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Monitoring MySQL Using Prometheus operator
Prometheus operator provides simple and Kubernetes native way to deploy and configure Prometheus server. This tutorial will show you how to use Prometheus operator to monitor MySQL database deployed with KubeDB.
Before You Begin
At first, you need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using kind.
To learn how Prometheus monitoring works with KubeDB in general, please visit here.
To keep database resources isolated, this tutorial uses a separate namespace called
demo
throughout this tutorial. Run the following command to prepare your cluster:$ kubectl create ns demo namespace/demo created
We need a Prometheus operator instance running. If you don’t already have a running instance, deploy one following the docs from here.
If you already don’t have a Prometheus server running, deploy one following tutorial from here.
Note: YAML files used in this tutorial are stored in docs/guides/mysql/monitoring/prometheus-operator/yamls folder in GitHub repository kubedb/docs.
Find out required labels for ServiceMonitor
We need to know the labels used to select ServiceMonitor
by a Prometheus
crd. We are going to provide these labels in spec.monitor.prometheus.labels
field of MySQL crd so that KubeDB creates ServiceMonitor
object accordingly.
At first, let’s find out the available Prometheus server in our cluster.
$ kubectl get prometheus --all-namespaces
NAMESPACE NAME VERSION REPLICAS AGE
default prometheus 1 2m19s
If you don’t have any Prometheus server running in your cluster, deploy one following the guide specified in Before You Begin section.
Now, let’s view the YAML of the available Prometheus server prometheus
in default
namespace.
$ kubectl get prometheus -n default prometheus -o yaml
apiVersion: monitoring.coreos.com/v1
kind: Prometheus
metadata:
annotations:
kubectl.kubernetes.io/last-applied-configuration: |
{"apiVersion":"monitoring.coreos.com/v1","kind":"Prometheus","metadata":{"annotations":{},"labels":{"prometheus":"prometheus"},"name":"prometheus","namespace":"default"},"spec":{"replicas":1,"resources":{"requests":{"memory":"400Mi"}},"serviceAccountName":"prometheus","serviceMonitorNamespaceSelector":{"matchLabels":{"prometheus":"prometheus"}},"serviceMonitorSelector":{"matchLabels":{"release":"prometheus"}}}}
creationTimestamp: "2020-08-25T04:02:07Z"
generation: 1
labels:
prometheus: prometheus
...
manager: kubectl
operation: Update
time: "2020-08-25T04:02:07Z"
name: prometheus
namespace: default
resourceVersion: "2087"
selfLink: /apis/monitoring.coreos.com/v1/namespaces/default/prometheuses/prometheus
uid: 972a50cb-b751-418b-b2bc-e0ecc9232730
spec:
replicas: 1
resources:
requests:
memory: 400Mi
serviceAccountName: prometheus
serviceMonitorNamespaceSelector:
matchLabels:
prometheus: prometheus
serviceMonitorSelector:
matchLabels:
release: prometheus
spec.serviceMonitorSelector
field specifies which ServiceMonitors should be included. The Above labelrelease: prometheus
is used to selectServiceMonitors
by its selector. So, we are going to use this label inspec.monitor.prometheus.labels
field of MySQL crd.spec.serviceMonitorNamespaceSelector
field specifies that theServiceMonitors
can be selected outside the Prometheus namespace by Prometheus using namespace selector. The Above labelprometheus: prometheus
is used to select the namespace where theServiceMonitor
is created.
Add Label to database namespace
KubeDB creates a ServiceMonitor
in database namespace demo
. We need to add label to demo
namespace. Prometheus will select this namespace by using its spec.serviceMonitorNamespaceSelector
field.
Let’s add label prometheus: prometheus
to demo
namespace,
$ kubectl patch namespace demo -p '{"metadata":{"labels": {"prometheus":"prometheus"}}}'
namespace/demo patched
Deploy MySQL with Monitoring Enabled
At first, let’s deploy an MySQL database with monitoring enabled. Below is the MySQL object that we are going to create.
apiVersion: kubedb.com/v1
kind: MySQL
metadata:
name: coreos-prom-mysql
namespace: demo
spec:
version: "8.0.35"
deletionPolicy: WipeOut
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
monitor:
agent: prometheus.io/operator
prometheus:
serviceMonitor:
labels:
release: prometheus
interval: 10s
Here,
monitor.agent: prometheus.io/operator
indicates that we are going to monitor this server using Prometheus operator.monitor.prometheus.labels
specifies that KubeDB should createServiceMonitor
with these labels.monitor.prometheus.interval
indicates that the Prometheus server should scrape metrics from this database with 10 seconds interval.
Let’s create the MySQL object that we have shown above,
$ kubectl create -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/guides/mysql/monitoring/prometheus-operator/yamls/prom-operator-mysql.yaml
mysql.kubedb.com/prom-operator-mysql created
Now, wait for the database to go into Running
state.
$ watch -n 3 kubectl get mysql -n demo coreos-prom-mysql
Every 3.0s: kubectl get mysql -n demo coreos-prom-mysql suaas-appscode: Tue Aug 25 11:53:34 2020
NAME VERSION STATUS AGE
coreos-prom-mysql 8.0.35 Running 2m53s
KubeDB will create a separate stats service with name {MySQL crd name}-stats
for monitoring purpose.
