Misplaced Pages

#509490

53-513: Oper may refer to: Technology Operator (disambiguation) IRC operator Outstanding Physical Education Preparation , a website for PE preparation Opera Deutsche Oper Berlin , Oper Leipzig , Komische Oper Berlin , Alte Oper Romantische Oper , genre of German opera Surname Andres Oper , Estonian football player Mathematics Oper (mathematics) (as defined by Alexander Beilinson and Vladimir Drinfeld),

106-406: A cluster which can run workloads in containers. It works with various container runtimes, such as containerd and CRI-O . Its suitability for running and managing workloads of all sizes and styles has led to its widespread adoption in clouds and data centers. There are multiple distributions of this platform – from independent software vendors (ISVs) as well as hosted-on-cloud offerings from all

159-433: A mathematical operation Logical operator or logical connective in mathematical logic Operator (mathematics) , mapping that acts on elements of a space to produce elements of another space, e.g.: Linear operator Differential operator Integral operator (disambiguation) Operational calculus Computers [ edit ] Computer operator , an occupation Operator (computer programming) ,

212-526: A 1993 song by Blue System from Backstreet Dreams "Operator", a 1995 song by Real McCoy from Another Night "Operator", a 1998 song by Miss Papaya from Pink "Operator" (Floy Joy song) , a song by British group Floy Joy Fiction [ edit ] Operator No. 5 , a pulp fiction hero from the 1930s Operator, a fictional group in the Ghost in the Shell series Operator (2015 film) ,

265-632: A 2015 American action thriller drama film starring Luke Goss Operator (2016 film) , a 2016 American comedy-drama film starring Martin Starr and Mae Whitman The Operator (film), a 2000 film The Operator ( Marble Hornets ), an entity that stalks the main characters in Marble Hornets . It is also known as the Slender Man. Operator (play) , a 2005 play by David Williamson Duties [ edit ] Operator (profession) ,

318-415: A ReplicaSet, serves the same purpose and behaves similarly to a ReplicaSet, which is to ensure that there will always be a specified number of pod replicas as desired. The ReplicationController workload was the predecessor of a ReplicaSet, but was eventually deprecated in favor of ReplicaSet to make use of set-based label selectors. Deployments are a higher-level management mechanism for ReplicaSets. While

371-630: A SWAT team Other uses [ edit ] Operator (sternwheeler) , a 1909 ship on the Skeena River Network operator , a phone carrier System operator , commonly abbreviated as sysop Operator grammar , a theory of human language See also [ edit ] Operation (disambiguation) Operator-precedence grammar , a grammar for formal languages The Operators (disambiguation) Oper (disambiguation) Cooperator (disambiguation) All pages with titles beginning with Operator Topics referred to by

424-500: A loose coupling within the infrastructure. For example, if an application's pods have labels for a system tier (with values such as frontend , backend , for example) and a release_track (with values such as canary , production , for example), then an operation on all of backend and canary nodes can use a label selector, such as: tier=backend AND release_track=canary Just like labels, field selectors also let one select Kubernetes resources. Unlike labels,

477-566: A mathematical bundle on a punctured disc, equipped with a flat connection and an additional extra structure, called the "oper structure" Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Oper . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Oper&oldid=810723959 " Category : Disambiguation pages Hidden categories: Short description

530-472: A minion, is a machine where containers (workloads) are deployed. Every node in the cluster must run a container runtime , as well as the below-mentioned components, for communication with the primary network configuration of these containers. kubelet is responsible for the running state of each node, ensuring that all containers on the node are healthy. It takes care of starting, stopping, and maintaining application containers organized into pods as directed by

583-433: A professional designation used in various industries, e.g.: Switchboard operator , a occupation at a company offering telephone services Heavy equipment operator , operates heavy equipment used in engineering and construction projects Operator (military) , a soldier in a special operations force Operator (law enforcement) , a law enforcement officer who has been trained and certified as an operator to serve on

SECTION 10

#1732772311510

636-476: A service can also be exposed outside a cluster (e.g., for clients to reach front-end pods). Filesystems in the Kubernetes container provide ephemeral storage , by default. This means that a restart of the pod will wipe out any data on such containers, and therefore, this form of storage is quite limiting in anything but trivial applications. A Kubernetes volume provides persistent storage that exists for

689-589: A set of building blocks ("primitives") that collectively provide mechanisms that deploy, maintain, and scale applications based on CPU , memory or custom metrics. Kubernetes is loosely coupled and extensible to meet the needs of different workloads. The internal components as well as extensions and containers that run on Kubernetes rely on the Kubernetes API. The platform exerts its control over compute and storage resources by defining resources as objects, which can then be managed as such. Kubernetes follows

