Serverless to Serving Elixir: Migrating Serverless app to run on Phoenix

Problem: Increasing productivity, affordability, scalability, and even less coding (gasp!) are the goals for any web application. Add on top unpredictable server traffic, then a solution you might consider is going serverless and throwing in one of those nifty NoSQL database solutions. Easy enough, but at what cost? You can unintentionally suffer vendor lock-in, deal with cold starts, architect your application improperly, and miscalculate cost structure at scale. But there is an even better solution you might want to consider, Elixir. Elixir and Pheonix can help developers solve all these technical challenges, allowing you to focus on the end-user experience.

Purpose: “Serverless to Serving Elixir: Migrating Serverless app to run on Phoenix” will demonstrate why migrating Elixir can solve all the same issues your serverless application would, make it faster, avoid vendor lock-in, and help future-proof your application. Maybe even have you second-guess if you ever need to go serverless again.

Live Demo/ Walkthru: In preparation for this talk, I will guide conference attendees through the libraries and strategies to take NodeJS Serverless applications using Firebase Firestore and migrate them to a single Phoenix application and Postgres database with no downtime.

Transcript

1. 1 Erik Guzman Full Stack Engineer @ ZEAL Ruby on Rails ReactJS Who am I? After Dark: Microsoft MVP Developer Tools Elixir Development Technical Content Creator Twitch 3rd Party Developer
2. SERVERLESS TO SERVING ELIXIR MIGRATING SERVERLESS APP TO RUN ON PHOENIX
3. 3 The Journey 1 2 3 4 5 Developing for twitch.tv Going Serverless Problems Faced Why Elixir? Migration Process
4. DEVELOPING FOR TWITCH.TV
5. 5 What is Twitch? Live video streaming platform • Users aka “channels” live stream activities • To watch a channel, viewers visit a channel page • Viewership can vary drastically, from 1 to 100k concurrent viewers • Twitch o ff ers various tools, like Extensions, to enhance a viewers experience
6. 6 What is a Twitch Extension? HTML/CSS/JS Website • Little website trapped in an iframe • Hosted on the Twitch CDN • Managed like an app store • You are in charge of hosting any backend • Installed by the Twitch Channel • Loaded by each viewer of the channel
7. 7 Recipe for Success Handle Large Bursts of Traffic Scalable Fast Affordable Easy to Deploy
8. GOING SERVERLESS
9. 9 Try out Serverless Functions Great! What’s Serverless Functions? Recommendations
10. 10 What’s Serverless Functions? Easy to Deploy A ff ordable Scalable Pay Per Invocation & Duration $0.20 per million executions plus potential execution time No long lived server costs Deploy single function or all functions easily Can handle large amount of requests Fully Managed Infrastructure Don’t worry about con fi guring servers or scaling
11. 11 Serverless Breaks Up The Band Traditional Hosting
12. 12 Serverless Breaks Up The Band Such micro
13. 13 Serverless Checks Out Handle Large Bursts of Traffic Scalable Fast Affordable Easy to Deploy
14. 14 What DB Do I Use?
15. Why? • Don’t have to pay for long run database server • Only pay for reads and writes exceeding a certain amount • Pay for network tra ff i c after a certain amount • I only pay if my extension is a success NoSQL: Firestore 15
16. 16 So I Built Stu f Github Projects Stream Team Better Information Panel Stream Closed Captioner What Next? Not actually serverless
17. MORE EXTENSION MORE PROBLEMS
18. 18 Serverless Cold starts for initial calls • Function need time to initialize • Not all your functions will be “hot” • Need to pay to keep them long lived
19. 19 Serverless Cold starts for initial calls Easy to end up with microservice zoo • Functions or new project for everything • Hard to manage
20. 20 Serverless Cold starts for initial calls Duplicated code and logic • Multiple functions or multiple projects can lead to duplicating code Easy to end up with microservice zoo
21. 21 Serverless Cold starts for initial calls Easy to end up with microservice zoo Duplicated code and logic More tra ff i c means higher and unpredictable costs $15
22. 22 Serverless $15 Forces you to go as lean as possible on number of requests When I realized any form of polling is a bad idea Cold starts for initial calls Easy to end up with microservice zoo Duplicated code and logic More tra ff i c means higher and unpredictable costs
23. 23 Firestore Easy to make bad schema design • Ability to store non structured data makes it easy to store mistakes
24. 24 Firestore You can’t easily export data • Lack of standardization means each vendor their own special export format Easy to make bad schema design
25. 25 Firestore Constant reads and writes are costly $ $$ Polling also meant more reads From the the DB You can’t easily export data Easy to make bad schema design
26. WHY ELIXIR? A Side Story
