Policy: AWS > Well-Architected Tool > AWS Well-Architected Framework > Reliability > REL 11. How do you design your workload to withstand component failures? > Use static stability to prevent bimodal behavior

Bimodal behavior is when your workload exhibits different behavior under normal and failure modes, for example, relying on launching new instances if an Availability Zone fails. You should instead build workloads that are statically stable and operate in only one mode. In this case, provision enough instances in each Availability Zone to handle the workload load if one AZ were removed and then use Elastic Load Balancing or Amazon Route 53 health checks to shift load away from the impaired instances.

See Use static stability to prevent bimodal behavior for more information.

Targets

This policy targets the following resource types:

AWS > Well-Architected Tool > AWS Well-Architected Framework

Primary Policy

This policy is used with the following primary policy:

AWS > Well-Architected Tool > AWS Well-Architected Framework > Reliability > REL 11. How do you design your workload to withstand component failures?

Controls

Setting this policy configures this control:

AWS > Well-Architected Tool > AWS Well-Architected Framework > Reliability > REL 11. How do you design your workload to withstand component failures?

Policy Specification

Schema Type	`string`
Default	`Skip`
Valid Values [YAML]	`Skip` `True` `False`

In Your Workspace

Policy Settings by Type report

Developers

Category URI

tmod:@turbot/turbot#/control/categories/other

Policy Type URI

tmod:@turbot/aws-wellarchitected-framework#/policy/types/rel11StaticStability

GraphQL

query policyType(id: "tmod:@turbot/aws-wellarchitected-framework#/policy/types/rel11StaticStability") { … }

query policySettings(filter: "policyTypeId:'tmod:@turbot/aws-wellarchitected-framework#/policy/types/rel11StaticStability'") { … }

query policyValues(filter: "policyTypeId:'tmod:@turbot/aws-wellarchitected-framework#/policy/types/rel11StaticStability'") { … }

CLI

Get Policy Type

turbot graphql policy-type --id "tmod:@turbot/aws-wellarchitected-framework#/policy/types/rel11StaticStability"

Get Policy Settings

turbot graphql policy-settings --filter "policyTypeId:tmod:@turbot/aws-wellarchitected-framework#/policy/types/rel11StaticStability"