What is StatefulSet?

StatefulSet is the workload API object used to manage stateful applications. Manages the deployment and scaling of a set of Pods. A Pod represents a set of running containers on your cluster. , and provides guarantees about the ordering and uniqueness of these Pods.

StatefulSets represent a set of Pods with unique, persistent identities and stable hostnames that GKE maintains regardless of where they are scheduled. The state information and other resilient data for any given StatefulSet Pod is maintained in persistent disk storage associated with the StatefulSet.

Secondly, how do I remove StatefulSet? Deleting a StatefulSet You can delete a StatefulSet in the same way you delete other resources in Kubernetes: use the kubectl delete command, and specify the StatefulSet either by file or by name. You may need to delete the associated headless service separately after the StatefulSet itself is deleted.

Also know, what is the difference between StatefulSet and deployment?

5 Answers. Deployments and ReplicationControllers are meant for stateless usage and are rather lightweight. StatefulSets are used when state has to be persisted. Therefore the latter use volumeClaimTemplates / claims on persistent volumes to ensure they can keep the state across component restarts.

What is volumeClaimTemplates?

volumeClaimTemplates is a list of claims that pods are allowed to reference. The StatefulSet controller is responsible for mapping network identities to claims in a way that maintains the identity of a pod.

What is DaemonSet?

DaemonSet. A DaemonSet ensures that all (or some) Nodes run a copy of a Pod. As nodes are added to the cluster, Pods are added to them. As nodes are removed from the cluster, those Pods are garbage collected. Deleting a DaemonSet will clean up the Pods it created.

How do I scale down DaemonSet?

DaemonSet ensures that every node run a copy of a Pod. So you can’t scale down it as Deployment. DaemonSet use DaemonSet Controller and Deployment use Replication Controller for replications. So You can simply delete the DaemonSet.

What is the difference between Replicaset and replication controller?

Replica Set and Replication Controller do almost the same thing. Both of them ensure that a specified number of pod replicas are running at any given time. The difference comes with the usage of selectors to replicate pods. Replica Set use Set-Based selectors while replication controllers use Equity-Based selectors.

Is Kubernetes stateless?

On a Kubernetes cluster, a stateless application has no persistent storage or volume associated with it. From an operations perspective, this is great news. Different pods all across the cluster can work independently with multiple requests coming to them simultaneously.

What is a persistent volume claim?

Persistent Volume Claim. Kubernetes persistent volumes are administrator provisioned volumes. These are created with a particular filesystem, size, and identifying characteristics such as volume IDs and names. A Kubernetes persistent volume has the following attributes.

What is PVC in Kubernetes?

Managing storage is a distinct problem from managing compute instances. A PersistentVolumeClaim (PVC) is a request for storage by a user. It is similar to a Pod. Pods consume node resources and PVCs consume PV resources. Pods can request specific levels of resources (CPU and Memory).

What is a stateful application?

A stateful app is a program that saves client data from the activities of one session for use in the next session. The data that is saved is called the application’s state. Apps can be stateful or stateless. Cookies are a common way such data is stored. Most desktop applications and operating systems are stateful.

What is Kubernetes replica?

Kubernetes – Replica Sets. Advertisements. Replica Set ensures how many replica of pod should be running. It can be considered as a replacement of replication controller.

What is stateless and stateful?

Stateless Protocol is a network protocol in which Client send request to the server and server response back as per the given state. Stateful Protocol is a network protocol in which if client send a request to the server then it expects some kind of response, in case of no response then it resend the request.

What is a headless service?

A headless service is a service with a service IP but instead of load-balancing it will return the IPs of our associated Pods.

What is Kubernetes service?

In Kubernetes, a Service is an abstraction which defines a logical set of Pods and a policy by which to access them (sometimes this pattern is called a micro-service). The set of Pods targeted by a Service is usually determined by a selector. (see below for why you might want a Service without a selector).

Is Kubernetes open source?

Kubernetes (commonly stylized as k8s) is an open-source container-orchestration system for automating application deployment, scaling, and management. It was originally designed by Google, and is now maintained by the Cloud Native Computing Foundation.

How do I get rid of Minikube?

Windows Installer cpl and hit Enter key. – In there, find an entry for the Minikube installer, right click on it & click on Uninstall. – Follow the onscreen prompts to uninstall minikube from your system.

How do you force delete a pod?

Procedure b. SSH on to the node and verify that that the container associated isn’t running by running the following command. $ docker ps. Once it’s verified that the container isn’t present, run the following command to delete the pod forcefully. $ kubectl delete pod -n –grace-period 0 –force.