New to KubeDB? Please start here.
This is an Enterprise-only feature. Please install
KubeDB Enterprise Edition to try this feature.
Vertical Scale MongoDB Standalone
This guide will show you how to use KubeDB Enterprise operator to update the resources of a MongoDB standalone database.
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.
Install KubeDB Community and Enterprise operator in your cluster following the steps here.
You should be familiar with the following KubeDB concepts:
To keep everything isolated, we are going to use a separate namespace called demo throughout this tutorial.
$ kubectl create ns demo
namespace/demo created
Note: YAML files used in this tutorial are stored in docs/examples/mongodb directory of kubedb/docs repository.
Apply Vertical Scaling on Standalone
Here, we are going to deploy a MongoDB standalone using a supported version by KubeDB operator. Then we are going to apply vertical scaling on it.
Prepare MongoDB Standalone Database
Now, we are going to deploy a MongoDB standalone database with version 3.6.8.
Deploy MongoDB standalone
In this section, we are going to deploy a MongoDB standalone database. Then, in the next section we will update the resources of the database using MongoDBOpsRequest CRD. Below is the YAML of the MongoDB CR that we are going to create,
apiVersion: kubedb.com/v1alpha2
kind: MongoDB
metadata:
name: mg-standalone
namespace: demo
spec:
version: "3.6.8-v1"
storageType: Durable
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
Let’s create the MongoDB CR we have shown above,
$ kubectl create -f https://github.com/kubedb/docs/raw/v2021.01.14/docs/examples/mongodb/scaling/mg-standalone.yaml
mongodb.kubedb.com/mg-standalone created
Now, wait until mg-standalone has status Running. i.e,
$ kubectl get mg -n demo 20:05:47
NAME VERSION STATUS AGE
mg-standalone 3.6.8-v1 Running 5m56s
Let’s check the Pod containers resources,
$ kubectl get pod -n demo mg-standalone-0 -o json | jq '.spec.containers[].resources'
{}
You can see the Pod has empty resources that means the scheduler will choose a random node to place the container of the Pod on by default.
We are now ready to apply the MongoDBOpsRequest CR to update the resources of this database.
Vertical Scaling
Here, we are going to update the resources of the standalone database to meet the desired resources after scaling.
Create MongoDBOpsRequest
In order to update the resources of the database, we have to create a MongoDBOpsRequest CR with our desired resources. Below is the YAML of the MongoDBOpsRequest CR that we are going to create,
apiVersion: ops.kubedb.com/v1alpha1
kind: MongoDBOpsRequest
metadata:
name: mops-vscale-standalone
namespace: demo
spec:
type: VerticalScaling
databaseRef:
name: mg-standalone
verticalScaling:
standalone:
requests:
memory: "150Mi"
cpu: "0.1"
limits:
memory: "250Mi"
cpu: "0.2"
Here,
spec.databaseRef.name specifies that we are performing vertical scaling operation on mops-vscale-standalone database.spec.type specifies that we are performing VerticalScaling on our database.spec.VerticalScaling.standalone specifies the desired resources after scaling.
Let’s create the MongoDBOpsRequest CR we have shown above,
$ kubectl apply -f https://github.com/kubedb/docs/raw/v2021.01.14/docs/examples/mongodb/scaling/vertical-scaling/mops-vscale-standalone.yaml
mongodbopsrequest.ops.kubedb.com/mops-vscale-standalone created
Verify MongoDB Standalone resources updated successfully
If everything goes well, KubeDB Enterprise operator will update the resources of MongoDB object and related StatefulSets and Pods.
Let’s wait for MongoDBOpsRequest to be Successful. Run the following command to watch MongoDBOpsRequest CR,
$ kubectl get mongodbopsrequest -n demo
Every 2.0s: kubectl get mongodbopsrequest -n demo
NAME TYPE STATUS AGE
mops-vscale-standalone VerticalScaling Successful 108s
We can see from the above output that the MongoDBOpsRequest has succeeded. If we describe the MongoDBOpsRequest we will get an overview of the steps that were followed to scale the database.
