The Fn Project is an open-source, multi-cloud serverless service focused on Functions-as-a-Service (FaaS), designed to enhance developer experience with a simple function model. It provides a container-based architecture that supports development, debugging, and monitoring while offering various integrations and plugins for databases and messaging systems. The project aims to streamline the building of reliable, scalable functions and is actively fostering community involvement.

1. The Fn Project
Microservices Meetup, December 2017
Chad Arimura
VP Serverless, Oracle
@chadarimura
Open Source Serverless Computing

2. About Me
● Engineer and builder
● 3x entrepreneur
○ 1999-2006: Founding CTO of AllDorm
○ 2008-2011: Founding Partner of Appoxy
○ 2011-2017: Founding CEO of Iron.io
● Now VP Serverless, Oracle
me

3. 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 is the compute component in a serverless architecture

4. 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.
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)

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

6. What about Microservices?

7. Introducing the Fn Project
● Launched in October focused on open source (apache 2),
multi-cloud, serverless services, starting with FaaS
● Iron.io team joined Oracle, now a 20-person “serverless” org
● Maniacal focus on the developer experience
● Independently governed at github.com/fnproject (currently)
● Members on the CNCF serverless working group
● We are building our community and partnerships

8. For Developers

9. An Fn Function
● Small chunk of code wrapped into a container image
● Gets input via STDIN and environment
● Produces output to STDOUT
● Logs to STDERR
The Fn server handles everything else, like the API gateway, piping
things around, storing logs, etc.

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

11. Function Development Kits (FDKs)
● Used to help with parsing input and writing output
● Familiar syntax for Lambda developers
● 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 hot functions

12. 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

13. Fn UI

14. Under the Hood

15. Architecture

16. 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

17. 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

18. Supporting Services
● DB, MQ, blob store are all pluggable modules that are thin
wrappers around their respective drivers.
○ DB: MySQL, sqlite3, Postgres
○ Queue: Redis, Kafka
○ Registry: Any Docker v2-compliant, even private
● Metrics/Monitoring
○ OpenTracing API for metrics
○ Prometheus support, pluggable backends
○ Logging via syslog

19. Kubernetes
● Fn is scheduler agnostic but lots of optimization/management
work in process to optimize on Kubernetes
● Helm chart available at https://github.com/fnproject/fn-helm
● Thinking about deeper Kubernetes integrations including CRD’s
to model functions

20. Fn Demo

21. More Advanced Fn

22. Fn Flow
● Build long-running, reliable, scalable functions with rich sets of
language-specific primitives including fork-join, chaining, delays
and error handling
● Supports complex parallel processes that are readable and
testable (including unit tests) with standard programming tools
● Java support using CompletableFuture API from Java 8 with
JS, Python, Go language support on the way!

23. Plate Detect
Function
Draw
Function
Slack
Function
Twitter
Function
Scraper

24. Scraper
Plate Detect
Function
Draw
Function
Slack
Function
Twitter
Function
FlowFuture.invoke()
thenCompose()
thenCompose()
allOf()
whenComplete()

25. Scraper
Plate Detect
Function
Draw
Function
Slack
Function
Twitter
Function
FlowFuture.invoke()
thenCompose()
thenCompose()
allOf()
whenComplete()
Flow Function

27. Flow Demo

28. Thank you!
1. Star the project: github.com/fnproject/fn
2. Join the conversation: slack.fnproject.io
3. Learn more: fnproject.io
4. We’re hiring engineers and evangelists:
chad.arimura@oracle.com
Chad Arimura
VP Serverless, Oracle
@chadarimura
Get Involved