Kubernetes Cluster
A Kubernetes Cluster is a computing cluster that is based on a Kubernetes platform.
- AKA: Kubernetes (K8s) Cluster.
- Context:
- It can (typically) consist of a Kubernetes Control Plane, oversees cluster management.
- It can (typically) consist of Kubernetes Worker Nodes which run Kubernetes pods (the smallest deployable units containing containers sharing resources).
- It can be deployed on physical machines or virtual machines, both on-premises and in the cloud.
- It can maintain the desired Networked application state via scheduling and monitoring.
- It can be an Automatic Scaling Cluster, Self-Healing Cluster, and Rolling Update Kubernetes Cluster.
- ...
- Example(s):
- Local Development Kubernetes Clusters:
- Minikube Kubernetes Cluster: A single-node cluster for local development and testing.
- Kind Kubernetes Cluster: A lightweight cluster running on a local machine using Docker containers as nodes.
- Managed Cloud Kubernetes Clusters:
- Google Kubernetes Engine (GKE) Cluster: A managed Kubernetes cluster in the Google Cloud Platform.
- Amazon Elastic Kubernetes Service (EKS) Cluster: A managed Kubernetes cluster in Amazon Web Services.
- Azure Kubernetes Service (AKS) Cluster: A managed Kubernetes cluster in Microsoft Azure.
- Self-Managed Kubernetes Clusters:
- On-Premises Kubernetes Cluster: A self-managed cluster in a private data center.
- Bare Metal Kubernetes Cluster: A cluster running directly on physical servers without a virtualization layer.
- ...
- Local Development Kubernetes Clusters:
- Counter-Example(s):
- See: Software Development Environments, Pod, Node, Kubernetes Dashboard, Container Orchestration, Docker, Microservices.
References
2024a
- (ChatGPT-OpenAI, 2024) ⇒ Prompt: Summarize the concept Kubernetes Cluster in 1- 2 paragraphs. ChatGPT (model:gpt-4-turbo-preview). Retrieved: 2024-05-05.
- QUOTE: A Kubernetes cluster is a set of node machines for running containerized applications. At its heart, Kubernetes is an open-source platform designed to automate deploying, scaling, and operating application containers across clusters of hosts. The cluster consists of at least one master node and multiple worker nodes. The master node manages the cluster, scheduling applications, and maintaining the desired state as defined by the user. Worker nodes actually run the applications and workloads.
Within a Kubernetes cluster, containers are organized into pods, which are the basic operational units. Pods can contain single or multiple containers that share storage and network resources. Kubernetes handles the orchestration of these pods across the worker nodes, dealing with tasks like scaling, failover, and load balancing automatically. This makes Kubernetes an essential tool for the deployment and management of microservices architectures, providing developers with a platform that ensures high availability, scalability, and deployment efficiency without the need for manual intervention in the management of individual containers.
- QUOTE: A Kubernetes cluster is a set of node machines for running containerized applications. At its heart, Kubernetes is an open-source platform designed to automate deploying, scaling, and operating application containers across clusters of hosts. The cluster consists of at least one master node and multiple worker nodes. The master node manages the cluster, scheduling applications, and maintaining the desired state as defined by the user. Worker nodes actually run the applications and workloads.
2024b
- (AWS, 2024) ⇒ AWS. (2024). "What is a Kubernetes Cluster?" In: AWS Documentation.
- QUOTE:A Kubernetes (K8s) cluster is a group of computing nodes, or worker machines, that run containerized applications. Containerization is a software deployment and runtime process that bundles an application’s code with all the files and libraries it needs to run on any infrastructure. Kubernetes is an open source container orchestration software with which you can manage, coordinate, and schedule containers at scale. Kubernetes places containers into pods and runs them on nodes. A Kubernetes cluster has, at a minimum, a master node running a container pod and a control plane that manages the cluster. When you deploy Kubernetes, you are essentially running a Kubernetes cluster.
2023
- (Menachem, 2023) ⇒ Guy Menachem (2023). "Kubernetes Clusters: The Basics and a Quick Tutorial.". In: Komodor Blog.
- QUOTE: A Kubernetes cluster is a set of nodes (physical or virtual machines) grouped together to achieve a common goal. A Kubernetes cluster provides advanced orchestration capabilities that make it a vital component in the world of DevOps. The cluster is a mechanism that manages containerized applications across multiple hosts, providing automated deployment, maintenance, and scaling of applications.
A key aspect of a Kubernetes cluster is the way it handles containers. Containers are lightweight, standalone, executable software packages, which include everything required to run an application: code, a runtime environment, libraries, environment variables, and configuration files. The Kubernetes cluster groups containers that perform the same function into pods. Pods run on nodes and are the smallest unit of management in a Kubernetes cluster.
The primary function of a Kubernetes cluster is to manage the lifecycle of pods and containers in a scalable and automated manner. It constantly checks the health of nodes, pods, and containers, restarting containers that fail, replacing and rescheduling pods when nodes die, and ensuring pods are only advertised to clients when they are ready for work.
- QUOTE: A Kubernetes cluster is a set of nodes (physical or virtual machines) grouped together to achieve a common goal. A Kubernetes cluster provides advanced orchestration capabilities that make it a vital component in the world of DevOps. The cluster is a mechanism that manages containerized applications across multiple hosts, providing automated deployment, maintenance, and scaling of applications.
2020
- (Red Hat, 2020) ⇒ "What is a Kubernetes cluster?" In: Red Hat Resources. Published January 15, 2020.
- QUOTE: A Kubernetes cluster is a set of node machines for running containerized applications. If you’re running Kubernetes, you’re running a cluster.
2019
- (VMware, 2019) ⇒ https://www.vmware.com/topics/glossary/content/kubernetes-cluster
- QUOTE: A Kubernetes cluster is a set of nodes that run containerized applications. Containerizing applications packages an app with its dependences and some necessary services. They are more lightweight and flexible than virtual machines. In this way, Kubernetes clusters allow for applications to be more easily developed, moved and managed.
Kubernetes clusters allow containers to run across multiple machines and environments: virtual, physical, cloud-based, and on-premises. Kubernetes containers are not restricted to a specific operating system, unlike virtual machines. Instead, they are able to share operating systems and run anywhere.
Kubernetes clusters are comprised of one master node and a number of worker nodes. These nodes can either be physical computers or virtual machines, depending on the cluster.
- The master node controls the state of the cluster; for example, which applications are running and their corresponding container images. The master node is the origin for all task assignments. It coordinates processes such as:
- Scheduling and scaling applications
- Maintaining a cluster’s state
- Implementing updates
- The worker nodes are the components that run these applications. Worker nodes perform tasks assigned by the master node. They can either be virtual machines or physical computers, all operating as part of one system.
- QUOTE: A Kubernetes cluster is a set of nodes that run containerized applications. Containerizing applications packages an app with its dependences and some necessary services. They are more lightweight and flexible than virtual machines. In this way, Kubernetes clusters allow for applications to be more easily developed, moved and managed.