5 Monitor the database¶

Finally, when we are done with backup, it’s time for one more step. In this section you will learn how to monitor the health of Percona Distribution for PostgreSQL with Percona Monitoring and Management (PMM) .

PMM is a client/server application. It includes the PMM Server and the number of PMM Clients running on each node with the database you wish to monitor.

A PMM Client collects needed metrics and sends gathered data to the PMM Server. As a user, you connect to the PMM Server to see database metrics on a number of dashboards.

PMM Client must be compatible with PMM server. You install them separately. This tutorial uses PMM3.

Install PMM Server¶

You must have PMM server up and running. You can run PMM Server as a Docker image, a virtual appliance, or in Kubernetes. Please refer to the official PMM documentation for the installation instructions.

Install PMM Client¶

PMM Client is installed as a side-car container in the database Pods in your Kubernetes-based environment. To install PMM Client, do the following:

Configure authentication¶

PMM uses Grafana service accounts to control access to PMM server components and resources. To authenticate in PMM server, you need a service account token. Generate a service account and token . Specify the Admin role for the service account.

Warning

When you create a service account token, you can select its lifetime: it can be either a permanent token that never expires or the one with the expiration date. PMM server cannot rotate service account tokens after they expire. So you must take care of reconfiguring PMM Client in this case.

Create a secret¶

Now you must pass the credentials to the Operator. To do so, create a Secret object.

Create a Secret configuration file. You can use the deploy/secrets.yaml secrets file.

Specify the service account token as the PMM_SERVER_TOKEN value in the secrets file:
```
apiVersion: v1
kind: Secret
metadata:
    name: cluster1-pmm-secret
type: Opaque
stringData:
    PMM_SERVER_TOKEN: ""
```

Create the Secrets object using the deploy/secrets.yaml file.

kubectl apply -f deploy/secrets.yaml -n postgres-operator

Expected output

secret/cluster1-pmm-secret created

Deploy a PMM Client¶

Update the pmm section in the deploy/cr.yaml file.
- Set pmm.enabled=true.
- Specify your PMM Server hostname / an IP address for the pmm.serverHost option. The PMM Server IP address should be resolvable and reachable from within your cluster.
- Specify the name of the Secret object that you created earlier
```
  pmm:
    enabled: true
    image: percona/pmm-client:3.9.1
#    imagePullPolicy: IfNotPresent
    secret: cluster1-pmm-secret
    serverHost: monitoring-service
```

Update the cluster

kubectl apply -f deploy/cr.yaml -n postgres-operator

Check that corresponding Pods are not in a cycle of stopping and restarting. This cycle occurs if there are errors on the previous steps:
```
kubectl get pods -n postgres-operator
kubectl logs <pod_name> -c pmm-client
```

Update the secrets file¶

The deploy/secrets.yaml file contains all values for each key/value pair in a convenient plain text format. But the resulting Secrets Objects contains passwords stored as base64-encoded strings. If you want to update the password field, you need to encode the new password into the base64 format and pass it to the Secrets Object.

To encode a password or any other parameter, run the following command:

Linux macOS

echo -n "password" | base64 --wrap=0

echo -n "password" | base64

For example, to set the new service account token in the my-cluster-name-secrets object, do the following:

Linux macOS

kubectl patch secret/cluster1-pmm-secret -p '{"data":{"PMM_SERVER_TOKEN": '$(echo -n <new-token> | base64 --wrap=0)'}}'

kubectl patch secret/cluster1-pmm-secret -p '{"data":{"PMM_SERVER_TOKEN": '$(echo -n <new-token> | base64)'}}'

Check the metrics¶

Let’s see how the collected data is visualized in PMM.

Log in to PMM server.
Click PostgreSQL from the left-hand navigation menu. You land on the Instances Overview page.
Click PostgreSQL → Other dashboards to see the list of available dashboards that allow you to drill down to the metrics you are interested in.

Next steps¶

What’s next

Last update: December 8, 2023
Created: September 15, 2023