Connecting MySQL Exporter

Application Scenario

MySQL Exporter collects MySQL database metrics. Core database metrics collected through Exporter are used for alarm reporting and dashboard display. Currently, Exporter supports MySQL 5.6 or later. If the MySQL version is earlier than 5.6, some metrics may fail to be collected.

You are advised to use CCE for unified Exporter management.

Prerequisites

A CCE cluster has been created and MySQL 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 mysql_exporter image to SoftWare Repository for Container (SWR). For details, see Uploading an Image Through a Container Engine Client.

Database Authorization

Log in to the cluster and run the following command:
```
kubectl exec -it ${mysql_podname} bash
mysql -u root -p
```
Figure 1 Executing the command

CREATE USER 'exporter'@'x.x.x.x(hostip)' IDENTIFIED BY 'xxxx(password)' WITH MAX_USER_CONNECTIONS 3;
GRANT PROCESS, REPLICATION CLIENT, SELECT ON *.* TO 'exporter'@'x.x.x.x(hostip)';

Check whether the authorization is successful.
Enter the following SQL statement to check whether there is any Exporter data. host indicates the IP address of the node where the MySQL database is located.
```
select user,host from mysql.user;
```
Figure 2 SQL statement

Deploying MySQL Exporter

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

Perform the following operations to deploy Exporter:

Use Secret to manage MySQL connection strings.
In the navigation pane, choose ConfigMaps and Secrets. In the upper right corner, click Create from YAML and enter the following .yml file. The password is encrypted based on Opaque requirements.
```
apiVersion: v1
kind: Secret
metadata:
    name: mysql-secret
    namespace: default
type: Opaque
stringData:
    datasource: "user:password@tcp(ip:port)/" # MySQL connection string, which needs to be encrypted.
```
For details about how to configure a secret, see Creating a Secret.

Deploy MySQL Exporter.

In the navigation pane, choose Workloads. In the upper right corner, click Create Workload. Then select the Deployment workload and select a desired namespace to deploy MySQL Exporter. YAML configuration example for deploying Exporter:

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    k8s-app: mysql-exporter # Change the name based on service requirements. You are advised to add the MySQL instance information, for example, ckafka-2vrgx9fd-mysql-exporter.
  name: mysql-exporter # Change the name based on service requirements. You are advised to add the MySQL instance information, for example, ckafka-2vrgx9fd-mysql-exporter.
  namespace: default # Must be the same as the namespace of MySQL.
spec:
  replicas: 1
  selector:
    matchLabels:
      k8s-app: mysql-exporter # Change the name based on service requirements. You are advised to add the MySQL instance information, for example, ckafka-2vrgx9fd-mysql-exporter.
  template:
    metadata:
      labels:
        k8s-app: mysql-exporter # Change the name based on service requirements. You are advised to add the MySQL instance information, for example, ckafka-2vrgx9fd-mysql-exporter.
    spec:
      containers:
      - env:
        - name: DATA_SOURCE_NAME
          valueFrom:
            secretKeyRef:
              name: mysql-secret
              key: datasource	
        image: swr.cn-north-4.myhuaweicloud.com/aom-exporter/mysqld-exporter:v0.12.1
        imagePullPolicy: IfNotPresent
        name: mysql-exporter
        ports:
        - containerPort: 9104
          name: metric-port 
        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: mysql-exporter
spec:
  type: NodePort
  selector:
    k8s-app: mysql-exporter
  ports:
    - protocol: TCP
      nodePort: 30337
      port: 9104
      targetPort: 9104

For details about Exporter parameters, see mysql-exporter.

Check whether MySQL 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.
1. 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}:9104/metrics
```
```
curl http://{Private IP address of any node in the cluster}:30337/metrics
```
  - In the instance list, choose More > Remote Login in the Operation column and run the following command:
```
curl http://localhost:9104/metric
```
  - Access http://{Public IP address of any node in the cluster}:30337/metrics.
    Figure 3 Accessing a cluster node

Collecting Service Data of the CCE Cluster

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

Configuration information:

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

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

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}/mysql-exporter to query custom metrics starting with mysql.

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.