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Presentations

Tue, 08 Mar 2016 22:49:55 GMT

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Here goes a list of slides that I used in various opensource events and school lectures.

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Year 2015

Application of Lua in Nginx

This talk was given at QCon Beijing 2015.

Talk summary (Chinese): http://2015.qconbeijing.com/speakers/201758

Video recording (Chinese): http://www.infoq.com/cn/presentations/application-of-lua-in-nginx

View slides in your web browser: http://agentzh.org/misc/slides/qcon-beijing-2015/

Download the slides as PDF: http://agentzh.org/misc/slides/qcon-beijing-2015/application-of-lua-in-nginx.pdf

The Past, Present, and Future of OpenResty

This talk was given at OpenResty Con Beijing 2015.

Video recording (Chinese): https://www.youtube.com/watch?v=vUgTHeXM5m8

View slides in your web browser: http://agentzh.org/misc/slides/openresty-con-2015/

Download the slides as PDF: http://agentzh.org/misc/slides/The-Past-Present-and-Future-of-OpenResty.pdf

Year 2014

The Latest and Greatest from ngx_lua: New Features & Tools

This talk was given at NGINX Conference 2014 on 21 October 2014.

Talk summary: https://nginx.busyconf.com/activities/53d854c1c9e255cf2d00007b

Video recording: https://www.youtube.com/watch?v=Z0fQabvVhIk

View slides in your web browser: http://agentzh.org/misc/slides/nginx-conf-2014/

Download the slides as PDF: http://agentzh.org/misc/slides/nginx-conf-2014.pdf

NGINX, Lua, and beyond

This talk was given at NGINX Inc's NGINX User Summit 2014 on 25 February 2014.

View slides in your web browser: http://agentzh.org/misc/slides/nginx-user-summit-2014/

Download the slides as PDF: http://agentzh.org/misc/slides/nginx-lua-and-beyond.pdf

Year 2013

The Way of Optimizing and Troubleshooting Our Lua Waf

This talk was given at CloudFlare's Beer Meeting on 19 April 2013.

View slides in your web browser: http://agentzh.org/misc/slides/beer-meeting-2013-04-19/

Download the slides as PDF: http://agentzh.org/misc/slides/beer-meeting-2013-04-19.pdf

sregex: matching Perl 5 regexes on data streams

This talk was given at YAPC::NA 2013 in Austin, TX, USA.

Talk summary: http://www.yapcna.org/yn2013/talk/4762

View slides in your web browser: http://agentzh.org/misc/slides/yapc-na-2013-sregex/

Download the slides as PDF: http://agentzh.org/misc/slides/yapc-na-2013-sregex.pdf

Flame Graphs for online performance profiling

This talk was given at YAPC::NA 2013 in Austin, TX, USA.

Talk summary: http://www.yapcna.org/yn2013/talk/4579

View slides in your web browser: http://agentzh.org/misc/slides/yapc-na-2013-flame-graphs/

Download the slides as PDF: http://agentzh.org/misc/slides/yapc-na-2013-flame-graphs.pdf

Introduction to off-CPU Time Flame Graphs

This talk was given at the CloudFlare Beer Meeting on 23 August 2013.

View slides in your web browser: http://agentzh.org/misc/slides/off-cpu-flame-graphs/

Download the slides as PDF: http://agentzh.org/misc/slides/off-cpu-flame-graphs.pdf

Year 2012

ngx_openresty: an Nginx ecosystem glued by Lua

This talk was given at Tech-Club Technical Salon held in the Xiamen city, China.

View slides in your web browser: http://agentzh.org/misc/slides/ngx-openresty-ecosystem/

Download the slides as PDF: http://agentzh.org/misc/slides/ngx-openresty-ecosystem.pdf

Scripting libdrizzle with Lua inside Nginx

This presentation was given at Percona Live MySQL Conference 2012 held in Santa Clara, CA, USA.

View slides in your web browser: http://agentzh.org/misc/slides/libdrizzle-lua-nginx/#2

Download the slides as PDF: http://agentzh.org/misc/slides/libdrizzle-lua-nginx.pdf

Year 2011

Applications of ngx_openresty and perl in lz.taobao.com

This talk was given at Beijing Perl Workshop 2011.

Watch the video online: http://v.ku6.com/show/TY8Vre59guTE_C8o.html

View slides in your web browser: http://agentzh.org/misc/slides/perl-lz-apps/

Download the slides as PDF: http://agentzh.org/misc/slides/perl-lz-apps.pdf

Year 2010

Introduction to nginx.conf scripting

This talk was given at the Beijing Perl Workshop 2010 April meeting and the Beijing OpenParty 2010 June event.

View slides in your web browser: http://agentzh.org/misc/slides/nginx-conf-scripting/

Download the slides as PDF: http://agentzh.org/misc/slides/nginx-conf-scripting.pdf

Please note that ngx_eval module is no longer recommended because we're in more favor of ngx_lua nowadays.

