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Auto Scaling:Manage scaling groups

Last Updated:Dec 28, 2023

A scaling group is a collection of Elastic Compute Service (ECS) instances or elastic container instances that can be used in similar business scenarios. If you want to automatically increase or decrease the number of instances of a specified type based on your business requirements and scaling policies, you can configure a scaling group. This topic describes how to create, view, modify, delete, enable, or disable a scaling group.

Prerequisites

The following table describes the prerequisites that must be met in different scenarios.

Scenario

Prerequisite

The first time you use Auto Scaling

Auto Scaling is activated. Follow the on-screen instructions to activate Auto Scaling. For more information, see Manage the service-linked role for Auto Scaling.

When you specify a launch template to automatically create ECS instances

A launch template is created. For information about how to create a launch template, see Create a launch template.

When you associate a Classic Load Balancer (CLB, formerly known as SLB) instance with a scaling group

  • One or more CLB instances are created. At least one CLB instance is in the Active state. For more information, see Create and manage a CLB instance.

  • The CLB instance must reside in the same region as the scaling group.

  • If the network type of the CLB instance and the scaling group is virtual private cloud (VPC), the CLB instance and the scaling group must reside in the same VPC.

  • If the network type of the CLB instance is classic network, the network type of the scaling group is VPC, and the backend server group of the CLB instance contains ECS instances or elastic container instances that reside in a VPC, the ECS instances and the scaling group must reside in the same VPC.

  • The CLB instance is configured with at least one listener. For information about how to configure listeners for CLB instances, see Listener overview.

  • The health check feature is enabled for the CLB instance. For information about how to enable the health check feature for CLB instances, see Configure and manage health checks.

When you associate an Application Load Balancer (ALB) instance with a scaling group

  • The network type of the scaling group must be VPC. The scaling group and the ALB server group must reside in the same VPC.

  • The ALB server group is in the Available state.

When you associate an ApsaraDB RDS instance with a scaling group

  • One or more ApsaraDB RDS instances are created. At least one ApsaraDB RDS instance is in the Running state. For more information, see What is ApsaraDB RDS?

  • The ApsaraDB RDS instance must reside in the same region as the scaling group.

Create scaling groups

Usage notes

  • You can create only a limited number of scaling groups in a region. To view the quota or request a quota increase, go to Quota Center.

  • When you create a scaling group, you must configure the Minimum Number of Instances and Maximum Number of Instances parameters. You can configure the Expected Number of Instances parameter based on your business requirements.

    • If you do not configure the Expected Number of Instances parameter and the number of existing instances in the scaling group is less than the value of the Minimum Number of Instances parameter, Auto Scaling triggers a scale-out to add the required number of instances to reach the value of the Minimum Number of Instances parameter.

    • If you set the Expected Number of Instances parameter to a value greater than 0 and the number of existing instances in the scaling group is less than the value of the Expected Number of Instances parameter, Auto Scaling triggers a scale-out to reach the expected number of instances.

    • If the number of existing instances in the scaling group is greater than the value of the Maximum Number of Instances parameter, Auto Scaling triggers a scale-in to remove excess instances from the scaling group until the number of instances is equal to the maximum number of instances.

    Note

    Auto Scaling triggers the preceding scaling activities without the need to execute scaling rules.

Procedure

  1. Log on to the Auto Scaling console.
  2. In the top navigation bar, select the region where Auto Scaling is activated.
  3. In the left-side navigation pane, click Scaling Groups.
  4. In the upper-left corner of the Scaling Groups page, click Create.

  5. Configure the parameters for the scaling group and click OK.

    The following table describes the parameters.

    Parameter

    Description

    Scaling Group Name

    The name of a scaling group must be 2 to 64 characters in length, and can contain letters, digits, periods (.), underscores (_), and hyphens (-). The name must start with a letter or a digit.

    Type

    The type of instances that provide computing power in the scaling group. The type of instances that Auto Scaling adds to or removes from the scaling group during a scaling activity is also based on the value of the Type parameter. Valid values:

    • ECS: ECS instances

    • ECI: elastic container instances

    Instance Configuration Source

    Auto Scaling creates instances based on the value of the Instance Configuration Source parameter. Valid values:

    • Launch Templates: A launch template contains information such as the key pair, RAM role, instance type, and network settings. A launch template does not contain passwords. The Launch Templates setting is available only if you set the Type parameter to ECS.