$ kubectl get svc -n demo --selector="app.kubernetes.io/instance=coreos-prom-mysql"
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
coreos-prom-mysql ClusterIP 10.103.228.135 <none> 3306/TCP 3m36s
coreos-prom-mysql-gvr ClusterIP None <none> 3306/TCP 3m36s
coreos-prom-mysql-stats ClusterIP 10.106.236.14 <none> 56790/TCP 50s
Here, coreos-prom-mysql-stats
service has been created for monitoring purpose.
Let’s describe this stats service.
$ kubectl describe svc -n demo coreos-prom-mysql-stats
Name: coreos-prom-mysql-stats
Namespace: demo
Labels: app.kubernetes.io/name=mysqls.kubedb.com
app.kubernetes.io/instance=coreos-prom-mysql
kubedb.com/role=stats
Annotations: monitoring.appscode.com/agent: prometheus.io/operator
Selector: app.kubernetes.io/name=mysqls.kubedb.com,app.kubernetes.io/instance=coreos-prom-mysql
Type: ClusterIP
IP: 10.106.236.14
Port: prom-http 56790/TCP
TargetPort: prom-http/TCP
Endpoints: 10.244.2.6:56790
Session Affinity: None
Events: <none>
Notice the Labels
and Port
fields. ServiceMonitor
will use these information to target its endpoints.
KubeDB will also create a ServiceMonitor
crd in demo
namespace that select the endpoints of coreos-prom-mysql-stats
service. Verify that the ServiceMonitor
crd has been created.
$ kubectl get servicemonitor -n demo
NAME AGE
kubedb-demo-coreos-prom-mysql 3m16s
Let’s verify that the ServiceMonitor
has the label that we had specified in spec.monitor
section of MySQL crd.
$ kubectl get servicemonitor -n demo kubedb-demo-coreos-prom-mysql -o yaml
apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
creationTimestamp: "2020-08-25T05:53:27Z"
generation: 1
labels:
release: prometheus
operation: Update
time: "2020-08-25T05:53:27Z"
...
name: kubedb-demo-coreos-prom-mysql
namespace: demo
ownerReferences:
- apiVersion: v1
blockOwnerDeletion: true
controller: true
kind: Service
name: coreos-prom-mysql-stats
uid: cf4ce3ec-a78e-4828-9fee-941c77eb965e
resourceVersion: "28659"
selfLink: /apis/monitoring.coreos.com/v1/namespaces/demo/servicemonitors/kubedb-demo-coreos-prom-mysql
uid: 9cec794a-dfee-49dc-a809-6c9d6faac1df
spec:
endpoints:
- bearerTokenSecret:
key: ""
honorLabels: true
interval: 10s
path: /metrics
port: prom-http
namespaceSelector:
matchNames:
- demo
selector:
matchLabels:
app.kubernetes.io/name: mysqls.kubedb.com
app.kubernetes.io/instance: coreos-prom-mysql
kubedb.com/role: stats
Notice that the ServiceMonitor
has label release: prometheus
that we had specified in MySQL crd.
Also notice that the ServiceMonitor
has selector which match the labels we have seen in the coreos-prom-mysql-stats
service. It also, target the prom-http
port that we have seen in the stats service.
Verify Monitoring Metrics
At first, let’s find out the respective Prometheus pod for prometheus
Prometheus server.
$ kubectl get pod -n default -l=app=prometheus
NAME READY STATUS RESTARTS AGE
prometheus-prometheus-0 3/3 Running 1 121m
Prometheus server is listening to port 9090
of prometheus-prometheus-0
pod. We are going to use port forwarding to access Prometheus dashboard.
Run following command on a separate terminal to forward the port 9090 of prometheus-prometheus-0
pod,
$ kubectl port-forward -n default prometheus-prometheus-0 9090
Forwarding from 127.0.0.1:9090 -> 9090
Forwarding from [::1]:9090 -> 9090
Now, we can access the dashboard at localhost:9090
. Open http://localhost:9090 in your browser. You should see prom-http
endpoint of coreos-prom-mysql-stats
service as one of the targets.
Check the endpoint
and service
labels marked by red rectangle. It verifies that the target is our expected database. Now, you can view the collected metrics and create a graph from homepage of this Prometheus dashboard. You can also use this Prometheus server as data source for Grafana and create beautiful dashboard with collected metrics.
Cleaning up
To cleanup the Kubernetes resources created by this tutorial, run following commands
# cleanup database
kubectl delete -n demo my/coreos-prom-mysql
# cleanup Prometheus resources if exist
kubectl delete -f https://raw.githubusercontent.com/appscode/third-party-tools/master/monitoring/prometheus/coreos-operator/artifacts/prometheus.yaml
kubectl delete -f https://raw.githubusercontent.com/appscode/third-party-tools/master/monitoring/prometheus/coreos-operator/artifacts/prometheus-rbac.yaml
# cleanup Prometheus operator resources if exist
kubectl delete -f https://raw.githubusercontent.com/prometheus-operator/prometheus-operator/release-0.41/bundle.yaml
# delete namespace
kubectl delete ns demo
Next Steps
- Monitor your MySQL database with KubeDB using out-of-the-box builtin-Prometheus.
- Detail concepts of MySQL object.
- Detail concepts of MySQLVersion object.
- Initialize MySQL with Script.
- Use private Docker registry to deploy MySQL with KubeDB.
- Want to hack on KubeDB? Check our contribution guidelines.