A presentation on the advantages and disadvantages of using the "serverless" methodology in software development.

1. 1

2. Hello
• Jürgen Brüder
• @jaybrueder
• Works for Infralovers / Commandemy
• Loves all things DevOps, Code and Infra
2

3. 3

4. 4

5. Agenda
• The concept
• Serverless vs FaaS
• Tooling
• Demo
• Cri7cism
• My experience with customer projects
5

6. What is "serveless"
• Serverless is about abstrac0ng away servers, infrastructure and
having to deal with low-level configura0on or the core opera0ng
system
• Code is not run as a full applica0on, but a set of small func0ons
• Next step a@er using containers
6

7. 7

8. To be real serverless
Func%ons need to run on ephemeral compute resources
8

9. There is more
• Command line tool of the same name
• Rethinking architecture of so6ware
9

10. 10

11. IT-Marke)ng term of the year?
Companies are looking for ways to brand their offerings as
serverless
11

12. Why call it "serverless"?
• It's a bad choice
• The server does not go away
• It gets even more abstracted than with a VM or a container
• Is there a be9er term?
12

13. 13

14. Let's look at what serverless is trying
to achieve
14

15. Lower opera)ons burden
• Fewer people
• Leaner teams
• Lower cost
• Be2er security
• Be2er resilience
15

16. It's about
• No maintenance
• Micro func0onality
• Simplicity, but is not necessarily simpler
• Rethinking code
16

17. Faster (me to market
Less to build = higher feature velocity
17

18. Focus on business value
What we’re talking about is outsourcing parts of our architecture
and implemen8on that are not core to delivering business value
- Ben Kehoe, iRobot
18

19. Compute in a system should not be
required to be con3nually-living
19

20. Compute infrastructure should not
even exist when not handling data
20

21. A persistent compu.ng resource is
a server no ma2er what form that
resource takes
21

22. Serverless is not FaaS
• Func&on as a Service (FaaS)
• FaaS is an integral component of serverless architecture
22

23. Func%on as a Service (FaaS)
• Deploy any individual piece of code, or func3on
• Code runs and returns a value, in turn ending the process
• Services and endpoints you would keep in one place are now
sliced up into a bunch of snippets
• Goal is to abstract away servers from the developer and bill
based on the amount of 3mes the func3ons were invoked
23

24. 24

25. Serverless is not event-driven compute
• "Serverless is all about the events" = wrong
• Event-driven compu;ng is a natural fit for serverless
architectures
• Possible and reasonable to build tradi;onal data flows in
serverless
25

26. 26

27. FaaS is not always F
• Containers can be FaaS
• Container have a stronger "contract" with the developer
• S8ll, decouples developer from pla=orm
• If container run during invoca8ons, and then are frozen/recycled,
the container is ac8ng as a func8on
27

28. 28

29. FaaS is not always aaS
• Serverless is not just public cloud
• You can be your own FaaS provider
• For big enterprises this makes sense
• Can enable rest of company to "do" serverless
• By running a lot of servers with so@ware on them
29

30. 30

31. A be%er term?
• Service-Full
• Coined by Patrick Debois, Townheroes
• h=ps://twi=er.com/patrickdebois
31

32. Service-Full
• As a applica*on becomes increasingly serverless, it relies more
on external services to provide the building blocks of the system
• E.g. using Amazon Elas*csearch Service (AES) instead of hos*ng
Elas*csearch yourself
• 12 factor apps
• Immutable infrastructure
32

33. 33

34. Service-Full FaaS
• FaaS applica*on on cluster using on-premise servers
• FaaS applica*on on cluster using public cloud IaaS
• FaaS applica*on on managed cluster (e.g. Google Container
Engine)
• Managed FaaS
• That are serverless if they use ephemeral compute resources
34

35. FaaS does not have to use
ephemeral compute resources
35

36. 36

37. 37

38. 38

39. Public FaaS offerings
39

40. 40

41. 41

42. 42

43. 43

44. Public billing model
• Pay-per-use pricing model
• Pay nothing at idle (except for data at rest)
• Know what part of your applica<on costs the most
44

45. 45

46. Summing up
• Spectrum
• Serverless != FaaS
• Service-full + ephemeral compute
• Tighter correspondence between resources used and resources
billed
• Smaller and more abstracted control plane
46

47. When should I consider serverless?
47

48. Reasons
• Easy scaling
• Low maintenance
• Any applica4on you have in produc4on where your user
throughput varies is a valid contender
• Response 4me is not your first concern
48

49. What about the developers?
49

50. Lastly, if you suck at the Linux shell,
and if DevOps is not your thing, you
have every reason to try Serverless.
- Adnan Rahić, Hackernoon
50