      If you set the Instance Configuration Source parameter to Launch Templates, you must also configure the Select Launch Template and Select Template Version parameters. To meet diverse business requirements, you can specify multiple instance types in the Extend Instance Type of Launch Template section. For information about how to specify weights for instance types, see Use performance metrics to measure Auto Scaling.

    • Select Existing Instance: You must select an existing instance. Auto Scaling extracts the basic configurations of the selected instance to create a default scaling configuration.

      If you set the Type parameter to ECS, the basic configurations that are extracted from the selected instance include the instance type, network type, security group, and base image. The instance logon password and tags are not included. The base image is the image that is used by the existing instance. The base image does not include instance data such as application data. If you want to obtain the system configurations and application data of the selected instance, create a custom image for the instance and use the custom image to replace the base image in the scaling configuration. For information about how to replace images, see Update an image in a scaling configuration.

    • Create from Scratch: You can continue to create the scaling group without the need to specify a template. You must specify a scaling configuration or launch template only after you create the scaling group. The steps that you must perform to create a scaling configuration vary based on the value of the Type parameter. For more information, see Create a scaling configuration of the ECS type and Create a scaling configuration of the Elastic Container Instance type.

    Note

    If you create a scaling group based on ECS instances in the ECS console, Auto Scaling automatically fills the instance configuration source and network type. We recommend that you do not modify the settings.

    Tag

    You can add tags to easily find and manage scaling groups. For more information, see Overview.

    Note

    The tags apply only to the scaling group. If you want to add tags to an instance in the scaling group, configure the tags in the scaling configuration or the launch template based on which the instance is created.

    Tags Propagated to Instances During Scale-out

    After you add one or more tags to the scaling group, you can continue to specify the tags that you want to add to instances during scale-outs.

    Scale-In Policy

    If you want to remove instances from the scaling group and you have multiple options, you can configure this parameter. If multiple instances meet the removal conditions after the scale-in policy takes effect, a random instance is removed. This parameter is available only if you set the Type parameter to ECS.

    The Scale-In Policy parameter contains the First Remove and Then Remove fields. Specify different values for the two fields. Valid values:

    Note

    If you set the Type parameter to ECI, Auto Scaling removes the instances that are created based on the earliest scaling configuration. Then, Auto Scaling removes the instances that are created at the earliest point in time from the results that are obtained based on the First Remove field.

    • Earliest Instance Created Using Scaling Configuration: Auto Scaling removes instances that are created based on the earliest scaling configuration or the earliest launch template. No scaling configuration or launch template is associated with instances that are manually added to the scaling group. Therefore, instances that are manually added are not removed first. If more instances need to be removed from a scaling group after Auto Scaling removes all instances with which the earliest scaling configuration or the earliest launch template is associated, Auto Scaling removes manually added instances in a random manner.

      Note

      The scaling configuration source in the Earliest Instance Created Using Scaling Configuration setting can be a scaling configuration or a launch template.

      The version of a launch template does not indicate the order in which the template is added. For example, if you specify the lt-foress V2 launch template when you create a scaling group, and then replace the template with the lt-foress V1 launch template when you modify the scaling group, Auto Scaling considers the lt-foress V2 launch template as the earliest template.

    • Earliest Created Instance: Auto Scaling removes the instances that are created at the earliest point in time.

    • Most Recent Created Instance: Auto Scaling removes the instances that are created at the most recent point in time.

    • Custom Policy: Auto Scaling removes instances from the scaling group based on a custom policy. The custom policy contains a service. service version, and function.

    If Auto Scaling removes instances based on the Earliest Instance Created Using Scaling Configuration setting, you can set the Then Remove field to one of the following values:

    • No Policy: Auto Scaling does not remove instances from the results that are obtained based on the First Remove field.

    • Earliest Created Instance: Auto Scaling removes the instances that are created at the earliest point in time from the results that are obtained based on the First Remove field.

    • Most Recent Created Instance: Auto Scaling removes the instances that are created at the most recent point in time from the results that are obtained based on the First Remove field.

    Note

    The value of the Scaling Policy parameter also affects the manner in which instances are removed from scaling groups. For information about how to remove ECS instances from scaling groups, see Configure a combination policy for removing instances.

