# Capacity configuration for your Elastic Beanstalk environment
This topic describes the different approaches to configure Auto Scaling capacity for your Elastic Beanstalk environment. You can use the Elastic Beanstalk console, the EB CLI, the AWS CLI, or namespace options.
**Important**
The `EnableSpot` option setting can cause Elastic Beanstalk to migrate an existing environment with launch configurations to launch templates. Doing so requires the necessary permissions to manage launch templates. These permissions are included in our managed policy. If you use custom policies instead of our managed policies, environment creation or updates might fail when you update your environment configuration. For more information and other considerations, see [Migrating your Elastic Beanstalk environment to launch templates](environments-cfg-autoscaling-launch-templates.md).
## Configuration using the console
You can configure the capacity management of an Auto Scaling group by editing **Capacity** on the environment's **Configuration** page in the [Elastic Beanstalk console](environments-console.md).
**To configure Auto Scaling group capacity in the Elastic Beanstalk console**
1. Open the [Elastic Beanstalk console](https://console.aws.amazon.com/elasticbeanstalk), and in the **Regions** list, select your AWS Region.
1. In the navigation pane, choose **Environments**, and then choose the name of your environment from the list.
1. In the navigation pane, choose **Configuration**.
1. In the **Capacity** configuration category, choose **Edit**.
1. In the **Auto Scaling group** section, configure the following settings.
+ **Environment type** – Select **Load balanced**.
+ **Min instances** – The minimum number of EC2 instances that the group should contain at any time. The group starts with the minimum count and adds instances when the scale-up trigger condition is met.
+ **Max instances** – The maximum number of EC2 instances that the group should contain at any time.
**Note**
If you use rolling updates, be sure that the maximum instance count is higher than the [**Minimum instances in service** setting](using-features.rollingupdates.md#rollingupdates-configure) for rolling updates.
+ **Fleet composition** – The default is **On-Demand Instances**. To enable *Spot Instance* requests, select **Combined purchase options and instances**.
**Important**
The `EnableSpot` option setting can cause Elastic Beanstalk to migrate an existing environment with launch configurations to launch templates. Doing so requires the necessary permissions to manage launch templates. These permissions are included in our managed policy. If you use custom policies instead of our managed policies, environment creation or updates might fail when you update your environment configuration. For more information and other considerations, see [Migrating your Elastic Beanstalk environment to launch templates](environments-cfg-autoscaling-launch-templates.md).
The following options are enabled if you select to enable *Spot Instance* requests:
+ **Spot allocation strategy** – Determines the method used to manage and provision the Spot Instances in your environment, based on available capacity, price, and selection of instance types. Select from *Capacity optimized* (default), *Price capacity optimized*, *Capacity optimized prioritized*, or *Lowest price*. For a description of each allocation strategy and more information, see [Spot Instance allocation strategy](environments-cfg-autoscaling-spot-allocation-strategy.md).
+ **Maximum spot price** – For recommendations about maximum price options for Spot Instances, see [Spot Instance pricing history](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-spot-instances-history.html) in the *Amazon EC2 User Guide*.
+ **On-Demand base** – The minimum number of On-Demand Instances that your Auto Scaling group provisions before considering Spot Instances as your environment scales out.
+ **On-Demand above base** – The percentage of On-Demand Instances as part of any additional capacity that your Auto Scaling group provisions beyond the On-Demand base instances.
**Note**
The options **On-Demand base** and **On-Demand above base** correlate to the **Min** and **Max** *Instances* options listed earlier. For more information about these options and examples, see [Spot Instance support for your Elastic Beanstalk environment](environments-cfg-autoscaling-spot.md).
+ **Capacity Rebalancing** – This option is only relevant when there is at least one Spot Instance in your Auto Scaling group. When this feature is enabled, EC2 automatically attempts to replace Spot Instances in the Auto Scaling group before they're interrupted, minimizing Spot Instance interruptions to your applications. For more information, see [Capacity Rebalancing](https://docs.aws.amazon.com/autoscaling/ec2/userguide/capacity-rebalance.html) in the *Amazon EC2 Auto Scaling User Guide*
+ **Architecture** – The processor architecture for your EC2 instances. The processor architecture determines the EC2 Instance types that become available in the next field.
