La nostra esperienza nell'uso dell'architettura Function as a Service (Serverless)

1. Nome Speaker
@twitter
Si fa presto a dire Serverless
Daniel Depaoli
@dedaniel_xp
Alessio Coser
@AlessioCoser

2. Si fa presto a dire Serverless
What we are going to talk about?
1. Introduction to Serverless
2. Our Dev Experience
3. Our Ops Experience

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What is Serverless?

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What is Serverless?

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Function as a Service

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What is a Function?
Custom code that’s run in an ephemeral context.

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What is a Function?
Custom code that’s run in an ephemeral context.
● The code/application that we want to execute
● The Service we provide to our users
● Responds to events

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What is a Function?
● Created only to run your code and then destroyed
● Has no state or persistence
● It’s still a server!
Custom code that’s run in an ephemeral context.

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What is a Function?

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Functions
Application
Runtime
Operating
System
Virtualization
Hardware
IaaS
Customer Managed
Unit of scale
Customer Managed
Abstract by vendor

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Functions
Application
Runtime
Operating
System
Virtualization
Hardware
Functions
Application
Runtime
Operating
System
Virtualization
Hardware
IaaS PaaS
Customer Managed
Unit of scale
Customer Managed
Abstract by vendor

12. Si fa presto a dire Serverless
Functions
Application
Runtime
Operating
System
Virtualization
Hardware
Functions
Application
Runtime
Operating
System
Virtualization
Hardware
Functions
Application
Runtime
Operating
System
Virtualization
Hardware
IaaS PaaS FaaS
Customer Managed
Unit of scale
Customer Managed
Abstract by vendor

13. ● No infrastructure maintenance
● Built-in automatic scaling
● Only pay for the execution time
● No persistence, no state
● Limited execution time
● Fully integrated with cloud provider’s services
Si fa presto a dire Serverless
Main features

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Cloud-Computing Providers
● Amazon AWS Lambda
● Google Cloud Functions
● Azure Functions

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Runtimes
● NODE.JS
● JAVA
● PYTHON
● More

16. Nome Speaker
@twitter
Our Dev experience
Si fa presto a dire Serverless

17. Our Dev experiences
aws.amazon.com/solutions/case-studies/photovogue

18. Our Dev experiences PhotoVogue

19. An online photography platform
● Allows upcoming photographers to showcase
their work.
● Each picture that’s submitted is carefully
reviewed by Vogue Italia’s editorial staff.
Our Dev experiences PhotoVogue

20. ● ~ 400,000 photos
● ~ 130,000 photographers
● ~ 3,000 uploaded images each day
An online photography platform
Our Dev experiences PhotoVogue

21. Our Dev experiences PhotoVogue
● Application that scales
● No state or sessions
● No long running scripts
● Upload and resize of photos in parallel
How FaaS applies to the domain

22. Upload and resize feature
Our Dev experiences PhotoVogue
FaaS
EVENT
S3
UPLOAD
RESIZED IMAGES
AWS

23. Benefits
Our Dev experiences PhotoVogue

24. Zero downtime deployment
Our Dev experiences PhotoVogue

25. > 1 deploy per day
Our Dev experiences PhotoVogue

26. Autoscaling
Our Dev experiences PhotoVogue

27. Average of
~ 650 invocation/minute
Our Dev experiences PhotoVogue

28. Maximum peaks
> 1500 invocation/minute
Our Dev experiences PhotoVogue

29. (as long as an entire AWS region does not crash)
[image]
Our Dev experiences PhotoVogue
No downtime

30. Challenges
Our Dev experiences PhotoVogue

31. Vendor lock-in
Our Dev experiences PhotoVogue

32. Decouple business logic from the cloud platform
Our Dev experiences PhotoVogue

33. Use a Framework like Serverless
Our Dev experiences PhotoVogue

34. Dependencies
Our Dev experiences PhotoVogue

35. Very common problem:
You have two distinct functionalities, and
they share some of their code
Our Dev experiences PhotoVogue

36. 1st solution:
Create a single function which responds
to two different events
Our Dev experiences PhotoVogue

37. Easy to update
No dependencies to manage
Big function
Violates Single Responsibility Principle
Our Dev experiences PhotoVogue

38. 2nd solution:
Create two different functions with the
same code
Our Dev experiences PhotoVogue

39. Common parts are easier to share
No dependencies to manage
Deploy takes longer
Unnecessary dependencies are also shared
Must deploy each function to update common code
Our Dev experiences PhotoVogue

40. 3rd solution:
Create two different functions with an
external shared dependency (es: git, npm)
Our Dev experiences PhotoVogue

41. No duplicated code
Can use different versions of dependency
Startup time increases
You have to manage an external library
Our Dev experiences PhotoVogue

42. 4th solution:
Create two different functions that will
invoke a third one (containing the shared
behaviour)
Our Dev experiences PhotoVogue

43. No duplicated code
Can use different versions of common function
Execution time increases
Additional point of failure
Our Dev experiences PhotoVogue

44. There isn’t a perfect solution
Our Dev experiences PhotoVogue

45. Nome Speaker
@twitter
Our Ops experiences
Si fa presto a dire Serverless

46. Our Ops experiences
Disaster Recovery and Testing

47. A Disaster Recovery implementation
Our Ops experiences Disaster Recovery and Testing

48. Our Ops experiences Disaster Recovery and Testing
AWS does not provide a DR solution

49. 1. Backup
a. Every night create VMs snapshot
b. Move snapshots to another AWS region
Our Ops experiences Disaster Recovery and Testing
Our implementation with FaaS

50. 2. Recovery
a. Activate the new environment in alternative region with
lastest snapshots
3. Test
a. Check services and send notification
Our Ops experiences Disaster Recovery and Testing
Our implementation with FaaS

51. Our Ops experiences
Interaction with infrastructure

52. Sometimes we need to schedule a task
Our Ops experiences Interaction with infrastructure

53. Our Ops experiences Interaction with infrastructure
Load
Balancer
Instance InstanceInstance task
Master
● Lambda direct SSH connection to instance
● Triggering or doing particular tasks

54. ● Check Backup S3
● Dump DB
● Clean EFS
● Etc.
Our Ops experiences Interaction with infrastructure
Some example:

55. Our Ops experiences
Operations and monitoring

56. Simulating user browsing session
Our Ops experiences Monitoring

57. Our Ops experiences Monitoring

58. Integration with versioning system hosting service
Our Ops experiences CI/CD

59. Benefits
Our Ops experiences Monitoring

60. No third party tools
Our Ops experiences

61. No instances for just one task
Our Ops experiences

62. Our Ops experiences
Trigger one shot action

63. Fully integrated with other AWS services
Our Ops experiences

64. Conclusions

65. FaaS - when?
Conclusions
● You need to simplify operational tasks
● Your app needs to scale
● Your domain logic is event based
● You need to process a large quantity of
data

66. ● You want some form of control over the
infrastructure
● You have to maintain some state into the app
● Your functions take a long time to run
FaaS - when not?
Conclusions

67. Nome Speaker
@twitter
Thanks!
PS: We are hiring -> www.xpeppers.com/carriere

68. Nome Speaker
@twitter
Questions?
PS: We are hiring -> www.xpeppers.com/carriere

69. www.xpeppers.com
/xpepperssrl@xpeppers