Autoscaling ML Workloads with ServiceMonitor Metrics
PythonAutoscaling machine learning (ML) workloads is essential for managing resources efficiently and ensuring that your ML models have enough computing power when needed, while minimizing costs during periods of low usage. To achieve this, you'll typically monitor certain metrics that indicate the workload's performance and demand, and scale your resources based on those metrics.
In Kubernetes, the
HorizontalPodAutoscaler
is a resource that automatically scales the number of pod replicas in a deployment or replicaset based on observed CPU utilization or custom metrics. When working with ML workloads, you might want to autoscale based on custom metrics, perhaps those exposed by aServiceMonitor
if you're using Prometheus for monitoring. This typically requires setting up custom metrics support for the horizontal pod autoscaler in your Kubernetes cluster.Below is a Pulumi program using Python that demonstrates how you would define a
HorizontalPodAutoscaler
that scales based on custom metrics from aServiceMonitor
. This example assumes that you have a functioning Kubernetes cluster with Prometheus and the custom metrics API installed and configured.import pulumi import pulumi_kubernetes as k8s # The name of your Kubernetes deployment that you want to autoscale. deployment_name = 'ml-workload-deployment' # Specification for the HorizontalPodAutoscaler that uses custom metrics. hpa = k8s.autoscaling.v2beta2.HorizontalPodAutoscaler( 'ml-workload-hpa', metadata=k8s.meta.v1.ObjectMetaArgs( name='ml-workload-hpa', namespace='default', # Adjust the namespace according to your setup. ), spec=k8s.autoscaling.v2beta2.HorizontalPodAutoscalerSpecArgs( scale_target_ref=k8s.autoscaling.v2beta2.CrossVersionObjectReferenceArgs( kind='Deployment', name=deployment_name, api_version='apps/v1', ), min_replicas=1, # Minimum number of replicas. max_replicas=10, # Maximum number of replicas. metrics=[k8s.autoscaling.v2beta2.MetricSpecArgs( type='Object', # For custom metrics, use type "Object." object=k8s.autoscaling.v2beta2.ObjectMetricSourceArgs( metric=k8s.autoscaling.v2beta2.MetricIdentifierArgs( name='service_monitor_metric_name', # Replace with your ServiceMonitor metric name. selector=k8s.meta.v1.LabelSelectorArgs( match_labels={ 'key': 'value', # Specify the labels that the ServiceMonitor uses. }, ), ), target=k8s.autoscaling.v2beta2.MetricTargetArgs( type='Value', # Use 'Value' or 'AverageValue' based on the metric type. value='100', # Specify the target value for your custom metric. ), described_object=k8s.autoscaling.v2beta2.CrossVersionObjectReferenceArgs( kind='Service', name='ml-workload-service', # Name of the service that the metric is coming from. api_version='v1', ), ), )], ), ) # Export the name of the HPA pulumi.export('hpa_name', hpa.metadata.apply(lambda metadata: metadata.name))
This code does the following steps:
- Imports the necessary Pulumi modules.
- Creates a
HorizontalPodAutoscaler
namedml-workload-hpa
that targets a deployment calledml-workload-deployment
. - Configures the autoscaler to have a minimum of 1 replica and a maximum of 10 replicas.
- Specifies the metrics to be used for autoscaling. In this case, it's a custom metric named
service_monitor_metric_name
from aService
namedml-workload-service
. - Exports the name of the
HorizontalPodAutoscaler
so that you can reference it externally if needed.
Make sure to replace
'service_monitor_metric_name'
,'ml-workload-service'
, and any other placeholder with the appropriate names based on your specific use case and cluster setup.This autoscaling configuration is crucial for ML workloads where the compute needs may vary significantly. For instance, a common pattern is to anticipate high load during business hours when models are being trained and less load at other times. Custom metrics can provide more fine-grained control over autoscaling behavior by scaling based on the actual demand of your ML workloads.