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Monitoring PerconaXtraDB 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 PerconaXtraDB 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 Prometheus resources isolated, we are going to use a separate namespace called
monitoring
to deploy respective monitoring resources. We are going to deploy database indemo
namespace.$ kubectl create ns monitoring namespace/monitoring created $ 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/examples/percona-xtradb 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
resource. We are going to provide these labels in .spec.monitor.prometheus.labels
field of PerconaXtraDB
object 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 AGE
monitoring prometheus 18m
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 monitoring
namespace.
$ kubectl get prometheus -n monitoring 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":"monitoring"},"spec":{"replicas":1,"resources":{"requests":{"memory":"400Mi"}},"serviceAccountName":"prometheus","serviceMonitorSelector":{"matchLabels":{"k8s-app":"prometheus"}}}}
creationTimestamp: 2019-01-03T13:41:51Z
generation: 1
labels:
prometheus: prometheus
name: prometheus
namespace: monitoring
resourceVersion: "44402"
selfLink: /apis/monitoring.coreos.com/v1/namespaces/monitoring/prometheuses/prometheus
uid: 5324ad98-0f5d-11e9-b230-080027f306f3
spec:
replicas: 1
resources:
requests:
memory: 400Mi
serviceAccountName: prometheus
serviceMonitorSelector:
matchLabels:
k8s-app: prometheus
Notice the .spec.serviceMonitorSelector
section. Here, k8s-app: prometheus
label is used to select ServiceMonitor
resource. So, we are going to use this label in .spec.monitor.prometheus.labels
field of PerconaXtraDB
resource.
Deploy PerconaXtraDB with Monitoring Enabled
At first, let’s deploy a sample PerconaXtraDB with monitoring enabled. Below is the PerconaXtraDB
object that we are going to create.
apiVersion: kubedb.com/v1alpha2
kind: PerconaXtraDB
metadata:
name: px-coreos-prom
namespace: demo
spec:
version: "5.7-cluster"
replicas: 3
storageType: Durable
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 50Mi
terminationPolicy: WipeOut
monitor:
agent: prometheus.io/operator
prometheus:
serviceMonitor:
labels:
k8s-app: prometheus
interval: 10s
Here,
.spec.monitor.agent: prometheus.io/operator
indicates that we are going to monitor this server using Prometheus operator..spec.monitor.prometheus.namespace: monitoring
specifies that KubeDB should createServiceMonitor
inmonitoring
namespace..spec.monitor.prometheus.labels
specifies that KubeDB should createServiceMonitor
with these labels..spec.monitor.prometheus.interval
indicates that the Prometheus server should scrape metrics from this database with 10 seconds interval.
Let’s create the PerconaXtraDB
object that we have shown above,
$ kubectl create -f https://github.com/kubedb/docs/raw/v2022.08.08/docs/examples/percona-xtradb/px-coreos-prom.yaml
perconaxtradb.kubedb.com/px-coreos-prom created
Now, wait for the database to go into Running
state.
$ kubectl get px -n demo px-coreos-prom
NAME VERSION STATUS AGE
px-coreos-prom 5.7-cluster Running 5m4s
KubeDB will create a separate stats service with name {PerconaXtraDB_obj_name}-stats
for monitoring purpose.
$ kubectl get svc -n demo --selector="app.kubernetes.io/instance=px-coreos-prom"
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
px-coreos-prom ClusterIP 10.107.58.214 <none> 3306/TCP 5m25s
px-coreos-prom-gvr ClusterIP None <none> 3306/TCP 5m25s
px-coreos-prom-stats ClusterIP 10.106.130.209 <none> 56790/TCP 48s
Here, px-coreos-prom-stats
service has been created for monitoring purpose.
Let’s describe this stats service.
