CMSC389L

CloudFront

CloudFront Concepts

• Content Delivery Networks (CDN): a globally-distributed network of proxy servers which cache content
  • Use cases: web streaming, static content acceleration

CDN Metrics

• Latency: Time taken until the first byte is downloaded
• Data Transfer Rates: Rate at which data is transferred to the client
• Cache Hit Ratio: The percent of requests where the data can be retrieved from the cache

CloudFront Concepts

• Edge Locations: Proxy server in the CloudFront network
• Regional Edge Caches: Proxy servers that intermediates between origin server and edge locations.

CloudFront Concepts

• Origin Server: The definitive store of content that CloudFront will accelerate (f.e., S3 or EC2 web server)
• Distribution: Configuration specifying your origin server, cache invalidation rules, etc. 
  • Shared with edge locations

CloudFront Costs

• Transfer from CloudFront to Internet: $0.085 / GB
  • ​Varies by region and throughput
    • Drops to $0.020 / GB
• Transfer from AWS (S3, etc.) to CloudFront: Free
• Per-request fee: $0.01 / 10k requests

EC2

EC2 Concepts

• EC2: Elastic Compute Cloud
  • Secure and resizable compute capacity
  • Enables you to run arbitrary computer programs
• Cheap because of multi-tenancy.

Multi-Tenancy

• Multi-Tenancy: Multiple VMs running on a single server.
• Hypervisors manage these VMs
  • f.e. VirtualBox (AWS uses Xen)
  • Similar to OS supervisors (which manage processes)
  • Provides VM isolation
• Instances: Virtual Machines

Launch an EC2 Instance

Machine Images

• AMI: Amazon Machine Images
  • Snapshot of a VM
  • Vary by OS, CPU architecture, libraries, etc.
  • You can/will create custom AMIs

Instance Types

• Variety of hardware options
• Instance families:
  • General Purpose
  • Compute Optimized
    • Extra vCPUs
  • Memory Optimized
    • RAM
  • Storage Optimized
    • Large instance storage
  • Accelerated Computing
    • GPUs

Storage

• Instance Storage: ephemeral storage attached to a specific instance
• EBS: Elastic Block Storage
  • Primitive is a file system block, instead of an object like S3
• Can create EBS volumes and attach them to EC2 instances to make them available.

Firewall: Security Groups

• Firewalls: Network-level system for whitelisting/blacklisting traffic based on security rules
• Security Groups: EC2 firewall allows whitelisting inbound traffic based on IP and port

• IP Address: Unique identifier of computer machines on a network (ex. 34.224.85.207)
• Port: Numbers that identify network services on a host.

SSH: Key Pairs

• EC2 server rely on key-based authentication.

• Authentication:  Verify that you are who you say you are.
  • Idea: use a secret that only you know
  • How can others verify that the secret is correct without having access to your secret key?
  • Use Public / Private Key Cryptography

Done!

EC2 Demo

aws.amazon.com

Worksheet: EC2

Complete the worksheet on EC2.