This topic describes the benefits of Auto Scaling.
Auto Scaling can automatically complete the following tasks based on your preconfigured information, which prevents errors caused by manual intervention.
- Auto Scaling can automatically adjust the number of Elastic Compute Service (ECS) instances in a scaling group. This ensures that the computing capabilities can meet your business requirements.
- During a scale-out activity, Auto Scaling automatically adds a specified number of ECS instances to the backend server group of the Server Load Balancer (SLB) instance that is associated with Auto Scaling. During a scale-in activity, Auto Scaling removes a specified number of ECS instances that are no longer needed from the backend server group of the SLB instance.
- During a scale-out activity, Auto Scaling automatically adds the IP addresses of a specified number of ECS instances to the whitelist of the ApsaraDB RDS instance that is associated with Auto scaling. During a scale-in activity, Auto Scaling removes the IP addresses of a specified number of ECS instances that are no longer needed from the whitelist of the ApsaraDB RDS instance.
Auto Scaling provisions resources when demand for the resources increases, and releases resources when demand for the resources decreases, which improves resource utilization and significantly reduces costs.
- With Auto Scaling, you do not need to prepare redundant ECS instances in advance of peak hours. Auto Scaling can immediately release the ECS instances that you no longer need. This way, you do not need to worry about cost increases caused by the waste of resources. Auto Scaling can flexibly adjust the computing capabilities, which reduces the ownership costs of resources.
- Auto Scaling can save a significant amount of time and effort because you do not need to invest a lot of manpower and time to adjust the computing resources.
Auto Scaling can monitor the health of running ECS instances. If Auto Scaling finds an ECS instance that is not running, Auto Scaling considers the ECS instance unhealthy, and immediately creates an ECS instance to replace the unhealthy instance. This ensures high availability of your business. You can use Auto Scaling to detect unhealthy ECS instances and create replacement instances without interruption to your business.
Flexibility and intelligence
Auto Scaling provides a variety of features. As a service with high flexibility and availability, Auto Scaling can free you from the complexity of manual configurations and improve operation efficiency.
- Scaling modes: Auto Scaling provides a variety of scaling modes, including fixed-number mode, health mode, scheduled mode, dynamic mode, and custom mode. You can combine the preceding modes to meet your business requirements. In dynamic mode, Auto Scaling interconnects with the external monitoring system CloudMonitor by using API operations. For more information, see Scaling modes.
- Instance configuration sources (templates based on which you can create ECS instances): Auto Scaling provides multiple instance types and disk categories. This improves the flexibility of templates and the success rate of scale-out.
- Scaling policies:
- Priority policy: Auto Scaling preferentially scales instances in zones that have the highest priority. If the scaling activity fails, Auto Scaling scales instances in zones that have the next highest priority.
- Balanced distribution policy: Auto Scaling evenly creates ECS instances in multiple zones, which ensures high availability for the ECS instances.
- Cost optimization policy: If you specify multiple instance types in the instance configuration source, Auto Scaling preferentially creates ECS instances that have the lowest unit price of vCPUs and removes ECS instances that have the highest unit price of vCPUs.
- Instance removal policy: You can remove ECS instances that are created from the earliest scaling configuration. You can also remove ECS instances that are created at the earliest or latest point in time.
- Instance reclaim policy: You can release ECS instances as a whole. You can also retain some resources to reduce your costs.
For more information, see Create a scaling group.
Auto Scaling records each scaling activity in details, which helps you effectively identify and troubleshoot issues.
You can use CloudMonitor to monitor the health of more than one ECS instances in a scaling group. This helps maintain service availability in an efficient manner.