    Suspend Process

    You can suspend processes before you perform specific operations. For example, you can suspend the health check process before you stop an instance. This way, if the health check fails, the instance is not removed from the scaling group. You can suspend the following processes in a scaling group:

    • Scale-out: If you suspend this type of process, Auto Scaling rejects all scale-out requests.

    • Scale-in: If you suspend this type of process, Auto Scaling rejects all scale-in requests.

    • Health Check: If you suspend this type of process, Auto Scaling suspends health checks and does not remove unhealthy instances.

    • Scheduled Task: If you suspend this type of process, Auto Scaling does not execute the scaling rules that are associated with a scheduled task when the execution time of the scheduled task arrives.

    • Event-triggered Task: If you suspend this type of process, Auto Scaling does not execute the scaling rules that are associated with an event-triggered task when the event-triggered task enters the Alert state.

    For more information, see Suspend and resume scaling group processes.

    Deletion Protection

    After you enable this feature, you cannot delete the scaling group in the Auto Scaling console or by calling API operations. This helps prevent scaling groups from being accidentally deleted.

    Instance Health Check

    After you enable this feature, Auto Scaling checks the status of instances on a regular basis. If Auto Scaling detects that an instance does not run as expected, Auto Scaling considers the instance unhealthy and removes the instance from the scaling group. For more information, see Instance lifecycles.

    Minimum Number of Instances

    If the number of instances in the scaling group is less than the value of this parameter, Auto Scaling adds instances to the scaling group until the number of instances in the scaling group reaches the minimum number.

    Maximum Number of Instances

    If the number of instances in the scaling group is greater than the value of this parameter, Auto Scaling removes instances from the scaling group until the number of instances in the scaling group does not exceed the maximum number.

    Expected Number of Instances

    If you enable the Expected Number of Instances feature for the scaling group, Auto Scaling maintains the expected number of instances in the scaling group. For more information, see Expected number of instances.

    Note

    You can enable the Expected Number of Instances feature when you create or modify a scaling group. If you want to disable the Expected Number of Instances feature, you can call the ModifyScalingGroup operation.

    Maximum Life Span of Instance (Seconds)

    The maximum life span of an instance in the scaling group. After the specified life span of the instance elapses, Auto Scaling creates a new instance to replace the instance.

    This parameter is available only if you set the Type parameter to ECS.

    Default Cooldown Time (Seconds)

    The cooldown period of the scaling group after a scaling activity is complete. During the cooldown period, Auto Scaling rejects all scaling requests that are triggered by event-triggered tasks. Scaling activities that are triggered by other types of tasks, such as scheduled tasks and manually executed tasks, are not subject to the cooldown period and can be immediately executed.

    Network type

    The following parameters are available only if you set the Network Type parameter to VPC: Scaling Policy, Instance Reclaim Mode, vSwitch, and Associate ALB and NLB Server Groups.

    Note

    If you create a scaling group based on ECS instances in the ECS console, Auto Scaling automatically fills the instance configuration source and network type. We recommend that you do not modify the settings.

    A scaling group and instances in the scaling group must belong to the same network type. For example, if a scaling group resides in a VPC, the instances in the scaling group must also reside in the VPC. If a scaling group resides in the classic network, the instances in the scaling group must also reside in the classic network.

    Important

    After you create a scaling group, you cannot change the network type of the scaling group.

    Scaling Policy

    The Scaling Policy parameter is available only if you set the Type parameter to ECS and the Network Type parameter to VPC. Valid values:

    • Priority Policy: Auto Scaling preferentially creates instances in the zone where the vSwitch that has the highest priority resides. If the scaling fails, Auto Scaling creates instances in the zone where the vSwitch that has the next highest priority resides.

      Note

      By default, if you set the Type parameter to ECI, Priority Policy is used.

    • Balanced Distribution Policy: This policy is valid only if the scaling group is associated with multiple vSwitches that are distributed across two or more zones. Auto Scaling evenly distributes instances across the zones where the vSwitches reside based on the policy. If instances are not evenly distributed across multiple zones due to insufficient resources, you can use Balanced Distribution Policy to evenly redistribute instances across the zones. For more information, see Rebalance the distribution of ECS instances.

