What is a replica set in MongoDB?

Vaibhav Kothia May 31, 2023 0 Comments

A replica set in MongoDB is a group of MongoDB instances that maintain the same data set. This means that each instance of the replica set contains the same data, and any changes made to the data on one instance will be automatically replicated to the other instances. For example, if you write a document to one instance, that document will be automatically replicated to the other instances in the replica set. Replica sets also provide redundancy and high availability, as they can continue to serve data even if one of the instances fails.

What is the difference between a Deployment and a ReplicaSet?

Vaibhav Kothia May 27, 2023 0 Comments

A Deployment is a higher-level object that is used to manage ReplicaSets and other objects. A Deployment can be used to create, scale, and update ReplicaSets.

A ReplicaSet is a lower-level object that ensures that a certain number of replicas (pods) are running at any given time. ReplicaSets are managed by Deployments.

Example:

Let’s say you have a web application running on Kubernetes. You want to ensure that the application is running on 5 nodes at any given time. To achieve this, you would create a Deployment object that would manage a ReplicaSet with 5 replicas. The Deployment would ensure that the ReplicaSet is always running 5 replicas, and would handle scaling and updating the ReplicaSet as needed.