Use ARMS Prometheus Monitoring to monitor Redis databases

Step 1: Capture data from a Redis database by using an external application

Deploy the redis-exporter image to a Container Service for Kubernetes (ACK) cluster to capture Redis data.

1. Log on to the Alibaba Cloud Container Service for Kubernetes console.
2. In the left-side navigation pane, click Clusters. On the Clusters page, click Applications in the Actions column corresponding to the cluster.
   
3. On the Workloads page, click the Deployments tab. On the Deployments tab, click Create from Template.
4. On the Deployments tab, select Custom from the Sample Template drop-down list. Enter the following text in the Template text editor and click Create to deploy the redis-exporter application to the ACK cluster.
   Note Replace values of <Address> and <Password> with the corresponding values of the Redis database. You can also use the following sample values provided by ARMS to experience the service:

   • Redis address: redis://r-bp167pgqkqh7h25coypd.redis.rds.aliyuncs.com:6379
   • Redis password: Arms1234

   apiVersion: extensions/v1beta1
   kind: Deployment
   metadata:
     name: redis-exporter
   spec:
     replicas: 1
     template:
       metadata:
         labels:
           app: redis-exporter
       spec:
         containers:
         - name: redis-exporter
           imagePullPolicy: Always
           env:
           - name: REDIS_ADDR
             value: "<Address>"
           - name: REDIS_PASSWORD
             value: "<Password>"
           - name: REDIS_EXPORTER_DEBUG
             value: "1"
           image: oliver006/redis_exporter
           ports:
           - containerPort: 9121
             name: redis-exporter

5. In the left-side navigation pane, choose Services and Ingresses > Services. On the Services page, click Create Resources in YAML.
6. On the Workloads tab, enter the following text in the Template text editor and click Create:

   apiVersion: v1
   kind: Service
   metadata:
     labels:
       app: redis-exporter
     name: redis-exporter
   spec:
     ports:
     - name: redis-exporter
       port: 9121
       protocol: TCP
       targetPort: 9121
     type: NodePort
     selector:
       app: redis-exporter

Step 2: Configure ARMS Prometheus Monitoring to receive data from the Redis database

1. Log on to the Alibaba Cloud Container Service for Kubernetes console.
2. Enable ARMS Prometheus Monitoring for the ACK cluster. For more information, see Get started with Prometheus Service.
3. Log on to the ARMS console.
4. In the left-side navigation pane, click Prometheus Monitoring.
5. In the upper-left corner of the Prometheus Monitoring page, select the region where your ACK cluster is deployed. Find the cluster and click Settings in the Actions column.
6. On the Settings page, click the Service Discovery tab. On the Service Discovery tab, click Add ServiceMonitor. In the Add ServiceMonitor dialog box, enter the following content and click OK:

   apiVersion: monitoring.coreos.com/v1
   kind: ServiceMonitor
   metadata:
     # Enter a unique name.
     name: redis-exporter
     # Enter the desired namespace.
     namespace: default
   spec:
     endpoints:
     - interval: 30s
       # The Redis Grafana template ID is 763.
       # Enter the value of the Name field for Port of Prometheus Exporter in the service.yaml file.
       port: redis-exporter
       # Enter the value of the Path field for Prometheus Exporter.
       path: /metrics
     namespaceSelector:
       any: true
       # Demo namespace:
       matchLabels:
         # Enter the value of the Label field in the service.yaml file to find the service.yaml file.
         app: redis-exporter

Step 3: Present data of the Redis database on the Grafana dashboard

Import the Grafana dashboard template and specify the ACK cluster where the Prometheus data source is located.

1. Go to Prometheus Grafana.
2. In the left-side navigation pane, choose + > Import, enter 763 in the Import via grafana.com field, and then click Load.
   
3. On the Import page, configure the following parameters and click Import.
   
   1. Enter a custom dashboard name in the Name field.
   2. Select your ACK cluster from the Folder drop-down list.
   3. Select your ACK cluster from the prom drop-down list.
   After the parameters are configured, the ARMS Prometheus Grafana Redis dashboard is displayed as shown in the following figure.

Step 4: Create a Prometheus Monitoring alert

1. Log on to the ARMS console.
2. In the left-side navigation pane, click Prometheus Monitoring.
3. In the top navigation bar, select a region. Then, click the name of the required Kubernetes cluster.
4. In the left-side navigation pane, choose Alarm configuration beta. Then, click Create Alert in the upper-right corner.
5. In the Create Alert dialog box, configure the following parameters, and then click OK.
   Note The Time parameter is not supported.
   1. Enter a name in the Rule Name field. Example: alerts for inbound traffic.
   2. Enter an expression that uses a PromQL statement. Example: (sum(rate(kube_state_metrics_list_total{job="kube-state-metrics",result="error"}[5m])) / sum(rate(kube_state_metrics_list_total{job="kube-state-metrics"}[5m]))) > 0.01.
      Notice An error may be reported if a PromQL statement contains a dollar sign ($). You must remove the equal sign (=) and the parameters on both sides of the equal sign (=) from the statement that contains the dollar sign ($). For example, change sum (rate (container_network_receive_bytes_total{instance=~"^$HostIp.*"}[1m])) to sum (rate (container_network_receive_bytes_total[1m])).
   3. In the Labels section, click Create Tag to specify alert tags. The specified tags can be used as options for a dispatch rule.
   4. In the Annotations section, specify a template for alert messages. Click Create Annotation. Set Key to message and Value to {{variable name}} alert message. The specified annotation is in the format of message:{{variable name}} alert notification. Example: message:{{$labels.pod_name}} restart.

      You can customize a variable name or select an existing tag as the variable name. Existing tags:

      • The tags that are carried in the metrics of an alert rule expression.
      • The tags that are created when you create an alert rule. For more information, see Create an alert.
      • The default tags provided by ARMS. The following table describes the default tags.

        Tag	Description
        alertname	The name of the alert. The format is <Alert name>_<Cluster name>.
        _aliyun_arms_alert_level	The level of the alert.
        _aliyun_arms_alert_type	The type of the alert.
        _aliyun_arms_alert_rule_id	The ID of the alert rule.
        _aliyun_arms_region_id	The ID of the region.
        _aliyun_arms_userid	The ID of the user.
        _aliyun_arms_involvedObject_type	The subtype of the associated object, for example, ManagedKubernetes or ServerlessKubernetes.
        _aliyun_arms_involvedObject_kind	The type of the associated object, for example, app or cluster.
        _aliyun_arms_involvedObject_id	The ID of the associated object.
        _aliyun_arms_involvedObject_name	The name of the associated object.