lambda

Question 1

EC2 vs Lambda

Answer 1

EC2 
Virtual Servers in the Cloud
• Limited by RAM and CPU
• Continuously running
• Scaling means intervention to add/remove servers

Lambda
• Virtual functions – no servers to manage!
• Limited by time - short executions
• Run on-demand
• Scaling is automated!

Question 2

Lambda Limits

Answer 2

• Execution:
Memory allocation: 128 MB – 10GB (64 MB increments)
Maximum execution time: 900 seconds (15 minutes)
Environment variables (4 KB)
Disk capacity in the “function container” (in /tmp): 512 MB
Concurrency executions: 1000 (can be increased)

• Deployment:
Lambda function deployment size (compressed .zip): 50 MB
Size of uncompressed deployment (code + dependencies): 250 MB
Can use the /tmp directory to load other files at startup
Size of environment variables: 4 KB

Question 3

lambda@edge has 4 functions(Picture mentioned in slide number 444 of Stephan)

Answer 3

Viewer request ->
After CloudFront receives a request from a viewer

Origin request ->
Before the request hits the origin layer.

Origin response ->
After CloudFront receives the response from the origin

Viewer Response ->
Before CloudFront forwards the response to the viewer(hits the viewer layer)

Question 4

Lambda@Edge: Use Cases

Answer 4

Website Security and Privacy
Dynamic Web Application at the Edge
Search Engine Optimization (SEO)
Intelligently Route Across Origins and Data Centers
Bot Mitigation at the Edge
Real-time Image Transformation
A/B Testing
User Authentication and Authorization
User Prioritization
User Tracking and Analytics