1. from the
TRENCHESTRENCHES
what you should know before you go to production
AWS LAMBDAAWS LAMBDA

2. hi,I’mYanCui

3. hi,I’mYanCui
AWS user since 2009

10. apr, 2016

11. hidden complexities and dependencies
low utilisation to leave room for traffic spikes
EC2 scaling is slow, so scale earlier
lots of cost for unused resources
up to 30 mins for deployment
deployment required downtime

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

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

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

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

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

18. nov, 2016

19. 170 Lambda functions in prod
1.2 GB deployment packages in prod
95% cost saving vs EC2
15x no. of prod releases per month

20. time
is a good fit

21. 1st function in prod!
time
is a good fit

22. ?
time
is a good fit
1st function in prod!

23. ALERTING
CI / CD
TESTING
LOGGING
MONITORING

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

25. Principles outlast Tools

26. 170 functions
WOOF!
? ?
time
is a good fit
1st function in prod!

27. SECURITY
DISTRIBUTED
TRACING
CONFIG
MANAGEMENT

28. evolving the PLATFORM

29. rebuilt search

30. Legacy Monolith Amazon Kinesis Amazon Lambda
Amazon CloudSearch

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

32. new analytics pipeline

33. Legacy Monolith Amazon Kinesis Amazon Lambda
Google BigQuery

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

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

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

37. Rebuilt
with Lambda

44. Rebuilt
with Lambda

45. BigQuery

46. BigQuery

47. grapheneDB
BigQuery

48. grapheneDB
BigQuery

49. grapheneDB
BigQuery

50. getting PRODUCTION READY

51. CHOOSE A
FRAMEWORK
DEPLOYMENT

52. http://serverless.com

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

54. http://apex.run

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

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

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

58. http://gosparta.io/

59. TESTING

60. amzn.to/29Lxuzu

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

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

64. handler

65. handler
test by invoking
the handler

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

67. Level of Testing
unit
integration
acceptance
feedback
confidence

68. “…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

69. “…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

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

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

72. LambdaAPI Gateway DynamoDB

73. LambdaAPI Gateway DynamoDB
Unit Tests

74. LambdaAPI Gateway DynamoDB
Unit Tests
Mock/Stub

75. 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…

77. 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

79. But it slows down
my feedback loop…
IT’S NOT
ABOUT YOU!

80. …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

81. “…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

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

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

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

85. integration tests exercise
system’s Integration with its
external dependencies

86. acceptance tests exercise
system End-to-End from
the outside

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

91. CI + CD PIPELINE

92. “the earlier you consider CI + CD, the
more time you save in the long run”
- me

93. “…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

94. “deployment scripts
that only live on the CI
box is a disaster
waiting to happen”
- me

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

96. 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

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

99. Auto Auto Manual

100. LOGGING

102. 2016-07-12T12:24:37.571Z 994f18f9-482b-11e6-8668-53e4eab441ae
GOT is off air, what do I do now?

103. 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

104. function name
date
function version

105. me
Logs are not easily searchable
in CloudWatch Logs.

106. LOG OVERLOAD

107. CENTRALISE LOGS

108. CENTRALISE LOGS
MAKE THEM EASILY
SEARCHABLE

109. + +
the elk stack

110. CloudWatch Logs

111. CloudWatch Logs AWS Lambda ELK stack

112. CloudWatch Events

114. http://bit.ly/2f3zxQG

115. DISTRIBUTED TRACING

117. “my followers didn’t
receive my new post!”
- a user

118. where could the
problem be?

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

120. ROLL YOUR OWN
CLIENTS

121. kinesis client
http client
sns client

122. http://bit.ly/2k93hAj

123. ROLL YOUR OWN
CLIENTS
X-RAY

124. Amazon X-Ray

125. Amazon X-Ray

126. traces do not span over
API Gateway

127. http://bit.ly/2s9yxmA

128. MONITORING + ALERTING

129. “where do I install
monitoring agents?”

130. you can’t

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

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

136. my code

137. my code

138. my code
internet internet
press button something happens

139. “how do I batch up
and send logs in the
background?”

140. you can’t
(kinda)

141. 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

142. CloudWatch Logs AWS Lambda
ELK stack
logs
metrics
CloudWatch

143. http://bit.ly/2gGredx

144. DASHBOARDS

145. DASHBOARDS
SET ALARMS

146. DASHBOARDS
SET ALARMS
TRACK APP-LEVEL
METRICS

147. Not Only CloudWatch

149. “you really don't want
your monitoring
system to fail at the
same time as the
system it monitors”
- me

150. CONFIG MANAGEMENT

151. easily and quickly propagate
config changes

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

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

155. CENTRALISED
CONFIG SERVICE

156. config service
goes here

160. SSM
Parameter
Store

161. sensitive data should be encrypted
in-flight, and at rest
(credentials, connection string, etc.)

162. role-based access

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

164. SSM Parameter Store
encrypt
role-based access

165. SSM Parameter Store
encrypted at-rest

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

167. CENTRALISED
CONFIG SERVICE
CLIENT LIBRARY

168. fetch & cache at Cold Start

169. invalidate at interval + signal

170. http://bit.ly/2yLUjwd

171. PRO TIPS

172. max 75 GB total deployment package size*
* limit is per AWS region

173. Janitor Monkey

174. Janitor Lambda
http://bit.ly/2xzVu4a

175. disable versionFunctions in

176. install Serverless framework as dev
dependency at project level
dev dependencies are excluded since 1.16.0

177. http://bit.ly/2vzBqhC

178. http://amzn.to/2vtUkDU

179. UNDERSTAND
COLDSTARTS

180. Amazon X-Ray
1st invocation
2nd invocation
cold start

181. source: http://bit.ly/2oBEbw2

182. http://bit.ly/2rtCCBz

183. C#
http://bit.ly/2rtCCBz

184. Java
http://bit.ly/2rtCCBz

185. NodeJs, Python
http://bit.ly/2rtCCBz

186. AVOID
COLDSTARTS

187. CloudWatch Event AWS Lambda

188. CloudWatch Event AWS Lambda
ping
ping
ping
ping

189. CloudWatch Event AWS Lambda
ping
ping
ping
ping

190. CloudWatch Event AWS Lambda
ping
ping
ping
ping
HEALTH CHECKS?

191. AVOID HARD
ASSUMPTIONS
ABOUT FUNCTION
LIFETIME

192. USE STATE
FOR
OPTIMISATION

193. max 5 mins execution time

194. USE RECURSION
FOR LONG
RUNNING TASKS

195. @theburningmonk
theburningmonk.com
github.com/theburningmonk

196. @theburningmonk
theburningmonk.com
github.com/theburningmonk
http://bit.ly/2yQZj1H
all my blog posts on Lambda