Installed on over 20 million devices worldwide on three different platforms, Glide is the world’s leading real-time video messenger. Rapid growth came with scalability and maintainability efforts to ensure a sub-second video messaging experience for our users. When searching for a solution to data analytics challenges, we turned to AWS Lambda. With a combination of Dynamo Streams and Kinesis Firehose we managed to speed up service for our end users and internal systems while simplifying our architecture and increasing savings, all without bothering the Dev-Ops team. In this lecture we will discuss some of the practical applications of AWS Lambda, how to maintain multiple Lambda functions from the same code base, debug issues (in production!), and practical tricks that can help you address known issues and unleash the power of AWS Lambda. Mo Kamioner, Backend Architect for Glide will be leading this lecture.

1. AWS Lambda
Mo Kamioner, Backend Architect
‫בס”ד‬
March 13, 2016

4. Installed on 20M+ devices
worldwide
Millions of active users
have sent billions of
messages
1PB+ videos
stored on S3
10K+ r/w
throughput in
Dynamo DB
Multi region
architecture ensures
sub-second
latency

6. Analytics 1.0
User
Redshift
Foreground EC2
Dynamo DB
MySQL
Background EC2 S3 SQS Analytics EC2
Duplicate data (consistency issues)
Difficult to make changes
2+ hours from creation to Redshift
Multiple DB writes per request

7. Analytics 2.0
User
Redshift
Foreground EC2
Dynamo DB Lambda S3 SQS Analytics EC2Kinesis Firehose
Duplicate data (consistency issues) Consistent data (found new bugs)
Difficult to make changes Deploy to Lambda is simple
2+ hours from creation to Redshift 15 minutes max
Multiple DB writes per request One database write

8. Why Lambda?
•Low maintenance
•Already work in NodeJS
•No database connections (sleek)
•Easily deployable
•Highly scalable

9. 10 Practical Lambda
lessons learned

10. JSLint your code
Douglas Crockford
http://www.jslint.com
> jslint badExample.js
badExample.js
#1 'notName' was used before it was defined.
if (notName === "Mudd") { // Line 5, Pos 5
"use strict";
var name = "Douglas Crockford";
if (notName === "Mudd") {
console.log("Your name is Mudd!");
}
badExample.js
> jslint goodExample.js
goodExample.js is OK.
"use strict";
var name = "Douglas Crockford";
if (name === "Mudd") {
console.log("Your name is Mudd!");
}
goodExample.js

11. Declare variables outside the handler
“Avoid declaring any function
variables outside the scope of the
handler. Lambda does not
guarantee those variables will be
refreshed between function
invocations”
AWS Lambda Best Practices March 2016
"use strict";
function mapDataLoadOnce(data) {
//...
}
doInitOnce();
module.exports.handler = function handler(event, context) {
function mapDataLoadOnEveryInvocation(data) {
//...
// `event` and `context` are in scope here
}
doInitOnEveryInvocation();
//...
context.succeed("Successfully processed " + event.Records.length + " records.");
};
lambda.js

12. Expect
multiple
events

13. Track versions of your code
Screenshot of version tracking

14. Know when to use the code editor

15. Keep your functions
light and fast

16. 128 MB is more than you think...

17. Stream your data!
https://gist.github.
com/maxrabin/e3e51abc365cd3f54d78

18. Don’t Ignore Errors

19. Watch your
timeouts

20. Live demo!

21. Takeaways
Lambda is simple, scalable and fast
1. JSLint your code
2. Declare variables outside the handler
3. Expect multiple events
4. Track versions of your code
5. Know when to use the code editor
6. Keep your functions light and fast
7. 128 MB is more than you think…
8. Stream your data!
9. Don’t ignore errors
10. Watch your timeouts

22. Mo Kamioner
Backend Architect
mo@glide.me
Glide ID: mo
W
e’re
hiring!
http://working.at.glide.rocks