ap4r on rubykaigi2007 (english only)

AP4RKiwamu Kato & Shun’ichi Shinohara

Future Architect, Inc.

1

RubyKaigi 2007

•Introduction　

•Demo　

•Real world examples　

•Technical topics　

2

Introduction

3

Self Introduction

4

•Majored in Civil Engineering

•Has Enhanced and maintained messaging middleware in company

Kiwamu Kato

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•Started Ruby since last year

•Leader of the AP4R team

•http://d.hatena.ne.jp/kiwamu/

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Kiwamu Kato

http://d.hatena.ne.jp/kiwamu/

http://d.hatena.ne.jp/kiwamu/

shino•Programmer, I love coding !

•The language of the year is C or Haskell

7

•Last year, made a debut to the OSS world

•http://d.hatena.ne.jp/ita-wasa/

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shino

http://d.hatena.ne.jp/ita-wasa/

http://d.hatena.ne.jp/ita-wasa/

What is AP4R ?

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Lightweight

Messaging

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What is AP4R ?

•Asynchronous Processing for Ruby

•Loose coupling by messaging

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What can we do w/ AP4R ?

•Quicker response to users

•Load distribution

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Press release 2006/09/05

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http://itpro.nikkeibp.co.jp/article/NEWS/20060905/247218/



Key points are ..

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Lightweight and

Robust

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When is it useful ?

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Quicker response to users

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If NO speedy response is needed,

execute it later

Before

Client Server

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A B C D ...

Client Server Messaging Server

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After

A B


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After

A B C D ...

Useful cases

•Logging

•Sending mail

•Creating heavy summary data

•Collaboration with other systems

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Moreover,load distribution

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Easy to scale out


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Easy to scale out

Client Server Messaging Servers

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Only good things ?

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Sounds easy ?

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(Maybe) No

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If message deliveriesare NOT guaranteed,...

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message lost and

message duplication

it may lead to

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In other words...

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•You can’t receive the goods despite payment !

•Double withdrawals !

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Messages should be delivered in a reliable way,

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No matter what happens

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•Database trouble

•Network trouble

•Server down

•Busy and timeout

• ... etc

Lightweight and

Robust35

In Future Architect ...

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•Developed own messaging library

•Named “RtFA”

We use messaging a lot

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•Pure Java

• Its own protocol, API (≠ JMS)

•Time-proven on various systems

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We use messaging a lot

One of illustrative cases

http://japan.internet.com/linuxtoday/20061228/5.html

Mission critical system in transportation business

39



• Over 100 million package data per day

• Load distribution and parallel processing on 8 nodes of Oracle 10g RAC

PJ summary

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•Approx 100 servers

•Used “RtFA”, an in-house middleware

PJ summary

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Messaging is important

Lightweight

Messaging44

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http://www.pragmaticprogrammer.com/titles/fr_j2r/

http://www.oreilly.co.jp/books/9784873113203/





From RtFA to AP4R

• Based on implementation/experiences with Java,kept good parts, improved bad parts

• Focus on ease of use（API, configuration）

46

Lightweight and

Robust

47

Demo

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•Shopping store application

•Order and payment

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Outline

Shopping store app.

Client Rails

50

.

Payment

Order

Loose couplingClient Rails AP4R Rails × 3

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Order


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Order Payment


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Order PaymentSleep 1

•Use mongrel cluster

•Stress by ab

•Monitor queue retaining status

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Outline

Real world examples

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Two examples

•Work With Rails

•Our internal project

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Working With Rails

http://workingwithrails.com/

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http://workingwithrails.com

http://workingwithrails.com

WWR

•is who’s who for Rails developers

• listed 7,000 people from 104 countries

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WWR

•aggregates feeds from user’s blog

•has scaling problem in fetching them slow/stale

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WWR solution

•Queue Feeds

•Fetch async’ly

"Getting Distributed with Ruby on Rails" slide #44 (from slideshare)

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http://www.slideshare.net/martinbtt/getting-distributed-with-ruby-on-rails




WWR solution

•Able to scale

•Flexible to feed types

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Internal project

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•Work sheet management app.newly-building in Ruby

Briefing

64

•Labor cost accounting app.existing in Java

Requirements

•Quick and rich UI

•Replicate data between Java and Ruby

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With AP4R

•Separate loads from UI

• Invoke Java from Ruby async’ly

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Separate loads from UIClient Server Messaging Server

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Separate loads from UI

Create summary data, Send mails, etc.

68


Async’ly invoke Java

69


Async’ly invoke Java

data replication, etc.

69


Utilize Async! when

• Needless proc. for responce data

• Disjoined transactions are allowable

• External calls (often slow, unstable)

70

Technical topics

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Two topics here

•API to put messages and process flow

•Stored and Forward

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API to put messagesand process flow

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ap4r.async_to({specify next}, {request data} [,{more opts}])

There’s also block stylec.f. RDoc: http://ap4r.rubyforge.org/doc/

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http://ap4r.rubyforge.org/doc/

http://ap4r.rubyforge.org/doc/

Class ShopController < ApplicationController

def order # synchronous side ... ap4r.async_to({:action => ‘payment’}, {:id => 1})

redirect_to ... end

def payment # asynchronous side id = params[:id] ... render :text => “true” end

end75

Process flow

76

User Apache Rails AP4R

77


order

message put

78


dispatch79


payment

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Able to separatesync/async servers

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82

Architecture

mongrel

reliable-msg

AP4R

XML-RPC

SOAP

HTTP

AP4R DRB

AP4R

HTTP

drubyDRB

MySQL

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4%10%

20%

66%

DRbreliable-msgmongrelrails

Thanks to

Stored And Forward

85

Stored ?

