Microservices are small services with independent lifecycles that work together. There is an underlying tension in that definition – how independent can you be when you have to be part of a whole? I’ve spent much of the last couple of years trying to understand how to find the right balance, and in this talk/tutorial I’ll be presenting the core seven principles that I think represent what makes microservices tick. After a brief introduction of what microservices are and why they are important, we’ll spend the bulk of the time looking at the principles themselves, wherever possible covering real-world examples and technology: - Modelled around business domain – using techniques from domain-driven design to find service boundaries leads to better team alignment and more stable service boundaries, avoiding expensive cross-service changes. - Culture of automation – all organisations that use microservices at scale have strong cultures of automation. We’ll look at some of their stories and think about which sort of automation is key. - Hide implementation details – how do you hide the detail inside each service to avoid coupling, and ensure each service retains its autonomous nature? - Decentralize all the things! – we have to push power down as far as we can, and this goes for both the system and organisational architecture. We’ll look at everything from autonomous self-contained teams and internal open source, to using choreographed systems to handle long-lived business transactions. - Deploy independently – this is all about being able to deploy safely. So we’ll cover everything from deployment models to consumer-driven contracts and the importance of separating deployment from release. - Isolate failure – just making a system distributed doesn’t make it more stable than a monolithic application. So what do you need to look for? - Highly observable – we need to understand the health of a single service, but also the whole ecosystem. How? In terms of learning outcomes, beginners will get a sense of what microservices are and what makes them different, whereas more experienced practitioners will get insight and practical advice into how to implement them.

1. PRINCIPLES OF
MICROSERVICES
Sam Newman
Velocity Santa Clara, May 2015
1

2. @samnewman@velocityconf

3. @samnewman@velocityconf
Sam Newman
Building
Microservices
DESIGNING FINE-GRAINED SYSTEMS

4. @samnewman@velocityconf
Accounts
Returns
Invoicing
Shipping
Inventory
Customer
Service

5. @samnewman@velocityconf
Accounts
Returns
Invoicing
Shipping
Inventory
Customer
Service
Small Autonomous services
that work together

6. @samnewman@velocityconf
5
Show Gilt, Groupon, Netflix, Amazon

7. @samnewman@velocityconf
5
Show Gilt, Groupon, Netflix, Amazon

8. @samnewman@velocityconf
5
Show Gilt, Groupon, Netflix, Amazon

9. @samnewman@velocityconf

10. @samnewman@velocityconf http://www.12factor.net/

11. @samnewman@velocityconf
Strategic Goals
Architectural
Principles
Design and Delivery
Practices
Enable scalable
business
More customers/transactions
Self-service for customers
Support entry into
new markets
Flexible operational processes
New products and operational
processes
Support innovation
in existing markets
Flexible operational processes
New products and operational
processes
Reduce inertia
Make choices that favour rapid
feedback and change, with reduced
dependencies across teams.
Eliminate accidental
complexity
Aggressively retire and replace
unnecessarily complex processes,
systems, and integrations so that we
can focus on the essential
complexity.
Consistent interfaces
and data flows
Eliminate duplication of data and
create clear systems of record, with
consistent integration interfaces.
No silver bullets
Off the shelf solutions deliver early
value but create inertia and
accidental complexity.
Standard REST/HTTP
Encapsulate legacy
Eliminate integration
databases
Consolidate and
cleanse data
Published integration
model
Small independent
Services
Continuous
deployment
Minimal customisation
of COTS/SAAS

12. @samnewman@velocityconf
Small Autonomous services
that work together

13. @samnewman@velocityconf
10
Principles Of
Microservices

14. @samnewman@velocityconf
10
Principles Of
Microservices
Modelled Around
Business Domain

15. @samnewman@velocityconf
10
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation

16. @samnewman@velocityconf
10
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details

17. @samnewman@velocityconf
10
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things

18. @samnewman@velocityconf
10
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things
Deploy
Independently

19. @samnewman@velocityconf
10
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things
Deploy
Independently
Consumer First

20. @samnewman@velocityconf
10
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things
Isolate Failure Deploy
Independently
Consumer First

