This document summarizes a workshop on migrating a monolithic application architecture to a microservices architecture using Amazon ECS. The workshop consists of 3 labs: 1) deploying the monolithic application as a container on ECS, 2) incrementally building microservices and deploying them on ECS to replace functionality in the monolith, and 3) using an Application Load Balancer to route requests to the monolith and microservices. The goal is to help Interstella 8888, an intergalactic trading company, scale its logistics platform for processing rare resource orders by adopting a microservices approach.

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AWS re:INVENT
Interstella 8888: Monolith to
Microservices with Amazon ECS
H u b e r t C h e u n g , A W S S o l u t i o n s A r c h i t e c t
A n d y M u i , A W S S o l u t i o n s A r c h i t e c t
D a v i d K u o , A W S S o l u t i o n s A r c h i t e c t
C O N 3 1 8
N o v e m b e r 2 8 , 2 0 1 7

2. © 2017, Amazon Web Services, Inc. or its Affiliates. All rights reserved.
AWS re:INVENT
Monolith to Microservices with Amazon ECS
H u b e r t C h e u n g , A W S S o l u t i o n s A r c h i t e c t
A n d y M u i , A W S S o l u t i o n s A r c h i t e c t
D a v i d K u o , A W S S o l u t i o n s A r c h i t e c t
C O N 3 1 8

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ABOUT ME
kuodavid@amazon.com
Solutions Architect
2.7 years at AWS
Based in Southern California

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WHAT TO EXPECT
Monolith versus Microservices Architectures
Strangler Application Pattern
Amazon EC2 Container Service (ECS)
Hands-On Lab
• Break Apart the Monolith
• Independently

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WHAT ARE MICROSERVICES?
“A software architecture style in which complex applications are composed
of small, independent processes communicating with each other using
language-agnostic APIs. These services are small, highly decoupled and
focus on doing a small task, facilitating a modular approach to system-
building.” –Wikipedia
Great article on the topic:
https://martinfowler.com/articles/microservices.html
Source: https://en.wikipedia.org/wiki/Microservices

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MONOLITHIC VERSUS MICROSERVICES
Admin UI
Orders Service
Inventory Service
Shipping Service
Admin UI
Orders
Service
Inventory
Service
Shipping
Service
Customer UI
Customer
UI

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MONOLITHIC CHALLENGES
Admin UI
Orders Service
Inventory Service
Shipping Service
Customer UI
Code Maintenance—large, complex code base, long
dev cycles
Deployments—lengthy, complicated process, often
becomes the bottleneck
Ownership—many developers, same codebase
Scale—difficult to scale efficiently
Tools—limited technology choices (for example,
database, programming language)
Dependencies—tight coupling, difficult to manage

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MICROSERVICES BENEFITS
Admin UI
Orders
Service
Inventory
Service
Shipping
Service
Customer
UICode Maintenance—smaller units of code
Deployments—each service has its own
roadmap and pipeline
Ownership—smaller teams own services
Scale—each service can scale independently
Tools—polyglot environment
Dependencies—loose coupling, standardized
communications

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MONOLITH TO MICROSERVICES
Rewrite the app
Look at all that technical debt and piled up
cruft
Is Bob the Wizard who wrote that glue code
even still around?
Potential downtime and risk for full cutover
Let’s consider the Strangler Application
Pattern for a more incremental approach…
Source: https://xkcd.com/292/

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STRANGLER APPLICATION PATTERN
Gradually build something new
alongside the monolith
New functionality replaces methods
in the monolith
Over time, the new system
“strangles” the old system, until the
old dies out
Ideal for web applications, API-
structured applications, queue-based
systems
Source: https://en.wikipedia.org/wiki/Strangler_fig

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MICROSERVICES & CONTAINERS
Portable units of work
Simple to model
Any app, any language
Image is the version
Test and deploy same artifact
Stateless servers reduce change risk
Admin UI
Orders
Service
Inventory
Service
Shipping
Service
Customer
UI

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AMAZON ECS
EC2 INSTANCES
ECS
AGENT
TASK
Container
TASK
Container
ECS
AGENT
TASK
Container
TASK
Container AGENT COMMUNICATION
SERVICE
Amazon
ECS
API
CLUSTER MANAGEMENT
ENGINE
KEY/VALUE STORE
ECS
AGENT
TASK
Container
TASK
Container
Internet LOAD
BALANCER
LOAD
BALANCER