+ **Instance types** – The types of Amazon EC2 instance launched to run your application. For details, see [Instance types](using-features.managing.ec2.console.md#using-features.managing.ec2.instancetypes).
+ **AMI ID** – The machine image that Elastic Beanstalk uses to launch Amazon EC2 instances in your environment. For details, see [AMI ID](using-features.managing.ec2.console.md#using-features.managing.ec2.customami).
+ **Availability Zones** – Choose the number of Availability Zones to spread your environment's instances across. By default, the Auto Scaling group launches instances evenly across all usable zones. To concentrate your instances in fewer zones, choose the number of zones to use. For production environments, use at least two zones to ensure that your application is available in case one Availability Zone goes out.
+ **Placement** (optional) – Choose the Availability Zones to use. Use this setting if your instances need to connect to resources in specific zones, or if you have purchased [reserved instances](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/concepts-on-demand-reserved-instances.html), which are zone-specific. If you launch your environment in a custom VPC, you cannot configure this option. In a custom VPC, you choose Availability Zones for the subnets that you assign to your environment.
+ **Scaling cooldown** – The amount of time, in seconds, to wait for instances to launch or terminate after scaling, before continuing to evaluate triggers. For more information, see [Scaling Cooldowns](https://docs.aws.amazon.com/autoscaling/ec2/userguide/Cooldown.html).
1. To save the changes choose **Apply** at the bottom of the page.
## Configuration using namespace options
Elastic Beanstalk provides [configuration options](command-options.md) for Auto Scaling settings in two namespaces: [`aws:autoscaling:asg`](command-options-general.md#command-options-general-autoscalingasg) and [`aws:ec2:instances`](command-options-general.md#command-options-general-ec2instances).
### The aws:autoscaling:asg namespace
The [`aws:autoscaling:asg`](command-options-general.md#command-options-general-autoscalingasg) namespace provides options for overall scale and availability.
The following [configuration file](ebextensions.md) example configures the Auto Scaling group to use two to four instances, specific availability zones, and a cooldown period of 12 minutes (720 seconds). It enables [Capacity Rebalancing](https://docs.aws.amazon.com/autoscaling/ec2/userguide/capacity-rebalance.html) for Spot Instances. This `EnableCapacityRebalancing` option only takes effect if `EnableSpot` is set to `true` in the [`aws:ec2:instances`](command-options-general.md#command-options-general-ec2instances) namespace, as shown in the configuration file example following this one.
```
option_settings:
aws:autoscaling:asg:
Availability Zones: Any
Cooldown: '720'
Custom Availability Zones: 'us-west-2a,us-west-2b'
MaxSize: '4'
MinSize: '2'
EnableCapacityRebalancing: true
```
### The aws:ec2:instances namespace
**Note**
When you update your environment configuration and remove one or more instance types from the `InstanceTypes` option, Elastic Beanstalk terminates any Amazon EC2 instances running on any of the removed instance types. Your environment's Auto Scaling group then launches new instances, as necessary to complete the desired capacity, using your current specified instance types.
The [`aws:ec2:instances`](command-options-general.md#command-options-general-ec2instances) namespace provides options related to your environment's instances, including Spot Instance management. It complements [`aws:autoscaling:launchconfiguration`](command-options-general.md#command-options-general-autoscalinglaunchconfiguration) and [`aws:autoscaling:asg`](command-options-general.md#command-options-general-autoscalingasg).
The following [configuration file](ebextensions.md) example configures the Auto Scaling group to enable Spot Instance requests for your environment. It designates three possible instance types that can be used. At least one On-Demand Instance is used for baseline capacity, and a sustained 33% of On-Demand Instances is used for any additional capacity.
The configuration sets the [spot allocation strategy](environments-cfg-autoscaling-spot-allocation-strategy.md) to `capacity-optimized-prioritized`. This particular allocation strategy prioritizes the instance launches from the pool based on the order of the instance types specified in the `InstanceTypes` option. If `SpotAllocationStrategy` is not specified it defaults to `capacity-optimized`.
```
option_settings:
aws:ec2:instances:
EnableSpot: true
InstanceTypes: 't2.micro,t3.micro,t3.small'
SpotAllocationStrategy: capacity-optimized-prioritized
SpotFleetOnDemandBase: '1'
SpotFleetOnDemandAboveBasePercentage: '33'
```
To choose Spot Instance types, use the [Spot Instance Advisor](https://aws.amazon.com/ec2/spot/instance-advisor/).