21. @samnewman@velocityconf
10
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things
Isolate Failure Deploy
Independently
Highly
Observable
Consumer First

22. @samnewman@velocityconf
10
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things
Isolate Failure Deploy
Independently
Highly
Observable
Consumer First

23. @samnewman@velocityconf
Presentation
Business Logic
Data Access

24. @samnewman@velocityconf
Presentation
Business Logic
Data Access

25. @samnewman@velocityconf
Presentation
Business Logic
Data Access

26. @samnewman@velocityconf
Accounts
Returns
Invoicing
Shipping
Inventory
Customer
Service

27. @samnewman@velocityconf
Accounts
Returns
Invoicing
Shipping
Inventory
Customer
Service

28. @samnewman@velocityconf
Accounts
Returns
Invoicing
Shipping
Inventory
Customer
Service

29. @samnewman@velocityconf
Accounts
Returns
Invoicing
Shipping
Inventory
Customer
Service

30. @samnewman@velocityconf
Accounts
Returns
Invoicing
Shipping
Inventory
Customer
Service

31. 13https://www.flickr.com/photos/glimeend/5692801655/

32. 14

33. 14
Register a new customer

34. 14
Register a new customer
Oil Change

35. 14
Register a new customer
Emission Test
Oil Change

36. 14
Register a new customer
Emission Test
Replace Tire
Oil Change

37. 14
Register a new customer
Order parts
Emission Test
Replace Tire
Oil Change

38. 14
Register a new customer
Order parts
Emission Test
Replace Tire
Oil Change
Send an invoice

39. 14
Register a new customer
Order parts
Emission Test
Replace Tire
Oil Change
Send an invoice
Make a repair

40. 14
Register a new customer
Order parts
Emission Test
Replace Tire
Oil Change
Send an invoice
Make a repair
Contact a customer

41. 14
Register a new customer
Order parts
Emission TestReplace Tire
Oil Change
Send an invoice
Make a repair
Contact a customer

42. 15
Customer
Management
Maintenance
Inventory

43. @samnewman@velocityconf

44. @samnewman@velocityconf
17
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things
Isolate Failure Deploy
Independently
Highly
Observable
✔
Consumer First

45. @samnewman@velocityconf
17
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things
Isolate Failure Deploy
Independently
Highly
Observable
✔
Consumer First

46. @samnewman@velocityconf

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3 Months
2 Microservices

48. @samnewman@velocityconf
3 Months
2 Microservices
12 Months
10 Microservices

49. @samnewman@velocityconf
3 Months
2 Microservices
12 Months
10 Microservices
18 Months
60 Microservices

50. @samnewman@velocityconf
Infrastructure Automation

51. @samnewman@velocityconf
Infrastructure Automation
Automated Testing

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Infrastructure Automation
Continuous Delivery
Automated Testing

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20
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things
Isolate Failure Deploy
Independently
Highly
Observable
✔ ✔
Consumer First

54. @samnewman@velocityconf
20
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation
Hide Implementation
Details
Decentralise All
The Things
Isolate Failure Deploy
Independently
Highly
Observable
✔ ✔
Consumer First

55. @samnewman@velocityconf
DB

56. @samnewman@velocityconf
DB

57. @samnewman@velocityconf
DB

58. @samnewman@velocityconf
DB

59. @samnewman@velocityconf
DB
HIDE YOUR DATABASE

60. @samnewman@velocityconf
http://martinfowler.com/bliki/images/boundedContext/sketch.png

61. @samnewman@velocityconf
http://martinfowler.com/bliki/images/boundedContext/sketch.png
BOUNDED CONTEXTS

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Client LibraryClient LibraryClient Library

65. @samnewman@velocityconf
Client Library
Client Library
Client Library

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Client Library
Client Library
Client Library

67. @samnewman@velocityconf
Client Library
BE CAREFUL OF CLIENT LIBRARIES
Client Library
Client Library

68. @samnewman@velocityconf
24
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things
Isolate Failure Deploy
Independently
Highly
Observable
✔ ✔ ✔
Consumer First

69. @samnewman@velocityconf
24
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things
Isolate Failure Deploy
Independently
Highly
Observable
✔ ✔ ✔
Consumer First

70. @samnewman@velocityconf

71. @samnewman@velocityconf
What is autonomy?