742-423: A single cluster. As such, scheduler plug-ins may be developed and installed as in-process extensions to the native vanilla scheduler by running it as a separate scheduler, as long as they conform to the Kubernetes scheduling framework. This allows cluster administrators to extend or modify the behavior of the default Kubernetes scheduler according to their needs. A controller is a reconciliation loop that drives

795-409: A special category including wh- interrogatives Operator (physics) , mathematical operators in quantum physics Music [ edit ] Operator (band) , an American hard rock band Operators, a synth pop band led by Dan Boeckner Operator (album) , a 2016 album by Mstrkrft "Operator" (Motown song) , a 1965 song recorded by Mary Wells and Brenda Holloway "Operator" (That's Not

848-423: A stable IP address and DNS name to the service, and load balances traffic in a round-robin manner to network connections of that IP address among the pods matching the selector (even as failures cause the pods to move from machine to machine). By default a service is exposed inside a cluster (e.g., back end pods might be grouped into a service, with requests from the front-end pods load-balanced among them), but

901-423: A strong authentication method, network separation, each its own process, that can run both on a single master node or on multiple masters supporting high-availability clusters . The various components of the Kubernetes control plane are as follows. Etcd is a persistent, lightweight, distributed, key-value data store (originally developed for Container Linux ). It reliably stores the configuration data of

954-477: A type of computer program function Operator (extension) , an extension for the Firefox web browser, for reading microformats Operator pattern , a provisioning automation and auto-scaling strategy for Kubernetes Ableton Operator , a software synthesizer developed by Ableton Science [ edit ] Operator (biology) , a segment of DNA regulating the activity of genes Operator (linguistics) ,

1007-411: Is a pod , which consists of one or more containers that are guaranteed to be co-located on the same node. Each pod in Kubernetes is assigned a unique IP address within the cluster, allowing applications to use ports without the risk of conflict. Within the pod, all containers can reference each other. A container resides inside a pod. The container is the lowest level of a micro-service, which holds

1060-614: Is an implementation of a network proxy and a load balancer , and it supports the service abstraction along with the other networking operations. It is responsible for routing traffic to the appropriate container based on IP and port number of the incoming request. In Kubernetes, namespaces are utilized to segregate the resources it handles into distinct and non-intersecting collections. They are intended for use in environments with many users spread across multiple teams, or projects, or even separating environments like development, test, and production. The basic scheduling unit in Kubernetes

1113-583: Is deciding where to store and manage configuration information, some of which may contain sensitive data. Configuration data can be anything as fine-grained as individual properties, or coarse-grained information like entire configuration files such as JSON or XML documents. Kubernetes provides two closely related mechanisms to deal with this need, known as ConfigMaps and Secrets , both of which allow for configuration changes to be made without requiring an application rebuild. The data from ConfigMaps and Secrets will be made available to every single instance of

SECTION 20

#1732772311510

1166-555: Is different from Wikidata All article disambiguation pages All disambiguation pages Operator (disambiguation) (Redirected from Operator (disambiguation) ) For technical reasons , "Operator #5" redirects here. For the pulp hero magazine, see Operator No. 5 . [REDACTED] Look up operator in Wiktionary, the free dictionary. Operator may refer to: Mathematics [ edit ] A symbol indicating

1219-543: Is different from Wikidata All article disambiguation pages All disambiguation pages Kubernetes#Custom resources, controllers and operators The name Kubernetes originates from the Greek κυβερνήτης (kubernḗtēs), meaning governor, ' helmsman ' or 'pilot'. Kubernetes is often abbreviated as K8s , counting the eight letters between the K and the s (a numeronym ). Kubernetes assembles one or more computers, either virtual machines or bare metal , into

1272-412: Is not scheduled in excess of available resources. For this purpose, the scheduler must know the resource requirements, resource availability, and other user-provided constraints or policy directives such as quality-of-service, affinity/anti-affinity requirements, and data locality. The scheduler's role is to match resource "supply" to workload "demand". Kubernetes allows running multiple schedulers within

1325-492: Is to maintain a stable set of replica pods running at any given time. As such, it is often used to guarantee the availability of a specified number of identical Pods. The ReplicaSet can also be said to be a grouping mechanism that lets Kubernetes maintain the number of instances that have been declared for a given pod. The definition of a ReplicaSet uses a selector, whose evaluation will result in identifying all pods that are associated with it. A ReplicationController , similar to

1378-420: The primary/replica architecture . The components of Kubernetes can be divided into those that manage an individual node and those that are part of the control plane. The Kubernetes master node handles the Kubernetes control plane of the cluster, managing its workload and directing communication across the system. The Kubernetes control plane consists of various components such as TLS encryption , RBAC , and

