Using Percona Kubernetes Operators for Percona XtraDB Cluster and Percona Server for MongoDB in Amazon

Percona Kubernetes Operators AWS

Percona Kubernetes Operators AWSUnless you are using Amazon Aurora or RDS, setting up clustering software still can be complicated and that’s why we want to offer options to simplify database cluster management in Amazon AWS. This time I will be looking at Percona Kubernetes Operators, for both Percona XtraDB Cluster and Percona Server for MongoDB.

Some time ago I showed some examples in Google Cloud in my post Percona DBaaS CLI to Simplify Deployment in Kubernetes, and now it’s time to take a look at AWS. The assumption is that you have Amazon Elastic Kubernetes Service running already; if not, there should be plenty of resources to look at and this is out of our scope.

To manage Kubernetes resources and Percona Kubernetes Operators we need access to a kubeconfig. Although it is possible to create kubeconfig manually, the easiest way to get it is to use the aws command line utility:

aws eks --region us-east-2 update-kubeconfig --name my-cluster2

Now I also assume you have a node pool running, which will be used to run our database instances on.

The easiest way to create Percona XtraDB Cluster is:

percona-dbaas mysql create-db cluster1

You will see confirmation of the successful operation:

Starting.......................................[done]
Database started successfully, connection details are below:
Provider:          k8s
Engine:            pxc
Resource Name:     cluster1
Resource Endpoint: cluster1-proxysql.default.pxc.svc.local
Port:              3306
User:              root
Pass:              28DQwnhtbDveIIvn
Status:            ready

And for Percona Server for MongoDB, the command is:

percona-dbaas mongodb create-db cluster1

Starting........................[done]
Database started successfully, connection details are below:
Provider:          k8s
Engine:            psmdb
Resource Name:     cluster1
Resource Endpoint: cluster1-rs0.default.psmdb.svc.local
Port:              27017
User:              clusterAdmin
Pass:              LkXSJHhgZMg2UiYlgC
Status:            ready

To access database please run the following commands:
kubectl port-forward svc/cluster1-rs0 27017:27017 &
mongo mongodb://clusterAdmin:LkXSJHhgZMg2UiYlgC@localhost:27017/admin?ssl=false

And just in a single command, we have 3 nodes of MongoDB replica-sets running, which we can check with:

kubectl get pods
NAME                                               READY   STATUS    RESTARTS   AGE
cluster1-rs0-0                                     1/1     Running   0          3m15s
cluster1-rs0-1                                     1/1     Running   0          2m38s
cluster1-rs0-2                                     1/1     Running   0          2m14s

There are a few points to review.

External Connection

As you can see, the command 

mongo mongodb://clusterAdmin:LkXSJHhgZMg2UiYlgC@localhost:27017/admin?ssl=false
 offers to connect from the localhost. How do we connect to the replica set from the outside network?

This can be done by creating LoadBalancer service in EKS, and AWS will automatically assign the public IP address:

kubectl expose service cluster1-rs0   --type=LoadBalancer  --name=cluster1-rs0-service

kubectl get service
NAME                        TYPE           CLUSTER-IP       EXTERNAL-IP                                                               PORT(S)           AGE
cluster1-rs0-service        LoadBalancer   10.100.226.122   a636d79b2646b4b12b10e3a1637f8f28-1009994397.us-east-2.elb.amazonaws.com   27017:31807/TCP   26s

And we can connect to our Percona Server for MongoDB instances as:

mongo mongodb://clusterAdmin:LkXSJHhgZMg2UiYlgC@a636d79b2646b4b12b10e3a1637f8f28-1009994397.us-east-2.elb.amazonaws.com:27017/admin?ssl=false

Or you can create external access from the percona-dbaas with:

percona-dbaas mysql create-db db-cluster1  --options="proxysql.serviceType=LoadBalancer"

Storage Type

Another thing you may want to customize is the storage type.

By default, you will see:

kubectl get pvc
NAME                         STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
mongod-data-cluster1-rs0-0   Bound    pvc-ab619e95-9784-4e3f-9b98-0122cff8a564   6Gi        RWO            gp2            11m
mongod-data-cluster1-rs0-1   Bound    pvc-220a447e-3891-425b-86dd-9839878dd13c   6Gi        RWO            gp2            10m
mongod-data-cluster1-rs0-2   Bound    pvc-f2280389-4642-4592-bc99-2afe2c54fcc3   6Gi        RWO            gp2            10m

The default-created storage class is “gp2”, which you can confirm from Amazon EC2 console:

 

(volumes were created and assigned automatically)

 

Volume Size

The default volume size is 6Gi, and it is also customizable:

percona-dbaas mongodb create-db  --options "replsets.volumeSpec.persistentVolumeClaim.resources.requests=storage:250Gi” cluster4

The command will create volumes 250Gi in size.

Takeaways

The points I wanted to show with this post are:

  • Creating database clusters in AWS should not be complicated, even beside Aurora and RDS.
  • At Percona we offer solutions you can use to create Percona XtraDB Cluster and Percona Server for MongoDB replicasets in minutes.
  • Kubernetes by itself may sound complicated, but it really allows us to simplify a lot of operations.

by Vadim Tkachenko via Percona Database Performance Blog

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