Recent developments in nginx.conf scripting

This talk was given at the Beijing OpenParty 2010 June event.

View slides in your web browser: http://agentzh.org/misc/slides/recent-dev-nginx-conf/

Download the slides as PDF: http://agentzh.org/misc/slides/recent-dev-nginx-conf.pdf

The state of the art of nginx.conf scripting

This talk was given at the ECUG 2010 event.

Watch the (Chinese-speech) video online: http://v.ku6.com/show/D00rqtnRwKzJdIsB.html

View the (English) slides in your web browser: http://agentzh.org/misc/slides/nginx-state-of-the-art/

Download the slides as PDF: http://agentzh.org/misc/slides/nginx-state-of-the-art.pdf

Year 2009

A Firefox cluster driven by JavaScript, Perl, & PL/PgSQL

This talk was given at the Beijing Perl Workshop 2009 Feb Meetup and Beijing OpenParty 2009 Feb event.

View the slides in your web browser: http://agentzh.org/misc/slides/BJPW200902/ffcluster.html

Download the slides as PDF: http://agentzh.org/misc/slides/bjpw200902-ffcluster.pdf

Introduction to our VDOM.pm & vdom-webkit cluster

Use vision information to do intelligent web scraping by rendering pages via a WebKit & VDOM cluster.

This talk was given at Beijing Perl Workshop 2009 and a meetup with Taobao.com's front-end engineers in the Hangzhou city.

View the slides in your browser: http://agentzh.org/misc/slides/taobao-fe/vdomwebkit.html

Download the slides as PDF: http://agentzh.org/misc/slides/taobao-fe-vdomwebkit.pdf

A Tour of Perl Testing

This talk was given at the Beijing Perl Workshop 2009 event.

View slides in your web browser: http://agentzh.org/misc/slides/BJPW2009/perl-testing.html

Download the slides as PDF: http://agentzh.org/misc/slides/bjpw2009-perl-testing.pdf

Year 2008

Nifty web apps on an OpenResty

This talk was given at the D2 Frontend Technology event organized by Yahoo! China.

View slides in your web browser: http://agentzh.org/misc/slides/openresty-d2/

Download the slides as PDF: http://agentzh.org/misc/slides/openresty-d2.pdf

OpenResty: Your Relational Cloud

OpenResty.pm is a general-purpose RESTful web service platform. In this talk I explained its origin, REST API, and its unusual applications.

This talk was given at the Beijing Perl Workshop 2008 event and the Yahoo! China Engineer Tech. Salon.

View slides in your web browser: http://agentzh.org/misc/slides/openresty-yes/

Download the slides as PDF: http://agentzh.org/misc/slides/openresty-yes.pdf

Year 2007

XUL::App - Jifty way of doing XUL

XUL::App is a nifty Firefox extension development framework based on Perl. It has a lot of parallels with Jifty. In particular, this framework allows you to build real-world modern Firefox extensions using Perl.

In this talk, I demonstrated how to use this framework to write a "hello, world" Firefox extension with I18N support in lines.

This talk was given at the Beijing Perl Workshop 2008 event.

View slides in your web browser: http://agentzh.org/misc/slides/xulapp/

Download the slides as PDF: http://agentzh.org/misc/slides/xulapp.pdf

Contribute to Pugs

Pugs is a Perl 6 compiler written in Haskell. In this talk, I introduced the Pugs project as well as my involvement in the automated testing work of the Perl 6 language to the PerlChina folks and encouraged people to contribute Pugs.

This talk was given at the Beijing Perl Workshop 2007 event.

View slides in your web browser: http://agentzh.org/misc/slides/contr_pugs/

Download the slides as PDF: http://agentzh.org/misc/slides/contr_pugs.pdf

Use UML::Class::Simple to generate simple UML class diagrams

UML::Class::Simple is my Perl CPAN module that can generate UML class diagrams automatically from arbitrary real-world Perl OO libraries.

This talk was given at the Beijing Perl Workshop 2007 event.

View slides in your web browser: http://agentzh.org/misc/slides/umlclass/

Download the slides as PDF: http://agentzh.org/misc/slides/umlclass.pdf

Year 2006

Introduction to XClips

XClips is an expert system development language designed by myself, which is implemented atop NASA's CLIPS. This talk explains the appearance of the language and some details of its implementation and applications.

This talk was given as a lecture at the Jiangsu University.

View slides in your web browser: http://agentzh.org/misc/slides/xclips/

Download the slides as PDF: http://agentzh.org/misc/slides/xclips.pdf

The Art of Naming

This talk teaches the art of naming for programmers, using lots of examples from Perl 6, C/C++, Java, and other programming languages.

This talk was given as a lecture at the Jiangsu University.

