Microservices are an architectural style that structures an application as a collection of small, independent services that communicate with each other. Each service runs a unique process and focuses on doing a small job, such as user authentication or shopping cart functionality. The advantages of microservices include improved scalability, maintainability, and ability to upgrade parts of the system independently. However, adopting microservices also introduces additional operational complexity and communication overhead between services.

1. Microservices
Small independent processes
architecture

2. The monolith
image by Kačka a Ondra (CC BY 2.0) https://www.flickr.com/photos/14548166@N03/

3. Microservices
image by _big_mouth_ (CC BY-SA 2.0) https://www.flickr.com/photos/big_mouth/

4. Warm up
#!/bin/sh
cat bla.txt | tr ‘ ‘ ‘n’ | sort | uniq -c | sort -rn

5. What are microservices?
#!/bin/sh
cat bla.txt | tr ‘ ‘ ‘n’ | sort | uniq -c | sort -rn
● Small
● Replaceable
● Independent
● Own process (for memory
and cpu profiling)
● Simple interfaces
(http+json~rest)
● Upgrade strategy
(versioning?)
● Communication via event
bus (pub/sub)
● Service boundaries
● Single responsibility
● Testable
● Fast + easy to startup
● Fail fast
● Monitoring
● Continuous delivery

6. What are microservices?
the upsides:
#!/bin/sh
cat bla.txt | tr ‘ ‘ ‘n’ | sort | uniq -c | sort -rn
● No long build cycles
● Less complexity
● Not the whole ship is sinking
● Deployments don’t have to be “all or nothing”
● Scalable
● Chunks that are easier to understand also for new team members or
in legacy code
● Finding the needle in the now smaller haystack in case of bugginess
● “multilingual”

7. What are microservices?
trade offs:
#!/bin/sh
cat bla.txt | tr ‘ ‘ ‘n’ | sort | uniq -c | sort -rn
● Many processes to manage
● Operational complexity
● Moving parts
● Latency? (Bound to one specific datacenter?)
● Overall memory consumption
● Might just be another way of building chaos
● Monitoring logic (“fucking nightmare”)
● Managing environments
not a silver bullet!

8. Container
Migration
User Interface
Logic
Data
Container
Shopping Cart
Static Content
Tracking
Recommandations
Core
Container Container

9. Construction manual
Proxy (+Load Balancing)
= top level resource
service service service
service service
Database
(may also be distributed)
Messaging (async)

10. Hands on example
live diagramming o/

11. Questions?

12. The end
sources + further reading:
http://www.slideshare.net/adriancockcroft/goto-berlin
http://www.infoq.com/news/2014/11/gotober-wunderlist-microservices
http://www.infoq.com/presentations/migration-cloud-microservices
http://martinfowler.com/articles/microservices.html
https://www.youtube.com/watch?v=-5QEnbpFp3Q
https://www.youtube.com/watch?v=BiFaBEOty8c