Connecting Memcached Exporter

Application Scenario

When using Memcached, you need to monitor their running and locate their faults in a timely manner. The Prometheus monitoring function monitors Memcached running using Exporter in the CCE container scenario. This section describes how to monitor Memcached.

You are advised to use CCE for unified Exporter management.

Prerequisites

A CCE cluster has been created and Memcached has been installed.
Your service has been connected for Prometheus monitoring and a CCE cluster has also been connected. For details, see Prometheus Instance for CCE.
You have uploaded the memcached_exporter image to SoftWare Repository for Container (SWR). For details, see Uploading an Image Through a Container Engine Client.

Deploying Memcached Exporter

Log in to the CCE console.
Click the connected cluster. The cluster management page is displayed.

Perform the following operations to deploy Exporter:

Configure a secret.
In the navigation pane, choose ConfigMaps and Secrets. Then click Create from YAML in the upper right corner of the page. YAML configuration example:
```
apiVersion: v1
kind: Secret
metadata:
    name: memcached-exporter-secret
    namespace: default
type: Opaque
stringData:
    memcachedURI: 120.46.215.4:11211  # Memcached address
```
- Format of the Memcached connection string: http://{ip}:{port}.
- For details about how to configure a secret, see Creating a Secret.

Deploy Memcached Exporter.

In the navigation pane, choose Workloads. On the Deployments tab page, click Create from YAML in the upper right corner and then configure a YAML file to deploy Exporter.

YAML configuration example:

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    k8s-app: memcached-exporter # Change the value based on service requirements.
  name: memcached-exporter # Change the value based on service requirements.
  namespace: default 
spec:
  replicas: 1
  selector:
    matchLabels:
      k8s-app: memcached-exporter # Change the value based on service requirements.
  template:
    metadata:
      labels:
        k8s-app: memcached-exporter # Change the value based on service requirements.
    spec:
      containers:
      - env:
          - name: Memcached_Url
            valueFrom:
              secretKeyRef:
                name: memcached-exporter-secret # Secret name specified in the previous step.
                key: memcachedURI # Secret key specified in the previous step.
          - name: Memcached_ALL
            value: "true"
        image: swr.cn-east-3.myhuaweicloud.com/aom-org/bitnami/memcached-exporter:0.13.0 # Image uploaded to SWR, as described in "Prerequisites".
        imagePullPolicy: IfNotPresent
        name: memcached-exporter
        ports:
        - containerPort: 9150
          name: metric-port
        securityContext:
          privileged: false
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
    dnsPolicy: ClusterFirst
    imagePullSecrets:
    - name: default-secret
    restartPolicy: Always
    schedulerName: default-scheduler
    securityContext: {}
    terminationGracePeriodSeconds: 30
---
apiVersion: v1
kind: Service
metadata:
  name: memcached-exporter
spec:
  type: NodePort
  selector:
    k8s-app: memcached-exporter
  ports:
    - protocol: TCP
      nodePort: 30122
      port: 9150
      targetPort: 9150

For more details about Exporter parameters, see memcached_exporter.

Check whether Memcached Exporter is successfully deployed.
1. On the Deployments tab page, click the Deployment created in 3.b. In the pod list, choose More > View Logs in the Operation column. The Exporter is successfully started and its access address is exposed.
2. Perform verification using one of the following methods:
  - Log in to a cluster node and run either of the following commands:
```
curl http://{Cluster IP address}:9150/metrics
```
```
curl http://{Private IP address of any node in the cluster}:30122/metrics
```
  - Access http://{Public IP address of any node in the cluster}:30122/metrics.
    Figure 1 Accessing a cluster node
  - In the instance list, choose More > Remote Login in the Operation column and run the following command:
```
curl http://localhost:9150/metric
```
    Figure 2 Executing the command

Adding a Collection Task

Add PodMonitor to configure a collection rule for monitoring the service data of applications deployed in the CCE cluster.

In the following example, metrics are collected every 30s. Therefore, you can check the reported metrics on the AOM page about 30s later.

apiVersion: monitoring.coreos.com/v1
kind: PodMonitor
metadata:
  name: memcached-exporter
  namespace: default
spec:
  namespaceSelector:
    matchNames:
      - default # Namespace where Exporter is located.
  podMetricsEndpoints:
  - interval: 30s
    path: /metrics
    port: metric-port
  selector:
    matchLabels:
      k8s-app: memcached-exporter

Verifying that Metrics Can Be Reported to AOM

Log in to the AOM 2.0 console.
In the navigation pane on the left, choose Prometheus Monitoring > Instances.
Click the Prometheus instance connected to the CCE cluster. The instance details page is displayed.
On the Metrics tab page of the Service Discovery page, select your target cluster.
Select job {namespace}/memcached-exporter to query metrics starting with go_memstats.

Setting a Dashboard and Alarm Rule on AOM

By setting a dashboard, you can monitor CCE cluster data on the same screen. By setting an alarm rule, you can detect cluster faults and implement warning in a timely manner.

Setting a dashboard
1. Log in to the AOM 2.0 console.
2. In the navigation pane, choose Dashboard. On the displayed page, click Add Dashboard to add a dashboard. For details, see Creating a Dashboard.
3. On the Dashboard page, select a Prometheus instance for CCE and click Add Graph. For details, see Adding a Graph to a Dashboard.
Setting an alarm rule
1. Log in to the AOM 2.0 console.
2. In the navigation pane, choose Alarm Management > Alarm Rules.
3. Click Create Alarm Rule to set an alarm rule. For details, see Creating a Metric Alarm Rule.