AWS Lambda has changed the way we deploy and run software, but this new serverless paradigm has created new challenges to old problems - how do you test a cloud-hosted function locally? How do you monitor them? What about logging and config management? And how do we start migrating from existing architectures? In this talk Yan and Scott will discuss solutions to these challenges by drawing from real-world experience running Lambda in production and migrating from an existing monolithic architecture.

1. in production
an experience reportan experience report
what you should know before you go to production
ServerlessServerless

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

3. “Netflix for sports”
offices in London, Leeds, Katowice and Tokyo

7. available in Austria, Switzerland, Germany,
Japan, Italy, Canada, Spain and USA

8. available on 30+ platforms

9. ~1,000,000 concurrent viewers

10. “Netflix for sports”
offices in London, Leeds, Katowice and Amsterdam
We’re hiring! Visit
engineering.dazn.com to
learn more.
follow @dazneng for updates
about the engineering team.

13. apr, 2016

15. hey guys, vote on this post
and I’ll announce a winner at
10PM tonight

16. 10PM
traffic

17. 10PM
traffic
70-100x

18. low utilisation to leave room for spikes
EC2 scaling is slow, so scale earlier

19. lots of $$$ for unused resources

20. up to 30 mins for deployment
deployment required downtime

21. - Dan North
“lead time to someone saying
thank you is the only reputation
metric that matters.”

23. “what would good
look like for us?”

24. be small
be fast
have zero downtime
have no lock-step
DEPLOYMENTS SHOULD...

25. FEATURES SHOULD...
be deployable independently
be loosely-coupled

26. WE WANT TO...
minimise cost for unused resources
minimise ops effort
reduce tech mess
deliver visible improvements faster

27. nov, 2016

28. 170 Lambda functions in prod
1.2 GB deployment packages in prod
95% cost saving vs EC2
15x no. of prod releases per month

29. time
is a good fit

30. 1st function in prod!
time
is a good fit

31. ?
time
is a good fit
1st function in prod!

32. ALERTING
CI / CD
TESTING
LOGGING
MONITORING

33. Practices ToolsPrinciples
what is good? how to make it good? with what?

34. Principles outlast Tools

35. 170 functions
? ?
time
is a good fit
1st function in prod!

36. SECURITY
DISTRIBUTED TRACING
CONFIG MANAGEMENT

37. evolving the PLATFORM

38. rebuilt search

39. Legacy Monolith Amazon Kinesis Amazon Lambda
Amazon CloudSearch

40. Legacy Monolith Amazon Kinesis Amazon Lambda
Amazon CloudSearchAmazon API Gateway Amazon Lambda

41. new analytics pipeline

42. Legacy Monolith Amazon Kinesis Amazon Lambda
Google BigQuery

43. Legacy Monolith Amazon Kinesis Amazon Lambda
Google BigQuery
1 developer, 2 days
design production
(his 1st serverless project)

44. Legacy Monolith Amazon Kinesis Amazon Lambda
Google BigQuery
“nothing ever got done
this fast at Skype!”
- Chris Twamley

45. - Dan North
“lead time to someone saying
thank you is the only reputation
metric that matters.”

46. Rebuilt
with Lambda

54. getting PRODUCTION READY

55. choose a tried-and-tested
deployment framework,
don’t invent your own

56. http://serverless.com

57. https://github.com/awslabs/serverless-application-model

58. http://apex.run

59. https://apex.github.io/up

60. https://github.com/claudiajs/claudia

61. https://github.com/Miserlou/Zappa

62. http://gosparta.io/

63. TESTING

64. amzn.to/29Lxuzu

65. Level of Testing
1.Unit
do our objects do the right thing?
are they easy to work with?

67. Level of Testing
1.Unit
2.Integration
does our code work against code we
can’t change?

68. handler

69. handler
test by invoking
the handler

70. Level of Testing
1.Unit
2.Integration
3.Acceptance
does the whole system work?

71. Level of Testing
unit
integration
acceptance
feedback
confidence

72. “…We find that tests that mock external
libraries often need to be complex to
get the code into the right state for the
functionality we need to exercise.
The mess in such tests is telling us that
the design isn’t right but, instead of
fixing the problem by improving the
code, we have to carry the extra
complexity in both code and test…”
Don’t Mock Types You Can’t Change

73. “…The second risk is that we have to be
sure that the behaviour we stub or mock
matches what the external library will
actually do…
Even if we get it right once, we have to
make sure that the tests remain valid
when we upgrade the libraries…”
Don’t Mock Types You Can’t Change

