Amazon EC2

Instances

Instances

• Amazon Machine Image
• Instance type:
  • m5.2xlarge:
    • m: instance class
    • 5: generation of instance class
    • 2xlarge: size
  • ec2instance.info
• Key pair
• Network
• Advanced details:
  • .
  • Stop - hibernation behavior:
    • stop but store the RAM state in a file in root EBS
      • root EBS volume must be encrypted
    • startup much faster
    • not more than 60 days
  • .
  • Spot instance: set max price
  • …
  • User data: script to be run when instance first created.

Instance types

Launch template

• AMI
• Instance type
• EC2 User data
• EBS volumes
• SGs
• SSH key pair
• IAM roles
• Network + subnet
• Load balancer

Spot requests

• Spot instance: set max price willing to pay, if price goes above, instance is stopped
• Spot fleet: set of spot instances + (optional) on-demand instances
  • automatically request spot instances to adjust to reach capacity or max defined cost
  • can have multiple launch pool for fleet to choose from
  • strats:
    • lowest price
    • diversified
    • capacity optimized
    • price-capacity optimized

Saving plans

Reserved Instances

• up to 72% discount compared to on-demand
• 1 year / 3 years: 3 years has more discount
• All upfront payment has more discount > partial > no upfront
• Convertible RI: can change EC2 instance type, family, os, scope

Dedicated hosts

• Dedicated Instances offer single-tenant virtual machines on shared hardware
• Dedicated Hosts provide entire physical servers for exclusive use.

Capacity reservation

• Reserve capacity in a specific AZ so work is uninterupted

Images: Amazon Machine Image

Amazon Elastic Block Store

Volumes

• exist in single az
• volume types:
  • gp2: general purpose SSD, IOPS depends on size
  • gp3: general purpose SSD, IOPS scales independently
  • io1: provisioned SSD, high max IOPS
    • allows for multi-attach in same az, up to 16
  • io2: provisioned SSD, higher max IOPS
    • allows for multi-attach in same az, up to 16
  • st1: HDD, slow
  • sc1: HDD, slowest
  • • HDD can be used for log processing and big data
• Volumes attached to root is deleted when instance is terminated by default

Snapshots

• snapshot of a volume’s point in time
• can use AWS Recycle Bin

Network & security

AWS Security Group

Amazon Elastic IP

Placement groups:

• Control over instance placements in a ASG
• Strategies:
  • Cluster: in single AZ
    • higher network speed between instances (turn on enhanced networking)
  • Spread: across multiple AZ (max 7 in each group per AZ)
  • Partition: across different partitions (different set of racks) for each AZs. Up to 100s of instance per group

Key pairs

Network interfaces:

• Virtual Network Interface Card
• Independent from instance, can be detached and moved
• Exist in a single AZ
• Has:
  • at least 1 private IPv4
  • 1 elastic IPv4 per private IPv4
  • max 1 elastic public IPv4
  • 1 or more SG
  • MAC address

Load Balancing

Elastic Load Balancer

AS

Auto Scaling Group

• Amazon AutoScaling
• Scale based on Alarms (avg cpu usage)

• Details:

• Activity:
• Automatic scaling policies:
  • Dynamic scaling policies
    • target tracking scaling: set to have avg cpu to x%
    • simple/step scaling: trigger when avg CPU > x% → add 1
  • scheduled scaling:
    • set to add 1 instance at x-AM
  • Predictive scaling: forecast load and schedule scaling ahead
• Instance management: