Tatsumaki is a non-blocking web framework for Perl built on Plack and AnyEvent. It allows building asynchronous applications that can handle thousands of concurrent connections. Tatsumaki uses psgi.streaming to enable asynchronous responses. It includes a non-blocking HTTP client and pure Perl message queue for building real-time applications like chat and comet. The framework is in a beta stage but plans include services for XMPP/IRC bots and a standard comet interface.

1. Tatsumaki
non-blocking web framework built on Plack/AnyEvent
Tatsuhiko Miyagawa
Nov. 30th, 2009 / Shibuya.pm Tech Talks #12

2. PSGI

3. Perl Web Server
Gateway Interface

4. Python’s WSGI
Ruby’s Rack

5. my $app = sub {
my $env = shift;
return [ $status, $headers, $body ];
};

6. Plain Old Perl

7. Servers
CGI, FastCGI, mod_perl1&2
Standalone, Prefork, AnyEvent, Coro, POE,
Danga::Socket, nginx, mod_psgi, evhttpd, Perlbal

8. Frameworks
Catalyst, Mason, Maypole, CGI::Application, Jifty
Dancer, HTTP::Engine, Sqauatting, Continuity
WebGUI, Movable Type, Ark, Angelos, Noe

9. Middleware
Static, ConditionalGET, AccessLog, Chunked, Deflater,
NYTProf, FCGIDispatcher, JSONP, StackTrace,
Auth::Basic, XSendfile, Rewrite, JSConcat ...

10. Servers
CGI, FastCGI, mod_perl1&2
Standalone, Prefork, AnyEvent, Coro, POE,
Danga::Socket, nginx, mod_psgi, evhttpd, Perlbal

11. Non-blocking?

12. psgi.streaming

13. # delayed response
my $app = sub {
my $env = shift;
return sub {
my $respond = shift;
$respond->([ $status, $headers, $body ]);
};

14. # streaming content
my $app = sub {
my $env = shift;
return sub {
my $respond = shift;
my $w = $respond->([ $status, $headers ]);
some_event_loop(sub {
$w->write($content);
$w->close;
});
};

15. WARNING
psgi.streaming is an interface
Servers may not work if event loop is not shared
(Recommended to use AnyEvent in your app)

16. Frameworks?

17. Most frameworks do not
support non-blocking interface.
(Mojo 0.99 has IOLoop and Client)

18. Let’s make one!

19. Tatsumaki
http://www.flickr.com/photos/88699006@N00/679056142/

20. Port of Tornado

22. Plack and AnyEvent
All the way from the bottom to the top
Handle thousands of connections with EV/epoll

23. Works with
AnyEvent, POE, Coro, Danga::Socket and perlbal
Because it’s AnyEvent!

24. You can use
Any of AnyEvent::* libraries to do
asynchronous tasks (unlike Mojo)

25. The first and only framework
that uses psgi.streaming

26. package MainHandler;
use base qw(Tatsumaki::Handler);
sub get {
my $self = shift;
$self->write(“Hello World”);
}
package main;
use Tatsumaki::Application;
my $app = Tatsumaki::Application->new([
‘/’ => ‘MainHandler’,
]);

27. Tatsumaki::HTTPClient
AnyEvent::HTTP wrapper
non-blocking HTTP client for Tatsumaki

28. package HTTPClientHandler;
use base qw(Tatsumaki::Handler);
__PACKAGE__->asynchronous(1);
use Tatsumaki::HTTPClient;
sub get {
my $self = shift;
my $client = Tatsumaki::HTTPClient->new;
$client->get($api_url, sub {
my $res = shift;
my $body = $res->content;
$self->write(...);
$self->finish;
});
}