1431-559: The shim in favor of directly interfacing with the container through containerd, or replacing Docker with a runtime that is compliant with the Container Runtime Interface (CRI). With the release of v1.24 in May 2022, the "dockershim" has been removed entirely. Examples of popular container runtimes that are compatible with kubelet include containerd (initially supported via Docker), rkt and CRI-O . kube-proxy

1484-509: The Deployment controller finds that only two instances are running (conflicting with the etcd declaration), it schedules the creation of an additional instance of that pod. The scheduler is an extensible component that selects the node that an unscheduled pod (the basic unit of workloads to be scheduled) runs, based on resource availability and other constraints. The scheduler tracks resource allocation on each node to ensure that workload

1537-475: The ReplicaSet controller manages the scale of the ReplicaSet, the Deployment controller manages what happens to the ReplicaSet – whether an update has to be rolled out, or rolled back, etc. When Deployments are scaled up or down, this results in the declaration of the ReplicaSet changing, and this change in the declared state is managed by the ReplicaSet controller. StatefulSets are controllers that enforce

1590-661: The Way It Feels) , a 1972 song by Jim Croce from You Don't Mess Around with Jim "Operator" (Midnight Star song) (1984), a 1984 #1 R&B/electronic dance single "Operator" (A Girl Like Me) , a 2008 song by Shiloh "Operator", a 1970 song by the Grateful Dead from American Beauty "Operator", a 1975 song by the Manhattan Transfer from The Manhattan Transfer "Operator", a 1986 song by Little Richard from Lifetime Friend "Operator",

1643-505: The actual cluster state toward the desired state, communicating with the API server to create, update, and delete the resources it manages (e.g., pods or service endpoints). An example controller is a ReplicaSet controller, which handles replication and scaling by running a specified number of copies of a pod across the cluster. The controller also handles creating replacement pods if the underlying node fails. Other controllers that are part of

Oper - Misplaced Pages Continue

1696-460: The application to which these objects have been bound via the Deployment. A Secret and/or a ConfigMap is sent to a node only if a pod on that node requires it, which will only be stored in memory on the node. Once the pod that depends on the Secret or ConfigMap is deleted, the in-memory copy of all bound Secrets and ConfigMaps are deleted as well. The data from a ConfigMap or Secret is accessible to

1749-536: The cluster, representing the overall state of the cluster at any given point of time. etcd favors consistency over availability in the event of a network partition (see CAP theorem ). The consistency is crucial for correctly scheduling and operating services. The API server serves the Kubernetes API using JSON over HTTP , which provides both the internal and external interface to Kubernetes. The API server processes, validates REST requests, and updates

1802-430: The cluster. Generally, most workloads scale in response to a desired replica count, depending on the availability and performance requirements as needed by the application. However, in other scenarios it may be necessary to deploy a pod to every single node in the cluster, scaling up the number of total pods as nodes are added and garbage collecting them as they are removed. This is particularly helpful for use cases where

1855-409: The control plane. kubelet monitors the state of a pod, and if not in the desired state, the pod re-deploys to the same node. Node status is relayed every few seconds via heartbeat messages to the API server. Once the control plane detects a node failure, a higher-level controller is expected to observe this state change and launch pods on another healthy node. A container runtime is responsible for

1908-453: The core Kubernetes system include a DaemonSet controller for running exactly one pod on every machine (or some subset of machines), and a Job controller for running pods that run to completion (e.g. as part of a batch job). Labels selectors often form part of the controller's definition that specify the set of pods that a controller manages. The controller manager is a single process that manages several core Kubernetes controllers (including

1961-399: The examples described above), is distributed as part of the standard Kubernetes installation and responding to the loss of nodes. Custom controllers may also be installed in the cluster, further allowing the behavior and API of Kubernetes to be extended when used in conjunction with custom resources (see custom resources, controllers and operators below). A node, also known as a worker or

2014-486: The lifecycle of containers, including launching, reconciling and killing of containers. kubelet interacts with container runtimes via the Container Runtime Interface (CRI), which decouples the maintenance of core Kubernetes from the actual CRI implementation. Originally, kubelet interfaced exclusively with the Docker runtime through a "dockershim". However, from November 2020 up to April 2022, Kubernetes has deprecated

2067-419: The lifetime of the pod itself. This storage can also be used as shared disk space for containers within the pod. Volumes are mounted at specific mount points within the container, which are defined by the pod configuration, and cannot mount onto other volumes or link to other volumes. The same volume can be mounted at different points in the file system tree by different containers. A common application challenge