**Important**
The `EnableSpot` option setting can cause Elastic Beanstalk to migrate an existing environment with launch configurations to launch templates. Doing so requires the necessary permissions to manage launch templates. These permissions are included in our managed policy. If you use custom policies instead of our managed policies, environment creation or updates might fail when you update your environment configuration. For more information and other considerations, see [Migrating your Elastic Beanstalk environment to launch templates](environments-cfg-autoscaling-launch-templates.md).
## Configuration using the AWS CLI
This section provides examples of how you can use the AWS CLI [create-environment](https://docs.aws.amazon.com/cli/latest/reference/elasticbeanstalk/create-environment.html) command to configure your environment with the Auto Scaling and Capacity options described in these sections. You'll notice the namespace settings for [`aws:autoscaling:asg`](command-options-general.md#command-options-general-autoscalingasg) and [`aws:ec2:instances`](command-options-general.md#command-options-general-ec2instances), as described in the previous [namespace configuration options](#environments-cfg-autoscaling-namespace) section are also configured with this example.
The AWS Command Line Interface provides commands to create and configure Elastic Beanstalk environments. With the `--option-settings` option, you can pass in namespace options that are supported by Elastic Beanstalk. This means that the [namespace configuration options](#environments-cfg-autoscaling-namespace) described previously can be passed into applicable AWS CLI commands to configure your Elastic Beanstalk environment.
**Note**
You can also use the [update-environment](https://docs.aws.amazon.com/cli/latest/reference/elasticbeanstalk/update-environment.html) command with `--option-settings` to add or update namespace options. If you need to remove any namespace options from your environment use the **update-environment** command with `--options-to-remove`.
The following example creates a new environment. Refer to the previous topic [namespace configuration options](#environments-cfg-autoscaling-namespace) for more context about the options that are passed in.
The fist option listed, `IamInstanceProfile` in the [aws:autoscaling:launchconfiguration](command-options-general.md#command-options-general-autoscalinglaunchconfiguration) namespace, is the Elastic Beanstalk [instance profile](concepts-roles-instance.md). It's required when you create a new environment.
**Example — create-environment with Auto Scaling options (namespace options inline)**
```
aws elasticbeanstalk create-environment \
--region us-east-1 \
--application-name my-app \
--environment-name my-env \
--solution-stack-name "64bit Amazon Linux 2023 v4.3.0 running Python 3.12" \
--option-settings \
Namespace=aws:autoscaling:launchconfiguration,OptionName=IamInstanceProfile,Value=aws-elasticbeanstalk-ec2-role
Namespace=aws:autoscaling:asg,OptionName=Availability Zones,Value=Any \
Namespace=aws:autoscaling:asg,OptionName=Cooldown,Value=720 \
Namespace=aws:autoscaling:asg,OptionName=Custom Availability Zones,Value=us-west-2a,us-west-2b \
Namespace=aws:autoscaling:asg,OptionName=MaxSize,Value=4 \
Namespace=aws:autoscaling:asg,OptionName=MinSize,Value=2 \
Namespace=aws:autoscaling:asg,OptionName=EnableCapacityRebalancing,Value=true \
Namespace=aws:ec2:instances,OptionName=EnableSpot,Value=true \
Namespace=aws:ec2:instances,OptionName=InstanceTypes,Value=t2.micro,t3.micro,t3.small \
Namespace=aws:ec2:instances,OptionName=SpotAllocationStrategy,Value=capacity-optimized-prioritized \
Namespace=aws:ec2:instances,OptionName=SpotFleetOnDemandBase,Value=1 \
Namespace=aws:ec2:instances,OptionName=SpotFleetOnDemandAboveBasePercentage,Value=33
```
**Important**
The `EnableSpot` option setting can cause Elastic Beanstalk to migrate an existing environment with launch configurations to launch templates. Doing so requires the necessary permissions to manage launch templates. These permissions are included in our managed policy. If you use custom policies instead of our managed policies, environment creation or updates might fail when you update your environment configuration. For more information and other considerations, see [Migrating your Elastic Beanstalk environment to launch templates](environments-cfg-autoscaling-launch-templates.md).