View slides in your web browser:

Or download the slides as PDF files:

XML in the real world

This talk shows various interesting applications of XML in the real world. It also introduces some of my web scraping tools based on Perl 5.

This talk was given as a lecture at the Jiangsu University.

View slides in your web browser: http://agentzh.org/misc/slides/xmlapp/

Download the slides as PDF: http://agentzh.org/misc/slides/xmlapp.pdf

Functions and Methods

This lecture discusses functions and methods in Object-Oriented Programming (OOP). This is one of my series of lectures on OOP given at the Jiangsu University.

View slides in your web browser: http://agentzh.org/misc/slides/func/

Download the slides as PDF: http://agentzh.org/misc/slides/func.pdf

Design Patterns - Using FAST

This talk explains the design patterns used in the construction process of the FAST (Flowchart Abstract Syntax Tree transformer) program, which can convert a program described by a flowchart into a structural program.

This talk was given as a lecture at the Jiangsu University.

View slides in your web browser: http://agentzh.org/misc/slides/patterns/

Download the slides as PDF: http://agentzh.org/misc/slides/patterns.pdf

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Fri, 08 Mar 2013 06:31:00 GMT

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ContactMe

Fri, 08 Feb 2013 19:43:00 GMT

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You're welcome to mail me via agentzh@gmail.com. This mail address is also my MSN account.

I'm quite active in the nginx and nginx-devel mailing lists. I'm also keeping an eye on the PerlChina, lua-l and erlang-questions mailing lists as well ;)

If you want to ask me questions about my Nginx or OpenResty related work, please join the OpenResty community and post there.

StyleSheet

Fri, 08 Feb 2013 19:43:00 GMT

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AboutMe

Wed, 04 Jul 2012 20:02:00 GMT

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I'm a happy programmer living in San Francisco, CA. My real name is Yichun Zhang, or 章亦春 in Chinese. I usually use the nick agentzh on the web.

I'm currently working as a systems engineer for CloudFlare and my main focus is on Nginx and OpenResty development.

I used to work for Yahoo! China and Taobao, Alibaba while working in Beijing, China.

OpenResty

Wed, 27 Jun 2012 07:04:00 GMT

OpenResty is a software bundle for various useful Nginx addons, LuaJIT/Lua, and the Nginx core that helps constructing high-performance web applications. See

http://openresty.org

Blogs

Tue, 06 Dec 2011 07:46:00 GMT

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I'm posting nginx related stuffs and other things to my blog site on Blogger: http://agentzh.blogspot.com/

I'm also posting Nginx tutorials for both users and developers in Chinese at Sina Blog here: http://blog.sina.com.cn/openresty

FollowMe

Wed, 16 Nov 2011 07:42:00 GMT

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I'm quite active in Sina Weibo (A twitter clone very popular in China): http://weibo.com/agentzh

I do own a twitter account, @agentzh.

If you're interested in my opensource development work, go follow me on GitHub! http://github.com/agentzh/

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Mon, 25 Jul 2011 15:37:00 GMT

ErlangFileReadLineBenchmark

Tue, 28 Jun 2011 09:28:00 GMT

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Source listing

reader.erl

Here's the Erlang implementation A, not using Erlang binaries:

-module(reader).
-export([main/0]).

main() ->
    {ok, File} = file:open("data.log", [read]),
    Lines = count_lines(File, 0),
    io:format("Found ~w lines.~n", [Lines]),
    halt().

count_lines(File, Count) ->
    case file:read_line(File) of
        {ok, _Line} ->
            count_lines(File, Count + 1);
        eof ->
            Count
    end.

reader-bin.erl

Here's the Erlang implementation B, using Erlang binaries:

-module(reader).
-export([main/0]).

main() ->
    {ok, File} = file:open("data.log", [read, binary]),
    Lines = count_lines(File, 0),
    io:format("Found ~w lines.~n", [Lines]),
    halt().

count_lines(File, Count) ->
    case file:read_line(File) of
        {ok, _Line} ->
            count_lines(File, Count + 1);
        eof ->
            Count
    end.

reader-bin-raw.erl

Here's the Erlang implementation C, using Erlang binaries, raw file mode, and big read_ahead:

-module(reader).
-export([main/0]).

main() ->
    {ok, File} = file:open("data.log", [read, binary, raw, {read_ahead, 1024 * 1024}]),
    Lines = count_lines(File, 0),
    io:format("Found ~w lines.~n", [Lines]),
    halt().

count_lines(File, Count) ->
    case file:read_line(File) of
        {ok, _Line} ->
            count_lines(File, Count + 1);
        eof ->
            Count
    end.

reader.pl

Here's the Perl 5 implementation:

open my $in, "data.log" or die;
my $n;
while (<$in>) {
    $n++;
}
print "Found $n lines.\n";

Test data file

The data file is from a real nginx error.log file snapshot in our production environment. Here's its basic information:

$ wc data.log
    412003  12957676 197733977 data.log
$ ls -lh data.log
-rw-r--r-- 1 agentz users 189M 2011-06-28 15:08 data.log

Benchmark

To help OS cache the disk data, we only take the time of the programs' second runs.

