TALK #2: Microservices vs. The First Law of Object Design We've been breaking systems and application into smaller components for a long time now. From Component-Based Design to Distributed Objects to SOA to what is today's preferred golden hammer: microservices. One definition of microservices is that it is a flavor of SOA that emphasizes many specialize services versus a few more generalist ones. Often these microservices are so small that they take care of a single "object". Distributed objects aren't new to this industry, and in 2003, Martin Fowler wrote a classic article where he discusses several problems with this model, and proposes the First Law of Distributed Objects: "Objects have been around for a while, and sometimes it seems that ever since they were created, folks have wanted to distribute them. However, distribution of objects, or indeed of anything else, has a lot more pitfalls than many people realize, especially when they're under the influence of vendors' cozy brochures. This article is about some of these hard lessons-lessons I've seen many of my clients learn the hard way... my First Law of Distributed Object Design: Don’t distribute your objects!" Reinventing the wheel is nothing new in our field, but if microservices are meant to be small, how can we avoid the same problems from the past? What are the technologies, architectures, protocols, and practices we need in place to make sure that our microservices architecture isn't just the largest bowl of spaghetti this organization has ever cooked? SPEAKER: Phil Calçado, Director of Software Engineering at DigitalOcean Phil Calçado works at DigitalOcean, where he helps build the cloud for developers. Before that, he spent four years building the team and architecture behind SoundCloud's move from a monolith to microservices. He tweets at @pcalcado writes at http://philcalcado.com.

1. Phil Calçado - @pcalcado
philcalcado.com
Microservices
vs. The First Law of
Distributed Objects

2. Phil Calçado - @pcalcado
philcalcado.com
Microservices
vs. The First Law of
Distributed Objects

3. (disclaimer)

4. Servers used to be
very expensive.
Efficient software
was mandatory.

5. Internet usage
was growing
drastically.
And so was the
demand for
engineers.

6. "The flexible, server-side infrastructure of
CORBA makes it feasible to develop
servers that can scale from handling a
small number of objects up to handling a
virtually unlimited number of objects. "

9. what are
objects
anyway?

10. "Smalltalk’s design—and existence—is
due to the insight that everything we can
describe can be represented by the
recursive composition of a single kind of
behavioral building block that hides its
combination of state and process inside
itself and can be dealt with only through
the exchange of messages."

11. i.e. annoying little
things that can’t do
anything on their
own.

12. An analogy from the meatspace

13. i.e. annoying little
things that can’t do
anything on their
own.

14. Communication isn’t free

17. don’t

18. don’t

19. don’t

20. and there
was much
rejoicing

21. fast forward
to 2017

22. microservices

23. what are
microservices
anyway?

24. "Microservices are small, autonomous
services that work together."

25. i.e. annoying little
things that can’t do
anything on their
own.

26. wtf?
and still…

27. 1. technology
did get better

28. no more
design-by-committee

29. 2. services are
coarse-grained

30. the problem with
microservices is the
micro
service microservice?

31. Monolith
Class
?

32. a real-world
example

33. billing

34. billing
BillableUser
?

36. it’s all about
the language

37. run-rate
invoice
credit card
user
droplet-started
droplet-destroyed
tax
currency
bank account
realised revenue

38. run-rate
invoice
credit card
user
droplet-started
droplet-destroyed
tax
currency
bank account
realised revenue
product price
charging model

39. rating invoicing
payment
-collectingusers

40. rating invoicing
payment
-collecting
users
Highly
visible
Not
visible
Novel Commodity

41. the ubiquitous
language can
give you a
blueprint

42. …unless you are
too big or too
small

43. Q&A