Configure delegate metrics

This topic explains how to configure the Prometheus monitoring tool for metrics collection and the Grafana analytics tool for metrics display.

Harness captures delegate agent metrics for delegates with an immutable image type. This process requires a delegate an immutable image. For more information, go to Delegate image types.

The delegate is instrumented for the collection of the following delegate agent metrics.

Metric name	Description
`io_harness_custom_metric_task_execution_time`	The time it takes to complete a task (in seconds).
`io_harness_custom_metric_tasks_currently_executing`	The number of tasks underway.
`io_harness_custom_metric_task_timeout`	The number of tasks that time out before completion.
`io_harness_custom_metric_task_completed`	The number of tasks completed.
`io_harness_custom_metric_task_failed`	The number of failed tasks.
`io_harness_custom_metric_task_rejected`*	The number of tasks rejected because of a high load on the delegate.
`io_harness_custom_metric_delegate_connected`	Indicates whether the delegate is connected. Values are 0 (disconnected) and 1 (connected).
`io_harness_custom_metric_resource_consumption_above_threshold`*	Delegate cpu/memory is above a threshold (defaults to 80%). Provide `DELEGATE_RESOURCE_THRESHOLD` as the env variable in the delegate YAML to configure the threshold. For more information, go to Configure delegate resource threshold.

note

Metrics notated with * above only visible if you start your delegate with DYNAMIC_REQUEST_HANDLING set to true in your delegate YAML. Go to Configure delegate resource threshold for more information.

Also note that the above metrics are available only if your delegate version is later than 23.05.79311.

This topic includes example YAML files you can use to create application manifests for your Prometheus and Grafana configurations.

Apply the prometheus.yml file

The configuration of Prometheus requires the installation of a Prometheus workload and service in your Kubernetes cluster. Use the following example configuration file to install the harness-delegate-prometheus-deployment workload and a service named harness-delegate-prometheus-service. The configuration includes a load balancer with an IP address you can use to access the Prometheus UI.

Example prometheus.yml file

apiVersion: v1
kind: Namespace
metadata:
  name: harness-delegate-ng

---

apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-delegate-conf
  labels:
    name: prometheus-delegate-conf
  namespace: harness-delegate-ng
data:
  CPU: "1"
  MEMORY: "2048"
  POD_MEMORY: "3072"
  prometheus.yml: |-
    global:
      scrape_interval: 10s
      evaluation_interval: 10s

    scrape_configs:
      - job_name: 'kubernetes-apiservers'

        kubernetes_sd_configs:
        - role: endpoints
        scheme: http
        metrics_path: '/api/metrics'

        relabel_configs:
        - source_labels: [__meta_kubernetes_namespace, __meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]
          action: keep
          regex: default;kubernetes;https

      - job_name: 'kubernetes-pods'

        kubernetes_sd_configs:
        - role: pod

        relabel_configs:
        - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_scrape]
          action: keep
          regex: true
        - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_path]
          action: replace
          target_label: __metrics_path__
          regex: (.+)
        - source_labels: [__address__, __meta_kubernetes_pod_annotation_prometheus_io_port]
          action: replace
          regex: ([^:]+)(?::\d+)?;(\d+)
          replacement: $1:$2
          target_label: __address__
        - action: labelmap
          regex: __meta_kubernetes_pod_label_(.+)
        - source_labels: [__meta_kubernetes_namespace]
          action: replace
          target_label: kubernetes_namespace
        - source_labels: [__meta_kubernetes_pod_name]
          action: replace
          target_label: kubernetes_pod_name

      - job_name: 'kubernetes-service-endpoints'

