This document discusses microservices architecture and defines it as an approach to developing applications as a suite of small services that work together and communicate using lightweight mechanisms like HTTP APIs. Each service runs in its own process and deals with a specific business capability. The document traces the origins of this approach back to principles of modularity in Unix programming and emphasizes that the power comes from the relationships between programs rather than the programs themselves. It compares microservices to service-oriented architecture and discusses communication approaches like REST APIs and message queues as well as deployment using containers like Docker.

1. Microservices Architecture
Ram Vijapurapu ~ @rvijapurapu

2. Agenda
2

3. *Terms & conditions apply.
3

4. 4
Monolith
tl;dr ….
Microservice

5. The Quest for Modularity
5
Sales Inventory Admin
Web
/shop /inventory /admin
Mobile
Controllers (& Services)
shopSvc inventorySvc adminSvc
DAOs
Security Framework
NAPPY_
SITE_DB

6. What if?
6
Web
/sales /inventory /admin
Mobile
Controllers (& Services)
shopSvc inventorySvc adminSvc
DAOs
Security Framework
IoT
Controllers (& Services)
shopSvc inventorySvc adminSvc
buttonOrderSvc
BIG_F$_
SITE_DB

7. What if?
7
Web
/sales /inventory /admin
Mobile
Controllers (& Services)
shopSvc inventorySvc adminSvc
DAOs
Security Framework
IoT
Controllers (& Services)
shopSvc inventorySvc adminSvc
buttonOrderSvc
BIG_F$_
SITE_DB

8. Something has to change….
8
Micro ervices
to the rescue….By Source, Fair use, https://en.wikipedia.org/w/index.php?curid=45003610

9. Is Microservices the new Hype?
9

10. https://de.wikipedia.org/wiki/Datei:Back-to-the-future-logo.svg
10

11. Let’s start at the very beginning
“Even though the UNIX system introduces a number of innovative programs and
techniques, no single program or idea makes it work well. Instead, what makes it
effective is the approach to programming, a philosophy of using the computer.
Although that philosophy can’t be written down in a single sentence, at its heart is the
idea that the power of a system comes more from the
relationships among programs than from the
programs themselves. Many UNIX programs do quite trivial things in
isolation, but, combined with other programs, become general and useful tools.”
– Brian Kernighan and Rob Pike, The UNIX Programming Environment
11

12. Let’s start at the very beginning
Write programs that do one
thing and do it well. Write
programs to work together. Write
programs to handle text streams, because that is a universal interface.
- Doug McIlroy, the inventor of Unix pipes
Read More: The Art of Unix Programming http://www.catb.org/~esr/writings/taoup/html/index.html 12

13. Whatever that means...
13

14. 14
So the secret ingredient is?
…..Data

15. Flow Based Programming….
15

16. Flow Based Programming….
16
Flow-based programming (FBP) is a programming
paradigm that defines applications as networks of
"black box" processes, which exchange data across
predefined connections by message passing, where
the connections are specified externally to the
processes.

17. Microservices in the wild….
17
● Intents
● Activities
● Services
● Broadcast Receivers
● Listeners

18. Microservices in the wild….
18

19. Just give me a definition, will ya!
The microservice architectural style is an approach to developing a
single application as a suite of small
services, each running in its own process and communicating with lightweight
mechanisms, often an HTTP resource API. These services are built around business
capabilities and independently deployable by fully automated deployment machinery.
There is a bare minimum of centralized management of these services, which may be
written in different programming languages and use different data storage
technologies. - James Lewis & Martin Fowler
Read More: Microservices a definition of this new architectural term http://martinfowler.com/articles/microservices.html 19

20. Isn’t that what SOA is?
20
Yes
NO!
Maybe

21. Let’s backup a bit….
21
Sales Inventory Admin
Web
/sales /inventory /admin
Mobile
Controllers (& Services)
shopSvc inventorySvc adminSvc
DAOs
Security Framework

22. Building Castles
22
Sales
/shop
SalesSvc
Shop DAO
Security
Inventory
/inventory
InventorySvc
Inventory
DAO
Security
Admin
/admin
AdminSvc
Admin DAO
Security

23. The focus will be on communication
23
Sales
/shop
SalesSvc
Shop DAO
Security
Inventory
/inventory
InventorySvc
Inventory
DAO
Security
Admin
/admin
AdminSvc
Admin DAO
Security

24. The focus will be on communication
24
Shop
/shop
SalesSvc
Shop DAO
Security
Inventory
/inventory
InventorySvc
Inventory
DAO
Security
Admin
/admin
AdminSvc
Admin DAO
Security

25. API First
25

26. Takes two to tango
26
REST
ATTR: Ginny Huo, "Pass the Message," Copyright 2016. http://www.ginnyhuo.com/pass-the-message/
Message Queues

27. Sync vs Async
27

28. So, are we just going to run one instance of each???
28
Shop
/shop
SalesSvc
Shop DAO
Security
Inventory
/inventory
InventorySvc
Inventory
DAO
Security
Admin
/admin
AdminSvc
Admin DAO
Security

29. Docker
29

30. Containers
30
Shop
Inventory
Admin
/shop
/inventory
/admin

31. 31

32. 32
Enough talk, ….
Kung Fu Panda (2008) - http://www.imdb.com/title/tt0441773/