Soam Vasani of Platform9 shares how Fission.io makes use of NATS and Kubernetes for Serverless workflows

1. Serverless for the
Cloud-Native Era
Event-driven processing with Fission, NATS, and Kubernetes
Soam Vasani
Software Engineer
Platform9 Systems

2. Fission Functions
● Easy lightweight services on Kubernetes
● Fast cold-starts using pools of ready containers
● Lots of languages supported (JS, Python, Go, Ruby, and lots more)
● Invoke functions using various triggers
○ HTTP for synchronous invocations

3. Fission and NATS
● Fission supports NATS
Streaming triggers
● Reliable Async Function
invocation using NATS
Streaming
● Request / Response
channels

4. Event-driven Function Systems
● Chain together functions
using channels managed by
a single NATS-Streaming
deployment
● This lets you compose
functions together in
powerful ways

5. Ops: Difficult in event driven systems
● Monitoring and Performance?
○ How can you tell how long a whole “workflow” takes?
● Upgrades
○ Upgrading without disruption in a complex system
○ What are the compatibility constraints?
● Cancellation, Restarts, Tracing, etc.

6. Workflows: “Managed” event driven systems
● Create “flowcharts” of function
● Specify dataflow and control flow
● Workflow engine abstracts away communication

7. Sample workflow
output: WhaleWithFortune
tasks:
GenerateFortune:
run: fortune
inputs: "{$.Invocation.Inputs.default}"
WhaleWithFortune:
run: whalesay
inputs: "{$.Tasks.GenerateFortune.Output}"
requires:
- GenerateFortune

8. Simple Workflow demo

9. Workflows architecture overview

10. Workflow dependencies demo

11. Questions? Comments?
● http://fission.io
● Github:
○ github.com/fission/fission
○ github.com/fission/fission-workflows
● Slack: http://slack.fission.io
● Twitter: @fissionio
● Fission is a project by Platform9 Systems and contributors