AWS::EC2::PlacementGroup
Specifies a placement group in which to launch instances. The strategy of the placement group determines how the instances are organized within the group.
A cluster
placement group is a logical grouping of instances within a
single Availability Zone that benefit from low network latency, high network throughput. A
spread
placement group places instances on distinct hardware. A
partition
placement group places groups of instances in different
partitions, where instances in one partition do not share the same hardware with instances
in another partition.
For more information, see Placement Groups in the Amazon EC2 User Guide.
Syntax
To declare this entity in your AWS CloudFormation template, use the following syntax:
JSON
{ "Type" : "AWS::EC2::PlacementGroup", "Properties" : { "PartitionCount" :
Integer
, "SpreadLevel" :String
, "Strategy" :String
, "Tags" :[ Tag, ... ]
} }
YAML
Type: AWS::EC2::PlacementGroup Properties: PartitionCount:
Integer
SpreadLevel:String
Strategy:String
Tags:- Tag
Properties
PartitionCount
-
The number of partitions. Valid only when Strategy is set to
partition
.Required: No
Type: Integer
Update requires: Replacement
SpreadLevel
-
Determines how placement groups spread instances.
-
Host – You can use
host
only with Outpost placement groups. -
Rack – No usage restrictions.
Required: No
Type: String
Allowed values:
host | rack
Update requires: Replacement
-
Strategy
-
The placement strategy.
Required: No
Type: String
Allowed values:
cluster | spread | partition
Update requires: Replacement
-
The tags to apply to the new placement group.
Required: No
Type: Array of Tag
Update requires: Replacement
Return values
Ref
When you pass the logical ID of this resource to the intrinsic Ref
function, Ref
returns the name of the placement group.
For more information about using the Ref
function, see Ref
.
Fn::GetAtt
The Fn::GetAtt
intrinsic function returns a value for a specified attribute of this type. The following are the available attributes and sample return values.
For more information about using the Fn::GetAtt
intrinsic function, see Fn::GetAtt
.
GroupName
-
The name of the placement group.
Examples
Create a placement group
The following example declares a placement group with a cluster placement strategy.
JSON
"PlacementGroup" : { "Type" : "AWS::EC2::PlacementGroup", "Properties" : { "Strategy" : "cluster" } }
YAML
PlacementGroup: Type: AWS::EC2::PlacementGroup Properties: Strategy: cluster