72. @samnewman@velocityconf
What is autonomy?
Giving people as much freedom as possible
to do the job at hand

73. @samnewman@velocityconf
What is autonomy?
Giving people as much freedom as possible
to do the job at hand

74. @samnewman@velocityconf
DEVOLUTION?

75. @samnewman@velocityconf
SELF-SERVICE
https://www.flickr.com/photos/katsrcool/15184711908/

76. @samnewman@velocityconf
http://tech.gilt.com/post/102628539834/making-architecture-work-in-microservice
SHARED GOVERNANCE

77. @samnewman@velocityconf
OWNER-OPERATOR
https://www.flickr.com/photos/stevendepolo/5939055612

78. @samnewman@velocityconf
INTERNAL OPEN SOURCE

79. @samnewman@velocityconf
DUMB-PIPES, SMART ENDPOINTS
Magical Mystery Bus

80. @samnewman@velocityconf
Magical Mystery Bus

81. @samnewman@velocityconf

82. @samnewman@velocityconf
Customer
Enrolment

83. @samnewman@velocityconf
Create
Customer
Record
Customer
Enrolment

84. @samnewman@velocityconf
Create
Customer
Record
Customer
Enrolment
Create Loyalty
Account

85. @samnewman@velocityconf
Create
Customer
Record
Customer
Enrolment
Dispatch
Welcome Pack
Create Loyalty
Account

86. @samnewman@velocityconf
Create
Customer
Record
Customer
Enrolment
Dispatch
Welcome Pack
Create Loyalty
Account
Send Welcome
Email

87. @samnewman@velocityconf
Create
Customer
Record
Customer
Enrolment
Dispatch
Welcome Pack
Create Loyalty
Account
Send Welcome
Email
Completed

88. @samnewman@velocityconf
ORCHESTRATION

89. @samnewman@velocityconf
Customer
Service
create
ORCHESTRATION

90. @samnewman@velocityconf
Customer
Service
create
Loyalty
Bank
create
ORCHESTRATION

91. @samnewman@velocityconf
Customer
Service
create
Loyalty
Bank
create
Email
send email
ORCHESTRATION

92. @samnewman@velocityconf
Customer
Service
create
Loyalty
Bank
create
Email
send email
Whitemail
send package
ORCHESTRATION

93. @samnewman@velocityconf
CHOREOGRAPHED

94. @samnewman@velocityconf
CHOREOGRAPHED
Customer
Service
create

95. @samnewman@velocityconf
CHOREOGRAPHED
Customer
Service
create
customer created

96. @samnewman@velocityconf
CHOREOGRAPHED
Customer
Service
create
customer created
Loyalty
Bank

97. @samnewman@velocityconf
CHOREOGRAPHED
Customer
Service
create
customer created
Loyalty
Bank
Email

98. @samnewman@velocityconf
CHOREOGRAPHED
Customer
Service
create
customer created
Loyalty
Bank
Email
Whitemail

99. @samnewman@velocityconf
CHOREOGRAPHED
Customer
Service
create
customer created
Loyalty
Bank
Email
Whitemail
Reporting
Dashboard

100. @samnewman@velocityconf

101. @samnewman@velocityconf
CHOREOGRAPHY OVER ORCHESTRATION

102. @samnewman@velocityconf
38
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Isolate Failure Deploy
Independently
Highly
Observable
✔ ✔ ✔
Decentralise All
The Things
✔
Consumer First

103. @samnewman@velocityconf
38
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Isolate Failure Deploy
Independently
Highly
Observable
✔ ✔ ✔
Decentralise All
The Things
✔
Consumer First

104. @samnewman@velocityconf
ONE SERVICE PER-HOST
Host
Service

105. @samnewman@velocityconf
ONE SERVICE PER-HOST
Host
Service
Host
Service Service
Service Service
VS

