Performance Tips for Apps (WWC London)

1. Performance Tips For
Apps

2. About Me
clairettran

3. Performance Is Important

4. Some Common Problems
Note: not an exhaustive list

5. What I’ll Cover
● Monitoring
● Caching
● Scaling
● Database
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6. Monitoring
How to know there is a performance problem?

7. Caching
How?
● Cache store
● Fragment caching
● SQL caching

8. Caching
Before: No Caching
After: With Caching!
Problem: Page making many external requests

9. Scaling
Load Balancer
Cache Cluster
Edge Cache / CDN

10. Database
● Add an index
● Profiling
● Batch queries
● Eager fetching
● Denormalisation
● Sharding

11. Other Techniques
● Queuing/Background Jobs
● Caching tech (e.g.
Elasticache)
● Dedicated services
● Rails engines
● C-extensions (gems)
● Sprites
● Asset pipeline
● Cache control headers
● Gzip assets*
● Less HTTP requests
● Dedicated Search Service
● Remove unused assets
● Static cluster
● AWS Auto-scaling
● Edge Caching (Akamai, Cloudfront)
● YSlow
● Local Storage
● Smaller Responses
● Async JS
● Chrome DevTools
● Ruby Flavours e.g. JRuby
● Asynchronous tasks

12. Further Reading
https://github.com/ianheggie/health_check
http://guides.rubyonrails.org/caching_with_rails.html
http://railscasts.com/episodes/380-memcached-dalli
https://developers.google.com/events/io/sessions/324511365
http://railscasts.com/episodes/366-sidekiq
http://www.slideshare.net/derekmbrown/netflix-strategic-
performance-analysis
http://blog.jphpsf.com/2012/04/28/front-end-performance-case-
study-github

14. Questions