custommetrics

README

package custommetrics

This package is a part of the Datadog Cluster Agent and is responsible for providing custom metrics to the Kubernetes apiserver for Horizontal Pod Autoscalers.

DatadogProvider

The DatadogProvider currently only implements the External Metrics Provider interface by providing external metrics from Datadog.

There is no guarantee that every replica returns the exact same list of metrics for ListAllExternalMetrics. It is possible for the leader to mutate the store between calls to ListAllExternalMetricValues from different replicas. This is the tradeoff of using a ConfigMap for persistent storage instead of a transactional store.

Store

The Store interface provides persistent storage of custom and external metrics. The default implementation stores metric values in a ConfigMap.

Only the leader replica should add or delete metrics from the store. Any replica is able to call ListAllExternalMetricValues to return the most up-to-date values for metrics.

configMapStore

The configMapStore provides simple persistent storage of custom and external metrics. This allows any replica of the Datadog Cluster Agent to serve metrics to the apiserver but still only have the leader replica query Datadog.

The configMapStore always performs operations on a local copy of the configmap but ListAllExternalMetricValues will always get the most up-to-date configmap from the apiserver before listing the metrics.

Summary of apiserver calls

• NewConfigMapStore: between 1 and 2 calls
• SetExternalMetricValues: 1 call to update configmap
• DeleteExternalMetricValues: 1 call to update configmap
• ListAllExternalMetricValues: 1 call to get configmap

Documentation

Overview

Package custommetrics implements the part of the Cluster Agent that's responsible for providing custom metrics to the Kubernetes apiserver for Horizontal Pod Autoscalers.

Index

• func GetStatus(_ interface{}) map[string]interface{}

Functions

func GetStatus

func GetStatus(_ interface{}) map[string]interface{}

GetStatus returns the status info of the Custom Metrics Server.