Slide 1
Slide 1 text
NOBODY TOLD ME ABOUT THAT
NOBODY TOLD ME ABOUT THAT
CHRONICLES ABOUT IMPLEMENTING MICROSERVICE
CHRONICLES ABOUT IMPLEMENTING MICROSERVICE
ARCHITECTURE
ARCHITECTURE
Khaled Souf
twitter: @khaledsouf
1 / 32
Slide 2
Slide 2 text
ABOUT ME
ABOUT ME
Developer/Cra ing So ware Coach/ DDD Expert/Trainer
Co-organizer of So ware Cra ers Montréal meetup
Co-organizer of SOCRATES Canada unconference
more details on : https://ksouf.com
2 / 32
Slide 3
Slide 3 text
3 / 32
Slide 4
Slide 4 text
4 / 32
Slide 5
Slide 5 text
I remain convinced that it is much
easier to partition an existing,
"brownfield" system than to do so up
front with a new, greenfield system. --
Sam Newman (Author of building
microservices)
5 / 32
Slide 6
Slide 6 text
If you can’t build a well-structured
monolith, what makes you think you
can build a well-structured set of
microservices? -- Simon Brown (Author
of So ware Architecture for
Developers)
6 / 32
Slide 7
Slide 7 text
source microservices.io -- Chris Richardson (Author of
microservices Patterns)
7 / 32
Slide 8
Slide 8 text
DOMAIN DRIVEN DESIGN TO THE RESCUE
DOMAIN DRIVEN DESIGN TO THE RESCUE
STRATEGIC DESIGN TO BE PRECISE
STRATEGIC DESIGN TO BE PRECISE
Extract your Microservice from the monolith based on business capabilities
Create New Feature on new Bounded Context (Bubble Context)
Use some Context Mapping Patterns for communication
8 / 32
Slide 9
Slide 9 text
ANTI-CORRUPTION LAYER (ACL)
ANTI-CORRUPTION LAYER (ACL)
9 / 32
Slide 10
Slide 10 text
OPEN HOST SERVICE (OHS)
OPEN HOST SERVICE (OHS)
10 / 32
Slide 11
Slide 11 text
More details on: Applied Domain Driven Design On
Legacy Code
11 / 32
Slide 12
Slide 12 text
Don't Make Microservices communicate with each
other (Directly)!!
12 / 32
Slide 13
Slide 13 text
UNLESS YOU WANT THIS!!!
UNLESS YOU WANT THIS!!!
13 / 32
Slide 14
Slide 14 text
14 / 32
Slide 15
Slide 15 text
HOW WE DO AVOID IT?
HOW WE DO AVOID IT?
Service registry: every instance of service is registered and can be found only by the
registry
Microservices publish messages to the bus to chain actions
Microservices consumes from queues that subscribed to specific event of the messaging
bus
Messages are used for asynchronous commands
Registry is used to find API's (REST for the most) for querying
15 / 32
Slide 16
Slide 16 text
MICROSERVICE ARCHITECTURE (WITH REGISTRY &
MICROSERVICE ARCHITECTURE (WITH REGISTRY &
MESSAGING BUS)
MESSAGING BUS)
Slide 17
Slide 17 text
16 / 32
Slide 18
Slide 18 text
WHAT ABOUT DATABASES?
WHAT ABOUT DATABASES?
Use choreography-based saga pattern (aka eventual consistency in Domain Driven
Design).
A Microservice manage his own data (shared database is Anti-Pattern).
Keep two copies for starting (one in monolith/ one in microservice).
17 / 32
Slide 19
Slide 19 text
CHOREOGRAPHY-BASED SAGA PATTERN
CHOREOGRAPHY-BASED SAGA PATTERN
18 / 32
Slide 20
Slide 20 text
BACK-END FOR FRONT-END (BFF)
BACK-END FOR FRONT-END (BFF)
Don't expose your Microservices directly
Use BFF as view and information aggregator for general purpose or specific customer
(depends on context)
Use a gateway if you're exposing BFF to something external
19 / 32
Slide 21
Slide 21 text
BFF: GENERAL PURPOSE API
BFF: GENERAL PURPOSE API
source samnewman.io
20 / 32
Slide 22
Slide 22 text
BFF: SPECIFIC PURPOSE API
BFF: SPECIFIC PURPOSE API
source samnewman.io
21 / 32
Slide 23
Slide 23 text
USE CONTRACTS TESTING FOR API
USE CONTRACTS TESTING FOR API
(INSTEAD OF END TO END TESTING)
(INSTEAD OF END TO END TESTING)
Let your consumer define the contract (Consumer Driven Contracts Testing)
Use a contract broker to publish/verify your contracts
22 / 32
Slide 24
Slide 24 text
CONSUMER DRIVEN CONTRACTS TESTING
CONSUMER DRIVEN CONTRACTS TESTING
23 / 32
Slide 25
Slide 25 text
USE MICRO FRONTEND
USE MICRO FRONTEND
24 / 32
Slide 26
Slide 26 text
INDUSTRIALIZE YOUR APPLICATIONS
INDUSTRIALIZE YOUR APPLICATIONS
Create Template by Type of Project.
Focus only Business Value when creating your Microservice.
Define Template by used language and capabilities.
Your Template should contain also you definition of build & deployment pipelines.
25 / 32
Slide 27
Slide 27 text
LOGGING
LOGGING
Use Centralized logs solution
Use structured logs
Log your input/output of your Microservice
Use Correlation Id to monitor cross Microservices requests
26 / 32
Slide 28
Slide 28 text
MONITORING
MONITORING
Implement always a health check for your Microservice
Centralize your metrics in one simple dashboard
Use alerting system when any weird behavior
27 / 32
Slide 29
Slide 29 text
PROVISIONING/CONFIGURATION MANAGEMENT
PROVISIONING/CONFIGURATION MANAGEMENT
Use tools to manage configuration (Ansible, Saltstack, ...).
build a git repository infrastructure as code to automate your provisioning.
Make sure that the only possible modification of infrastructure is by modifying infra as
code.
28 / 32
Slide 30
Slide 30 text
SECRETS MANAGEMENT
SECRETS MANAGEMENT
Separate your Secrets from your configuration in a secrets server (Vault Server)
Use key rotation technique to change keys periodically to prevent that a key is
compromised
29 / 32
Slide 31
Slide 31 text
WARP-UP
WARP-UP
Don't start with microservices
Use Strategic Design of Domain Driven Design and Strangler Pattern to split your
monolith
don't make microservices communicate directly (Service Registry for API Query,
Messaging BUS for Command)
Use Consumer Driven Contracts Technique instead of End to End Testing
Centralize your cutting-edge concern (logging, monitoring, secrets, configuration,
infrastructure)
Automate as much as possible (infrastructure provisioning, config management, secrets
management,build & deployment, ..)
30 / 32
Slide 32
Slide 32 text
BEFORE FINISHING: I DID NOT INVENTED ALL THESE
BEFORE FINISHING: I DID NOT INVENTED ALL THESE
TECHNIQUES!!!
TECHNIQUES!!!
Domain Driven Design
Microservices Patterns (The Book)
Twelve Factor
DevOps Practices
31 / 32
Slide 33
Slide 33 text
THANK YOU FOR ATTENDING
THANK YOU FOR ATTENDING
Questions ?
twitter: @khaledsouf
32 / 32