51. Requires us to change our approach
• Serverless architecture is "special"
• Se1ng it up takes a fair share of mental power
• Live with the fact that we do not have overview of our whole
system
51

52. An example
52

53. We will be using AWS Lambda
AWS Lambda is a compute service that lets you run code without
provisioning or managing servers.
— AWS Documenta/on
53

54. 54

55. AWS Lambda
• Event based system for running code in the cloud
• "No servers"
• Just code
• Scales automa;cally
• Easy to integrate into CI/CD pipelines
55

56. AWS Lambda Docs say
• It takes )me to set up a container and do the necessary
bootstrapping, which adds some latency each )me the Lambda
func)on is invoked.
• You typically see this latency when a Lambda func)on is invoked
for the first )me or a@er it has been updated because AWS
Lambda tries to reuse the container for subsequent invoca)ons
of the Lambda func)on.
h"p://docs.aws.amazon.com/lambda/latest/dg/lambda-
56

57. How it works
• Lambda maintains the container for some 2me in an2cipa2on of
another Lambda func2on invoca2on
• It freezes the container a8er a Lambda func2on completes
• If no further requests occur, it destroys the container
57

58. Available run,mes
• NodeJS (4.3.2 and 6.10.3)
• Java (8)
• Python (3.6, 2.7)
• .NET Core
58

59. AWS API Gateway
• Instant API
• To reach my code, I want to put it behind an API
• API Requests will be the events that trigger the code
59

60. Problems
• Manual interac-on with AWS dashboard
• Code editor, Drag n Drop etc.
• I am an automa-ons guy, I avoid manual steps whenever I can
60

61. Can I automate this right away?
61

62. 62

63. The Serverless Framework
Serverless is your toolkit for deploying and opera4ng serverless
architectures. Focus on your applica4on, not your infrastructure.
— serverless.com
63

64. The Serverless Framework
• Removes the manual component of interac4ng with AWS
Lambda / API Gateway
• Node NPM package you control through the command line
• bundles all the tools you need into a manageable package
• Simplifies crea4on and deployments of applica4ons
64

65. Our applica*on
65

66. Be-Nice API
• Setup a simple data processing pipeline
• Expose one HTTP endpoint that allows use to submit a text note
• The message is processed in the background
• Messages above a certain sen>ment level are "saved"
66

67. Sen$ment
• AFINN-based sen.ment analysis for Node.js
• Returns score for a specific string
var sentiment = require('sentiment');
var r1 = sentiment('Cats are stupid.');
console.dir(r1); // Score: -2, Comparative: -0.666
var r2 = sentiment('Cats are totally amazing!');
console.dir(r2); // Score: 4, Comparative: 1
67

68. AFINN
AFINN is a list of English words rated for valence with an integer
between minus five (nega<ve) and plus five (posi<ve). The words
have been manually labeled by Finn Årup Nielsen in 2009-2011.
The file is tab-separated.
h"p://www2.imm.dtu.dk/pubdb/views/publica6on_details.php?
id=6010
68

69. We also use Amazon SNS
• Amazon Simple No/fica/on Service (SNS)
• Fully managed pub/sub messaging and mobile no/fica/ons
service
• publish-subscribe mode / retries
• Is an event that can trigger a func/on for us
• Helps us "unblock" ephemeral compute resources
69

70. 70

71. That's basically every mobile/web
app backend in the world covered ;)
71

72. I have prepared the environment
already to save 2me
72

73. Step 1: Installing serverless
Have NodeJs installed on your worksta4on
$ npm install -g serverless
73

74. Step 2: Create an IAM User in your AWS
Console
• Have an AWS account
• Create an IAM user with programma:c access
• Add permissions according to whatever you want that user to do
• Get Access Key ID and Secret Access Key
74

75. Step 3: Tie your creden1als to serverless
$ serverless config credentials --provider aws --key xxxxxxxxxxxxxx --secret xxxxxxxxxxxxxx
Serverless: Setting up AWS...
Serverless: Saving your AWS profile in "~/.aws/credentials"...
Serverless: Success! Your AWS access keys were stored under the "default" profile.
75

76. With that, we are ready to conquer
the world!
76

77. Create the service
$ serverless create --template aws-nodejs --path benice
Serverless: Generating boilerplate...
Serverless: Generating boilerplate in "/Users/juergen/.../demo/benice"
_______ __
| _ .-----.----.--.--.-----.----| .-----.-----.-----.
| |___| -__| _| | | -__| _| | -__|__ --|__ --|
|____ |_____|__| ___/|_____|__| |__|_____|_____|_____|
| | | The Serverless Application Framework
| | serverless.com, v1.24.1
-------'
Serverless: Successfully generated boilerplate for template: "aws-nodejs"
77

