Putting the F in FaaS: Functional Compositional Patterns in a Serverless World

Putting the F in FaaS

! @trieloff

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#serverlessconf ! 2017

#serverlessconf! 2016(glad to be back)

! @adobeio

Opinions are my own

Ideas are not

⚡ Putting the F in FaaS

WTF?

WT !?

F is for Functions

Fundamentally, there are only two

programming styles: functional and dysfunctional.

Functions in FaaS

Stateless

StatelessShort-lived

StatelessShort-lived

Single-purpose

StatelessShort-lived

Single-purposeBoring

!"

⚡ Serverless Functional Patterns for the

Aspiring Enterprise Architect

Fundamentally, there are only two

architecture styles: functional and dysfunctional.

#serverlessconf ! 2017

#serverlessconf ! 2017(sorry, I missed it)

#serverlessconf ! 2017(sorry, I missed it)

(but I read all the tweets)

! @timallenwagnerThe Serverless Manifesto1. Functions are the unit of deployment and scaling

2. bla

3. bla

4. bla

5. Never pay for idle

! @yochaykApplied Serverless Design Patterns1. Function Chaining

2. ASync HTTP (HTTP 202)

3. Fanout (Parallel)

4. Fanout + Fan-in

5. Long Running Function with Timeout

! @ben11kehoe

What's Missing From Serverless Providers

Node is the WRONG runtime for serverless

! @ben11kehoeWhat's Missing From Serverless Providers

Node is the WRONG runtime for serverless

! @ben11kehoeWhat's Missing From Serverless Providers

Node is the WRONG runtime for serverless

(because it’s making you do async wrong)

!

!

Greenspun's tenth rule

Any sufficiently complicated C or Fortran program contains an ad-hoc, informally-specified, bug-ridden, slow implementation of half of Common Lisp.

tl;dr: LISP did it first

⚡ What LISP can Teach You About Serverless

Patterns

LISP !" Clojure

map/pmap (a.k.a. Fan-Out)(map some-function some-data)Apply some-function to each entry of the array of data in some-data. Then return the result as a new array. In parallel: use pmap.Why? To process lots of data.

apply (a.k.a. Proxy)(apply some-function x y z)Call some-function with arguments x, y, and z. Why? To make the function to be called a variable itself.

comp (a.k.a. Function Chaining)(comp some-function some-other-function)Create a function that first calls some-function on the arguments, and then some-other-function on the results.Why? To call multiple services in order.

reduce (a.k.a. Fan-In)(reduce some-function some-data)Call some-function on the first item of some-data, then call some-function again, using the result of the prior invocation and the next item in some-data as arguments.Why? To compress large data sets into small results.

fold (a.k.a. Fan-In with ! on Top)(fold reducef combined some-data)Break some-data into multiple sets, run (reduce reducef) on each, then run (combine combinef) on the results.Why? To compress really large data sets into small results, in multiple steps.

iterate (a.k.a. Endless Function)(iterate start-value some-function)Create a function that creates a data stream starting with start-value from repeated calls to some-function.Why? To turn some-function into a data emitter, without some-function needing state.

juxt (a.k.a. Parallel Functions)(juxt some-function some-other-function)Makes a function that calls some-function and some-other-function and returns a combined result.Why? To combine the results of multiple functions in one call.

memoize (a.k.a. Good Ol’ Cache)(memoize some-function)Return a cached version of some-function that returns the same value for the same arguments.Why? To trade slow computing against fast cache lookups.

partial (a.k.a. Wrapper)(partial some-function value)Creates a function that calls some-function with value as an argument, in addition to other arguments.Why? To provide default values and make powerful functions less dangerous.

That’s all the F you need

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Can my Serverless Vendor do this?

Probably. You need:1. A Serverless (FaaS) Runtime

2. An Event Passing System

3. A Document Database with Triggers

! @trieloff