Demolishing Monolith

 Getting Started with Microservices

www.mfranc.com

@francmichal

WIFI

PGS Guest

pgswelcome

Michal Franc

• 5 mln users
• 4.5 bln gbp raised
• acquired last week (95 mln gbp)

• 20 mln active users
• 5 bln gbp valuation
• In the top 10 eu unicorns

• 1200+ ec2 instances on prod
• 3200+ on all envs
• microservice event based architecture

• monolith -> microservices
• self server -> cloud
• 300+ ec2 instances

Workshop Goals

• explore 'microservices'

• practical monolith -> distributed

• distributed data

• pros / cons

• scalability / availability

• any other expectations?

• 50 min / section

• 10 min breaks

Agenda

1. Why microservices

2. First microservice

3. Introduction to Monolith

4. Evolution to microservice based architecture

5. QA / Discussion

Preparation

• git clone git@github.com:mfranc-workshop/wroclaw-pgs-08072017.git

• docker pull

  • microsoft/dotnet

  • unix - rabbitmq:3-management

  • win - micdenny/rabbitmq-windows

• httpie

  • windows - https://goo.gl/berTLb

  • unix - https://httpie.org/#installation 

• slack
  • devwarsztaty.octal.pl - kanal #29-mikroserwisy

Lets go!

Microservices are on the rise

SOA

Microservices

SOA was not the silver bullet

https://setandbma.files.wordpress.com/2012/05/technology-adoption.png

Microservices

Why?

MicroService?

Specific Business Goal

Bounded Context

Microservice

Simple Microservice
Demo

Micro Service

Architecture

Monolithic app

https://www.nginx.com/blog/introduction-to-microservices/

https://www.nginx.com/blog/introduction-to-microservices/

Monolithic Shop

Introduction

• SimpleInjector

• Quartz

• EntityFramework

Run and pray!

• dotnet ef migrations add Init
• dotnet ef database update Init
• dotnet restore
• dotnet run <portnumber>
• /initdb

Functional Decomposition

Functional Decomposition

Email Service

Demo-Service

dotnet new micro-basic 
--name micro-email 
-o micro-email

http POST localhost:5000/email emailAddress=lam.michal.franc@gmail.com
message=test 
-v

Communication
Http

Demo-Monolith

• dotnet add package RestEase
• Changing to call the emailService

RabbitMQ

Preparation

• RabbitMQ

  • docker run -d --name rabbitmq -p 5672:5672 -p 15672:15672 rabbitmq:3-management

  • test -> http://localhost:15672/ | guest / guest

Demo-Publisher

• dotnet add package RawRabbit
• dotnet add package RawRabbit.vNext
• dotnet add package Newtonsoft.Json

http://localhost:15672

Exchange

Consuming Messages

• dotnet add package RawRabbit
• dotnet add package RawRabbit.vNext
• dotnet add package Newtonsoft.Json

EmailService

Demo-subscriber

Database as Integration Layer

Database as Integration Layer

• easy

• not complex

• solves a lot of problems

• good for transitional period

Consume Message

Produce Message

<Check Transfer>

<Transfer Received>

Demo Time

monolithic-producer
payment-controller

Demo Time

microservice-consumer

dotnet new -i micro-job-rabbit

dotnet new micro-job-rabbit -o micro-transfer --name micro-transfer

'Private' Data Snapshot

dotnet add package Microsoft.EntityFrameworkCore

dotnet add package Microsoft.EntityFrameworkCore.Design

dotnet add package Microsoft.EntityFrameworkCore.Sqlite

  <ItemGroup>
    <DotNetCliToolReference Include="Microsoft.EntityFrameworkCore.Tools.DotNet" Version="1.0.1" />
  </ItemGroup>

dotnet add package Microsoft.EntityFrameworkCore.Sqlite

- consume message

- persist order Id in DB

- run job checking the DB 

- produce message of order transfer is finished

Database per service?

Distributed Data

Bounded Context Isolation

How to update Order now?

Payments

&

Warehouse

Simple CQRS

Where is the Master Database?

Rebuilding Read Model

Master

DB

Read Model

Where is the Master Database?

Read Model

Event

Store

Domain Events

OrderTransferFinished

Commands vs Events

UpdateOrder vs OrderStatusChanged

Time For Docker

docker build

docker build -t workshop/micro-mail .

docker build -t workshop/micro-shop .

docker build -t workshop/micro-transfer .

docker run --name micro-email -d -p 5001:5001 workshop/micro-email 5001

Scaling

Registry & Management

And more and more stuff ...

Conclusion

Q/A
Discussion
AMA