Don't Panic – Launching Websites Confidently and Successfully

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Don’t Panic! How to launch a large-scale website confidently and successfully Photo by SpaceX on Unsplash DevOps Tallinn 2018

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Who am I? @ryantownsend Ryan Townsend, CTO

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Relaunched May 2017

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“Just use auto-scaling and forget about it” Kris Quigley – Lead Developer @ SHIFT (sarcasm)

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Timeline Development Pre-launch Launch ! Post-launch

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• Functional Testing • Deployment Pipelines • Configuration & Implementation

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Development http://www.spacex.com/media-gallery/detail/149431/9391

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Keep Things Simple

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Limit Project Scope

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New Problem or New Technology

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“A l m o s t a l l t h e c a s e s w h e r e I ' v e h e a r d o f a
system that was built as a microservice system from scratch, it has ended up in serious trouble.” – Martin Fowler, ThoughtWorks CTO

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Clear Decoupling

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Admin Panel API Website

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Use Boring Mature Technology

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Load Testing

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Don’t wait until the end

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It’s A LOT harder than people let on

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• Use real metrics and logged user behaviour • Use a wide variety of metrics, not just traffic • Post-test validate the metrics at source

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Assume user behaviour will change

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Stress Test

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Web Performance Testing

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Remember: it’s not just for you!

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Caching

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Client CDN Application Database

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Write-through caches

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Start small… low TTLs

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Front-end – static assets & redirects

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Higher hit ratios = less traffic hitting our servers

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Feature Toggles

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Ideal Fallback Off On

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On Ideal Fallback Off

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• Built into your application • Content Delivery Network • A/B testing tool

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Circuit Breakers

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Ideal Fallback Open Error Closed

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Ideal Fallback Open Error Closed

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Ideal Fallback Open Error Closed

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Pre-launch Preparations https://www.flickr.com/photos/spacex/31450835954/

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Communication

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• Build a trusting relationship with stakeholders • Understand their metrics • Get their perspective • Determine authority

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Visibility

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• System monitoring   – infrastructure & client-side

• Client / stakeholder dashboards & reporting   – see what they see

• Customer engagement   – social media, customer support

• Instant access to logs   – filterable, searchable

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Above shows how New Relic tracked a 3rd party script harming site performance but the server-side was fine.

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Roleplay

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• What could go wrong? • Who would you escalate to? • How would you solve? • What people do you need access to? • What systems do you need access to?

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Traffic Reduction

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• Avoid scheduling big campaigns • Paid advertising is easy to turn off • Reduce offering

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Launch Day https://unsplash.com/photos/yJv97tE7GDM

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Scale-up

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“Big Bang” vs Canary Release

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Feature Toggles: Off

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Keep Calm and Carry On

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• Expect issues • Keep a level-head • Remain professional • You’re an expert – you’ve got this "

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Post-launch https://unsplash.com/photos/-p-KCm6xB9I

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Continue Building Confidence

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• Gather actual real metrics & usage patterns • Revisit your load tests and re-assess • Re-run load tests for future releases • Ship some safe releases • Ship small releases, often