106. @samnewman@velocityconf
CONSUMER-DRIVEN CONTRACTS
Shipping Inventory

107. @samnewman@velocityconf
CONSUMER-DRIVEN CONTRACTS
Expectations
Shipping Inventory

108. @samnewman@velocityconf
CONSUMER-DRIVEN CONTRACTS
Expectations
Shipping Inventory

109. @samnewman@velocityconf
CONSUMER-DRIVEN CONTRACTS
Expectations
Prod
Shipping Inventory

110. @samnewman@velocityconf
CONSUMER-DRIVEN CONTRACTS
Expectations
Prod
Shipping Inventory

111. @samnewman@velocityconf
https://github.com/realestate-com-au/pact

112. @samnewman@velocityconf
CO-EXIST ENDPOINTS
Customer Service
Shipping

113. @samnewman@velocityconf
CO-EXIST ENDPOINTS
Customer Service
Shipping
V2V1

114. @samnewman@velocityconf
CO-EXIST ENDPOINTS
Customer Service
Shipping
V2V1

115. @samnewman@velocityconf
CO-EXIST ENDPOINTS
Customer Service
Shipping
V2

116. @samnewman@velocityconf
43
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Isolate Failure
Highly
Observable
✔ ✔ ✔
Decentralise All
The Things
✔
Deploy
Independently✔
Consumer First

117. @samnewman@velocityconf
43
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Isolate Failure
Highly
Observable
✔ ✔ ✔
Decentralise All
The Things
✔
Deploy
Independently✔Consumer First

118. @samnewman@velocityconf
DOCUMENTATION

119. @samnewman@velocityconf

120. @samnewman@velocityconf
API GATEWAYS

121. @samnewman@velocityconf
SERVICE DISCOVERY

122. @samnewman@velocityconf
SERVICE DISCOVERY

123. @samnewman@velocityconf
SERVICE DISCOVERY

124. @samnewman@velocityconf
HUMANE REGISTRIES

125. @samnewman@velocityconf
49
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Isolate Failure
Highly
Observable
✔ ✔ ✔
Decentralise All
The Things
✔
Deploy
Independently✔
Consumer First✔

126. @samnewman@velocityconf
49
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Isolate Failure
Highly
Observable
✔ ✔ ✔
Decentralise All
The Things
✔
Deploy
Independently✔
Consumer First✔

127. @samnewman@velocityconf

128. @samnewman@velocityconf

129. @samnewman@velocityconf

130. @samnewman@velocityconf

131. @samnewman@velocityconf

132. @samnewman@velocityconf
AVOID THE DISTRIBUTED SINGLE POINT OF FAILURE!

133. @samnewman@velocityconf
Strangler App

134. @samnewman@velocityconf
Strangler App
Legacy App
Legacy AppLegacy App

135. @samnewman@velocityconf
Strangler App
Legacy App
Legacy App
Requests
Legacy App

136. @samnewman@velocityconf
Strangler App
Legacy App
Legacy App
Requests
Legacy App

137. @samnewman@velocityconf
Strangler App
Legacy App
Legacy App
Requests
Legacy App

138. @samnewman@velocityconf
Strangler App
Legacy App
Legacy App
Requests
Legacy App
30 - 60 Concurrent Requests

139. @samnewman@velocityconf
Strangler App
Legacy App
Legacy App
Requests
Legacy App
30 - 60 Concurrent Requests
> 800 Concurrent Requests

140. @samnewman@velocityconf
Strangler App
Legacy App
Legacy App
Requests
Legacy App
30 - 60 Concurrent Requests
> 800 Concurrent Requests

141. @samnewman@velocityconf
Strangler App
Legacy App Legacy App Legacy App
Thread Pool

142. @samnewman@velocityconf
Strangler App
Legacy App Legacy App Legacy App
Thread Pool
Failing…slowly!

143. @samnewman@velocityconf
Strangler App
Legacy App Legacy App Legacy App
Thread Pool
Failing…slowly!

