Serverless technologies like AWS Lambda has drastically simplified the task of building reactive systems - drop a file into S3 and a Lambda function would be triggered to process it, push an event into a Kinesis stream and magically it'll be processed by a Lambda function in real-time, you can even use Lambda to automate the process of auditing and securing your AWS account by automatically reacting to rule violations to your security policy. Join us in this talk to see some architectural design patterns that have emerged with AWS Lambda, and learn how to pick the right event source based on the tradeoffs you want. Amongst the many patterns we'll explore, here are a few to whet your appetite : pub-sub, cron, push-pull, saga and decoupled invocation.

1. SERVERLESS DESIGN PATTERNS

2. Yan Cui
http://theburningmonk.com
@theburningmonk
Principal Engineer @

3. 2014

9. “Serverless”

11. Gojko Adzic
It is serverless the same way
WiFi is wireless.
http://bit.ly/2yQgwwb

12. Serverless means…
don’t pay for it if no-one uses it
don’t need to worry about scaling
don’t need to provision and manage servers

13. “Function-as-a-Service”
AWS Lambda
Azure Functions
Google Cloud Functions
Auth0 Webtask
Spotinst Functions Kubeless
IBM Cloud Functions

14. AWS Lambda

15. AWS Lambda
API Gateway IOT SNS Kinesis CloudWatch

16. IaaS
Function
Application
Runtime
Container
OS
Virtualization
Hardware
CaaS
Function
Application
Runtime
Container
OS
Virtualization
Hardware
PaaS
Function
Application
Runtime
Container
OS
Virtualization
Hardware
FaaS
Function
Application
Runtime
Container
OS
Virtualization
Hardware
User User (scalable unit) Provider

17. IaaS
Function
Application
Runtime
Container
OS
Virtualization
Hardware
CaaS
Function
Application
Runtime
Container
OS
Virtualization
Hardware
PaaS
Function
Application
Runtime
Container
OS
Virtualization
Hardware
FaaS
Function
Application
Runtime
Container
OS
Virtualization
Hardware
User User (scalable unit) Provider

18. Serverless
FaaS
other
Databas
Storage
BI

19. SERVERLESS WILL FUNDAMENTALLY
CHANGE HOW WE BUILD BUSINESS
AROUND TECHNOLOGY AND HOW YOU
CODE.
Simon Wardley

20. more Scalable
(and scales faster!)

21. Cheaper
(don’t pay for idle servers)

22. Resilience
(built-in redundancy and multi-AZ)

23. idea production
choose language
+ framework
master language
+ framework
figure out
deployment
configure AMI
configure ELB
configure
autoscaling
capacity planning
over-provision for
launch
are we doing
microservices?
configure CI/CD

24. idea production
choose language
+ framework
master language
+ framework
figure out
deployment
configure AMI
configure ELB
configure
autoscaling
capacity planning
over-provision for
launch
are we doing
microservices?
configure CI/CD

25. idea production
greater Velocity from idea to product

26. minimise Undifferentiated
heavy-lifting

27. Less ops responsibility on
your shoulders

28. https://www.youtube.com/watch?v=pptsgV4bKv8

30. http://bit.ly/2Dpidje

31. events are an enabler for
COMPOSABILITY

32. AWS LAMBDA
is the...

34. PATTERNS

35. WARNING!!

36. A DESIGN PATTERN IS NOT...
A RECIPE FOR SUCCESS

37. Pattern
/pat(ə)n/
A pattern is the repeated or
regular way in which something
happens or is done.

38. UNDERSTAND YOUR PROBLEMS
AND CONSTRAINTS OVER
FOLLOWING A PATTERN.
me

39. http://bit.ly/2Goq5mY

40. I’m not trying to sell you a “magic” elixir!

41. there are no silver bullets

42. Pattern
/pat(ə)n/
A pattern is the repeated or
regular way in which something
happens or is done.

43. CRON

44. AWS LambdaCloudWatch Events

45. CloudWatch Events

48. OPS
AUTOMATION

49. AWS Lambda CloudWatch Logs

50. CloudWatch Logs

51. AWS Lambda CloudWatch Logs AWS Lambda

52. CloudWatch Logs

53. AWS Lambda CloudWatch Logs
CloudTrail

54. CloudWatch Events

57. AWS Lambda CloudWatch Logs
CloudWatch Events
CloudTrail
AWS Lambda

58. AWS Lambda CloudWatch Logs
CloudWatch Events
CloudTrail
AWS Lambda
AWS Lambda

59. AWS Lambda CloudWatch Logs
CloudWatch Events
CloudTrail
AWS Lambda
AWS Lambda

60. auto-update CloudWatch retention policy
auto-create alarms for new APIs
auto-create dashboards for new APIs
alert on suspicious console logins
alert on EC2 activities in unused regions
…