As an alternative, use an `options.json` file to specify the namespace options instead of including them inline.
**Example —create-environment with Auto Scaling options (namespace options in `options.json` file)**
```
aws elasticbeanstalk create-environment \
--region us-east-1 \
--application-name my-app \
--environment-name my-env \
--solution-stack-name "64bit Amazon Linux 2023 v4.3.0 running Python 3.12"
--option-settings file://options.json
```
**Example**
```
### example options.json ###
[
{
"Namespace": "aws:autoscaling:launchconfiguration",
"OptionName": "IamInstanceProfile",
"Value": "aws-elasticbeanstalk-ec2-role"
},
{
"Namespace": "aws:autoscaling:asg",
"OptionName": "Availability Zones",
"Value": "Any"
},
{
"Namespace": "aws:autoscaling:asg",
"OptionName": "Cooldown",
"Value": "720"
},
{
"Namespace": "aws:autoscaling:asg",
"OptionName": "Custom Availability Zones",
"Value": "us-west-2a,us-west-2b"
},
{
"Namespace": "aws:autoscaling:asg",
"OptionName": "MaxSize",
"Value": "4"
},
{
"Namespace": "aws:autoscaling:asg",
"OptionName": "MinSize",
"Value": "2"
},
{
"Namespace": "aws:autoscaling:asg",
"OptionName": "EnableCapacityRebalancing",
"Value": "true"
},
{
"Namespace": "aws:ec2:instances",
"OptionName": "EnableSpot",
"Value": "true"
},
{
"Namespace": "aws:ec2:instances",
"OptionName": "InstanceTypes",
"Value": "t2.micro,t3.micro,t3.small"
},
{
"Namespace": "aws:ec2:instances",
"OptionName": "SpotAllocationStrategy",
"Value": "capacity-optimized-prioritized"
},
{
"Namespace": "aws:ec2:instances",
"OptionName": "SpotFleetOnDemandBase",
"Value": "1"
},
{
"Namespace": "aws:ec2:instances",
"OptionName": "SpotFleetOnDemandAboveBasePercentage",
"Value": "33"
}
]
```
## Configuration using the EB CLI
When creating an environment using the [**eb create**](eb3-create.md) command, you can specify a few options that are related to your environment's Auto Scaling group. These are some of the options that help you control the capacity of your environment.
`--single`
Creates the environment with one Amazon EC2 instance and no load balancer. If you don't use this option, a load-balancer is added to the environment that's created.
`--enable-spot`
Enables Spot Instance requests for your environment.
The `enable-spot` option setting can cause Elastic Beanstalk to migrate an existing environment with launch configurations to launch templates. Doing so requires the necessary permissions to manage launch templates. These permissions are included in our managed policy. If you use custom policies instead of our managed policies, environment creation or updates might fail when you update your environment configuration. For more information and other considerations, see [Migrating your Elastic Beanstalk environment to launch templates](environments-cfg-autoscaling-launch-templates.md).
The following options for the [**eb create**](eb3-create.md) command can only be used with `--enable-spot`.
`--instance-types`
Lists the Amazon EC2 instance types that you want your environment to use.
`--spot-max-price`
The maximum price per unit hour, in US dollars, that you're willing to pay for a Spot Instance. For recommendations about maximum price options for Spot Instances, see [Spot Instance pricing history](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-spot-instances-history.html) in the *Amazon EC2 User Guide*.
`--on-demand-base-capacity`
The minimum number of On-Demand Instances that your Auto Scaling group provisions before considering Spot Instances as your environment scales up.
`--on-demand-above-base-capacity`
The percentage of On-Demand Instances as part of additional capacity that your Auto Scaling group provisions that's more than the number of instances that's specified by the `--on-demand-base-capacity` option.
The following example creates an environment and configures the Auto Scaling group to enable Spot Instance requests for the new environment. For this example, three possible instance types can be used.
```
$ eb create --enable-spot --instance-types "t2.micro,t3.micro,t3.small"
```
**Important**
There is another similarly named option that's called `--instance-type` (no “s”) that the EB CLI only recognizes when processing On-Demand Instances. Don't use `--instance-type` (no "s") with the `--enable-spot` option. If you do, the EB CLI ignores it. Instead use `--instance-types` (with "s") with the `--enable-spot` option.