29. Long-poll (comet)

30. package AsyncHandler;
use base qw(Tatsumaki::Handler);
__PACKAGE__->asynchronous(1);
sub get {
my $self = shift;
my $t; $t = AE::timer 3, 0, sub {
undef $t;
$self->write(“Hello World”);
$self->finish;
});
}
package main;
use Tatsumaki::Application;
my $app = Tatsumaki::Application->new([
‘/’ => ‘AsyncHandler’,
]);

31. Tatsumaki::MessageQueue
Pure perl MQ (in AnyEvent)

32. package LongPollHandler;
use base qw(Tatsumaki::Handler);
__PACKAGE__->asynchronous(1);
use Tatsumaki::MessageQueue;
sub get {
my $self = shift;
my $mq = Tatsumaki::MessageQueue-
>instance(‘ch-name’);
$mq->poll_once($client_id, sub {
my @events = @_;
$self->write(@events);
$self->finish;
});
}

33. package EventPostHandler;
use base qw(Tatsumaki::Handler);
sub post {
my $self = shift;
my $mq = Tatsumaki::MessageQueue-
>instance(‘ch-name’);
$mq->publish({
name => “NewComment”, ...
});
$self->write({ success => 1 });
}

34. Multipart XHR
JavaScript hack to emulate server push

35. package MXHRPollHandler;
use base qw(Tatsumaki::Handler);
__PACKAGE__->asynchronous(1);
use Tatsumaki::MessageQueue;
sub get {
my $self = shift;
$self->multipart_xhr_push(1);
my $mq = Tatsumaki::MessageQueue-
>instance(‘ch-name’);
$mq->poll($client_id, sub {
my @events = @_;
$self->stream_write(@events);
});
}

36. JS Client libraries
jquery.ev
DUI.Stream
raphaeljs

37. DEMO

38. http://192.168.100.50:5000/chat/demo

39. Other apps
github.com/gugod/Social
github.com/miyagawa/Subfeedr
github.com/audreyt/socialcalc
github.com/clkao/Finance-GeniusTrader-Chart
github.com/lestrrat/Hamaki
github.com/yusukebe/Nagare

40. WHY

41. Web server resource

42. I/O bound
!CPU bound

43. I/O bound web apps
HTTP API proxy (e.g. OpenSocial)
Mash up (XML, REST API)
Real-time Web (Comet)

44. CPU bound jobs
Database Servers
Job Workers (TheSchwartz etc.)

45. Tatsumaki for
I/O bound web

46. ✓ Non-blocking HTTP client
✓ Pure perl Message Queue
✓ I/O libraries (AnyEvent::*)
✓ DB libraries (AnyEvent::DBI)
✓ Job dispatcher (AE::Gearman)

47. Status
0.1.x on CPAN, considered beta
AnyEvent server has bugs on Linux

48. Plans

49. Tatsumaki::Service
Inspired by Google AppEngine Email/XMPP service
Webhook pattern

50. XMPP/IRC
Write Jabber/IRC bot as a web application

51. # see Tatsumaki-Service-XMPP/eg/translate.psgi
package XMPPTranslateHandler;
use base qw(Tatsumaki::Handler::XMPP);
sub post {
my $self = shift;
my $msg = $self->xmpp_message;
my $uri = “http://ajax.googleapis.com/...”;
my $client = Tatsumaki::HTTPClient->new;
$client->get($uri, $self->async_cb(sub {
my $res = shift;
my $r = JSON::decode_json($res->content);
$msg->reply($r->{translatedText});
$self->finish;
}));
}

52. Standard Comet Interface
a.k.a Stardust

53. Bayeux
HTTP push relay

54. “Real” PubSub interface
for Tatsumaki::MQ

55. Pluggable MQ
using “real” MQ like ActiveMQ or RabbitMQ

56. DataStore interface
using AnyEvent::DBI, Redis etc.

57. See Subfeedr
for Redis integration
http://github.com/miyagawa/Subfeedr

58. cpan> install Tatsumaki
http://github.com/miyagawa/Tatsumaki
irc://irc.perl.org/#plack

59. That’s it!
Questions?