61. WEB APPS

62. CloudFront S3
Browser

63. API Gateway AWS Lambda DynamoDBRoute53
CloudFront S3
Browser

64. API Gateway AWS Lambda DynamoDBRoute53
CloudFront S3
Browser
Cognito

65. Federated
Identities
Sync
User Flows
Registration
Verify email/phone
Secure sign-in
Forgotten password
Change password
Sign out
Cognito User
Pools

66. Federated
Identities
Sync
Leading Practices
Secure password handling
with SRP protocol
Encrypt all data server-side
Password policies
Token-based authentication
MFA
Support CAPTCHA
Cognito User
Pools

67. Cognito
Federated Identities
Cognito
User Pools
Facebook TwitterGoogle
…
identity providers
authenticate

68. Cognito
Federated Identities
Cognito
User Pools
Facebook TwitterGoogle
…
identity providers
authenticate token

69. Cognito
Federated Identities
Cognito
User Pools
Facebook TwitterGoogle
…
identity providers
authenticate token
token

70. validate
Cognito
Federated Identities
Cognito
User Pools
Facebook TwitterGoogle
…
identity providers
authenticate token
token

71. validate
Cognito
Federated Identities
Cognito
User Pools
Facebook TwitterGoogle
…
identity providers
authenticate token
token
IAM credential

72. validate
Cognito
Federated Identities
Cognito
User Pools
Facebook TwitterGoogle
…
identity providers
API Gateway S3 DynamoDB SNSIOT Kinesis
authenticate token
token
IAM credential
IAM credential

73. what about Multi-Region support?

74. https://aws.amazon.com/dynamodb/global-tables

75. http://amzn.to/2Bwb5j6

76. API Gateway AWS Lambda
DynamoDB
Route53
CloudFront S3
Browser
API Gateway AWS Lambda
eu-west-1
us-east-1

77. http://bit.ly/2FGKsuA

78. DATA LAKES

79. S3 Buckets

80. S3 Buckets
IAM

81. S3 Buckets
KMSIAM

82. S3 Buckets
KMS MacieIAM

83. S3 BucketsKinesis Streams Kinesis Firehose
KMS MacieIAM

84. S3 BucketsKinesis Streams
AWS Lambda
KMS MacieIAM
Kinesis Firehose

85. S3 BucketsKinesis Streams
AWS Lambda
KMS MacieIAM
AWS Lambda
Kinesis Firehose

86. S3 BucketsKinesis Streams
AWS Lambda AWS Lambda
KMS MacieIAM
AWS Lambda
Kinesis Firehose

87. S3 BucketsKinesis Streams
AWS Lambda AWS Lambda
KMS MacieIAM
AWS Lambda
DynamoDB
ElasticSearch
Kinesis Firehose

88. S3 BucketsKinesis Streams
AWS Lambda AWS Lambda
KMS MacieIAM
AWS Lambda Google BigQuery
Kinesis Firehose

89. S3 BucketsKinesis Streams
AWS Lambda AWS Lambda
Athena QuickSight
KMS MacieIAM
AWS Lambda
Kinesis Firehose

90. S3 BucketsKinesis Streams
AWS Lambda AWS Lambda
Athena QuickSight
KMS MacieIAM
AWS Lambda
Kinesis Firehose

91. DECOUPLED
INVOCATION

92. Decoupled Invocation
How can a service handle normal
request loads, peak request loads,
and a continuous period of high
load without failing?

93. business logic requires expensive processing

94. API Gateway
max integration timeout is 29 seconds
http://amzn.to/2BwW5Bx

95. downstream systems not as scalable

97. decouple reply from the initial request

98. APIClient
POST /do_something

99. workerAPIClient
POST /do_something
202 /result_location
do work

100. workerAPIClient
POST /do_something
202 /result_location
GET /result_location
202 /result_location
do work

101. workerAPIClient
POST /do_something
202 /result_location
GET /result_location
202 /result_location
do work
work done

102. workerAPIClient
POST /do_something
202 /result_location
GET /result_location
202 /result_location
do work
work done
GET /result_location
200 OK

103. amortises spikes in load

105. allows fast response back to caller whilst
promises to finish work later

107. allows flexible retry strategies by removing the
urgency of having to reply to caller right away

108. DynamoDB
API Gateway
POST
task id created at result
xxx xxx <null>
xxx xxx <null>
… … …
task results
not ready
PutItem

