arpio-config:depends-on:

Control the order in which Arpio recovers your resources

arpio-config:depends-on:<label> = <dependee-arn>

<label>

A short string you choose that describes the resource being depended on. You can use any characters that are allowed in tag names for the type of resource being tagged. Arpio does not interpret the label you choose, but the label part is required in order to support setting multiple arpio-config:depends-on: tags on the same primary environment resource, since tag names must be unique for a tagged resource.

Use multiple distinct labels to express multiple dependency relationships from the tagged resource to other resources.

<dependee-arn>

The ARN of an Arpio-protected resource in the primary environment that should be recovered before the tagged resource is recovered.

Supported Resources

• All

Description

You can use the arpio-config:depends-on: configuration tag to partially control the order in which Arpio recovers your resources. Arpio will recover a resource with the arpio-config:depends-on: configuration tag after it recovers the resource identified by the tag's value.

A common use case is preventing an EC2 instance that runs a web application server from starting until after the RDS database instance it depends on is available. You would add the arpio-config:depends-on: tag to the EC2 instance in your primary environment, using the ARN of the RDS database instance as the tag's value. When arpio recovers your application, it will wait until the RDS database instance is available before launching the web application server EC2 instance.

You can set multiple arpio-config:depends-on: tags on a resource, using different <label> parts to distinguish them. When a resource has multiple arpio-config:depends-on: tags Arpio recovers the tagged resource after all of the resources named in all those tags' values are recovered.

Setting an arpio-config:depends-on: tag doesn't change or remove the resource dependencies that Arpio discovers automatically. For instance, if you set an arpio-config:depends-on: tag on an EC2 instance with an RDS database instance as the value, Arpio still recovers the EC2 instance's automatically discovered dependencies like subnets and security groups before recovering the tagged EC2 instance (after the RDS database instance, of course).

Be careful to avoid creating dependency cycles, also known as circular dependencies, when you set arpio-config:depends-on: tags. A dependency cycle occurs when a resource depends on another resource that, either directly or through some sequence of additional resources, depends on that original resource. Arpio cannot protect applications with dependency cycles and will create issues when they are discovered during recovery point creation.

Examples

arpio-config:depends-on:db

arpio-config:depends-on:log-server

arpio-config:depends-on:ad-server-1

arpio-config:depends-on:ad-server-2