Defining Microservices

Defining Microservices

Matt McLarty

DevOps: API Management and Application Development

CA Technologies

VP, API Academy

Session DO3X70E

@MattMcLartyBC

#CAWorld

5 © 2015 CA. ALL RIGHTS RESERVED.@CAWORLD #CAWORLD

Agenda

MICROSERVICES – A BRIEF HISTORY

GOALS

PUTTING IT ALL TOGETHER

PRINCIPLES

MICROSERVICES – A DEFINITION

DEPENDENCIES & PITFALLS

1

2

3

4

5

6



Somebody does something new, then shares it

• Amazon, Netflix, Gilt, SoundCloud…

A pattern emerges, and so do evangelists

• Martin Fowler, Adrian Cockroft, Sam Newman…

The trend goes mainstream, sects emerge

• SOA revivalists, container devotees, DevOps purists…

A Study in IT Trends

Let’s take a step back…


Enterprise IT TimelinesOrganization, Architecture & SDLC

2012-20152008-112004-072000-031996-99

Organization IT city states CIO centralization Efficiency, stability and cost savings

Mobile and Shadow IT

Rise of the Chief Digital Officer

Architecture Web meets the Enterprise

Rise of SOA SOA Golden Age A New Paradigm APIs everywhere

Lifecycle Waterfall ITIL and CMM Rise of Agile Cloud and CI/CD Decentralization & DevOps


CI/CDCloud

ComputingWeb APIs

DevOpsOpen Source

EverythingJavascript

Frameworks

GitHubContainers/

DockerMicroserviceArchitecture

Resulting Trends…


• No more fear of changeCI/CD

• Instantaneous provisioningCloud Computing

• Self-serve integrationWeb APIs

• An empathetic, agile cultureDevOps

• Instant pluggable codeOpen Source Everything

• A way to create more developersJavascript Frameworks

• A way to connect all these developersGitHub

• Exact replication of code deploymentsContainers/Docker

• Optimal application style for DevOps…Microservice Architecture

What do these trends bring?



The architectural realization of DevOps?

SOA 2.0?

Single function container-based applications?

OR

By business value…

Take Two


Microservices Business Value – A Technologist’s View

Technology heterogeneity

Resilience ScalingEase of

deployment

Organizational alignment

ComposabilityOptimizing for replaceability

From “Building Microservices” by Sam Newman

http://shop.oreilly.com/product/0636920033158.do


Microservices Business Value – A VC’s View

Agility Efficiency

Resiliency Revenue

From “Innovate or Die: The Rise of Microservices” by Matt Miller

http://blogs.wsj.com/cio/2015/10/05/innovate-or-die-the-rise-of-microservices/


Microservices Business Value – A Combined View

Increased Revenue

Agility

Technology heterogeneity

Ease of deployment

Organizational alignment

Composability

Cost Savings

Efficiency

Resiliency ScalingOptimizing for replaceability


Business Value Stories

“We can scale our operation independently, maintain unparalleled system availability, and introduce new services quickly without the need for massive reconfiguration.”

•Werner Vogels, Amazon (2006) https://queue.acm.org/detail.cfm?id=1142065

“…the next generation [architecture] that we are building will give Netflix a strong foundation to meet the needs of our massive and growing scale, enabling us to delight our global audience.”

•Netflix (2015) http://techblog.netflix.com/2015/01/netflixs-viewing-data-how-we-know-where.html

“Lessens dependencies between teams - resulting in faster code to production.”

•Adrian Trenaman, Gilt (2015) http://www.infoq.com/news/2015/04/scaling-microservices-gilt

“With the new architecture framework, we were able to reduce our lead time for new features to something that…was much more acceptable for a company trying to play in the highly competitive music industry.”

•Phil Calçado, SoundCloud (2015) http://philcalcado.com/2015/09/08/how_we_ended_up_with_microservices.html

https://queue.acm.org/detail.cfm?id=1142065

http://techblog.netflix.com/2015/01/netflixs-viewing-data-how-we-know-where.html

http://www.infoq.com/news/2015/04/scaling-microservices-gilt

http://philcalcado.com/2015/09/08/how_we_ended_up_with_microservices.html


Microservices Principles

ModularityDomain

alignmentSystems thinking


Modularity

“Modularity … is to a technological economy what the division of labor is to

a manufacturing one.”

- W. Brian Arthur, The Nature of Technology

http://tuvalu.santafe.edu/~wbarthur/thenatureoftechnology.htm


Modularity…

• APIs, containers and cloud

• Heroku’s 12 factors

• Encapsulation: “Smart endpoints and dumb pipes” (Fowler, Lewis)

In the technology

• Componentized infrastructure

• Evolvable architecture

• Granular ownership (Newman)

In the system

http://12factor.net/

http://martinfowler.com/articles/microservices.html


But Modularity is not enough on its own…

Fine-grained services


Domains

“The heart of software is its ability to solve domain-related problems for its user.”

― Eric Evans, Domain-Driven Design: Tackling Complexity in the Heart of Software

https://domainlanguage.com/ddd/


Defining Domains

• “Bounded Contexts”Domain-Driven Design

• Separate models for Query and Command (state change)

Command Query Responsibility

Segregation (CQRS)

• Client-focused and iterative• http://www.christenseninstitute.org/key-concepts/jobs-to-be-done/

“Jobs-to-be-done”

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

http://www.christenseninstitute.org/key-concepts/jobs-to-be-done/


Microservice Boundaries

The consequence of domain definition, or the driver?

Defining service boundaries is an art, not a science

Optimal service boundaries will be fluid over time

So… Design for evolvability!


Organizational Alignment with DomainsConway’s Law - http://www.melconway.com/Home/Conways_Law.html

Any organization that designs a system (defined broadly) will produce a design

whose structure is a copy of the organization's communication structure.

- Mel Conway

http://www.melconway.com/Home/Conways_Law.html


Organizational Alignment with DomainsIllustration from Fowler & Lewis - http://martinfowler.com/articles/microservices.html

vs.



But Domains are part of a System…

Image retrieved from https://upload.wikimedia.org/wikipedia/commons/d/d2/Internet_map_1024.jpg

https://upload.wikimedia.org/wikipedia/commons/d/d2/Internet_map_1024.jpg


Systems Thinking

A complex system that works is invariably found to have evolved from a simple system

that worked. A complex system designed from scratch never works and cannot be patched up to make it work. You have to start over with a

working simple system.

- John Gall, Systemantics: How Systems Really Work and How They Fail

http://www.amazon.com/gp/product/0961825170/ref=pd_lpo_sbs_dp_ss_1?pf_rd_p=1944687462&pf_rd_s=lpo-top-stripe-1&pf_rd_t=201&pf_rd_i=0812906748&pf_rd_m=ATVPDKIKX0DER&pf_rd_r=12PF00CRT0QJ527VSVY6


Systems, not Applications

The “Monolith First” movement

Complex vs. Complicated– “A car key is simple. A car is complicated. A car in traffic is complex.” –

From Michael Lewis’ Flash Boys

Monoliths are complex systems disguised as applications

Understand that you are not “building an application”…

…You are likely “changing a system”

http://michaellewiswrites.com/index.html#flash-boys


Respecting the System

The Butterfly Effect and the echo chamber

Focus on the interdependencies between components and domains– Interfaces, APIs

Design for constant change

http://www.boston.com/bostonglobe/ideas/articles/2008/06/08/the_meaning_of_the_butterfly/?page=full


System Control

The system cannot be controlled…– “REST emphasizes evolvability to sustain an

uncontrollable system” – Roy Fielding

…But it can be monitored and influenced– Think of public policy influencing financial markets

Focus on shortening the time between data collection, analysis and resulting action



An architectural style for building an application as a network-based system of modular services

organized by business domains in order to improve the application’s evolvability,

deployability, composability, scalability, resiliency and replaceability

Take Three


Microservices Dependencies

Cloud infrastructure

Continuous delivery

DevOps culture

System management

APIs Containers?

Adapted from http://martinfowler.com/bliki/MicroservicePrerequisites.html

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


Potential Pitfalls with Microservices

Technological myopia

Ignoring the pre-requisites

Ignoring service boundaries

Overlooking the system

Trying to control the system

Boiling the ocean


Putting it all together

•The culmination of the Agile/API/Decentralization movementUnderstand where Microservices

fit in the evolution of IT

• Increase agility and efficiency to drive revenue and save costsStay focused on business goals

•Pre-reqs like CI/CD, DevOps and Cloud have standalone value

•Modularity is not enoughKnow where the benefits are

coming from

•Defining business domains and service boundaries

•Designing, managing and evolving the systemDon’t ignore the hard problems


Sources

Sam Newman, “Building Microservices” - http://shop.oreilly.com/product/0636920033158.do

“The Business Behind Microservices”, Daniel Bryant - https://www.opencredo.com/2015/09/24/the-

business-behind-microservices-webinar-replay/

Wall Street Journal Blog on Microservices, Matt Miller - http://blogs.wsj.com/cio/2015/10/05/innovate-or-

die-the-rise-of-microservices/

Fowler and Lewis’ blog post - http://martinfowler.com/articles/microservices.html

“Seven Microservices Anti-patterns”, Vijay Alagarasan - http://www.infoq.com/articles/seven-uservices-

antipatterns

Learning CTO blog post - http://thelearningcto.com/2015/04/24/the-hidden-costs-of-paas-microservice-

engineering-innovation/

“REST in AEM”, Roy Fielding - http://www.slideshare.net/AEMHub2014/rest-in-aem-by-roy-fielding

http://shop.oreilly.com/product/0636920033158.do

https://www.opencredo.com/2015/09/24/the-business-behind-microservices-webinar-replay/

http://blogs.wsj.com/cio/2015/10/05/innovate-or-die-the-rise-of-microservices/


http://www.infoq.com/articles/seven-uservices-antipatterns

http://thelearningcto.com/2015/04/24/the-hidden-costs-of-paas-microservice-engineering-innovation/

http://www.slideshare.net/AEMHub2014/rest-in-aem-by-roy-fielding


Q & A

Defining Microservices

Technology

Transcript of Defining Microservices