@groups = $ec2->describe_placement_groups(@group_names)

@groups = $ec2->describe_placement_groups(\%filters)

@groups = $ec2->describe_placement_groups(-group_name=>\@ids,-filter=>\%filters)

This method will return information about cluster placement groups as a list of VM::EC2::PlacementGroup objects.

Optional arguments:

 -group_name         -- Scalar or arrayref of placement group names.
 -filter             -- Tags and other filters to apply.

The filters available are described fully at: http://docs.amazonwebservices.com/AWSEC2/latest/APIReference/ApiReference-query-DescribePlacementGroups.html

    group-name
    state
    strategy

$success = $ec2->create_placement_group($group_name)

$success = $ec2->create_placement_group(-group_name=>$name,-strategy=>$strategy)

Creates a placement group that cluster instances are launched into.

Required arguments:
-group_name -- The name of the placement group to create

Optional:
-strategy -- As of 2012-12-23, the only available option is 'cluster'
so the parameter defaults to that.

Returns true on success.

$success = $ec2->delete_placement_group($group_name)

$success = $ec2->delete_placement_group(-group_name=>$group_name)

Deletes a placement group from the account.

Required arguments:
-group_name -- The name of the placement group to delete

Returns true on success.