27. 27 Stream Closed Captioner Description: Allows a Twitch channel add closed captions to their stream. • Built with Ruby on Rails • Uses WebSockets to send captions from client side to server • Send captions from server to Twitch using Twitch APIs
28. 28 The Past STREAM CLOSED CAPTIONER ORIGINAL ARCHITECTURE Ruby on Rails Redis Postgres Twitch API
29. 29 My Life After Awhile With Success Came Problems • WebSockets in Ruby on Rails is a memory hog • To many requests on small servers leading to timeouts • Getting expensive to scale • I don’t have time to baby sit server
30. 30 The Present STREAM CLOSED CAPTIONER ZOOMER ARCHITECTURE Elixir Phoenix Postgres Redis Twitch API
31. 31 Deploy it and Forget it • Completely removed the need for Redis • Websockets run amazing!!! • Memory e ff i cient and you never have to restart • A ff ordable hosting and blazing fast • Fail fast, recovers fast My Life Now
32. 32 Elixir Hits All The Marks Handle Large Bursts of Traffic Scalable Fast Affordable Easy to Deploy
33. THE GREAT MIGRATION Serverless to Serverful
34. 34 Stream Team Extension Concept: Create, manage, and display a Twitch team Features: ๏ A channel can choose to display an o ffi cial team they are apart of ๏ They can create a custom team and add channels ๏ Upon installation all viewers of their channel can browse and view another team member’s channel Application to Migrate
35. 35 Top Goals Migrate Data to Postgres Zero Down Time No Loss of Data 1 2 3
36. 36 Road Map 1 2 3 4 5 Create API Proxy Create Schema Replicate Logic & Tap Data Export Firebase to Postgres Switch to GQL
37. THE GREAT MIGRATION 1. Create API Proxy
38. Current Request Flow 38
39. 39 Creating API Proxy GET FLOW All in sequence UPSERT FLOW
40. 40 Creating API Proxy Time to Terraform terraform Terraform is a simple plug designed to work with Phoenix. Terraform allows you to incrementally transform a HTTP API into one powered by Phoenix - one endpoint at a time.
41. 41 Creating API Proxy GET FLOW Terraforming UPSERT FLOW Excuse me. I’d like to ask you about your cars extended warranty
42. 42 Creating API Proxy GET FLOW Successful Proxy UPSERT FLOW
43. 43 Creating API Proxy GET FLOW Successful Proxy UPSERT FLOW Proxy the request to serverless function Pass response back
44. 44 Creating API Proxy GET FLOW Successful Proxy UPSERT FLOW Why? 1 2 Able to update server con fi guration in the Twitch Extension before any serious work is done I can now easily deploy backend changes without releasing a new extension version
45. THE GREAT MIGRATION 2. Create Schema
46. 46 Create Schema Firebase schema Channel Record Channel’s Custom Team
47. Bad idea if members wanted to share the same team 47 Create Schema Firebase schema Channel Record Channel’s Custom Team
48. 48 Create Schema Redesign time FIREBASE SCHEMA ECTO SCHEMA
49. 49 Create Schema Ecto & Contexts Two Contexts Four new tables
50. Two Contexts Four new tables 50 Create Schema Ecto & Contexts Why? 1 2 Separate team from channel entity A channel can see who their memberships 3 Channels can have other app data associated with them in the future
51. THE GREAT MIGRATION 3. Replicate Logic & Tap Data
52. 52 Replicate Logic Data Flow
53. 53 Replicate Logic Data Flow All the business logic done here Reimplemented Here
54. 54 Replicate Logic Tapping into the fl ow
55. 55 Replicate Logic Tapping into the fl ow 1. Auth 2. Validate 3. Save to Postgres
56. 56 Replicate Logic Tapping into the fl ow Auth Validate Save to Postgres Why? 1 2 Test my schema against real world data Test server performance 3 I can save data in fl ight while performing database export
57. THE GREAT MIGRATION 4. Export Firebase to Postgres
58. 58 Firebase to Postgres Supabase to the rescue Supa Cool Library fi rebase-to-supabase Converts Firebase collections into JSON fi le which can then be imported into you Supabase Postgres DB.
59. 59 Firebase to Postgres How to get data into Postgres?
60. 60 Uploader & Processor Built-in Upload Feature Oban Job Processing Super Easy to Setup Simple Page to Upload Exports LIVEVIEW UPLOADER Finally a reason to use LiveView!
61. 61 LiveView File Upload Built-in Upload Feature Oban Job Processing Super Easy to Setup Simple Page to Upload Exports PHOENIX LIVEVIEW Finally a reason to use LiveView!
62. 62 LiveView File Upload Built-in Upload Feature Oban Job Processing Super Easy to Setup Simple Page to Upload Exports PHOENIX LIVEVIEW Finally a reason to use LiveView! Why? 1 2 Get away from vendor lock in Stable/Consistent Cost 3 No data loss since I am saving new upserts
63. THE GREAT MIGRATION 5. Switch to GQL
64. 64 Switch to GQL Just one more change
65. 65 Switch to GQL Multiple endpoints is so 2010s POST DESTROY
66. 66 Switch to GraphQL Ask for what I need
67. 67 Switch to GraphQL Profound reasons…
68. 68 Switch to GraphQL Profound reasons… 838 Why? 1 2 GraphQL is cool I felt like it
69. 69 Recap Why did I do all this work? 1 2 3 4 5 6 Avoid vendor lock-in Consistent Costs Extremely Performant Very low cost to run (Actually runs on fl y.io free tier) Relational Databases are great Easy to manage
70. 70 Site: guzman.codes Socials: THANKS Talk2MeGooseman