Keda ScaledObject using the Application Insights custom query

Question

My usecase is to scale the AKS POD based on application insights custom query results. But i am unable to find any example which does that. KEDA document only suggesting to use the built in metric id.

Below is something i wanted to achieve. But it always says the metric id not provided. But i wanted to use the custom query rather than existing metric id.

apiVersion: keda.sh/v1alpha1
kind: TriggerAuthentication
metadata:
name: trigger-podidentity-auth
spec:
podIdentity:
 provider: azure-workload
 identityId: 6d12e654-770d-4607-8a31-0ade5472e803
---
apiVersion: keda.sh/v1alpha1 
kind: ScaledObject
metadata:
name: webapp-demo-scaleobject
namespace: demo-cluster-ns
spec:
scaleTargetRef:
 name: webapp-demo
minReplicaCount: 1 #Change to define how many minimum replicas you want
maxReplicaCount: 4
triggers:
- type: azure-app-insights
 metadata:
   query: "requests | summarize sum(itemCount) by name | where  name == 'GET WeatherForecast/Get' | project sum_itemCount"
   timespan: "PT10S"
   targetValue: "10"
 authenticationRef:
   name: trigger-podIdentity-auth

Any suggestions how to achieve using KEDA? Can it be achieved with the built in metric id?

Answer 1

But i wanted to use the custom query rather than existing metric id.

That cannot be done using the Application Insights scaler.

If you have a workspace based application insights resource, or you are able to convert your classic resource, you can use the Azure Log Analytics scaler. An example from the docs:

triggers:
  - type: azure-log-analytics
    metadata:
      tenantId: "AZURE_AD_TENANT_ID"
      clientId: "SERVICE_PRINCIPAL_CLIENT_ID"
      clientSecret: "SERVICE_PRINCIPAL_PASSWORD"
      workspaceId: "LOG_ANALYTICS_WORKSPACE_ID"
      query: |
        let AppName = "web";
        let ClusterName = "demo-cluster";
        let AvgDuration = ago(10m);
        let ThresholdCoefficient = 0.8;
        Perf
        | where InstanceName contains AppName
        | where InstanceName contains ClusterName
        | where CounterName == "cpuUsageNanoCores"
        | where TimeGenerated > AvgDuration
        | extend AppName = substring(InstanceName, indexof((InstanceName), "/", 0, -1, 10) + 1)
        | summarize MetricValue=round(avg(CounterValue)) by CounterName, AppName
        | join (Perf
                | where InstanceName contains AppName
                | where InstanceName contains ClusterName
                | where CounterName == "cpuLimitNanoCores"
                | where TimeGenerated > AvgDuration
                | extend AppName = substring(InstanceName, indexof((InstanceName), "/", 0, -1, 10) + 1)
                | summarize arg_max(TimeGenerated, *) by AppName, CounterName
                | project Limit = CounterValue, TimeGenerated, CounterPath, AppName)
                on AppName
        | project MetricValue, Threshold = Limit * ThresholdCoefficient        
      threshold: "10.7"
      activationThreshold: "1.7"
      # Alternatively, you can use existing environment variables to read configuration from:
      # See details in "Parameter list" section
      workspaceIdFromEnv: LOG_ANALYTICS_WORKSPACE_ID_ENV_NAME # Optional. You can use this instead of `workspaceId` parameter.
      clientIdFromEnv: SERVICE_PRINCIPAL_CLIENT_ID_ENV_NAME # Optional. You can use this instead of `clientId` parameter.
      tenantIdFromEnv: AZURE_AD_TENANT_ID_ENV_NAME # Optional. You can use this instead of `tenantId` parameter.
      clientSecretFromEnv: SERVICE_PRINCIPAL_PASSWORD_ENV_NAME # Optional. You can use this instead of `clientSecret` parameter.
      # Optional (Default: AzurePublicCloud)
      cloud: Private
      # Required when cloud = Private
      logAnalyticsResourceURL: https://api.loganalytics.airgap.io/
      # Required when cloud = Private.
      activeDirectoryEndpoint: https://login.airgap.example/
      # Optional (Default: false)
      unsafeSsl: "false"