Sample Policies XML File

<policies>
    <policy name="single" isDefault="true">
        <description>Single - Instances: Min 1, Max 1</description>
        <min_app_instances>1</min_app_instances>
        <max_app_instances>1</max_app_instances>
        <max_requests_per_second>5</max_requests_per_second>
        <alarming_upper_rate>0.7</alarming_upper_rate>
        <alarming_lower_rate>0.2</alarming_lower_rate>
        <scale_down_factor>0.25</scale_down_factor>
        <rounds_to_average>2</rounds_to_average>
    </policy>
    <policy name="elastic" isDefault="false">
        <description>Elastic - Instances: Min 1, Max 4</description>
        <min_app_instances>1</min_app_instances>
        <max_app_instances>4</max_app_instances>
        <max_requests_per_second>5</max_requests_per_second>
        <alarming_upper_rate>0.7</alarming_upper_rate>
        <alarming_lower_rate>0.2</alarming_lower_rate>
        <scale_down_factor>0.25</scale_down_factor>
        <rounds_to_average>2</rounds_to_average>
    </policy>
</policies>

Element Definitions

Click the respective element link for in-depth information.

policy

Criteria	Description
XML Syntax	<policy>
Description	Used to define an individual autoscaling policy.
Mandatory/Optional	Mandatory
Attribute	name
Description	Name of the policy
Type	String
Mandatory/Optional	Mandatory
Attribute	isDefault
Description	Specifies whether or not this policy will be set as the default Cartridge. If the user does not select a policy, the default policy will be applied.
Type	Boolean
Mandatory/Optional	Mandatory

description

Criteria	Description
XML Syntax	<description>
Description	Description on the policy. This description is displayed in the Stratos Controller subscribe page.
Type	String
Mandatory/Optional	Mandatory

min_app_instances

Criteria	Description
XML Syntax	<min_app_instances>
Description	Minimum number of maintained Cartridge instances.
Type	Integer
Mandatory/Optional	Mandatory

max_app_instances

Criteria	Description
XML Syntax	<max_app_instances>
Description	Maximum number of maintained Cartridge instances.
Type	Integer
Mandatory/Optional	Mandatory

max_requests_per_second

Criteria	Description
XML Syntax	<max_requests_per_second>
Description	Number of requests a service instance can withstand per second
Type	Integer
Mandatory/Optional	Mandatory

alarming_upper_rate

Criteria	Description
XML Syntax	<alarming_upper_rate>
Description	Upper bound of the alarming rate.
Type	Decimal
Mandatory/Optional	Mandatory

alarming_lower_rate

Criteria	Description
XML Syntax	<alarming_lower_rate>
Description	Lower bound of the alarming rate.
Type	Decimal
Mandatory/Optional	Mandatory

scale_down_factor

Criteria	Description
XML Syntax	<scale_down_factor>
Description	Factor that is needed to slow down the scaling down process.
Type	Decimal
Mandatory/Optional	Mandatory

rounds_to_average

Criteria	Description
XML Syntax	<rounds_to_average>
Description	Number of ‘autoscaling decision making’ task iterations that need to take place before an autoscaling decision is made.
Type	Integer
Mandatory/Optional	Mandatory

For more information please see the ELB decision making variables and the Autoscaling service instances sections.