109. DynamoDB
API Gateway
POST
task id created at result
xxx xxx <null>
xxx xxx <null>
… … …
task results
not ready
SQS

110. DynamoDB
API Gateway
202
task id created at result
xxx xxx <null>
xxx xxx <null>
… … …
task results
not ready
SQS

111. use “created at” timestamp to timeout
polling requests and avoid infinite retry

112. DynamoDBAPI Gateway
GET
task id created at result
xxx xxx <null>
xxx xxx <null>
… … …
task results
not ready
SQS

113. DynamoDBAPI Gateway
202
task id created at result
xxx xxx <null>
xxx xxx <null>
… … …
task results
not ready
SQS

114. DynamoDB
task id created at result
xxx { … }
xxx <null>
… …
task results
done
UpdateItem
xxx
xxx
…
SQS

115. DynamoDBAPI Gateway
GET
task id created at result
xxx xxx { … }
xxx xxx <null>
… … …
task results
done

116. DynamoDBAPI Gateway
200 { … }

117. also consider using Kinesis Streams or
DynamoDB Streams as queue

118. but SNS is a poor choice
(invocation-per-message means no amortisation)

119. PUB-SUB

120. msg broker
subscriber
subscriber
subscriber
subscriber
…

121. one message, many consumers

122. good for decoupling data processing

123. independent failures
partial failures are easier to manage

124. SNS, Kinesis Streams, DynamoDB Streams, etc…

125. SNS

126. 2 retries then DLQ
SNS

127. 2 retries then DLQ
invocation per msg
SNS

128. 2 retries then DLQ
invocation per msg
might run into
throttling limits
consider impact on
downstream
SNS

129. suffers from temporal issues

130. msg/s
time
max throughput
erred and retried

131. msg/s
time
max throughput
erred and retried

132. msg/s
time
max throughput
downstream outage

133. Kinesis

134. retried until success
Kinesis

135. retried until success
invocation per shard
Kinesis

136. better handling of temporal issues

137. msg/s
time
processed
max throughput amortised
received

138. msg/s
time
max throughput
downstream outage
processed
received

139. DynamoDB
Streams
DynamoDB

140. Kinesis Streams or DynamoDB Streams?

141. what is your source of truth?

142. limited to events from one table

143. records describe DynamoDB events,
not events from your domain

144. auto-scales no. of shards

145. cannot extend data retention beyond 24 hours

146. charged based on no. of requests
($0.02 per 100,000 read request units)

148. 1 msg/s for a month, 1KB per msg
$0.47
1 x 60s x 60m x 24hr x 30days
@ $0.014 per mil
+
24hrs x 30days
@ $0.015 per hr
$10.836
1 x 60s x 60m x 24hr x 30days
@ $0.5 per mil
$1.296
DynamoDB StreamsSNSKinesis Streams
1 Write Capacity Unit
@ $0.47 per unit

149. 1k msg/s for a month, 1KB per msg
1k x 60s x 60m x 24hr x 30days
@ $0.014 per mil
+
24hrs x 30days
@ $0.015 per hr
$47.088
1k x 60s x 60m x 24hr x 30days
@ $0.5 per mil
$1296.00
DynamoDB StreamsSNSKinesis Streams
$470.00
1k Write Capacity Unit
@ $0.47 per unit

150. DON’T take these projections at face value!

151. SNS

152. no restriction on
destination target
SNS

153. no restriction on
destination target
need to handle partial
failures & retries
SNS

154. SAGA

155. pattern for managing failures where each
action has a compensating action for rollback

156. https://www.youtube.com/watch?v=xDuwrtwYHu8

157. Begin transaction
Start book hotel request
End book hotel request
Start book flight request
End book flight request
Start book car rental request
End book car rental request
End transaction

158. model actions and compensating
actions as Lambda functions

159. actions

160. compensating actions

161. state machine in AWS Step Functions as
the coordinator for the saga

162. AWS Step Functions
http://bit.ly/2uTJBE3

163. input

167. source code available here:
https://github.com/theburningmonk/lambda-saga-pattern

168. @theburningmonk
theburningmonk.com
github.com/theburningmonk

170. API Gateway and Kinesis
Authentication & authorisation (IAM, Cognito)
Testing
Running & Debugging functions locally
Log aggregation
Monitoring & Alerting
X-Ray
Correlation IDs
CI/CD
Performance and Cost optimisation
Error Handling
Configuration management
VPC
Security
Leading practices (API Gateway, Kinesis, Lambda)
Canary deployments
http://bit.ly/prod-ready-serverless
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