Had it with your hard-to-maintain, difficult-to-scale and overly-complex monolithic application? In this three-part series on Microservices for enterprise architects, we go over why it makes sense to learn about Microservices architectures, which are comprised of small, independent services and provide more flexibility than the traditional all-in-one systems that continue to dominate today’s enterprise landscape. In Part 2 of our series for Enterprise Architects, Lightbend CTO and Akka creator Jonas Bonér shares the 6 characteristics of Reactive Microservices that matter for having responsive, elastic, resilient systems. Starting with importance of decomposing systems in discrete, isolated services that are decoupled in both time (i.e. concurrency) and space (i.e. distribution and mobility), and continuing with reiterating the need for asynchronous, message-driven communication and maintaining service mobility, we cover everything an Enterprise Architect needs to know about Reactive Microservices in these sections: *Isolate All the Things *
Act Autonomously *Do One Thing, and Do It Well *Own Your State, Exclusively *Embrace Asynchronous Message-Passing *Stay Mobile, but Addressable 
 Stay tuned for part 3 of the series, when we welcome Jonas back to continue his deep dive into the nature of Microservices working together in systems (and the need to bend reality to make things happen).

2. IT'S A NEW WORLD
YESTERDAY VS TODAY

3. Traditional application
architectures and
platforms
are obsolete.
— Gartner

4. THE REACTIVE ESSENCE OF A MICROSERVICE
1. Isolation
2. Asynchronicity
3. Autonomicity
4. Single Responsibility
5. Exclusive State
6. Mobility

5. DIVIDEAND
CONQUER

6. ISOLATION
THE FOUNDATION

7. IT WILL SLICE UP YOUR
1. ORGANIZATION
2. ARCHITECTURE

8. Organizations which
design systems...are
constrained to produce
designs which are
copies of the
communication
structures of these
organizations.
— Melvin Conway

9. USE BULKHEADING

10. BUTWHAT ABOUT THE
TITANIC?

11. RESILIENCEIS THE ABILITY TO SELF-HEAL, AND REQUIRES
COMPARTMENTALIZATION
OF FAILURE

12. GOASYNCHRONOUS

13. ASYNC IO
—IS ABOUT NOT BLOCKING THREADS
ASYNC COMMUNICATION
—IS ABOUT NOT BLOCKING REQUESTS

14. ASYNCHRONOUS
IO

15. WHY IS BLOCKING SO BAD?

16. SYNCHRONOUS DISPATCH

17. ASYNCHRONOUS DISPATCH

18. ASYNCHRONOUS
COMMUNICATION

19. ASYNC COMMUNICATION ALLOWS DECOUPLING IN
SPACEAND
TIME

20. ASYCHRONOUS MESSAGE-PASSING
EMBRACES THE CONSTRAINTS OF
DISTRIBUTED SYSTEMS

21. THE WORLD IS GOING STREAMING

22. ACTAUTONOMOUSLY

23. PROMISE THEORY
LEADS THE WAY

24. THE WORD 'MICROSERVICE'
CONSIDERED HARMFUL

25. A SERVICE SHOULD DO
DO ONE THING
AND
DO IT WELL

26. The Unix philosophy:
Write programs that do
one thing & do it well.
Write programs to
work together.
— Doug McIlroy

27. BUT WHAT ABOUT
STATE?

28. OWN YOUR STATE, EXCLUSIVELY

29. THERE IS NO SUCH THING AS A
"STATELESS" ARCHITECTURE
IT'S JUST SOMEONE ELSE'S PROBLEM

30. BOUNDED
CONTEXTS

31. POLYGLOT
PERSISTENCE

32. The truth is the log.
The database is a cache
of a subset of the log.
— Pat Helland

33. FAVOR
EVENT LOGGING

34. GREAT FIT FOR MESSAGE-PASSING SYSTEMS
> Signal Intent: Use Commands
> Publish Facts: Use Events
SINGLE WRITER PRINCIPLE
> Minimized Contention
> High throughput & Low latency

35. EVENT SOURCING
WITH CQRS

36. AVOIDS THE INFAMOUS
OBJECT-RELATIONAL
IMPEDENCE MISMATCH

37. STAY MOBILE
BUT ADDRESSABLE

38. But I'll take my time
anywhere.
I'm free to speak my
mind anywhere.
And I'll redefine
anywhere.
Anywhere I roam.
Where I lay my head is
home.
— Wherever I May Roam by Lars Ulrich,
James Hetfield (Metallica)

39. WHY VIRTUAL ADRESSING?
1. Load-balancing between stateless services
2. State replication between stateful services
3. Relocation of a stateful service

40. REFERENCES SHOULD ALWAYS WORK

41. SO, THERE YOU HAVE IT
THE 6 TRAITS OF A REACTIVE MICROSERVICE
1. Isolation
2. Asynchronicity
3. Autonomicity
4. Single Responsibility
5. Exclusive State

42. BY NOW WE SHOULD HAVE A PRETTY GOOD UNDERSTANDING OF WHAT
CHARACTERIZES A SINGLE
REACTIVE MICROSERVICE

43. HOWEVER
ONE MICROSERVICE
IS NOT OF MUCH USE
THEY COME IN SYSTEMS
STAY TUNED FOR EPISODE 3