1. Zero Downtime Deployment for AI Systems with AWS CodeDeploy


    Zero downtime deployment is a critical requirement for production AI systems where constant availability is necessary. To achieve zero downtime deployments on AWS, we can make use of AWS CodeDeploy, which is a fully managed deployment service that automates software deployments to various compute services such as Amazon EC2, AWS Fargate, AWS Lambda, and your on-premises servers.

    AWS CodeDeploy utilizes deployment configurations to avoid downtime. This includes options for doing a rolling update or a blue/green deployment:

    • Rolling Update: New instances with the updated version are gradually rolled out while old ones are terminated.
    • Blue/Green Deployment: A complete new version (green) is deployed alongside the old version (blue). Traffic is then gradually switched over to the new version.

    Below is a Pulumi program that demonstrates setting up a CodeDeploy application and deployment group for managing the deployment process. We'll also use an ECS service, as it's a common compute platform for running containerized AI systems. In this script, we are focusing on a high-level concept without delving into the specifics of setting up an entire CI/CD pipeline, ECS Cluster, or Task Definitions.

    import pulumi import pulumi_aws as aws # Create a CodeDeploy Application. This resource represents the application you want to deploy. codedeploy_app = aws.codedeploy.Application("ai-codedeploy-app", compute_platform="ECS", # Specifying ECS as we are deploying to an ECS Service ) # Set up the ECS Cluster and Service here, or use an already configured one's ARN. # Assuming 'ecs_cluster_arn' and 'ecs_service_name' are available from your ECS setup. # Define the Deployment Group for the CodeDeploy Application. A deployment group defines the deployment configuration. deployment_group = aws.codedeploy.DeploymentGroup("ai-deployment-group", app_name=codedeploy_app.name, service_role_arn=aws_iam_role.codedeploy_role.arn, # IAM role that allows CodeDeploy to act on your behalf deployment_config_name="CodeDeployDefault.ECSAllAtOnce", # This configuration updates all tasks simultaneously. ecs_service=aws.codedeploy.DeploymentGroupEcsServiceArgs( # Connect to the ECS Service cluster_name=ecs_cluster_arn, service_name=ecs_service_name, ), deployment_style=aws.codedeploy.DeploymentGroupDeploymentStyleArgs( # Define the deployment style deployment_type="BLUE_GREEN", # Choose blue/green deployment for zero downtime deployment_option="WITH_TRAFFIC_CONTROL", # Enables traffic rerouting to the new version ), blue_green_deployment_config=aws.codedeploy.DeploymentGroupBlueGreenDeploymentConfigArgs( # Configure blue/green deployments terminate_blue_instances_on_deployment_success=aws.codedeploy.DeploymentGroupBlueGreenDeploymentConfigTerminateBlueInstancesOnDeploymentSuccessArgs( action="TERMINATE", # Terminate blue instances after the deployment's success termination_wait_time_in_minutes=5, # Set the wait time before terminating old instances ), ) ) pulumi.export("codedeploy_app_name", codedeploy_app.name) pulumi.export("deployment_group_name", deployment_group.name)

    In this Pulumi program:

    • We define a codedeploy.Application to represent the application we are deploying. We specify that it's an ECS application by setting the compute_platform to "ECS".

    • We create an IAM Role separately that grants CodeDeploy permission to deploy applications to ECS (not shown in the above code). You would need to create an IAM role with the necessary permissions and pass the ARN to the service_role_arn property of the DeploymentGroup.

    • The codedeploy.DeploymentGroup resource is where we configure how our deployments should occur. We reference our application by name and specify ECS-specific settings.

    • We use deployment_style to specify that we want a blue/green deployment, which is the deployment type that facilitates zero-downtime updates.

    • The blue_green_deployment_config parameter further configures the blue/green deployment, including what action to take with the old "blue" instances after successful deployment of the new "green" instances.

    The exported values provide the names of the CodeDeploy application and deployment group that were created.

    This program sets up the AWS CodeDeploy infrastructure for a zero downtime deployment. Additional steps required to complete the CI/CD pipeline include creating a task definition, setting up a listener and load balancer for routing traffic, and defining CodePipeline actions to trigger the deployment process.

    For more detailed steps and setup, refer to AWS CodeDeploy Documentation and the Pulumi CodeDeploy Documentation.