VS 2025: Running MongoDB on Kubernetes with StatefulSets
Introduction
Kubernetes is a powerful container orchestration platform that allows you to deploy, manage, and scale your applications in a highly available and fault-tolerant manner. MongoDB is a popular NoSQL database that is known for its scalability, performance, and flexibility. Running MongoDB on Kubernetes with StatefulSets allows you to take advantage of both technologies to create a highly available and durable MongoDB deployment.
Why Use StatefulSets for MongoDB?
StatefulSets are a Kubernetes resource that allows you to manage stateful applications. Stateful applications are those that require persistent storage and cannot be recreated from scratch if they fail. MongoDB is a stateful application because it stores data in a persistent volume.
Using StatefulSets for MongoDB provides the following benefits:
- Persistent storage: StatefulSets ensure that MongoDB’s data is persisted to a durable storage volume. This means that if a MongoDB pod fails, its data will not be lost.
- Headless service: StatefulSets create a headless service for MongoDB, which allows the pods to communicate with each other without exposing the service to the outside world.
- Rolling updates: StatefulSets allow you to perform rolling updates of your MongoDB deployment. This means that you can update your MongoDB pods one at a time, without causing any downtime.
How to Deploy MongoDB on Kubernetes with StatefulSets
To deploy MongoDB on Kubernetes with StatefulSets, you will need to create the following resources:
- A PersistentVolume to store MongoDB’s data
- A PersistentVolumeClaim to bind the PersistentVolume to the MongoDB pods
- A StatefulSet to create and manage the MongoDB pods
- A Service to expose the MongoDB pods to the outside world
Here is an example of a YAML file that you can use to create these resources:
apiVersion: v1
kind: PersistentVolume
metadata:
name: mongo-pv
spec:
capacity:
storage: 1Gi
accessModes:
- ReadWriteOnce
persistentVolumeReclaimPolicy: Retain
storageClassName: standard
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: mongo-pvc
spec:
storageClassName: standard
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
volumeName: mongo-pv
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
name: mongo
spec:
serviceName: mongo
replicas: 3
selector:
matchLabels:
app: mongo
template:
metadata:
labels:
app: mongo
spec:
containers:
- name: mongo
image: mongo:latest
ports:
- containerPort: 27017
volumeMounts:
- name: mongo-data
mountPath: /data/db
volumes:
- name: mongo-data
persistentVolumeClaim:
claimName: mongo-pvc
---
apiVersion: v1
kind: Service
metadata:
name: mongo
spec:
selector:
app: mongo
ports:
- port: 27017
targetPort: 27017
Once you have created these resources, you can deploy MongoDB on Kubernetes by running the following command:
kubectl apply -f mongo.yaml
Tips and Tricks
Here are some tips and tricks for running MongoDB on Kubernetes with StatefulSets:
- Use a persistent storage class to provision PersistentVolumes for MongoDB. This will ensure that your MongoDB data is stored on a durable and reliable storage medium.
- Use a headless service for MongoDB. This will allow the pods to communicate with each other without exposing the service to the outside world.
- Perform rolling updates of your MongoDB deployment. This will allow you to update your MongoDB pods one at a time, without causing any downtime.
- Monitor your MongoDB deployment. This will help you to identify and resolve any issues that may occur.
Conclusion
Running MongoDB on Kubernetes with StatefulSets is a great way to create a highly available and durable MongoDB deployment. By following the tips and tricks in this guide, you can ensure that your MongoDB deployment is up and running smoothly.