$ kubectl describe svc -n demo px-coreos-prom-stats
Name: px-coreos-prom-stats
Namespace: demo
Labels: app.kubernetes.io/name=perconaxtradbs.kubedb.com
app.kubernetes.io/instance=px-coreos-prom
kubedb.com/role=stats
Annotations: monitoring.appscode.com/agent: prometheus.io/operator
Selector: app.kubernetes.io/name=perconaxtradbs.kubedb.com,app.kubernetes.io/instance=px-coreos-prom
Type: ClusterIP
IP: 10.106.130.209
Port: prom-http 56790/TCP
TargetPort: prom-http/TCP
Endpoints: 10.244.1.7:56790,10.244.2.11:56790,10.244.2.9:56790
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
resource in monitoring
namespace that select the endpoints of px-coreos-prom-stats
service. Verify that the ServiceMonitor
resource has been created.
$ kubectl get servicemonitor -n monitoring
NAME AGE
kubedb-demo-px-coreos-prom 2m45s
Let’s verify that the ServiceMonitor
has the label that we had specified in .spec.monitor
section of PerconaXtraDB
object.
$ kubectl get servicemonitor -n monitoring kubedb-demo-px-coreos-prom -o yaml
apiVersion: monitoring.coreos.com/v1
kind: ServiceMonitor
metadata:
creationTimestamp: "2019-12-19T07:17:11Z"
generation: 1
labels:
k8s-app: prometheus
monitoring.appscode.com/service: px-coreos-prom-stats.demo
name: kubedb-demo-px-coreos-prom
namespace: monitoring
ownerReferences:
- apiVersion: v1
blockOwnerDeletion: true
kind: Service
name: px-coreos-prom-stats
uid: fb353fac-9945-48ca-ad81-f79dcf5e8e24
resourceVersion: "13989"
selfLink: /apis/monitoring.coreos.com/v1/namespaces/monitoring/servicemonitors/kubedb-demo-px-coreos-prom
uid: 07fd2ae4-d294-4e7f-88d8-960ca3a63a40
spec:
endpoints:
- honorLabels: true
interval: 10s
path: /metrics
port: prom-http
namespaceSelector:
matchNames:
- demo
selector:
matchLabels:
app.kubernetes.io/name: perconaxtradbs.kubedb.com
app.kubernetes.io/instance: px-coreos-prom
kubedb.com/role: stats
Notice that the ServiceMonitor
has label k8s-app: prometheus
that we had specified in PerconaXtraDB
object.
Also notice that the ServiceMonitor
has selector which match the labels we have seen in the px-coreos-prom-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 monitoring -l=app=prometheus
NAME READY STATUS RESTARTS AGE
prometheus-prometheus-0 3/3 Running 1 51m
Prometheus server is listening to port 9090
of prometheus-prometheus-0
Pod. We are going to use port forwarding to access Prometheus dashboard.
Run the following command on a separate terminal to forward the port 9090 of prometheus-prometheus-0
Pod,
$ kubectl port-forward -n monitoring 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 px-coreos-prom-stats
service as one of the targets.
Check the followings:
- Endpoint URLs of backend servers marked by green rectangles
endpoint
,pod
, andservice
labels marked by red rectangles
They all indicate 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 px/px-coreos-prom
# cleanup prometheus resources
$ kubectl delete -n monitoring prometheus prometheus
$ kubectl delete clusterrolebinding prometheus
$ kubectl delete clusterrole prometheus
$ kubectl delete -n monitoring serviceaccount prometheus
$ kubectl delete -n monitoring service prometheus-operated
# cleanup prometheus operator resources
$ kubectl delete -n monitoring deployment prometheus-operator
$ kubectl delete clusterrolebinding prometheus-operator
$ kubectl delete clusterrole prometheus-operator
$ kubectl delete -n monitoring serviceaccount prometheus-operator
# delete namespace
$ kubectl delete ns monitoring
$ kubectl delete ns demo
Next Steps
- Monitor your PerconaXtraDB database with KubeDB using out-of-the-box builtin-Prometheus.
- Initialize PerconaXtraDB with Script.
- Use private Docker registry to deploy PerconaXtraDB with KubeDB.
- How to use custom configuration.
- How to use custom rbac resource for PerconaXtraDB.
- Use Stash to Backup PerconaXtraDB.
- Detail concepts of PerconaXtraDB object.
- Detail concepts of PerconaXtraDBVersion object.
- Want to hack on KubeDB? Check our contribution guidelines.