78. This generates 3 files
• serverless.yml contains all the configura1on se2ngs
• handler.js
• .gi1gnore
78

79. serverless.yml
# serverless.yml
service: my-service
provider:
name: aws
runtime: nodejs6.10
functions:
hello:
handler: handler.hello
79

80. What we can see
• The func*ons property lists all the func*ons in the service.
• You can see hello is the only func*on in the handler.js file
80

81. handler.js
'use strict';
module.exports.hello = (event, context, callback) => {
const response = {
statusCode: 200,
body: JSON.stringify({
message: 'Go Serverless v1.0! Your function executed successfully!',
input: event,
}),
};
callback(null, response);
// Use this code if you don't use the http event with the LAMBDA-PROXY integration
// callback(null, { message: 'Go Serverless v1.0! Your function executed successfully!', event });
};
81

82. Let's add some real func1onality
82

83. DEMO
83

84. What happens during a deployment
• CloudForma+on is used to orchestrate all this
• It creates an S3 (AWS data store) bucket and stores the code in it
• Creates IAM role (permissions) for the func+on
• API Gateway gets created
• Logging
84

85. There is more than AWS Lambda
85

86. How we use it in the wild
86

87. How we use it in the wild
• ChatOps
• Empowering Devs to manage their own stuff on AWS with min.
permissions
• Alexa Skills / FAQ Bot
• Personally: Mobile API prototype
87

88. This means we can get rid of Ops
altogehter, right?
88

89. The cri$cal part
89

90. DevOps does not go away
• Infrastructure management is not the only task that DevOps is
doing
• Automa;on, deployment, tes;ng, security, and monitoring
90

91. Ops won’t go away in serverless
• Serverless compu.ng is a form of u.lity compu.ng
• Infrastructure completly abstracted from the developer
91

92. 92

93. Main problems for developers
• Monitoring, debugging, tes0ng, latency, deployment
• Basically everything you need Ops for
93

94. How to test locally?
Serverless offline plugin
h"ps://github.com/dherault/serverless-offline
94

95. We observed some pa-ers
• First, there is a genuine concern about cloud provider lock-in
• Second, there is a desire and hope to avoid or at least minimize
such lock-in by embracing open source abstrac<ons and
pla=orms
• Most notably Docker and Kubernetes
95

96. Complex applica,ons
• An experiences Java Dev may not work on an applica7on with
"just a few func7ons"
• It sounds like a lot of extra work to move something like this into
FaaS
96

97. Architectural complexity
• Tiny func*ons are nice from an architectural standpoint
• Isn't the complexity moved to somewhere else?
• Isn't complex code moved into complex configura*on?
• AWS Lambda, for now, limits you to how many concurrent
execu*ons you can be running of all your lambdas
97

98. That means if someone, somewhere,
in your organiza4on does a load test
and starts trying to execute 1000
concurrent Lambda func4ons you’ll
Denial of service (DoS) your
produc4on applica4ons
98

99. You can probably guess my standpoint
• If you run something that complex, Lambda is not the right
choice
• You should think about running your own FaaS cluster
• FaaS != Public cloud offerings
99

100. Vendor lock-in
• If that complex configura4on is proprietary, aren't we walking
into a venor lock-in?
• Unexpected limits / cost changes
• This is true for IaaS and PaaS as well
100

101. Secruity concerns
• Third-Party API systems
• What happens under the hood
101

102. Control
• Dependent on vendors for debugging and monitoring tools
• At least your team will have these tools now ;)
102

103. Integra(on tes(ng is #1
• The units of integra0on with Serverless are a lot smaller
• Integra0on tes0ng becomes your #1 concern here
103

104. Ar#facts
• Problems related to deployment, versioning and packaging also
exist
• You may need to deploy a FaaS ar<fact separately for every
func<on in your en<re logical applica<on
104

105. Does every func-on start a new container?
• Sounds like a lot of used resources
• How does this affect startup 7mes?
105

106. I introduced Serverless and all I got
was a remote API
106

107. What I would use it for
• Applica(on Prototypes (e.g. for StartUp ideas)
• Applica(ons in produc(on (if not (me sensi(ve)
• Microservices
• Bots
• Orchestra(on and maintenance
• Repor(ng
107

108. What I would not use it for
• Monoliths
• Anything were every milisecond counts
108

109. How is your experience with
Serverless?
109

110. Discussion
110

111. Sources
• h#ps://m.subbu.org/serverless-looking-back-to-see-
forward-74dd1a02cb62
• h#ps://read.acloud.guru/the-serverless-
spectrum-147b02cb2292
• h#ps://www.stardog.com/blog/5-hard-lessons-about-serverless/
• h#ps://medium.com/@PaulDJohnston/what-is-serverless-
architecture-43b9ea4babca
111