Unix Programming with Perl 2 (my slides at YAPC::Asia 2011)

Today's slides are here:

Unix Programming with Perl 2

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Last year's slides are here:

Unix Programming with Perl

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mysql_json - a MySQL UDF for parsing JSON

Somewhat related to (or rather not related to) やったーJavaScriptの動くMySQLできたよー - 愛と勇気と缶ビール, I have written a MySQL UDF that parses JSON strings.

The UDF introduces one function: json_get, that parses a JSON object or an array and returns one of the properties.

SELECT json_get('{"a":1}', 'a')       => 1
SELECT json_get('{"a":1}', 'b')       => NULL
SELECT json_get('[1,2,3]', 2)         => 3
SELECT json_get('{"a":[2]}', 'a', 0)  => 2

By using to the UDF it is possible to write queries accessing the properties of JSON objects stored in MySQL.

SELECT json_get(data,'title') FROM message WHERE id=1;
SELECT id,data FROM message WHERE json_get('data','from')='hidek';

Source code of the UDF can be found at github.com/kazuho/mysql_json. The installation process may vary, but I did the following for my ubuntu server.

% g++ -shared -fPIC -Wall -g mysql_json.cc -o mysql_json.so
% sudo cp mysql_json.so /usr/lib/mysql/plugin
% mysql -u root
mysql> create function json_get returns string soname 'mysql_json.so';

「例えば牛丼を避ける」 - Cooking for Geeks! で話してきました

あとで書く。

例えば牛丼を避ける - slideshare

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「オープンソース開発者がDeNAを選ぶ理由」 (OSC 2011-Kyoto 発表資料)

結果として、かなり個人的な話になっちゃって恥ずかしいのですが、僕の経験がなにかの役に立つことがあればいいのかなと思って、表題のタイトルで話してきました。

オープンソース開発者がDeNAを選ぶ理由

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まあそんな感じで楽しく元気でやっておりますので心配しないでください。

ウェブアーキテクチャの歴史と未来 (デブサミ2011発表資料)

Developers Summit 2011 の発表資料です。ウェブアーキテクチャの変遷を構成技術の変化という視点から概説。

ウェブアーキテクチャの歴史と未来

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Webアプリケーションの無停止稼働 - Server::Starter, Parallel::Prefork, Starlet を使って (SoozyConference 7 発表資料)

１月に開催された SoozyConference 7 の発表資料です。

Webアプリケーションの無停止稼働

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転職のおしらせ

最近は株式会社ディー・エヌ・エーで働いています。今後ともよろしくお願いいたします。

5x performance - switching from LWP to Furl & Net::DNS::Lite

Recently I rewrote some of our code that used LWP::UserAgent to use Furl instead, and have been observing more than 5x increase in performance (the CPU time spent for each HTTP request in average has dropped 82%).

The fact clearly shows that if you are having performance issues with LWP::UserAgent it is a good idea to switch to Furl.  And here are my recommendations when doing so:

use the low-level interface (Furl::HTTP)

The OO-interface provided by Furl.pm is not as fast as the low level interface, though it is still about twice as fast as LWP::UserAgent.

use Net::DNS::Lite for accurate timeouts

The timeout parameter of LWP::UserAgent is not accurate.  The module may wait longer than the specified timeout while looking up hostnames.  Furl provides a callback to use non-default hostname lookup functions with support for timeouts, and Net::DNS::Lite can be used for the purpose.

use Cache::LRU to cache DNS queries

In general DNS queries are lightweight but caching the responses can still have positive effect (if the cache is very fast).  Cache::LRU is suitable for such an usecase.

The below code snippet illustrates how to setup a Furl::HTTP object with the described configuration.

use Cache::LRU;
use Furl;
use Net::DNS::Lite;

# setup cache for Net::DNS::Lite
$Net::DNS::Lite::CACHE = Cache::LRU->new(
    size => 256,
);

# create HTTP object...
my $furl = Furl::HTTP->new(
    inet_aton => \&Net::DNS::Lite::inet_aton,
    timeout   => $timeout_in_seconds,
    ...