3/lib/python2.7/site-packages/Twisted-10.2.0-py
2.7-linux-x86_64.egg/twisted/internet/tcp.py", line 752, in __init__
            self.startReading()
          File
"/usr/local/encap/Python-2.7.3/lib/python2.7/site-packages/Twisted-10.2.0-py
2.7-linux-x86_64.egg/twisted/internet/abstract.py", line 365, in
startReading
            self.reactor.addReader(self)
          File
"/usr/local/encap/Python-2.7.3/lib/python2.7/site-packages/Twisted-10.2.0-py
2.7-linux-x86_64.egg/twisted/internet/epollreactor.py", line 100, in
addReader
            self._add(reader, self._reads, self._writes, self._selectables,
_epoll.IN, _epoll.OUT)
          File
"/usr/local/encap/Python-2.7.3/lib/python2.7/site-packages/Twisted-10.2.0-py
2.7-linux-x86_64.egg/twisted/internet/epollreactor.py", line 88, in _add
            self._poller._control(cmd, fd, flags)
          File "_epoll.pyx", line 125, in _epoll.epoll._control

        exceptions.IOError: [Errno 2] No such file or directory

If I restart the server, it will be stable for a couple of weeks, until some
event triggers this problem again. We hope that this problem is fixed before
we are really forced to migrate to newer Python, otherwise there's no real
upgrade path for us using Twisted.

From: twisted-python-bounces at twistedmatrix.com
[mailto:twisted-python-bounces at twistedmatrix.com] On Behalf Of Gelin Yan
Sent: Saturday, May 25, 2013 7:51 AM
To: Twisted general discussion
Subject: Re: [Twisted-Python] any progress for Ticket #6346, #6378?

On Sat, May 25, 2013 at 3:22 AM, <exarkun at twistedmatrix.com> wrote:
On 04:21 pm, dynamicgl at gmail.com wrote:
>Hi All

Hi Gelin,

I don't have anything extra to add about the status of those two tickets
(I think you meant #6373 rather than #6378, by the way) - which is
exactly why I'm replying.

Twisted development doesn't take place in secret.  The issue tracker
should always reflect the latest state of the development process.  If
an issue has had no comments and a branch no commits for a couple
months, then it's almost certainly because no one has worked on the
issue for a couple months.

So you generally don't need to ask if there has been any progress,
because progress will always be reflected in ticket history or in
version control.
>    I am quite concerned about these two tickets due to recently I may
>port
>one of my systems to Ubuntu.
Perhaps you can help out with the tickets, then!  As hopefully you've
noticed, one of them is currently up for review.  This means a developer
believes a fix for the problem has been created and is just waiting for
someone else to look it over and agree that it should be applied to
trunk.  If this happens, then the fix will be available in the next
release of Twisted, 13.1.0, which will probably happen in just a few
weeks.

For more details about how the review process works, please take a look
at this wiki page:

    http://twistedmatrix.com/trac/wiki/ReviewProcess

Jean-Paul
>   By reading these comments, It looks like recent version of twisted
>may
>suffer from this problem. So what version of twisted should  I use? Do
>I
>need to keep using 10.1?
>
>  I always use the latest version on windows.
>
>Regards
>
>gelin yan
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Hi exarkun

    I noticed "review" tag has been removed for a while so does it imply
this ticket is still pending? 

   I am not quite familiar how epoll works on linux so my help probably can
be neglected. I event can't sure how to reproduce this bug.

   By the way, Is it possible to use the "old" epoll implementation instead
of the built in epoll from python with the latest version? It looks like
this old one works quite well.  Thanks

Regards

gelin yan 