Introduction to the open source Fn Project.

1. Democratizing Serverless
Shaun Smith
Director of Product Management
Oracle Cloud Infrastructure—Serverless
The Open Source Fn Project

2. What is Serverless?
● Serverless is an abstraction of infrastructure and its operations
including provisioning, scaling, patching, etc.
● Serverless architecture is when an app is built entirely on
serverless components (compute, storage, networking)
● FaaS (Functions as a Service) is the compute component in a
serverless architecture
2

3. Functions as a Service
● Functions are small bits of code that do one thing well and are
easy to understand and maintain
● As a Service means no complicated plumbing, the system
takes care of provisioning, scaling, patching, maintaining, etc.
Each function scales independently. 3
In mathematics, a function is a relation between
a set of inputs and a set of permissible outputs
with the property that each input is related to
exactly one output.
Function (mathematics) - Wikipedia
https://en.wikipedia.org/wiki/Function_(mathematics)

4. Why Serverless?
4
AgilityEconomics InnovationReliability

5. There are still servers
5

6. There are still servers
6

7. Hockey-stick ready
time
users

8. The Ideal Functions Platform
● Open Source—no vendor lock-in
● Platform Independent—laptop, server, cloud
● Approachable—easy for new users, low level controls for
advanced users
● Docker Based—leverage Docker ecosystem
● Scheduler Independent—deploy to Kubernetes, Swarm,
Mesos, etc.
8

9. www.fnproject.io

10. Introducing the Fn Project
● Open-source serverless compute platform
● Can be deployed to any cloud and on-premise
● Simple, elegant, and extensible by design
● Containers are primitives
● Active w/ 2500+ commits across 50+ contributors
● Independently governed with representation at Container
Native Compute Foundation (CNCF)
● Strong enterprise focus (security, scalability, observability, etc.)
10

11. An Fn Function
11
● Code wrapped in a container
image
● Input from STDIN and
environment
● Output to STDOUT
● Logs to STDERR
The Fn server handles everything else

12. Function Development Kits (FDKs)
● Used to help with parsing input and writing output
● Simply write a `handler` function that adheres to the FDK’s
interface and it will parse STDIN and provide the input data to
your function and deal with writing the proper output format.
● Makes it a lot easier to write functions
12

13. Functions == Containers
13
Functions are packaged as
containers—so any
container can be deployed
as a function
Package and reuse open
source libraries as functions!

14. Containers vs Functions
Fn Function is a container with
a set of known traits:
● Short running
● Ephemeral
● Stateless
● Invoked
● Single Purpose
● Self-contained
14

15. Fn CLI
● fn init --runtime go
● fn run
● fn test
● fn deploy --app myapp
● fn call myapp myfunc
route → http://localhost:8080/r/myapp/myfunc 15

16. Architecture

17. Fn Server
● Handles CRUD operations for setting up routes and functions
● Executes sync functions, returning responses to clients
immediately
● Queues async function calls
● Executes async functions when capacity is available
● Written in Go, easy to extend via plugin module system

18. Fn LB
● Simple, fast load balancer that routes functions to certain
nodes consistently for hot function efficiency
● Scales each function independently based on traffic to any
particular function
● Can be used to scale Fn servers and infrastructure as well as it
has a view of global state of all fn servers

19. Fn Demo
19

20. fn deploy details
1. Builds container (multi-stage) + bumps version
MyFunc:0.0.2
Your code
1
20

21. fn deploy details
1. Builds container (multi-stage) + bumps version
2. Pushes container to registry
MyFunc:0.0.2
MyFunc:0.0.2
Your code
1 2
21

22. fn deploy details
1. Builds container (multi-stage) + bumps version
2. Pushes container to registry
3. Creates/updates function route (fn servers lazy load images)
MyFunc:0.0.2
MyFunc:0.0.2 MyFunc:0.0.2
Your code
Fn Service
myfunc →
/r/myapp/myfunc:0.0.2
1 2 3
22

23. fn deploy --local
1. Builds container (multi-stage) + bumps version
2. Pushes container to registry
3. Creates/updates function route (fn servers lazy load images)
MyFunc:0.0.2
MyFunc:0.0.2
Your code
Fn Service
myfunc →
/r/myapp/myfunc:0.0.2
1
MyFunc:0.0.2
2 3
23

24. Debugging
● fn calls list myapp
● fn calls get myapp <call-id>
● fn logs get myapp <call-id>
● Metrics created using OpenTracing w/ initial collectors and
extensions for Prometheus, ZipKin, and soon Jaeger
24

25. OpenCensus and Prometheus
25

26. Fn UI
26

27. Fn Flow
27

28. Composing Functions

29. Fn Flow
● For long-running, reliable, scalable functions with primitives for
fork-join, chaining, delays and error handling
● Java support using CompletableFuture API from Java 8—
Node, Python, Go support on the way!
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30. Fn Flow Example—Generate Resized Images
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public Response handleRequest(byte[] imageBuffer) {
String id = java.util.UUID.randomUUID().toString();
CloudThreadRuntime runtime = CloudThreads.currentRuntime();
mm.notify("Resizing " + imageBuffer.length + " with id " + id);
runtime.allOf(
runtime.invokeFunction("myapp/resize128", imageBuffer)
.thenAccept((img) -> swiftClient.swiftUpload(img, id + "-128.png"))
.thenRun(() -> mm.notify("Uploaded 128px image")),
runtime.invokeFunction("myapp/resize256", imageBuffer)
.thenAccept((img) -> swiftClient.swiftUpload(img, id + "-256.png"))
.thenRun(() -> mm.notify("Uploaded 256px image")),
runtime.invokeFunction("myapp/resize512", imageBuffer)
.thenAccept((img) -> swiftClient.swiftUpload(img, id + "-512.png"))
.thenRun(() -> mm.notify("Uploaded 512px image")),
runtime.invokeAsync(() -> swiftClient.swiftUpload(imageBuffer, id + ".png"))
).whenComplete((val,err) -> {
if(err!= null){
mm.notify("An error occurred while uploading images " + err.getMessage());
} else {
mm.notify("All images uploaded to id " + id);
}
});
return new Response(id);
}

31. 31
Fn Flow Example—Multiple Stages & Threads
Notify the user “Resizing is being performed”
Do all of the following in parallel:
Run function "myapp/resize128” to resize image to 128px
Then upload the 128px image to storage
Then notify the user the 128px image was uploaded
Run function "myapp/resize256” to resize image to 256x256
Then upload the 128px image to storage
Then notify the user the 128px image was uploaded
Run function “myapp/resize512” to resize image to 512x512
Then upload the 128px image to storage
Then notify the user the 128px image was uploaded
Upload the original image to storage
When all functions are complete:
Then notify the user that "All images uploaded"
2.a
2.b
2.c
2.d
3
1

32. Fn Flow Demo
32

34. http://microservices.io/patterns/data/saga.html

35. It’s (still) just Java

36. It’s (still) just Java or Go or Node.js or …

37. Fn—An Ideal Functions Platform?
✅ Open Source—no vendor lock-in
✅ Platform Independent—laptop, server, cloud
✅ Approachable—easy for new users, low level controls for
advanced users
✅ Docker Based—leverage Docker ecosystem
✅ Scheduler Independent—deploy to Kubernetes, Swarm,
Mesos, etc.
37
http://fnproject.io

38. Thank you!
1. Star the project: github.com/fnproject/fn
2. Join the conversation: slack.fnproject.io
3. Learn more: fnproject.io
Shaun Smith
@shaunMsmith
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