Cross-Region VM Backup for High-Availability AI Workloads

Question

Pulumi · Accepted Answer

Cross-region virtual machine (VM) backup is a strategy used to enhance the high-availability of workloads by storing backup data in geographically separate regions. This approach can protect against region-specific failures, such as natural disasters or service outages, that could lead to data loss if backups were only kept in a single region.

In a cloud environment like AWS, cross-region backup can be implemented using AWS Backup. This service allows you to create backup vaults, define backup policies, and automate the process of backing up your resources across different regions.

In the following program, we will set up an AWS Backup Vault and use AWS Backup to configure a backup rule that automates the backup of an Amazon EC2 instance, thus demonstrating how to configure cross-region VM backups. The backup rule will specify retention settings and the frequency of the backups.

The essential components of the backup strategy involve creating a backup vault, defining a backup plan with rules, and then assigning resources to the backup plan.

Let's walk through the setup in Pulumi using Python:

AWS Backup Vault: A secure location to store your backup data. A Backup Vault is identified by a name and can optionally be associated with AWS KMS for encryption.
Backup Plan: Describes when and how you want to back up your AWS resources, such as your EC2 instances. You can specify multiple backup rules within a backup plan, each with its own schedule and retention policy.
Backup Selection: Connects the resources, in this case, VMs, with the backup plan. It defines the resources you are backing up within the backup plan.

Please note that cross-region backup requires that you create resources in multiple regions. This is typically handled through the AWS Management Console by switching regions or by specifying the region in the client or API call. In Pulumi, this can be achieved by creating a provider instance for the desired region.

Here is a Pulumi program illustrating these steps:

import pulumi
import pulumi_aws as aws

# Create an AWS provider for the primary region.
primary_region_provider = aws.Provider("primary-provider", region="us-east-1")

# Create a Backup Vault in the primary region.
backup_vault = aws.backup.Vault("primary-vault",
    # You can set custom tags if needed
    tags={"Name": "PrimaryVault"},
    # Encrypt backups using AWS KMS key arn
    # Please replace '<KMS_KEY_ARN>' with your actual KMS Key ARN for the vault
    # kms_key_arn="<KMS_KEY_ARN>",
    opts=pulumi.ResourceOptions(provider=primary_region_provider),
)

# Create a Backup Plan with a rule in the primary region.
backup_plan = aws.backup.Plan("primary-plan",
    # The backup plan rules
    rules=[
        aws.backup.PlanRuleArgs(
            rule_name="daily",
            target_vault_name=backup_vault.name,
            schedule="cron(0 12 * * ? *)", # Daily backups at 12:00pm (UTC)
            start_window=120, # Minutes a backup can be delayed
            completion_window=360, # Maximum completion window in minutes
            lifecycle=aws.backup.PlanRuleLifecycleArgs(
                cold_storage_after=7, # Move to cold storage after 7 days
                delete_after=90, # Retention period of 90 days
            ),
        ),
    ],
    opts=pulumi.ResourceOptions(provider=primary_region_provider),
)

# Define which resources to apply the backup plan to.
backup_selection = aws.backup.Selection("primary-selection",
    plan_id=backup_plan.id,
    # Define the backup resources. Replace 'resource_arn' with your actual resource ARN.
    resources=[
        # f"arn:aws:ec2:us-east-1:<ACCOUNT_ID>:instance/<INSTANCE_ID>",
        # Add more resources if necessary
    ],
    opts=pulumi.ResourceOptions(provider=primary_region_provider),
)

# Create an AWS provider for the secondary (backup) region.
secondary_region_provider = aws.Provider("secondary-provider", region="us-west-1")

# Create a Backup Vault in the secondary region.
secondary_backup_vault = aws.backup.Vault("secondary-vault",
    # You can set custom tags if needed
    tags={"Name": "SecondaryVault"},
    # Encrypt backups using AWS KMS key arn
    # Please replace '<KMS_KEY_ARN>' with your actual KMS Key ARN for the vault
    # kms_key_arn="<KMS_KEY_ARN>",
    opts=pulumi.ResourceOptions(provider=secondary_region_provider),
)

# Each AWS resource is represented as a class in Pulumi's AWS SDK, which abstracts away the complexity of dealing with raw AWS API calls.
# The `opts` parameter tells Pulumi which provider to use for the resource deployment when dealing with multiple regions or accounts.

# Expose the ARN of the primary backup vault.
pulumi.export('primary_backup_vault_arn', backup_vault.arn)

# Expose the ARN of the secondary backup vault.
pulumi.export('secondary_backup_vault_arn', secondary_backup_vault.arn)

This program sets up a backup system using cross-region backup vaults. Please remember that you need to replace the placeholders for KMS Key ARNs and resource ARNs with actual values from your setup.

Additionally, you must ensure that your Pulumi stack configuration includes the necessary AWS credentials and default region. Pulumi respects the AWS environment variables (AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, and AWS_DEFAULT_REGION), AWS profiles, or the Pulumi configuration system to set these values. For simplicity, these details are assumed to have been configured before running the Pulumi program.

You should also consider the costs and network implications of cross-region backups, as transferring large amounts of data across regions can incur higher costs and latency. Always refer to the AWS Backup pricing page for the latest cost information.