james lewis: microservices - systems that are #neverdone at i t.a.k.e. unconference 2015

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never donebuilding systems that are

[email protected]

@boicy

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agile

XPTDD

BDD

YAGNI

DRY

SOLID

Continuous Delivery

Refactoring

GoF

GRASP

emergent design

World of Warcraft

KISS

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the future is scary

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"ever accelerating progress of technology and changes in the mode of human life, which gives the appearance of approaching some essential singularity in the history of the race beyond which human affairs, as we know them, could not continue”

John von Neumann, as recorded by Ulam, 1958

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“Around the world, laboring women produce forty-five thousand babies a day, representing 1023 MIPS of processing power. Also around the world, fab lines casually churn out thirty million microprocessors a day, representing 1023 MIPS. In another ten months, most of the MIPS being added to the solar system will be machine-hosted for the first time”

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“Self-Driving Trucks Are Going to Hit Us Like a Human-Driven Truck”

https://medium.com/basic-income/self-driving-trucks-are-going-to-hit-us-like-a-human-driven-truck-b8507d9c5961

source: Morgan Stanley

This is where we’re at and this is what we face as we look towards a quickly approaching horizon of over 3 million unemployed truckers and millions more unemployed service industry workers in small towns all over the country dependent on truckers as consumers of their services.

https://medium.com/basic-income/self-driving-trucks-are-going-to-hit-us-like-a-human-driven-truck-b8507d9c5961

“If you aren’t worried about strong AI within the next 5-10 years then you aren’t working closely enough with AI teams”

(paraphrasing Elon Musk)

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closer to home?

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Singularity

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SingularityJavaScript

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SingularityJavaScript

Container

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SingularityJavaScriptLog aggregation

Container

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even closer to home

HOW WE DESIGN SOFTWARE IS CHANGING

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“the first post-devops architectural style”Neal Ford

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replaceable component architecturesDan North

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never done

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never done

Incomplete

adjective not having all the necessary or appropriate parts

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never done

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“This, milord, is my family's axe. We have owned it for almost nine hundred years, see. Of course, sometimes it needed a new blade. And sometimes it has required a new handle, new designs on the metalwork, a little refreshing of the ornamentation . . . but is this not the nine hundred-year-old axe of my family? And because it has changed gently over time, it is still a pretty good axe, y'know. Pretty good.”

never done

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microservices should be:

cheap to replace

and should allow us to go as “fast as possible”?

quick to scale

able to withstand failure

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Hardest things to do:

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Hardest things to do: End-to-end testing

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Independent deployment

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Independent deployment

Service versioning / evolution

TESTING MICROSERVICES IS HARD

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Service A

Service

Large

Medium

Small

Service Stub

TESTING MICROSERVICES IS HARD

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Service A

Large

Medium

Small

INTEGRATING MICROSERVICES IS HARD

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Integration Test


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Integration Test Prod…

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WHAT DOES THIS MEAN FOR THE CRAFT OF SOFTWARE DEVELOPMENT?

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<thinks>

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well crafted software

steadily adding value

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Nat Pryce Steve Freeman Dan North Sydney ‘Hoppalong’ Redelinghuys Jim Webber Ian Robinson Ivan Moore Liz Keogh Simon Stewart Jez Humble Dave Farley Jay Fields Dan Worthington-Bodart Joe Walnes

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APPEAL TO AUTHORITY

WARNING!

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TW is an XP shop

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agile

XPTDD

BDD

YAGNI

DRY

SOLID

Continuous Delivery

Refactoring

GoF

GRASP

emergent design

World of Warcraft

KISS

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does this still make sense?

