[Taras Postument] How to Go with AWS Lambda?

Presentation from GDG DevFest Ukraine 2018 - the biggest community-driven Google tech conference in the CEE.

Learn more at: https://devfest.gdg.org.ua

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This talk will cover internal workings of Golang on the AWS Lambda platform, discover some tips and tricks for being more productive with it

Transcript

2. Agenda • How does it differ from servers? • What Gophers Squirrels have to do with it? • How does it work? • To Go or to NodeJS not to Go? • What is Half Life AWS Lambda?
3. AWS Lambda is... ...Serverless Computing Platform
5. https://www.deviantart.com/mikoneyoru/art/VILIFY-213975744 How does it differ from running code on servers? - Pay per invocation (and time) (and resources) - “Cold” starts - “Warm” periods - Limited execution time - Stateless (mostly) - Event driven code execution - Generous free tier - “Endless” horizontal scaling - No operations (reboots, patching, etc)
6. Meet SAM (Serverless Application Model) & serverless framework
7. How does it work then?
8. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 package main import "github.com/aws/aws-lambda-go/lambda" func init() { // do some initialization } func hello() (string, error) { return "Hello DevFest!", nil } func main() { lambda.Start(hello) } Minimal viable example // Valid handler function signatures: // func () // func () error // func (TIn), error // func () (TOut, error) // func (context.Context) error // func (context.Context, TIn) error // func (context.Context) (TOut, error) // func (context.Context, TIn) (TOut, error)
9. Slide taken from the highly recommended AWS Webinar Become a Serverless Black Belt: YouTube | SlideShare
10. https://djhworld.github.io/post/2018/01/27/running-go-aws-lambda-functions-locally/
11. Do I need to write code differently?
12. • Avoid “fat”/monolithic functions • Read only what you need • Do lazy initialization • Think twice before adding new dependency/lib • Try allocating more resources … and try to reduce them Cold starts are bad… so stay warm :)
13. - Environment is ephemeral, you can’t rely on it, but you can reuse it: • Reuse global variables • Use file system as cache (512mb in /tmp) • Keep open connections - Language level concurrency not always needed since lambda executions are concurrent by itself
14. Handle failures! - Understand retry policies • Sync calls never retried • Async calls retried 2 times • Stream retries until data expires - Leverage Dead Letter Queues • Use SQS/SNS for replays Retry billed as new execution
15. Compare node, golang, python package size... Slide taken from the highly recommended AWS Webinar Become a Serverless Black Belt: YouTube | SlideShare Find the best resources allocation for your function: alexcasalboni/aws-lambda-power-tuning
16. • Go: ◦ If you love Go, then the rest of the functions To Go or not to Go? • NodeJS/Python: ◦ Small functions (with no or little dependencies) ◦ Functions that depend on AWS SDK only • Java: ◦ Never
17. Your reading homework: • https://mikhail.io/2018/08/serverless-cold-start-war/ • https://djhworld.github.io/post/2018/01/27/running- go-aws-lambda-functions-locally/ • https://hackernoon.com/lambda-internals-exploring -aws-lambda-462f05f74076 • https://medium.com/@galbashan1/aws-lambda-int ernals-part-2-going-deeper-1e12b9d2515f
18. Many thanks to Mart Vikus (@arcaderage) for this amazing Gordon Freeman arts: • https://twitter.com/hashtag/30DaysOfHalfLife • https://arcaderage.co/2016/10/06/30-days-of-half-life/
19. Questions are welcome www.linkedin.com/in/taras-postument trane9991@gmail.com
20. Demo!!!!!!!!!!!!!!!!!!!!!!