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AMAZON ECS—TASK DEFINITION
{
"containerDefinitions": [
{
"name": "wordpress",
"links": [ "mysql" ],
"image": "wordpress",
"essential": true,
"portMappings": [
{
"containerPort": 80,
"hostPort": 80
} ],
"memory": 500,
"cpu": 10
},
{
"name": "mysql",
"image": "mysql",
"cpu": 10,
"memory": 500,
Instructions used by ECS to launch
containers
JSON template
Used to launch tasks and services
Maps to docker run parameters

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HANDS-ON LAB

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WELCOME TO INTERSTELLA 8888
Interstella 8888 is an intergalactic trading company that was
established to import and export rare resources in the universe.
Interstella was a thriving company, but business has been
declining despite a booming economy. You and a few other
consultants have been brought on board to turn this around. Will
you be able to restore Interstella to its former glory?

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YOUR MISSION
Interstella 8888 operates a logistics platform to control the processing centers of
the four rare resources—tiberium, vespene gas, spice melange, and dilithium
crystals. We believe microservices will help us scale more efficiently and adopt a
more agile development pipeline. We need your help to incrementally break down
the monolith codebase and roll out the new microservices that our developers have
been working on. Each microservice will be responsible for processing orders for a
specific resource.
Lab 1: Build and deploy monolith container using ECS
Lab 2: Incrementally build and deploy each microservice
Bonus Lab: Scale microservices with an Application Load Balancer (ALB)

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WORKSHOP ENVIRONMENT
Public subnet – AZ #1 Public subnet – AZ #2
Amazon SNS
EC2 Instance
ECS Cluster
EC2 Instance
Amazon
ECR
Amazon API
Gateway
ORDER
Amazon S3
bucket
Amazon
DynamoDB
Amazon
ECS
Orders come into
the logistics
platform as HTTP
POST messages via
Amazon Simple
Notification Service
(Amazon SNS)
Amazon S3 hosts
web content and
utilities—API key
generator, order
subscription, order
dashboard
The logistics platform
communicates with an
order fulfillment API
running on Amazon
API Gateway; order
data is stored in
Amazon DynamoDB
Amazon
CloudWatch

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LAB 1 (ECS REFRESHER)
Public subnet – AZ #1 Public subnet – AZ #2
Amazon SNS
EC2 Instance
ECS Cluster
EC2 Instance
Amazon API
Gateway
ORDER
Amazon S3
bucket
Amazon
DynamoDB
1. Build a Docker image
for the monolith
from the provided
Dockerfile; Push
image to ECR
2. Create an ECS task
definition to deploy
the monolith image
and log to
CloudWatch Logs
3. Deploy the monolith
using ECS
M
FULFILL
Amazon
CloudWatch
Amazon
ECR
Amazon
ECS
LOGS

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LAB 2
Public subnet – AZ #1 Public subnet – AZ #2
Amazon SNS
EC2 Instance
ECS Cluster
EC2 Instance
Amazon
ECR
Amazon API
Gateway
ORDER
Amazon S3
bucket
Amazon
DynamoDB
Amazon
ECS
1. Build a Docker image for
a resource microservice
and store in ECR
2. Create an an ECS task
definition to deploy the
microservice image
3. Deploy the microservice
image using ECS to start
processing orders for that
resource
4. Modify the monolith code
to remove functionality
of the microservice;
rebuild
the monolith image and
re-deploy
M
FULFILL
Amazon
CloudWatch
m
FULFILL

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BONUS LAB
Public subnet – AZ #1 Public subnet – AZ #2
Amazon SNS
EC2 Instance
ECS Cluster
EC2 Instance
Amazon
ECR
Amazon API
Gateway
ORDER
Amazon S3
bucket
Amazon
DynamoDB
Amazon
ECS
1. Create an Application
Load Balancer (ALB)
2. Create an ECS service
that ties in the ALB
for routing orders to
monolith and resource
microservices; ALB
will use path-based
routing to route to
each microservice
target group
3. Repeat until all
microservices are
deployed
M
FULFILL
Amazon
CloudWatch Application
Load Balancer
m
FULFILL
/vespene
/melange
m

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LOGISTICS
INSTRUCTIONS:
http://interstella.trade/workshop2/
ORDERS TOPIC:
arn:aws:sns:us-west-2:270206935686:monolith
Raise your hand if you have any questions. High five your neighbors and
have fun!
Please fill out feedback forms once you are done! Feel free to email us
with comments/questions/feedback: aws-interstella-team@amazon.com

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Thank you!