Summary of AWS CloudWatch Metrics for Auto Scaling Groups (ASG)

ASG-Level Metrics (Opt-In)

• GroupMinSize: Minimum size of the ASG over time.
• GroupMaxSize: Maximum size of the ASG over time.
• GroupDesiredCapacity: Desired capacity of the ASG over time.
• GroupInServiceInstances: Number of instances in service.
• PendingInstances: Number of instances pending.
• StandbyInstances: Number of instances on standby.
• TerminatingInstances: Number of instances terminating.
• TotalInstances: Total number of instances in the ASG.

EC2-Level Metrics (Default Enabled)

• CPU Utilization: Percentage of allocated EC2 compute units that are currently in use on the instance.
• NetworkIn: Incoming network traffic to the instance.
• NetworkOut: Outgoing network traffic from the instance.
• DiskReadOps: Completed read operations from all instance store volumes.
• DiskWriteOps: Completed write operations to all instance store volumes.
• StatusCheckFailed: Reports whether the instance has passed both the instance status check and the system status check.

Monitoring Granularity

• Basic Monitoring: Metrics are available with 5-minute granularity.
• Detailed Monitoring: Metrics are available with 1-minute granularity (additional charges may apply).