$ kubectl describe mongodbopsrequest -n demo mops-vscale-standalone
Name: mops-vscale-standalone
Namespace: demo
Labels: <none>
Annotations: API Version: ops.kubedb.com/v1alpha1
Kind: MongoDBOpsRequest
Metadata:
Creation Timestamp: 2020-08-25T05:12:17Z
Finalizers:
kubedb.com
Generation: 1
Managed Fields:
API Version: ops.kubedb.com/v1alpha1
Fields Type: FieldsV1
fieldsV1:
f:metadata:
f:annotations:
.:
f:kubectl.kubernetes.io/last-applied-configuration:
f:spec:
.:
f:databaseRef:
.:
f:name:
f:type:
f:verticalScaling:
.:
f:standalone:
.:
f:limits:
.:
f:memory:
f:requests:
.:
f:memory:
Manager: kubectl
Operation: Update
Time: 2020-08-25T05:12:17Z
API Version: ops.kubedb.com/v1alpha1
Fields Type: FieldsV1
fieldsV1:
f:metadata:
f:finalizers:
f:spec:
f:verticalScaling:
f:standalone:
f:limits:
f:cpu:
f:requests:
f:cpu:
f:status:
.:
f:conditions:
f:observedGeneration:
f:phase:
Manager: kubedb-enterprise
Operation: Update
Time: 2020-08-25T05:12:57Z
Resource Version: 4991494
Self Link: /apis/ops.kubedb.com/v1alpha1/namespaces/demo/mongodbopsrequests/mops-vscale-standalone
UID: 99935637-43f4-45a2-8538-9b3a63fb3ca1
Spec:
Database Ref:
Name: mg-standalone
Type: VerticalScaling
Vertical Scaling:
Standalone:
Limits:
Cpu: 0.2
Memory: 250Mi
Requests:
Cpu: 0.1
Memory: 150Mi
Status:
Conditions:
Last Transition Time: 2020-08-25T05:12:17Z
Message: MongoDB ops request is being processed
Observed Generation: 1
Reason: Scaling
Status: True
Type: Scaling
Last Transition Time: 2020-08-25T05:12:17Z
Message: Successfully halted mongodb: mg-standalone
Observed Generation: 1
Reason: HaltDatabase
Status: True
Type: HaltDatabase
Last Transition Time: 2020-08-25T05:12:17Z
Message: Successfully updated StatefulSets Resources
Observed Generation: 1
Reason: UpdateStatefulSetResources
Status: True
Type: UpdateStatefulSetResources
Last Transition Time: 2020-08-25T05:12:57Z
Message: Successfully updated Standalone resources
Observed Generation: 1
Reason: UpdateStandaloneResources
Status: True
Type: UpdateStandaloneResources
Last Transition Time: 2020-08-25T05:12:57Z
Message: Successfully Resumed mongodb: mg-standalone
Observed Generation: 1
Reason: ResumeDatabase
Status: True
Type: ResumeDatabase
Last Transition Time: 2020-08-25T05:12:57Z
Message: Successfully completed the modification process
Observed Generation: 1
Reason: Successful
Status: True
Type: Successful
Observed Generation: 1
Phase: Successful
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal HaltDatabase 6m12s KubeDB Enterprise Operator Pausing Mongodb mg-standalone in Namespace demo
Normal HaltDatabase 6m12s KubeDB Enterprise Operator Successfully Halted Mongodb mg-standalone in Namespace demo
Normal Starting 6m12s KubeDB Enterprise Operator Updating Resources of StatefulSet: mg-standalone
Normal UpdateStatefulSetResources 6m12s KubeDB Enterprise Operator Successfully updated StatefulSets Resources
Normal UpdateStandaloneResources 6m12s KubeDB Enterprise Operator Updating Standalone Resources
Normal UpdateStandaloneResources 5m32s KubeDB Enterprise Operator Successfully Updated Resources of Pod (master): mg-standalone-0
Normal UpdateStandaloneResources 5m32s KubeDB Enterprise Operator Successfully Updated Standalone Resources
Normal ResumeDatabase 5m32s KubeDB Enterprise Operator Resuming MongoDB
Normal ResumeDatabase 5m32s KubeDB Enterprise Operator Successfully Resumed mongodb
Normal Successful 5m32s KubeDB Enterprise Operator Successfully Scaled Database
Now, we are going to verify from the Pod yaml whether the resources of the standalone database has updated to meet up the desired state, Let’s check,
$ kubectl get pod -n demo mg-standalone-0 -o json | jq '.spec.containers[].resources'
{
"limits": {
"cpu": "200m",
"memory": "250Mi"
},
"requests": {
"cpu": "100m",
"memory": "150Mi"
}
}
The above output verifies that we have successfully scaled up the resources of the MongoDB standalone database.
Cleaning Up
To clean up the Kubernetes resources created by this tutorial, run:
kubectl delete mg -n demo mg-standalone
kubectl delete mongodbopsrequest -n demo mops-vscale-standalone