    • Cost Optimization Policy: This policy is valid only if you specify multiple instance types in the scaling configuration. When a scale-out is triggered, Auto Scaling preferentially creates ECS instances that have the lowest-priced vCPUs. When a scale-in is triggered, Auto Scaling preferentially removes ECS instances that have the highest-priced vCPUs from the scaling group. If you specify Preemptible Instance as the billing method in the scaling configuration, Auto Scaling preferentially creates preemptible instances. If preemptible instances cannot be created due to insufficient resources, Auto Scaling creates pay-as-you-go instances.

      If you select Cost Optimization Policy, configure the following parameters based on your business requirements:

      • Minimum Pay-as-you-go Instances: the minimum number of pay-as-you-go ECS instances in the scaling group. Default value: 0. If the number of pay-as-you-go ECS instances in the scaling group is less than the value of this parameter, Auto Scaling preferentially creates pay-as-you-go instances.

      • Percentage of Pay-as-you-go Instances: the percentage of pay-as-you-go ECS instances among all ECS instances that are automatically created. Default value: 70%. When you calculate the percentage, the pay-as-you-go ECS instances do not include the minimum number of pay-as-you-go ECS instances that is specified by the Minimum Pay-as-you-go Instances parameter.

      • Lowest Cost Instance Types: the number of lowest-priced instance types. Default value: 1. This parameter takes effect only when multiple instance types are specified in the scaling configuration. Auto Scaling evenly creates preemptible ECS instances of the lowest-priced instance types.

      • Enable Supplemental Preemptible Instances: After you enable this feature, Auto Scaling automatically creates preemptible instances five minutes before the existing instances are reclaimed.

      • Use Pay-as-you-go Instances to Supplement Preemptible Capacity: By default, this feature is enabled. Auto Scaling creates pay-as-you-go instances to meet the requirement on the number of preemptible instances when preemptible instances cannot be created due to factors such as cost-related issues and insufficient resources.

    • Custom Combination Policy: You can create a custom scaling policy. If you want to adjust the ratio of pay-as-you-go instances to preemptible instances, balance the instance distribution between multiple zones, or select desired instance types, you can set the Scaling Policy parameter to Custom Combination Policy.

    Instance Reclaim Mode

    The Instance Reclaim Mode parameter is available only if you set the Type parameter to ECS and the Network Type parameter to VPC. Valid values:

    • Release: releases instances that are removed from the scaling group. In this case, no resources are retained. If a scale-out is triggered, Auto Scaling creates new instances and adds the instances to the scaling group.

      Note

      If you set the Type parameter to ECI, elastic container instances that are removed from the scaling group are released.

    • Economical Mode: stops instances that are removed from the scaling group in Economical Mode. In this case, you are still charged for resources that are retained. If a scale-out is triggered, Auto Scaling preferentially adds the instances that are stopped in Economical Mode to the scaling group. If the number of instances that are in Economical Mode does not meet the scale-out requirement, Auto Scaling creates and adds new instances. The Economical Mode setting helps improve the efficiency of scaling. For more information, see Use the Economical Mode feature to scale instances faster.

      Important
      • Data that is stored on instances may be lost when the instances are reclaimed. To prevent data loss, do not store application data or logs on instances.

      • In the following scenarios, instances that are stopped in Economical Mode may be released:

        • If you manually modify the value of the Maximum Number of Instances parameter for the scaling group and the number of instances in all status in the scaling group is less than the new value of the Maximum Number of Instances parameter, Auto Scaling preferentially releases instances that are stopped in Economical Mode.

        • If your Alibaba Cloud account has overdue payments or insufficient resources, instances that are stopped in Economical Mode may fail to be added to the scaling group during a scale-out. In this case, Auto Scaling may release the failed instances.

      • You can put only pay-as-you-go instances into Economical Mode. For more information about the Economical Mode feature, see the "Prerequisites", "Application resources", and "Trigger effects" sections in the Economical mode topic.

    • Forcibly Release: forcibly releases ECS instances that are in the Running state during scale-ins. Forcible release is equivalent to power outage. If you allow the system to forcibly release an instance, ephemeral data on the instance will be cleared beyond recovery. Exercise caution when you select this option.

    VPC

    Select an existing VPC.

