Use Spot VMs with prediction

Overview

You can reduce the cost of running your prediction jobs by using Spot VMs. Spot VMs are virtual machine (VM) instances that are excess Compute Engine capacity. Spot VMs have significant discounts, but Compute Engine might preemptively stop or delete (preempt) Spot VMs to reclaim the capacity at any time.

To learn more, see Spot VMs.

Limitations and requirements

Consider the following limitations and requirements when using Spot VMs with Vertex AI:

  • All Spot VMs limitations apply when using Spot VMs with Vertex AI.
  • Using Spot VMs with Vertex AI is supported for only custom training and prediction.
  • Using Spot VMs with TPU Pods isn't supported.
  • Submitting your job through the Google Cloud console is not supported.

Billing

If your workloads are fault-tolerant and can withstand possible VM preemption, Spot VMs can reduce your compute costs significantly. If some of your VMs stop during processing, the job slows but does not completely stop. Spot VMs complete your batch processing tasks without placing additional load on your existing VMs and without requiring you to pay full price for additional standard VMs. See Preemption handling.

When you use Spot VMs, you're billed by job duration and machine type. You don't pay for the time that the job is in a queue or preempted.

Preemption handling

Spot VMs can be reclaimed by Compute Engine at any time. Therefore, your prediction job must be fault tolerant to get the most benefit from Spot VMs. When Spot VMs are preempted, the prediction job fails with a STOCKOUT error and Compute Engine tries to restart the job up to six times. To learn how to get the most out of your Spot VMs, see Spot VM best practices.

The following are some of the methods that you can use to make your prediction job fault tolerant:

  • Create checkpoints to save progress. By periodically storing the progress of your model, you can ensure that a terminated prediction job can resume from the last stored checkpoint, instead of starting over from the beginning.
  • Use a shutdown script. When Compute Engine preempts a Spot VM, you can use a shutdown script that tries to perform cleanup actions before the VM is preempted. To learn more, see Handle preemption with a shutdown script.

Get predictions by using Spot VMs

To use Spot VMs when you deploy a model to get predictions, you can use the REST API or the Vertex AI SDK for Python.

REST

Before using any of the request data, make the following replacements:

  • LOCATION_ID: The region where you are using Vertex AI.
  • PROJECT_ID: Your project ID.
  • ENDPOINT_ID: The ID for the endpoint.
  • MODEL_ID: The ID for the model to be deployed.
  • DEPLOYED_MODEL_NAME: A name for the DeployedModel. You can use the display name of the Model for the DeployedModel as well.
  • MACHINE_TYPE: Optional. The machine resources used for each node of this deployment. Its default setting is n1-standard-2. Learn more about machine types.
  • ACCELERATOR_TYPE: Optional. The type of accelerator to be attached to the machine. Learn more.
  • ACCELERATOR_COUNT: Optional. The number of accelerators for each replica to use.
  • MIN_REPLICA_COUNT: The minimum number of nodes for this deployment. The node count can be increased or decreased as required by the prediction load, up to the maximum number of nodes and never fewer than this number of nodes. This value must be greater than or equal to 1.
  • MAX_REPLICA_COUNT: The maximum number of nodes for this deployment. The node count can be increased or decreased as required by the prediction load, up to this number of nodes and never fewer than the minimum number of nodes.
  • TRAFFIC_SPLIT_THIS_MODEL: The percentage of the prediction traffic to this endpoint to be routed to the model being deployed with this operation. Defaults to 100. All traffic percentages must add up to 100. Learn more about traffic splits.
  • DEPLOYED_MODEL_ID_N: Optional. If other models are deployed to this endpoint, you must update their traffic split percentages so that all percentages add up to 100.
  • TRAFFIC_SPLIT_MODEL_N: The traffic split percentage value for the deployed model id key.
  • PROJECT_NUMBER: Your project's automatically generated project number.

HTTP method and URL: 

POST https://LOCATION_ID-aiplatform.googleapis.com/v1/projects/PROJECT_ID/locations/LOCATION_ID/endpoints/ENDPOINT_ID:deployModel

Request JSON body: 

{


"acceleratorCount": 1}, "spot": true, "minReplicaCount": 1, "maxReplicaCount": 1}}, "trafficSplit": {"0": 100}}' \
  "https://LOCATION_ID-aiplatform.googleapis.com/v1beta1/projects/PROJECT_ID/locations/LOCATION_ID/endpoints/ENDPOINT_ID:deployModel"

  "deployedModel": {
    "model": "projects/PROJECT/locations/us-central1/models/MODEL_ID",
    "displayName": "DEPLOYED_MODEL_NAME",
    "enableContainerLogging": true,
    "dedicatedResources": {
      "machineSpec": {
        "machineType": "MACHINE_TYPE",
        "acceleratorType": "ACCELERATOR_TYPE",
        "acceleratorCount": ACCELERATOR_COUNT
      },
      "spot": true,
      "minReplicaCount": MIN_REPLICA_COUNT,
      "maxReplicaCount": MAX_REPLICA_COUNT
    },
  },
  "trafficSplit": {
    "0": TRAFFIC_SPLIT_THIS_MODEL,
    "DEPLOYED_MODEL_ID_1": TRAFFIC_SPLIT_MODEL_1,
    "DEPLOYED_MODEL_ID_2": TRAFFIC_SPLIT_MODEL_2
  },
}

To send your request, expand one of these options:

You should receive a JSON response similar to the following:

{
  "name": "projects/PROJECT_ID/locations/LOCATION/endpoints/ENDPOINT_ID/operations/OPERATION_ID",
  "metadata": {
    "@type": "type.googleapis.com/google.cloud.aiplatform.v1beta1.DeployModelOperationMetadata",
    "genericMetadata": {
      "createTime": "2020-10-19T17:53:16.502088Z",
      "updateTime": "2020-10-19T17:53:16.502088Z"
    }
  }
}

Python

To learn how to install or update the Vertex AI SDK for Python, see Install the Vertex AI SDK for Python. For more information, see the Vertex AI SDK for Python API reference documentation. 

endpoint5.deploy(
    model = model,
    deployed_model_display_name=DEPLOYED_NAME,
    traffic_split=TRAFFIC_SPLIT,
    machine_type="MACHINE_TYPE",
    accelerator_type="ACCELERATOR_TYPE",
    accelerator_count=ACCELERATOR_COUNT,
    min_replica_count=MIN_REPLICA_COUNT,
    max_replica_count=MAX_REPLICA_COUNT,
    spot=True,
    sync=True
)

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