        kubernetes_sd_configs:
        - role: endpoints

        relabel_configs:
        - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scrape]
          action: keep
          regex: true
        - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scheme]
          action: replace
          target_label: __scheme__
          regex: (https?)
        - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_path]
          action: replace
          target_label: __metrics_path__
          regex: (.+)
        - source_labels: [__address__, __meta_kubernetes_service_annotation_prometheus_io_port]
          action: replace
          target_label: __address__
          regex: ([^:]+)(?::\d+)?;(\d+)
          replacement: $1:$2
        - action: labelmap
          regex: __meta_kubernetes_service_label_(.+)
        - source_labels: [__meta_kubernetes_namespace]
          action: replace
          target_label: kubernetes_namespace
        - source_labels: [__meta_kubernetes_service_name]
          action: replace
          target_label: kubernetes_name
---
apiVersion: v1
kind: Service
metadata:
  name: harness-delegate-prometheus-service
  namespace: harness-delegate-ng
spec:
  selector:
    app: prometheus-delegate
  type: LoadBalancer
  ports:
    - port: 8084
      targetPort: 9090
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: harness-delegate-prometheus-deployment
  namespace: harness-delegate-ng
spec:
  replicas: 1
  template:
    metadata:
      labels:
        app: prometheus-delegate
    spec:
      containers:
        - name: prometheus
          image: prom/prometheus:v2.6.0
          args:
            - "--config.file=/etc/prometheus/prometheus.yml"
            - "--storage.tsdb.path=/prometheus/"
          ports:
            - containerPort: 9090
          volumeMounts:
            - name: prometheus-config-volume
              mountPath: /etc/prometheus/
            - name: prometheus-storage-volume
              mountPath: /prometheus/
      volumes:
        - name: prometheus-config-volume
          configMap:
            defaultMode: 420
            name: prometheus-delegate-conf

        - name: prometheus-storage-volume
          emptyDir: {}
  selector:
    matchLabels:
      app: prometheus-delegate

Use the following command to deploy the configuration file.

kubectl apply -f prometheus.yml

Set up Grafana

To set up Grafana, use the following example grafana.yml file.

Example grafana.yml file

apiVersion: v1
kind: ConfigMap
metadata:
  name: grafana-datasources
  namespace: harness-delegate-ng
data:
  prometheus.yaml: |-
    {
        "apiVersion": 1,
        "datasources": [
            {
               "access":"proxy",
                "editable": true,
                "name": "prometheus",
                "orgId": 1,
                "type": "prometheus",
                "url": "http://harness-delegate-prometheus-service:8084",
                "version": 1
            }
        ]
    }

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: grafana
  namespace: harness-delegate-ng
spec:
  replicas: 1
  selector:
    matchLabels:
      app: grafana
  template:
    metadata:
      name: grafana
      labels:
        app: grafana
    spec:
      containers:
      - name: grafana
        image: grafana/grafana:latest
        ports:
        - name: grafana
          containerPort: 3000
        resources:
          limits:
            memory: "1Gi"
            cpu: "1000m"
          requests: 
            memory: 500M
            cpu: "500m"
        volumeMounts:
          - mountPath: /var/lib/grafana
            name: grafana-storage
          - mountPath: /etc/grafana/provisioning/datasources
            name: grafana-datasources
            readOnly: false
      volumes:
        - name: grafana-storage
          emptyDir: {}
        - name: grafana-datasources
          configMap:
              defaultMode: 420
              name: grafana-datasources

---
apiVersion: v1
kind: Service
metadata:
  name: grafana
  namespace: harness-delegate-ng
  annotations:
      prometheus.io/scrape: 'true'
      prometheus.io/port:   '3000'
spec:
  selector: 
    app: grafana
  type: LoadBalancer  
  ports:
    - port: 3000
      targetPort: 3000     

Copy the grafana.yml file.
If you're not using the default harness-delegate-ng namespace, replace it with the namespace into which you deployed your delegate.
Use the following command to apply the Grafana configuration file to your deployment:
```
kubectl apply -f grafana.yml
```
note
This manifest also creates a load balancer and service in your Kubernetes cluster.
Select the exposed URL to access Grafana.

Configure delegate resource threshold

You can set the delegate to reject new tasks if x% of memory is being consumed. You can then spin up new delegates when resources are above the threshold.

note

The io_harness_custom_metric_resource_consumption_above_threshold metric is only visible if you start your delegate with DYNAMIC_REQUEST_HANDLING set to true in your delegate YAML.

To configure the delegate resource threshold, make the following changes to the delegate YAML file:

Set the JAVA_OPTS env variable.

env:
    - name: JAVA_OPTS
      value: "-Xmx1536M"

Set the DYNAMIC_REQUEST_HANDLING env variable to true to enable dynamic task rejection.
```
env:
   - name: DYNAMIC_REQUEST_HANDLING
     value: "true"
```
Set the DELEGATE_RESOURCE_THRESHOLD env variable to the cpu/memory threshold. When the threshold is exceeded, the delegate rejects new tasks.
```
env:
   - name: DELEGATE_RESOURCE_THRESHOLD
     value: "80"
```
note
This step is optional if you want to use the default value of 80%.

Apply the prometheus.yml file​

Example prometheus.yml file​

Set up Grafana​

Example grafana.yml file​

Configure delegate resource threshold​

Apply the prometheus.yml file

Example prometheus.yml file

Set up Grafana

Example grafana.yml file

Configure delegate resource threshold