    Note

    If you create a scaling group based on ECS instances in the ECS console, Auto Scaling automatically fills the instance configuration source and network type. We recommend that you do not modify the settings.

    vSwitch

    After you select a VPC, you must select one or more vSwitches. Each vSwitch resides in a single zone. To deploy instances across multiple zones, you can specify multiple vSwitches. We recommend that you select multiple zones to increase the success rate of scale-outs.

    Note

    If you create a scaling group based on ECS instances in the ECS console, Auto Scaling automatically fills the instance configuration source and network type. We recommend that you do not modify the settings.

    When you create a scaling group, you must specify VPCs and vSwitches. If the launch template that is used by the scaling group also has VPCs and vSwitches, the VPCs and vSwitches of the scaling group override the VPCs and vSwitches of the launch template during scale-outs. In this case, Auto Scaling creates ECS instances in the zones where the vSwitches of the scaling group reside, instead of the zones where the vSwitches of the launch template that is used by the scaling group reside. Example:

    • Set the VPC parameter to VPC-A.

    • Set the vSwitch parameter to vSwitch-A.

    • Set the Instance Configuration Source parameter to Launch Templates.

      The selected launch template uses VPC-B as the value of the VPC parameter and vSwitch-B as the value of the vSwitch parameter.

    In this example, Auto Scaling creates ECS instances of the VPC-A network type in the zone where vSwitch-A resides during a scale-out.

    Add Existing Instance

    The Add Existing Instance parameter is available only if you set the Type parameter to ECS and set the Instance Configuration Source parameter to Launch Template or Select Existing Instance.

    If you configure the Expected Number of Instances and Add Existing Instance parameters at the same time, the value of the Expected Number of Instances parameter automatically increases. For example, if you set the Expected Number of Instances parameter to 1 and set the Add Existing Instance parameter to 2 when you create a scaling group, the value of the Expected Number of Instances parameter automatically increases from 1 to 3.

    If you want to use the scaling group to manage the instance lifecycles, you can select Enable the scaling group to manage the instance lifecycle.

    • If you enable this feature, Auto Scaling may remove instances that are considered unhealthy. Auto Scaling may also release the instances that you manually remove from the scaling group.

    • If you do not enable this feature, Auto Scaling does not release instances that are removed from the scaling group.

    Note

    You can add subscription instances to the scaling group, but you cannot enable the scaling group to manage the lifecycles of the subscription instances.

    Associate CLB Instance

    After you associate a CLB instance with a scaling group, Auto Scaling adds the instances in the scaling group to the backend server groups of the CLB instance as backend servers. Then, the CLB instance forwards requests to the backend servers.

    You can specify the following types of server groups to which you can add instances. Valid values:

    • Default server group: the group of instances that are used to receive requests. If you do not specify a vServer group or a primary/secondary server group for a listener, requests are forwarded to the instances in the default server group.

    • vServer group: If you want to forward requests to backend servers that are not in the default server group or configure domain name- or URL-based routing methods, you can use vServer groups.

    If you specify the default server group and multiple vServer groups at the same time, the instances are added to all specified server groups.

    Note

    You can associate only a limited number of CLB instances and vServer groups with a scaling group. To view the quota or request a quota increase, go to Quota Center.

    Associate ALB and NLB Server Groups

    The Associate ALB and NLB Server Groups parameter is available only if you set the Network Type parameter to VPC. After you associate an ALB or NLB server group with a scaling group, Auto Scaling adds instances in the scaling group to the ALB or NLB server group as backend servers. Then, the ALB or NLB instance forwards requests to the backend servers. You must specify the port number and weight for each backend server. By default, the weight of a backend server is 50. If you increase the weight of a server, the number of requests that are forwarded to the server also increases. If you set the weight of a backend server to 0, no requests are forwarded to the server.

    If you associate multiple ALB or NLB server groups with the same scaling group, Auto Scaling adds instances in the scaling group to all associated ALB or NLB server groups at the same time.

    Note

    You can associate only a limited number of ALB or NLB server groups with a scaling group. To view the quota or request a quota increase, go to Quota Center.

