PlacementGroup

class aws_cdk.aws_ec2.PlacementGroup(scope, id, *, partitions=None, placement_group_name=None, spread_level=None, strategy=None)

Bases: Resource

Defines a placement group.

Placement groups give you fine-grained control over where your instances are provisioned.

ExampleMetadata:: fixture=with-vpc infused

Example:

# instance_type: ec2.InstanceType


pg = ec2.PlacementGroup(self, "test-pg",
    strategy=ec2.PlacementGroupStrategy.SPREAD
)

ec2.Instance(self, "Instance",
    vpc=vpc,
    instance_type=instance_type,
    machine_image=ec2.MachineImage.latest_amazon_linux2023(),
    placement_group=pg
)

Parameters:

scope (Construct) –
id (str) –
partitions (Union[int, float, None]) – The number of partitions. Valid only when Strategy is set to partition. Default: 0
placement_group_name (Optional[str]) – the name of this placement group. Default: - generated by CFN
spread_level (Optional[PlacementGroupSpreadLevel]) – Places instances on distinct hardware. Spread placement groups are recommended for applications that have a small number of critical instances that should be kept separate from each other. Launching instances in a spread level placement group reduces the risk of simultaneous failures that might occur when instances share the same equipment. Spread level placement groups provide access to distinct hardware, and are therefore suitable for mixing instance types or launching instances over time. If you start or launch an instance in a spread placement group and there is insufficient unique hardware to fulfill the request, the request fails. Amazon EC2 makes more distinct hardware available over time, so you can try your request again later. Placement groups can spread instances across racks or hosts. You can use host level spread placement groups only with AWS Outposts. Default: - no spread level
strategy (Optional[PlacementGroupStrategy]) – Which strategy to use when launching instances. Default: - PlacementGroupStrategy.PARTITION if partitions is defined, CLUSTER otherwise

Methods

apply_removal_policy(policy)

Apply the given removal policy to this resource.

The Removal Policy controls what happens to this resource when it stops being managed by CloudFormation, either because you’ve removed it from the CDK application or because you’ve made a change that requires the resource to be replaced.

The resource can be deleted (RemovalPolicy.DESTROY), or left in your AWS account for data recovery and cleanup later (RemovalPolicy.RETAIN).

Parameters:

policy (RemovalPolicy) –

Return type:

None

to_string()

Returns a string representation of this construct.

Return type:: str

Attributes

env

The environment this resource belongs to.

For resources that are created and managed by the CDK (generally, those created by creating new class instances like Role, Bucket, etc.), this is always the same as the environment of the stack they belong to; however, for imported resources (those obtained from static methods like fromRoleArn, fromBucketName, etc.), that might be different than the stack they were imported into.

node: The tree node.

partitions

The number of partitions.

Valid only when Strategy is set to PARTITION.

placement_group_name: The name of this placement group.

spread_level

Places instances on distinct hardware.

Spread placement groups are recommended for applications that have a small number of critical instances that should be kept separate from each other. Launching instances in a spread level placement group reduces the risk of simultaneous failures that might occur when instances share the same equipment. Spread level placement groups provide access to distinct hardware, and are therefore suitable for mixing instance types or launching instances over time. If you start or launch an instance in a spread placement group and there is insufficient unique hardware to fulfill the request, the request fails. Amazon EC2 makes more distinct hardware available over time, so you can try your request again later. Placement groups can spread instances across racks or hosts. You can use host level spread placement groups only with AWS Outposts.

stack: The stack in which this resource is defined.

strategy: Which strategy to use when launching instances.

Static Methods

classmethod from_placement_group_name(scope, id, placement_group_name)

Import a PlacementGroup by its arn.

Parameters:

scope (Construct) –
id (str) –
placement_group_name (str) –

Return type:

IPlacementGroup

classmethod is_construct(x)

Checks if x is a construct.

Use this method instead of instanceof to properly detect Construct instances, even when the construct library is symlinked.

Explanation: in JavaScript, multiple copies of the constructs library on disk are seen as independent, completely different libraries. As a consequence, the class Construct in each copy of the constructs library is seen as a different class, and an instance of one class will not test as instanceof the other class. npm install will not create installations like this, but users may manually symlink construct libraries together or use a monorepo tool: in those cases, multiple copies of the constructs library can be accidentally installed, and instanceof will behave unpredictably. It is safest to avoid using instanceof, and using this type-testing method instead.

Parameters:: x (Any) – Any object.
Return type:: bool
Returns:: true if x is an object created from a class which extends Construct.

classmethod is_owned_resource(construct)

Returns true if the construct was created by CDK, and false otherwise.

Parameters:

construct (IConstruct) –

Return type:

bool

classmethod is_resource(construct)

Check whether the given construct is a Resource.

Parameters:

construct (IConstruct) –

Return type:

bool