74. Don’t Mock Types You Can’t Change
Services

75. Paul Johnston
The serverless approach to
testing is different and may
actually be easier.
http://bit.ly/2t5viwK

76. LambdaAPI Gateway DynamoDB

77. LambdaAPI Gateway DynamoDB
Unit Tests

78. LambdaAPI Gateway DynamoDB
Unit Tests
Mock/Stub

79. is our request correct?
is the request mapping
set up correctly?is the API resources
configured correctly?
are we assuming the
correct schema?
LambdaAPI Gateway DynamoDB
is Lambda proxy
configured correctly?
is IAM policy set
up correctly?
is the table created?
what unit tests will not tell you…

81. most Lambda functions are simple
have single purpose, the risk of
shipping broken software has largely
shifted to how they integrate with
external services
observation

83. optimize towards shipping working
software, even if it means slowing
down your feedback loop…

84. …if a service can’t provide
you with a relatively easy
way to test the interface in
reality, then you should
consider using another one.
Paul Johnston

85. “…Wherever possible, an acceptance
test should exercise the system end-to-
end without directly calling its internal
code.
An end-to-end test interacts with the
system only from the outside: through
its interface…”
Testing End-to-End

86. Legacy Monolith Amazon Kinesis Amazon Lambda
Amazon CloudSearchAmazon API Gateway Amazon Lambda

87. Legacy Monolith Amazon Kinesis Amazon Lambda
Amazon CloudSearchAmazon API Gateway Amazon Lambda
Test Input

88. Legacy Monolith Amazon Kinesis Amazon Lambda
Amazon CloudSearchAmazon API Gateway Amazon Lambda
Test Input
Validate

89. integration tests exercise
system’s Integration with its
external dependencies
my code

90. acceptance tests exercise
system End-to-End from
the outside
my code

91. integration tests differ from
acceptance tests only in HOW the
Lambda functions are invoked
observation

94. CI + CD PIPELINE

95. me
the earlier you consider CI/CD
the more time you save in
the long run

96. “…We prefer to have the end-to-end
tests exercise both the system and the
process by which it’s built and
deployed…
This sounds like a lot of effort (it is), but
has to be done anyway repeatedly
during the software’s lifetime…”
Testing End-to-End

97. me
deployment scripts that only
live on the CI box is a disaster
waiting to happen…

98. Jenkins build config deploys and tests
unit + integration tests
deploy
acceptance tests

99. if [ "$1" = "deploy" ] && [ $# -eq 4 ]; then
STAGE=$2
REGION=$3
PROFILE=$4
npm install
AWS_PROFILE=$PROFILE 'node_modules/.bin/sls' deploy -s $STAGE -r $REGION
elif [ "$1" = "int-test" ] && [ $# -eq 4 ]; then
STAGE=$2
REGION=$3
PROFILE=$4
npm install
AWS_PROFILE=$PROFILE npm run int-$STAGE
elif [ "$1" = "acceptance-test" ] && [ $# -eq 4 ]; then
STAGE=$2
REGION=$3
PROFILE=$4
npm install
AWS_PROFILE=$PROFILE npm run acceptance-$STAGE
else
usage
exit 1
fi

100. if [ "$1" = "deploy" ] && [ $# -eq 4 ]; then
STAGE=$2
REGION=$3
PROFILE=$4
npm install
AWS_PROFILE=$PROFILE 'node_modules/.bin/sls' deploy -s $STAGE -r $REGION
elif [ "$1" = "int-test" ] && [ $# -eq 4 ]; then
STAGE=$2
REGION=$3
PROFILE=$4
npm install
AWS_PROFILE=$PROFILE npm run int-$STAGE
elif [ "$1" = "acceptance-test" ] && [ $# -eq 4 ]; then
STAGE=$2
REGION=$3
PROFILE=$4
npm install
AWS_PROFILE=$PROFILE npm run acceptance-$STAGE
else
usage
exit 1
fi
install Serverless framework
as dev dependency

101. if [ "$1" = "deploy" ] && [ $# -eq 4 ]; then
STAGE=$2
REGION=$3
PROFILE=$4
npm install
AWS_PROFILE=$PROFILE 'node_modules/.bin/sls' deploy -s $STAGE -r $REGION
elif [ "$1" = "int-test" ] && [ $# -eq 4 ]; then
STAGE=$2
REGION=$3
PROFILE=$4
npm install
AWS_PROFILE=$PROFILE npm run int-$STAGE
elif [ "$1" = "acceptance-test" ] && [ $# -eq 4 ]; then
STAGE=$2
REGION=$3
PROFILE=$4
npm install
AWS_PROFILE=$PROFILE npm run acceptance-$STAGE
else
usage
exit 1
fi
install Serverless framework
as dev dependency
mitigate version conflicts

102. build.sh allows repeatable builds on both local & CI

104. Auto Auto Manual

106. LOGGING

108. 2016-07-12T12:24:37.571Z 994f18f9-482b-11e6-8668-53e4eab441ae
GOT is off air, what do I do now?