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Gemini Project, Rogallo wing

Source: wikipedia.org

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<thinks>

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Gemini Project, Rogallo wing

Source: wikipedia.org

it’s turtles all the way down

http://wikipedia.org

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agile

XPTDD

BDD

YAGNI

DRY

SOLID

Continuous Delivery

Refactoring

GoF

GRASP

emergent design

World of Warcraft

KISS

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agile

XPTDD

BDDYAGNIDRY

SOLID

Continuous Delivery

Refactoring

GoF

GRASP

emergent design

World of Warcraft

KISS

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http://martinfowler.com/bliki/Yagni.html

http://martinfowler.com/bliki/Yagni.html

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Build out services as you need

them

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agile

XPTDD

BDD

YAGNI

DRY

SOLID

Continuous Delivery

Refactoring

GoFGRASPemergent design

World of Warcraft

KISS

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Fulfilment

Retail

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Fulfilment Retail

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Fulfilment Retail

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Fulfilment Retail

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Fulfilment Retail

High cohesion

Low coupling

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(incidentally, if you were playing the Conway’s law lottery, that’s

when you number came up)

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agile

XPTDD

BDD

YAGNI

DRYSOLID

Continuous Delivery

Refactoring

GoF

GRASP

emergent design

World of Warcraft

KISS

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git clone https://github.com/boicy/service-template

(note this doesn’t exist)

https://github.com/boicy/service-template

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DRY within services

duplication between services

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agile

XP

TDDBDD

YAGNI

DRY

SOLID

Continuous Delivery

Refactoring

GoF

GRASP

emergent design

World of Warcraft

KISS

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“The London school of Test Driven Development”

Mike Feathers

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should we write unit tests?

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http://moleseyhill.com/blog/2009/08/27/dreyfus-model/

should we write unit tests?

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personally I think it’s more important than *ever*

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agile

XPTDD

BDD

YAGNI

DRY

Continuous Delivery

Refactoring

GoF

GRASP

emergent design

World of Warcraft

KISS

SOLID

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a class should be no bigger than my head

6666

a:Class

6767

a:Class

a:Class

a:Class

a:Class

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SRP

a service should be no bigger than

my head

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agile

XPTDD

BDD

YAGNI

DRY

SOLID

Continuous Delivery

Refactoring

GoF

GRASP

emergent design

World of Warcraft

KISS

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WWJD?

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WWJD?(what would Joe do?)

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cron, python, boto, pydot, graphviz

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cron, python, boto, pydot, graphviz

Do the simplest thing possible

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but what about testing and deployment

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SEMANTIC MONITORING

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Customer ServiceWeb Shop

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Small

Medium

Large

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Small

Medium

LargeConsumer Driven Contracts

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80


Expectations

80


Expectations

Prod

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https://github.com/realestate-com-au/pact

https://github.com/realestate-com-au/pact

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Prod

Prod

Prod

Prod

QA

Good Monitoring

Fast Remediation

TESTING IN PRODUCTION

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CHANGING SERVICES INDEPENDENTLY

84Thomas J. Allen, 1977

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0 10 20 30 40 50 60 70 80 90 1000

0.05

0.10

0.15

0.20

0.25

0.30

m

Probability of weekly interaction

x

x x

x xxxxxxxxx

x

x xx

x xx x

The effect of distance on communication

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Low change rate

inter-company integration

High stability

Semantic Versioning

Contract Testing

Tolerant Reader

“Conversational change”

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higher change rate

inter-team integration

lower stability

Semantic Versioning

Contract Testing

Tolerant Reader


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highest change rate

intra-team

lowest stability

Semantic Versioning

Contract Testing

Tolerant Reader


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integration environment

the death of the

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production != live

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the future is scary

we are learning how to:

Craft my families axe

Deploy microservices independently

Test microservices in isolation Test microservices in production

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the future is bright

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we have old techniques that apply:

SRP GRASP YAGNI KISS TDD DRY

and new techniques to apply:

Consumer Driven Contracts Semantic Monitoring Semantic Versioning Testing in Production

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software craftsmanship is around the code too

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chunk up and think about the “gaps”

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and

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do the simplest thing possible

and

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Now…

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Go forth and craft software

[email protected]

@boicy

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Go forth and craft software

[email protected]

@boicy

Thanks!Go forth and craft software

drink beer!

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I, for one, welcome our new overlords

james lewis: microservices - systems that are #neverdone at i t.a.k.e. unconference 2015

Software

service large medium

hardest things

essential singularity

small towns

pretty good axe

unemployed truckers

human aairs

new designs