144. @samnewman@velocityconf
Strangler App
Legacy App Legacy App Legacy App
Thread Pool
Failing…slowly!
Thread-pool
exhausted

145. @samnewman@velocityconf
Strangler App
Legacy App Legacy App Legacy App
Thread Pool
Failing…slowly!
Thread-pool
exhausted
No requests to other
downstream apps

146. @samnewman@velocityconf
Strangler App
Legacy App Legacy App Legacy App
Thread Pool
Failing…slowly!
Thread-pool
exhausted
No requests to other
downstream apps

147. @samnewman@velocityconf
Strangler App
Legacy App Legacy App Legacy App
Thread Pool
Failing…slowly!
Thread-pool
exhausted
Requests
Building Up
No requests to other
downstream apps

148. @samnewman@velocityconf
Strangler App
Legacy App Legacy App Legacy App
Thread Pool

149. @samnewman@velocityconf
Strangler App
Legacy App Legacy App Legacy App
Fix Timeouts
Thread Pool

150. @samnewman@velocityconf
Strangler App
Legacy App Legacy App Legacy App
Fix Timeouts
Thread Pool

151. @samnewman@velocityconf
Strangler App
Legacy App Legacy App Legacy App
Fix Timeouts
Thread Pool Thread PoolThread Pool

152. @samnewman@velocityconf
Strangler App
Legacy App Legacy App Legacy App
Fix Timeouts
Thread Pool Thread PoolThread Pool
Bulkhead
Downstream
Connections

153. @samnewman@velocityconf
Strangler App
Legacy App Legacy App Legacy App
Fix Timeouts
Thread Pool Thread PoolThread Pool
Bulkhead
Downstream
Connections

154. @samnewman@velocityconf
Strangler App
Legacy App Legacy App Legacy App
Fix Timeouts
Thread Pool Thread PoolThread Pool
Bulkhead
Downstream
Connections
Circuit Breakers

155. @samnewman@velocityconf
55
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Highly
Observable
✔ ✔ ✔
Decentralise All
The Things
✔
Deploy
Independently✔
Isolate Failure✔ Consumer First✔

156. @samnewman@velocityconf
55
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Highly
Observable
✔ ✔ ✔
Decentralise All
The Things
✔
Deploy
Independently✔
Isolate Failure✔ Consumer First✔

157. @samnewman@velocityconf

158. @samnewman@velocityconf
STATS PAGES

159. @samnewman@velocityconf
STATS PAGES

160. @samnewman@velocityconf
AGGREGATION

161. @samnewman@velocityconf
LOGS
AGGREGATION

162. @samnewman@velocityconf
LOGS
STATS
AGGREGATION

163. @samnewman@velocityconf
CORRELATION IDS

164. @samnewman@velocityconf
CORRELATION IDS
ID 8964

165. @samnewman@velocityconf
CORRELATION IDS
ID 8964
ID 8964
ID 8964
ID 8964
ID 8964

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SEMANTIC MONITORING

170. @samnewman@velocityconf

171. @samnewman@velocityconf
Principles Of
Microservices

172. @samnewman@velocityconf
Principles Of
Microservices
Modelled Around
Business Domain

173. @samnewman@velocityconf
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation

174. @samnewman@velocityconf
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details

175. @samnewman@velocityconf
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things

176. @samnewman@velocityconf
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things
Deploy
Independently

177. @samnewman@velocityconf
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things
Deploy
Independently
Consumer First

178. @samnewman@velocityconf
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things
Isolate Failure Deploy
Independently
Consumer First

179. @samnewman@velocityconf
Principles Of
Microservices
Modelled Around
Business Domain
Culture Of
Automation Hide Implementation
Details
Decentralise All
The Things
Isolate Failure Deploy
Independently
Highly
Observable
Consumer First

180. @samnewman@velocityconf
Sam Newman
Building
Microservices
DESIGNING FINE-GRAINED SYSTEMS
http://buildingmicroservices.com/

181. @samnewman@velocityconf
Office Hours

182. @samnewman@velocityconf
Office Hours
(well, 30mins)

183. @samnewman@velocityconf
Office Hours
12.30pm on Thursday
(well, 30mins)

184. @samnewman@velocityconf
http://lanyrd.com/profile/samnewman/

185. Sam Newman
@samnewman
THANKS!