Forward ?

86

at-least-oncebetween Producer and Channel

87

88

Enterprise Integration Patterns: Designing, Building, and Deploying Messaging Solutions by Gregor Hohpe,Bobby Woolf

Guaranteed Delivery [122]

http://www.amazon.com/dp/0321200683

http://www.amazon.com/dp/0321200683

Typical flowto create async. messages

89

start

end

90

CRUDstart

end

90

CRUD

commit

start

end

90

CRUD

commit

message put / commit

start

end

90

CRUD

commit


start

end

90

data

CRUD

commit


start

end

90

data messages

Ensure (some)

Atomicnessof

updating database andmessage creation

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•Error occurs,

•Any following messages must NOT be queued

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On updating database

•Everything succeeded,

•All following messages must be queued

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On updating database

Relief

☺

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Lightweight and

Robust95

Ap4r::Client#transaction Class ShopController < ApplicationController def order # synchronous side ap4r.transaction do ... # CRUD on database

ap4r.async_to ... end redirect_to ... end end

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Process flow changesin queueing sequence

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ap4r.transaction do ... # CRUD on database

ap4r.async_to(...)

end

Behind ap4r.transaction

98


ap4r.async_to(...)

end


Insert into SAF table

98


ap4r.async_to(...)

end



Commit database

98


ap4r.async_to(...)

end



Commit databaseQueue messages

98


ap4r.async_to(...)

end




Store

98


ap4r.async_to(...)

end




Store

Forward

98

Sequence in detailWithout SAF

99

CRUD

commit


start

end

100

data messages

CRUD

commit


start

end

101

data messages

CRUD

commit


start

end

101

data messages☠

CRUDstart

end

102

data messages

counterchangecommit


CRUD

commit


start

end

103

data messages

counterchange

CRUD

commit


start

end

104

data messages

CRUD

commit


start

end

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data messages

☠

CRUD

commit


start

end

105

data messages

•Database trouble

•Network trouble

•Server down

•busy and timeout

• ... etc

Better Safe than Sorry

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Embrace every exceptions☺

☠

107

Sequence in detailWith SAF

108

CRUD

commitmessage put / commit

start

end

109

data messages

SAF create

SAF update


SAF update

CRUDstart

end

110

data messages

SAF create


SAF update

CRUDstart

end

111

data messages

SAF create


SAF update

CRUDstart

end

111

data messages

SAF create

☺


SAF update

CRUDstart

end

112

data messages

SAF create

message put / commitcommit

SAF update

CRUDstart

end

113

data messages

SAF create


SAF update

CRUDstart

end

113

data messages

SAF create

messages


SAF update

CRUDstart

end

113

data messages

SAF create

☺messages


SAF update

CRUDstart

end

113

data messages

SAF create

☺messages

Recoverable


SAF update

CRUDstart

end

113

data messages

SAF create

☺messages


SAF update

CRUDstart

end

114

data messages

SAF create


SAF update

CRUDstart

end

115

data messages

SAF create


SAF update

CRUDstart

end

115

data messages

SAF create

messages


SAF update

CRUDstart

end

115

data messages

SAF create

☺messages


SAF update

CRUDstart

end

115

data messages

SAF create

☺messages

Duplicated


SAF update

CRUDstart

end

115

data messages

SAF create

☺messages

Ensure (some)

Atomicnessof data and messages

116

at-least-oncebetween Producer and Channel

117

Summary

118

•Messaging with simple API, simple configuration.

•Seamless collaboration with Rails

119

•Automatic invocation of async proc.

•Guaranteed delivery by SAF

120

Lightweight and

Robust

121

Future Plans

122

Smooth operation ver.0.3.x

☑ Daemonize

☑ URL-rewrite filter

□ DLQ / SAF recovery

□ Protocols: Stomp, HTTP

123

Monitoring ver.0.4.x

□ Coordinate with Cacti, Nagios, etc.

□ Many AP4R processes

□ Interactive management tool

124

Step to large scale ver.0.5.x

□ Dynamic configuration

□ Automatic recovery

□ Long running

125

Others

□ Security

□ Application testing support

□ Blocking queues

126

Your patches are welcome! Thank you.

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AP4R@RubyForge

•wiki: http://ap4r.rubyforge.org/wiki/wiki.pl?HomePage

• source: svn co svn://rubyforge.org/var/svn/ap4r

http://ap4r.rubyforge.org/wiki/wiki.pl?HomePage

http://ap4r.rubyforge.org/wiki/wiki.pl?HomePage

128

• Future Architect logo belong to Future Architect, Inc. Japan. All rights reserved.

• Rails logo are trademarks of David Heinemeier Hansson. All rights reserved.

• The Ruby logo is copyright c 2006, Yukihiro Matsumoto. It is released under the terms of the Creative Commons Attribution-ShareAlike 2.5 License.

ap4r on rubykaigi2007 (english only)

Technology

client rails order

ap4r separate loads

messaging library

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rails developers

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ruby loose coupling