Finagle-Based Microservices at SoundCloud

Phil Calçado http://philcalcado.com

@pcalcado

Quick Report:

> 11 hours of audio uploaded every minute

~ 300 million people every month

Like everybody else around that time…

Like everybody else around that time…

Because ${reasons}, we decided to break the monolith. But how?

The Mothership

SoundCloud.com

The Mothership

Sounds ˝& Sets

Social Graph

Premium ˝Features Search

Activity Stream

API

Reminds me of something…

Monoliths exist when building within it is cheaper than the overhead associated with coordination of multiple components. !

!

We need an inexpensive services framework

Realistic options

Summary in a picture

Phase 1: Finatra

Good stuff

• Model is very intuitive to people coming from other languages

• Production-ready service in minutes

Main issues we had

• Not always on latest Finagle version

• Doesn't compose with Filters

• Internals aren’t very flexible

• twitter-server is too far away from our infra

Phase 2: Filters and Services

Where the gold was

We followed suit

(114 LOC)

Routes are defined in a single file

Each controller is a Service

Lots of filters

Today

• 100% Traffic hitting Finagle-based services

• Redis, memcached, MySQL drivers used in production

• About one month to ramp-up non-Scala developers

What is still hard

• Config flags implementation isn't very flexible, we use env vars not properties

• API surface space for Finagle is too large. What’s user land, what’s test, what’s internal?

• Bespoke scatter-gather code all over our apps

• Every organization builds their own Finagle routing

Up next

Containers for Continuous Delivery

Thrift/Protocol Buffers?

}JSON parsing?

phil calçado

www.soundcloud.com

http://philcalcado.com

@pcalcado

http://soundcloud.com/pcalcado