A bit late for this sort of post, I know, but (as my previous post
indicates) I spent the week following PyCon convalescing. I'm feeling a bit
better now, so I figure I should share.
Things started off at the sprints, during which Twisted 2.0 was released.
Chris Armstrong, the release manager, was in Australia, but it was well
timed anyway. We had a nice big sign and I think that the whole sprints
qualified as the "release party". The Twisted table this year was
huge - we probably could have had an entire room to ourselves and
still been short on space. The final day of the sprints people were
literally having to stand around for want of chairs. It's fun to be at the
center of a whirlwind like that.
Early on James Knight and I sat down with Jim Fulton and talked about Zope
Interfaces. I wish I could say that something earth-shattering came out of
that, but mostly we just agreed that they have been working wonderfully for
Twisted so far and that we will continue to use them.
There were some new faces this year: I got to meet Thomas Vander Stichele
from Fluendo, Abe Fettig of Hep fame, Patrick O'Brien from the Twisted list,
and Timothy Fitz from IRC - not to mention Phil Frost, the only member of
the Divmod team I'd never physically seen before.
During the conference, 5 Divmod people gave presentations. In the order they
appeared:
- An overview of LivePage, by Donovan Preston
- A talk in Open Space about using the Xen virtual machine monitor to
facilitate secure, "agoric" restricted execution for Python programs, by
Allen Short.
- Xapian indexing & Xapwrap, by Michael Salib.
- A demonstration in Open Space of the Quotient application and the
Divmod service, by Amir Bakhtiar.
- A description of the in-development peer-to-peer application protocol,
Q2Q, by me.
All five talks were awesome, of course. In both Mike and Donovan's
talks I learned surprisingly pleasant things about our own code, which I
guess is an indication that we should go to more conferences...
I spent a good deal of the sprints, and the conference, preparing for my
talk and writing code to test the ideas in it, so I missed a lot of talks
that I wanted to see.
The nice thing about being at a conference like PyCon though, is that if a
talk is good you'll hear it repeated 3 or 4 times in the halls as people are
discussing it. I heard a few very, very interesting talks in this manner
either from their authors or from attendees of the talks. "How to Build an
Air Traffic Control System" involved Twisted, and it really blew my mind how
good a fit it was. "Yarn: Working with Messages in Diverse Formats and
Protocols" was some real food for thought, and I've been looking at yarn
quite a bit since then - I really like it. The Chandler demo talk impressed
my co-workers enough that we are now anxiously awating a release we can
target as our primary client platform. Finally, of course, I've been hearing
about Itamar's "Fast Networking with Python" talk for the last few months
and I can't wait until the optimizations he's working on are just part of
the default Twisted reactor.
There was a lot to assimilate in only a few short days - and of course I've
left out days' worth of side-conversations with old friends and
acquaintances from previous conferences about a huge variety of Python,
Twisted, and Divmod-related topics.
Unfortunately the Divmod team came to the conference after a very hectic
month where most of our preparation time was eaten up by more pressing
concerns
1, so we
weren't able to update the divmod.org website in time for the conference,
which was disappointing. Also, the whole conference was a rollercoaster ride
for me, since I was still working on proving the concept that my talk was
supposed to be about.
Still, we managed to sign up a bunch of new customers
2, and there were a lot of people
randomly walking up to me throughout the conference and saying how they
thought Divmod was cool. Hearing that from people who aren't involved in the
daily struggle is energizing, and worth the cost of admission by itself, for
me.
As great as all that stuff was, I wouldn't be accurately summarizing my
experience of this conference for myself if I didn't talk at least a bit
about Q2Q. I explained it about 12 different times, slightly differently
each time, to other programmers at the sprints, then I paired with a half
dozen other people throughout the rest of the week.
Since there is no real documentation yet (still working on it!), I'll give a
brief overview.
On today's internet, when you want to connect to a service, you have to know
a host name, and a port number (or at least an implied port number). Q2Q is
an attempt to take the same underlying model of TCP - end-to-end streams of
bytes with the physical transport medium abstracted away - but identify the
endpoints in a more human readable way, and remove some of the
transport-layer obstacles that have crept into TCP over the years. Rather
than connecting to your-host.com on port 80, you connect to
"your-user@big-host.com" over the named protocol "http". Also, you specify
who you are connecting
as, which is a persistent, reverseable
identifier, unlike the IP address and port number associated with a TCP
connection. Additionally, since Q2Q introduces a new level of indirection
and a new lookup layer, it also adds some automatic NAT-traversal logic,
which means that it will let you connect to computers that are behind
firewalls which normally disallow incoming connections - without creating a
security problem, because Q2Q connections have to be explicitly requested by
first creating (and maintaining) an outgoing connection.
There are also some interesting security properties of connections
established with Q2Q, but those are more difficult to explain and more in
development, so I'll leave it brief - you're a lot surer of where the
connection is coming from over Q2Q than you would be over regular TCP, and
it's got some built-in features to help prevent problems of spamming. There
is a SSL-secured trust-web automatically expanded by every new connection,
which can be used to detect spoofing attempts and trace the origin of
malicious traffic.
Also, by using that trust-web established between servers, Q2Q can be used
as a distributed authentication mechanism for the web, or as the kids are
calling it these days, a "federated identity" system.
I am personally very excited about working on Q2Q. I feel like in these days
where everyone has 50 different accounts on 50 different websites, and
there's no simple way to even transfer a file between two computers that
will reliably work without always wasting huge amounts of some passive third
party's bandwidth, let alone reliably hook up a private peer-to-peer chat
room, something that offers these features is really necessary.
A few people have pointed out that the SVN URL that I gave at the end of my
talk was wrong. Since it hasn't yet been merged into Quotient's trunk
(though it will be any day now - I'll post an update when it is!) for the
time being you can see it at:
svn://divmod.org/svn/Quotient/branches/glyph/pycon-q2q/
Although the demo at the end of my talk was a disaster (just a terminal
window with a traceback in it, basically), some good did come out of the
late nature of its development - I got to work with a bunch of people on q2q
that I otherwise wouldn't have. Since I wasn't going to blame the broken
demo on them, I didn't mention them at the end of my talk, but now that
things are working again (albeit in a branch), I want to send a really big
thank you to the following people who paired with me on Q2Q
during the conference:
- Pavel Pergamenshchik
- Alex Levy
- Moshe Zadka
- Brian Warner
Without their help I wouldn't have had a talk at all, nor any code to
show now.
To sum up - PyCon 2005 DC was fantastic, as in previous years. It still
makes the #1 spot on my conference calendar. I am sad to see Steve Holden go
as the organizer, since he really rescued the Python conference scene. IPC11
was starting to feel a little pathetic, and the Python track at OSCon isn't
really a conference of its own. Still, I think that AMK is going to do a
great job next year, and it looks like attendance is going to keep going up
and up.
It's a great time to be a part of the Python universe, the Twisted cabal and
the Divmod team. I'm already looking forward to next year's conference.
drop me a line.
contact our marketing & support
"department" and let us know you'd like a ticket. We're trying to grow
our user base by a few people each week, to gradually scale our server up to
more and more load.