Results on Slackware Linux x86_64

Linux Kernel: 2.6.33.1
CPU: Intel Core2Duo T9600
Hard disk: SATA 7200'
Erlang OTP: R14B01 (erts-5.8.2)
Perl: 5.12.1

The Erlang program A compiled in bytecode

$ erlc reader.erl
$ time erl -noshell -s reader main
Found 412003 lines.

real	0m14.023s
user	0m13.237s
sys	0m0.742s

The Erlang program A compiled in native code

$ erlc +native reader.erl
$ time erl -noshell -s reader main
Found 412003 lines.

real	0m14.007s
user	0m13.233s
sys	0m0.739s

The Erlang program B compiled in bytecode

$ erlc reader-bin.erl
$ time erl -noshell -s reader main
Found 412003 lines.

real	0m4.451s
user	0m4.322s
sys	0m0.104s

The Erlang program B compiled in native code

$ erlc +native reader-bin.erl
$ time erl -noshell -s reader main
Found 412003 lines.

real	0m4.531s
user	0m4.417s
sys	0m0.095s

The Erlang program C compiled in bytecode

$ erlc reader-bin-raw.erl
$ time erl -noshell -s reader main
Found 412003 lines.

real	0m10.001s
user	0m8.520s
sys	0m1.386s

The Erlang program C compiled in native code

$ erlc +native reader-bin-raw.erl
$ time erl -noshell -s reader main
Found 412003 lines.

real	0m10.398s
user	0m8.673s
sys	0m1.359s

The Perl 5 program

$ time perl reader.pl
Found 412003 lines.

real	0m0.332s
user	0m0.271s
sys	0m0.061s

Results on Mac OS X 10.6.7

CPU: Intel Core2Duo 1.86GHz
Hard disk: SSD
Erlang OTP: R14B02 (erts-5.8.3)
Perl: 5.12.3

The Erlang program A compiled in bytecode

$ erlc reader.erl
$ time erl -noshell -s reader main
Found 412003 lines.

real	0m32.254s
user	0m27.532s
sys	0m4.681s

The Erlang program A compiled in native code

$ erlc +native reader.erl
$ time erl -noshell -s reader main
Found 412003 lines.

real	0m32.043s
user	0m27.356s
sys	0m4.646s

The Erlang program B compiled in bytecode

$ erlc reader-bin.erl
$ time erl -noshell -s reader main
Found 412003 lines.

real	0m6.700s
user	0m6.447s
sys	0m0.212s

The Erlang program B compiled in native code

$ erlc +native reader-bin.erl
$ time erl -noshell -s reader main
Found 412003 lines.

real	0m6.721s
user	0m6.461s
sys	0m0.218s

The Perl 5 program

$ time perl reader.pl
Found 412003 lines.

real	0m0.677s
user	0m0.480s
sys	0m0.182s

Conclusion

Erlang's file:read_line/1 is painfully slow on both Linux and Mac OS X, as of the latest version R14. It's more than one order of magnitude slower than plain Perl 5. Enabling native code generation can make the Erlang version a little faster.

Update: Excluding the time involved in beam startup and quit only makes the result <100ms faster according to my tests on the Linux box.

AboutThisSite

Fri, 24 Jun 2011 03:01:00 GMT

This is site is powered by the excellent TiddlyWiki.

The site's source is hosted on GitHub: https://github.com/agentzh/agentzh.org

MainMenu

Fri, 24 Jun 2011 02:59:00 GMT

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Projects

Tue, 21 Jun 2011 08:04:00 GMT

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The most important opensource project that I've been working on for years is OpenResty.

You can find most of my opensource projects on my GitHub homepage:

https://github.com/agentzh

Nginx

I've started or participated in the development of a bunch of nginx modules:

http://wiki.nginx.org/3rdPartyModules

Perl

I'm a Perl programmer that writes dozens of CPAN modules.

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Tue, 21 Jun 2011 07:42:00 GMT

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This site's RSS feed is available at http://agentzh.org/index.xml .

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Mon, 20 Jun 2011 09:29:00 GMT

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SiteUrl

Mon, 20 Jun 2011 09:19:00 GMT

http://agentzh.org/

SiteTitle

Fri, 17 Jun 2011 08:12:00 GMT

agentzh's home

SiteSubtitle

Fri, 17 Jun 2011 03:33:00 GMT

yet another idiot who loves programming

YichunZhang

Tue, 14 Jun 2011 04:39:00 GMT

The owner of this site. He loves the nick agentzh though. But please do not capitalize the nick!