This presentation walks you through building a very simple proof-of-concept FaaS platform using Redis. By Paulo Arruda to RedisConf19 - 03/04/2019.

1. PRESENTED BY
Building a FaaS platform with Redis
Paulo Arruda
faastRuby, Founder

2. PRESENTED BY
1 What is faastRuby?
A brief introduction to the platform.
2 Demo
Agenda:
3 Designing a simple FaaS architecture with Redis

3. PRESENTED BY
SERVERLESS?

4. PRESENTED BY
RUBY?
CRYSTAL?

5. PRESENTED BY
Serverless Software Development
platform for Ruby & Crystal
Components:
• faastRuby Local - A local emulator
to develop & test Ruby and Crystal
Serverless Apps
• faastRuby FaaS - Cloud or
Self-Hosted FaaS solution

6. PRESENTED BY
Develop
• Develop and test on your local
machine from your favorite code
editor
• Optionally synchronize your local
code changes to cloud-based
staging environments instantly
Run
• When you invoke your functions
via an HTTP request, the code is
executed in a self-contained,
isolated sandbox inside of an
always-warm Runner
Workflow
Deploy
• Deploy your functions to a workspace
in the cloud.
• Workspaces are groups of functions
that can be used to mimic
environments and compose a set of
routes for a distributed app built with
functions.

7. PRESENTED BY
DEMO

8. PRESENTED BY
* Redis and storage scalability, as well as overall
security, are out of the scope of this presentation.
From inception to first release
Requirements
● Fast
● Scalable*
● Secure*
● Triggered via HTTP
● Multiple Environments

9. PRESENTED BY
The idea
● Responds to 1 request at a
time
● Cleans itself up after each
run

10. PRESENTED BY
API

11. PRESENTED BY
Using Redis to store metadata

12. PRESENTED BY
Workspace Metadata
Fields
● ID
2938
● Name
my_workspace
● Disk path
/workspaces/my_workspace
Key
● w:[workspace_name]

13. PRESENTED BY
Function Metadata
Fields
● ID
2938
● Name
my_function
● Runtime
ruby:2.5
● Disk path
[workspace_path]/my_function
Key
● w:[workspace_name]:my_function

14. PRESENTED BY
Adding more replicas

15. PRESENTED BY
The Loadbalancing Problem
● Can't predict execution
time
● Complex Loadbalancing
algorithm

16. PRESENTED BY
Redis to the rescue: Reliable Queue Pattern

17. PRESENTED BY
Decoupling HTTP Server from Code Execution

18. PRESENTED BY
Runners

19. PRESENTED BY
Request

20. PRESENTED BY
Request / Response
{
"function_metadata": (disk path, workspace_name, etc),
"event": (body, query, headers, etc),
"response_queue": "042b42aa-f274-4ba1-a2b8-ec883697ff51"
}
HTTP Server pushes job to input queue and listens on volatile queue with name
042b42aa-f274-4ba1-a2b8-ec883697ff51

21. PRESENTED BY
● We used Redis as main database for the platform
● We used the Reliable Queue Pattern to distribute the execution
between Runners
Recap

22. Thank you!
faastRuby.io
Twitter: @parrudanet

23. PRESENTED BY