109. 2016-07-12T12:24:37.571Z 994f18f9-482b-11e6-8668-53e4eab441ae
GOT is off air, what do I do now?
UTC Timestamp API Gateway Request Id
your log message

110. Me
Logs are not easily searchable
in CloudWatch Logs.

111. CloudWatch Logs

112. AWS Lambda
invokes
AWS Lambda
stdout
asynchronously
any log aggregation service
CloudWatch Logs

113. CloudWatch Logs
AWS Lambda
AWS Lambda
stdout
any log aggregation service
asynchronously
invokes

114. …

115. CloudWatch Events

116. http://bit.ly/sar-cwlogs-to-arn

118. http://bit.ly/sar-auto-set-cwlogs-retention

119. DISTRIBUTED TRACING

121. a user
my followers didn’t receive
my new post!

122. where could the
problem be?

123. correlation IDs*
* eg. request-id, user-id, yubl-id, etc.

124. wrap HTTP client & AWS SDK clients
to forward captured correlation IDs

125. kinesis client
http client
sns client

127. use X-Ray for performance tracing

128. Amazon X-Ray

129. Amazon X-Ray

130. X-Ray traces do not span over async
event sources

131. https://lumigo.io

132. https://epsagon.com

133. MONITORING + ALERTING

134. no place to install agents/daemons

135. • invocation Count
• error Count
• latency
• throttling
• granular to the minute
• support custom metrics

136. • same metrics as CW
• better dashboard
• support custom metrics
https://www.datadoghq.com/blog/monitoring-lambda-functions-datadog/

140. my code

141. my code

142. my code
internet internet
press button something happens

143. those extra 10-20ms for
sending custom
metrics would
compound when you
have microservices and
multiple APIs are called
within one slice of user
event

144. Amazon found every 100ms of latency
cost them 1% in sales.
http://bit.ly/2EXPfbA

145. no more background processing,
other than what the platform provides

146. console.log(“hydrating yubls from db…”);
console.log(“fetching user info from user-api”);
console.log(“MONITORING|1489795335|27.4|latency|user-api-latency”);
console.log(“MONITORING|1489795335|8|count|yubls-served”);
timestamp metric value
metric type
metric namemetrics
logs

147. CloudWatch Logs AWS Lambda
ELK stack
logs
metrics
CloudWatch

149. don’t forget to setup dashboards
& CW alarms

150. CONFIG MANAGEMENT

152. me
Environment variables make it
hard to share configurations
across functions.

153. me
Environment variables make it
hard to implement fine-grained
access to sensitive info.

154. config service
goes here

157. SSM
Parameter
Store

158. Secrets
Manager

159. sensitive data should be encrypted
in-flight, and at-rest

160. enforce role-based access to
sensitive configuration values

161. SSM Parameter Store
HTTPS
role-based access
encrypted in-flight

162. SSM Parameter Store
encrypt
role-based access

163. SSM Parameter Store
encrypted at-rest

164. HTTPS
role-based access
SSM Parameter Store
encrypted in-flight

165. invest into a robust client library

166. fetch & cache at cold-start

167. https://github.com/middyjs/middy

169. Recap

170. is our request correct?
is the request mapping
set up correctly?is the API resources
configured correctly?
are we assuming the
correct schema?
LambdaAPI Gateway DynamoDB
is Lambda proxy
configured correctly?
is IAM policy set
up correctly?
is the table created?
what unit tests will not tell you…

171. AWS Lambda
invokes
AWS Lambda
stdout
asynchronously
any log aggregation service
CloudWatch Logs

172. CloudWatch Logs
AWS Lambda
AWS Lambda
stdout
any log aggregation service
asynchronously
invokes

173. correlation IDs*
* eg. request-id, user-id, yubl-id, etc.

174. Amazon X-Ray

175. https://lumigo.io

176. https://epsagon.com

177. my code
internet internet
press button something happens

178. console.log(“hydrating yubls from db…”);
console.log(“fetching user info from user-api”);
console.log(“MONITORING|1489795335|27.4|latency|user-api-latency”);
console.log(“MONITORING|1489795335|8|count|yubls-served”);
timestamp metric value
metric type
metric namemetrics
logs

182. 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/production-ready-serverless
get 40% off
with: ytcui

183. @theburningmonk
theburningmonk.com
github.com/theburningmonk