    Associate ApsaraDB RDS Instance

    The Associate ApsaraDB RDS Instance parameter is available only if you set the Type parameter to ECS. After you associate an ApsaraDB RDS instance with a scaling group, Auto Scaling adds the private IP addresses of the ECS instances in the scaling group to the IP address whitelist of the ApsaraDB RDS instance. This way, the ECS instances in the scaling group can communicate with the ApsaraDB RDS instance over an internal network.

    Note

    You can associate only a limited number of ApsaraDB RDS instances with a scaling group. To view the quota or request a quota increase, go to Quota Center.

    Create Regular Rule

    When a scaling activity succeeds, fails, or is rejected, Auto Scaling notifies you by text messages, internal messages, or emails based on the rule. For more information, see Create a regular notification rule.

    Resource Group

    You can add scaling groups to resource groups. Then you can manage scaling group resources by resource group. This facilitates resource isolation and permission control. For more information, see Use resource groups to manage scaling groups in a fine-grained manner.

    Synchronize Alert Rule to CloudMonitor

    You can enable or disable this feature only when you create a scaling group. After you enable this feature, Alibaba Cloud creates and associates a CloudMonitor application group with the scaling group. The alert rules of the scaling group are displayed in the CloudMonitor console in a synchronous manner.

  6. In the Create Scaling Group dialog box, click OK.

    On the Scaling Groups page, you can view the scaling group that you create. The scaling group is in the Disabled state. Scale-outs and scale-ins can be triggered only in scaling groups that are in the Enabled state. For more information, see Enable or disable scaling groups.

Enable or disable scaling groups

Precautions

  • If a scaling group is in the Disabled state and the scaling group has a specific launch template or an active scaling configuration, you must enable the scaling group before scaling activities can be triggered in the scaling group.

  • If a scaling group is in the Enabled state and you no longer require the scaling group, you can disable the scaling group. If a scaling activity is in progress when you disable a scaling group, the scaling activity continues until the activity is complete. Scaling requests that are initiated after the scaling group is disabled are rejected.

Procedure

  1. Log on to the Auto Scaling console.
  2. In the left-side navigation pane, click Scaling Groups.
  3. In the top navigation bar, select the region where Auto Scaling is activated.
  4. Enable or disable a scaling group.

    • Enable a scaling group: Find the scaling group that you want to enable and choose more > Enable in the Actions column. Then, the scaling group enters the Enabled state.

    • Disable a scaling group: Find the scaling group that you want to disable and choose more > Disable in the Actions column. In the Disable Scaling Group message, click OK. Then, the scaling group enters the Disabled state.

View or modify scaling groups

Precautions

  • After you create a scaling group, you can view the basic information, instance list, scaling configuration source, scaling rules, and lifecycle hooks of the scaling group in the Auto Scaling console. This way, you can understand the basic configurations of the scaling group and the basic information about the ECS instances or elastic container instances in the scaling group.

  • If your scaling group no longer meets your business requirements, you can modify the parameter settings of the scaling group, instead of creating a new scaling group. The following table describes the parameters that you can modify.

    Parameter

    Description

    Minimum Number of Instances, Maximum Number of Instances, and Expected Number of Instances

    • If the number of ECS instances or elastic container instances is outside the new range after you reconfigure the Minimum Number of Instances and Maximum Number of Instances parameters, Auto Scaling adds instances to or removes instances from the scaling group until the number of instances is within the new range.

    • If you do not specify an expected number of instances for the scaling group and the number of instances drops below the minimum number of instances that must be contained after you reconfigure the Minimum Number of Instances parameter, Auto Scaling adds instances to the scaling group until the number of instances is equal to the new value of the Minimum Number of Instances parameter.

    • If you specify an expected number of instances for the scaling group and the current number of instances in the scaling group does not match the value of the Expected Number of Instances parameter after you reconfigure the Expected Number of Instances parameter, Auto Scaling adds or removes instances until the number of instances matches the new value of the Expected Number of Instances parameter.

    Associate ApsaraDB RDS Instance

    If you want to modify the setting of the ApsaraDB RDS Instance parameter for a scaling group of the ECS type or Elastic Container Instance type, select the When you associate RDS instances with or disassociate RDS instances from the scaling group, existing ECS instances in the scaling group are added to or removed from the whitelists of the RDS instances check box based on your business requirements.

    • If you select the check box, Auto Scaling adds the private IP addresses of the ECS instances or elastic container instances to the IP address whitelist of the associated ApsaraDB RDS instance during scale-outs and removes the private IP addresses from the IP address whitelist during scale-ins.

