Compute Services Management

Launching Instances

1. Bootstrapping: Provide code to be run on an instance launch.
2. VM Import/Export: Import existing VM into EC2.

Instance Metadata

• Security groups
• Instance Id
• Instance type
• AMI base of the instance

To change an instance type, just need to stop it and switch it.

Security Groups in Instances

Security Groups vs ACLs

Security Groups	ACLs
Operates at the instance level.	Operates at the subnet level.
Supports allow rules only.	Supports allow and deny.
Stateful: Return traffic is automatically allowed, regardless of rules.	Stateless: Return traffic must be explicitly allowed by the rules.
Evaluate all rules before deciding whether to allow traffic.	Process rules in number order when deciding whether to allow traffic.
Applies to an instance only if someone specifies the security group when launching the instance, or associates it later on.	Automatically applies to all instances in the subnets its associated with.

** Security Group Constraints**:

• By default, security groups are only bound to the primary network interface.

Advanced EC2 Management

• Provides cost optimization recommendations in AWS console.
• Host recovery restarts EC2 instances when a problem is detected or when a new host is available.
• Traffic monitoring copies network traffic from an Elastic Network Interface (ENI) of an EC2 instance and sends it where you need it.

AWS Batch

• Enables running batch processing of scripts within the AWS environment.
• Batch jobs can run at any scale.
• A job is a unit of work executed by an AWS batch.

Elastic Container Service (ECS)

• Implement Docker container in AWS.
• No VM builds required.
• Leverages Amazon Fargate to automatically build environments.

Elastic Beanstalk Environment

• Creates an EC2 instance with extra bells and whistles.
• Handles multi-container Docker (compose equivalent)