modules or microservices?

Modules or Microservices?

@Sander_Mak

About SanderFellow, Software Architect

@ Luminis

Experience in modular development stacks

Conference Speaker & Author

@Sander_Mak


@Sander_Mak


YES

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Modules XOR Microservices?

YES

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Modules XOR Microservices?

IT DEPENDS

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Let's Talk About Modularity

Why Modularity?

Why Modularity?

No. 1 Software Architecture Principle

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The Three Tenets of Modularity

Strong Encapsulation

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Well-Defined Interfaces

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Explicit Dependencies



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Modularity is the ultimate Agile Tool

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Let's Talk About Microservices

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A Microservice is...

Independently deployableImplementing a business capability

Doing one thing, and doing it wellCommunicating over the network

What's This?

What's This?

Microservices Devroom

What's This?


Despair

What's This?


DespairPraying for a

Better Solution

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Yes, Microservices Are Hard However...

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Introspection: When (not)

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Introspection: When (not)Alternative: Modules

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Why?

Manage Complexity

Scaling

Resilience

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Why?

Manage Complexity

Scaling

Resilience Modularity In Disguise!

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users

assignmentslearningmaterial

students

gradingcourses

attendance

Microservices

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users


students

gradingcourses

attendance

Microservices Monolith?

usersstudentslearningmaterial

shipping

coursesforecasting

attendance

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Features

Cost

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Messy Monolith

Features

Cost

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Messy Monolith

Microservices All The Way

Features

Cost

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Microservices:Distributed system

Service Discovery

?

?

?

?

users


students

gradingcourses

attendance

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users


students

gradingcourses

attendance


Network Fallacies

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users


students

gradingcourses

attendance


Deployment

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Config. Managementv1 v2 v3

v2 v3

at least x4 (DTAP)

users


students

gradingcourses

attendance

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Microservices: Securityusers


students

gradingcourses

attendance

Distributed system

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Messy Monolith


Features

Cost

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Messy Monolith


Features

Cost

But... vendors?!

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Messy Monolith


Features

Cost

But... vendors?! Won't magically transform your organization!

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Let's Talk About Modules

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users


students

gradingcourses

attendance

Microservices

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users


students

gradingcourses

attendance

Microservices Monolith?

usersstudentslearningmaterial

shipping

coursesforecasting

attendance

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Microservices Modules!users


students

gradingcourses

attendance

Modular app users


students

gradingcourses

attendance

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Messy Monolith


Modular App

Features

Cost

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So, Modules. Did You Mean Objects?

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So, Modules. Did You Mean Objects?

Close, but Too Fine-grained.

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Module Systems

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Module SystemsJava OSGi

Java 9

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Java 9

JavaScript ...

ES2015 Modules

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Java 9

JavaScript ...

ES2015 Modules

C++

C++20?

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Java 9

JavaScript ...

ES2015 Modules

C++

C++20?

.Net NuGet

.Net Core

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Java 9

JavaScript ...

ES2015 Modules

C++

C++20?

.Net NuGet

.Net Core

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Module Systems: Java 9module attendance {

exports attendance.api; requires students; requires courses;

}

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}


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Module Systems: Java 9Module Resolution (Reliable Configuration)

Increased Security (Hide Platform Internals)

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Module Systems: ES2015export function sq(i) { return secret(i); }

function secret(i) { return i * i; }

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import { sq } from mymodule;

console.log("Two squared", sq(2));

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Consider TypeScript

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Consider TypeScript

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console.log("Two squared", sq(2)); (let's not go there...)

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Module Systems: C++20?module mymodule;

export int sq(int i) { return secret(i); }

int secret(int i) { return i * i; }

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#include <stdio.h> import std.io import mymodule

int main() { printf("Two squared %d", sq(2)); return 0; }

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So, Modules Everywhere!

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So, Modules Everywhere! > Objects

< Applications

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users

app.users.User app.users.UserInfo

app.users.internal.UserImpl app.users.internal.Util;

assignments ... ...

courses ... ...

students ... ...

attendance ... ...

grading ... ...

learningmaterial ... ...

Not Just on the Whiteboard

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users

app.users.User app.users.UserInfo

app.users.internal.UserImpl app.users.internal.Util;

assignments ... ...

courses ... ...

students ... ...

attendance ... ...

grading ... ...

learningmaterial ... ...

Not Just With Discipline

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IT DEPENDS

@Sander_Mak

Manage Complexity

Scaling

Resilience

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Manage Complexity

Scaling

Resilience??

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Advantages of Modules

Ease of Deployment & Management

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Ease of Deployment & Management

Modular Application

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Strong but Refactorable Boundaries

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https://www.infoq.com/presentations/microservices-future

~1800 microservices

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"The [Linux] project is structured so people can work independently, Torvalds explained. "We've been able to really modularize the code and development model so we can do a lot in parallel." - El Reg

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Strongly typed, In-Process Communication

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Strongly typed, In-Process CommunicationNo Serialization or Network Latency

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Strongly typed, In-Process CommunicationEver Tried Serializing a Function?

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Strongly typed, In-Process CommunicationGraphQL or Protobuf > REST

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Strongly typed, In-Process Communication

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Strongly typed, In-Process *Synchronous* Communication

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Eventual Consistency is a Choice

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Eventual Consistency is a ChoiceIt's Still a Good Idea to Partition Data

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Advantages of Microservices

Best Stack for Each Service

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Best Stack for Each Service

learningmaterial students assignments

(but is your org ready for this?)

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Independent Deployment

learningmaterial students assignmentsv2 v3 v1

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(beware of deployment dependencies!)

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Modularized App > Distributed Monolith

(beware of deployment dependencies!)

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Independent Failure


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Independent Failure


(when your services are truly autonomous...)

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Independent Scaling


4x g2.2xlarge 2x t2.medium 1x t2.micro

students

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vs. Uniform ScalingModular Application

3x t2.large

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It's Time to Wrap Up

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At the speed of light, everything changes!

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Dude, chill. The apple still doesn't fall far from the tree.

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Don't Solve Problems You Don't Have


Dude, chill. The apple still doesn't fall far from the tree.

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You Are (most likely) Not at Uber or Netflix Scale

scale

organizations

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You Are (most likely) Not at Uber or Netflix Scale

scale

organizations

the 80% of us

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Solve Problems You Do Have In The Simplest Possible Way

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Solve Problems You Do Have In The Simplest Possible Way

At Least Read Up on Modular Development In Your Tech Stack of Choice




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Design as Microservices,Build as Modules

You Can Move to (Micro)services Later.

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You Can Move to (Micro)services Later.Modules EnableLarger Services!

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Don't worry, you can still do: Reactive NoSQL Cloud DevOps DDD

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Messy Monolith


Modular App

Features

Cost

Thanks. Read More: bit.ly/modularapps bit.ly/java9book

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http://bit.ly/modularapps

http://bit.ly/java9book