All 7 Auto Scaling Groups questions
More in Auto Scaling Groups
What is an Auto Scaling Group in AWS and what problem does it solve? What is a launch template and how is it used by an Auto Scaling Group? What scaling policies are available in Auto Scaling Groups, such as target tracking and step scaling? How do health checks work within an Auto Scaling Group to maintain a healthy fleet of instances? How do lifecycle hooks in Auto Scaling Groups let you customize instance launch and termination behavior? How can predictive scaling in Auto Scaling Groups improve upon reactive scaling policies?
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AWS › Auto Scaling Groups

How can Auto Scaling Groups span multiple Availability Zones to improve application availability?

Intermediate

Answer

An Auto Scaling Group can be configured to launch instances across multiple Availability Zones within a region, automatically distributing instances as evenly as possible, so if an entire Availability Zone experiences an outage, the application continues running on instances located in the remaining healthy zones, and the Auto Scaling Group automatically launches replacement capacity in the available zones to maintain desired capacity.
aws autoscaling update-auto-scaling-group --auto-scaling-group-name my-asg --vpc-zone-identifier 'subnet-111,subnet-222,subnet-333'
Real-world example A company running a critical application spreads its Auto Scaling Group across three separate Availability Zones, ensuring that even a complete failure of one entire data center does not take down the application for its users.

Common follow-ups: How does the Auto Scaling Group decide how many instances to place in each Availability Zone?;What happens to capacity distribution if one Availability Zone runs out of available capacity for a specific instance type?

AWS Global Infrastructure (Regions AZs & Edge Locations);AWS Backup & Disaster Recovery
All 7 Auto Scaling Groups questions