    • If you do not select the check box, the IP address whitelist of the associated ApsaraDB RDS instance remains unchanged after scaling activities are complete.

    Associate CLB Instance and Associate ALB and NLB Server Groups

    If you want to modify the settings of the Associate CLB Instance and Associate ALB and NLB Server Groups parameters for a scaling group of the ECS or ECI type, select the When you associate SLB instances with or disassociate SLB instances from the scaling group, existing instances in the scaling group are added to or removed from the server groups of the SLB instances check box based on your business requirements.

    • If you select the check box, Auto Scaling adds the instances during scale-outs to the backend server groups of the CLB, ALB, or NLB instances and removes the instances during scale-ins from the backend server groups of the CLB, ALB, or NLB instances.

    • If you do not select the check box, the backend server groups remain unchanged after scaling activities are complete.

Procedure

  1. Log on to the Auto Scaling console.
  2. In the left-side navigation pane, click Scaling Groups.
  3. In the top navigation bar, select the region where Auto Scaling is activated.
  4. View or modify a scaling group.

    Action

    Procedure

    View a scaling group

    1. On the Scaling Groups page, find the scaling group whose information you want to view.

      The page that appears displays the following information about the scaling group: the scaling group name or ID, type, status, instance configuration source, and network settings.

      Note

      If an exception occurs on the scaling group, the 图标 icon appears in the Status column. You can move the pointer over the icon to view the error message and troubleshoot the error.

    2. Find the scaling group and click Details in the Actions column.

    3. In the upper part of the scaling group details page, click different tabs to view the details of the scaling group.

      You can view the basic information, instance configuration source, instance list, monitoring information, scaling rules, scaling activities, lifecycle hooks, notification rules, and rolling updates of the scaling group.

    Modify a scaling group

    1. On the Scaling Groups page, find the scaling group that you want to modify and click Edit in the Actions column.

    2. Modify the parameter settings of the scaling group.

      For information about the parameters of a scaling group, see Manage scaling groups.

    3. Click OK.

Delete scaling groups

Usage notes

  • If you no longer require a scaling group, you can delete the scaling group to free up the scaling group quota. If you delete a scaling group, the scaling configurations and scaling rules of the scaling group are also deleted. If the scaling group that you want to delete contains ECS instances or elastic container instances that are in the In Service state, Auto Scaling stops the instances and then removes all manually added instances from the scaling group and releases all automatically created instances in the scaling group before the scaling group is deleted.

    Note

    Before you delete a scaling group, make sure that the Deletion Protection feature is disabled for the scaling group. If the Deletion Protection feature is enabled for the scaling group, you must disable the feature in the Edit Scaling Group dialog box before you can delete the scaling group.

  • If you enable the Deletion Protection feature when you create a scaling group, you cannot delete the scaling group in the Auto Scaling console or by using an API operation. The Deletion Protection feature helps prevent scaling groups from being accidentally deleted.

  • If you enable the Release Protection feature when you create an ECS instance and you want to delete the scaling group that manages the ECS instance, Auto Scaling forcibly removes the ECS instance from the scaling group and releases all automatically created ECS instances together with the scaling group.

    Important

    To prevent an ECS instance in a scaling group from being forcibly released after you delete the scaling group, in addition to enabling the Release Protection feature for the ECS instance, you must also put the ECS instance into the Protected state. For information about how to put ECS instances into the Protected state, see SetInstancesProtection.

Procedure

  1. Log on to the Auto Scaling console.
  2. In the left-side navigation pane, click Scaling Groups.
  3. In the top navigation bar, select the region where Auto Scaling is activated.
  4. Find the scaling group that you want to delete and choose menu > Set Deletion Protection in the Actions column.

  5. In the dialog box that appears, check whether the Deletion Protection feature is enabled.

    • If the Deletion Protection feature is enabled, disable the feature and click OK.

    • If the Deletion Protection feature is disabled, click OK.

  6. Find the scaling group that you want to delete and click Delete in the Actions column.

  7. In the Delete Scaling Group message, click OK.

    The scaling group enters the Deleting state. After the scaling group is deleted, the scaling group is no longer displayed on the Scaling Groups page.