2120-414: The major public cloud vendors. Kubernetes is one of the most widely deployed software systems in the world being used across companies including Google , Microsoft , Amazon , Apple , Meta , Nvidia , Reddit and Pinterest . Kubernetes ( Ancient Greek : κυβερνήτης , romanized :  kubernḗtēs , ' steersman, navigator ' or ' guide ' , and the etymological root of cybernetics )

2173-401: The notion of a primary instance and secondary instances. In this case, the notion of ordering of instances is important. Other applications like Apache Kafka distribute the data amongst their brokers; hence, one broker is not the same as another. In this case, the notion of instance uniqueness is important. DaemonSets are responsible for ensuring that a pod is created on every single node in

Oper - Misplaced Pages Continue

2226-602: The pod through one of the following ways: The biggest difference between a Secret and a ConfigMap is that Secrets are specifically designed for containing secure and confidential data, although they are not encrypted at rest by default, and requires additional setup in order to fully secure the use of Secrets within the cluster. Secrets are often used to store confidential or sensitive data like certificates, credentials to work with image registries, passwords, and ssh keys. Kubernetes enables clients (users or internal components) to attach keys called labels to any API object in

2279-581: The principal competitors rallied around Kubernetes and announced adding native support for it: On March 6, 2018, Kubernetes Project reached ninth place in the list of GitHub projects by the number of commits , and second place in authors and issues, after the Linux kernel . Until version 1.18, Kubernetes followed an N-2 support policy, meaning that the three most recent minor versions receive security updates and bug fixes. Starting with version 1.19, Kubernetes follows an N-3 support policy. Kubernetes defines

2332-500: The properties of uniqueness and ordering amongst instances of a pod, and can be used to run stateful applications. While scaling stateless applications is only a matter of adding more running pods, doing so for stateful workloads is harder, because the state needs to be preserved if a pod is restarted. If the application is scaled up or down, the state may need to be redistributed. Databases are an example of stateful workloads. When run in high-availability mode, many databases come with

2385-434: The running application, libraries, and their dependencies. Kubernetes supports several abstractions of workloads that are at a higher level over simple pods. This allows users to declaratively define and manage these high-level abstractions, instead of having to manage individual pods by themselves. Several of these abstractions, supported by a standard installation of Kubernetes, are described below. A ReplicaSet 's purpose

2438-413: The same term [REDACTED] This disambiguation page lists articles associated with the title Operator . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Operator&oldid=1246984252 " Category : Disambiguation pages Hidden categories: Short description

2491-524: The selection is based on the attribute values inherent to the resource being selected, rather than user-defined categorization. metadata.name and metadata.namespace are field selectors that will be present on all Kubernetes objects. Other selectors that can be used depend on the object/resource type. Add-ons are additional features of the Kubernetes cluster implemented as applications running within it. The pods may be managed by Deployments, ReplicationControllers, and so on. There are many add-ons. Some of

2544-478: The state of the API objects in etcd, thereby allowing clients to configure workloads and containers across worker nodes. The API server uses etcd's watch API to monitor the cluster, roll out critical configuration changes, or restore any divergences of the state of the cluster back to the desired state as declared in etcd. As an example, a human operator may specify that three instances of a particular "pod" (see below) need to be running, and etcd stores this fact. If

2597-666: The system, such as pods and nodes . Correspondingly, label selectors are queries against labels that resolve to matching objects. When a service is defined, one can define the label selectors that will be used by the service router/load balancer to select the pod instances that the traffic will be routed to. Thus, simply changing the labels of the pods or changing the label selectors on the service can be used to control which pods get traffic and which don't, which can be used to support various deployment patterns like blue–green deployments or A/B testing . This capability to dynamically control how services utilize implementing resources provides

2650-455: The workload has some dependency on the actual node or host machine, such as log collection, ingress controllers, and storage services. A Kubernetes service is a set of pods that work together, such as one tier of a multi-tier application. The set of pods that constitute a service are defined by a label selector. Kubernetes provides two modes of service discovery , using environment variables or using Kubernetes DNS. Service discovery assigns

2703-473: Was announced by Google on June 6, 2014. The project was conceived and created by Google employees Joe Beda, Brendan Burns, and Craig McLuckie. Others at Google soon joined to help build the project including Ville Aikas, Dawn Chen, Brian Grant, Tim Hockin, and Daniel Smith. Other companies such as Red Hat and CoreOS joined the effort soon after, with notable contributors such as Clayton Coleman and Kelsey Hightower . The design and development of Kubernetes

SECTION 50

#1732772311510

2756-621: Was announced in June, 2014 and version 1.0 was released on July 21, 2015. Google worked with the Linux Foundation to form the Cloud Native Computing Foundation (CNCF) and offered Kubernetes as the seed technology. Google was already offering a managed Kubernetes service, GKE , and Red Hat was supporting Kubernetes as part of OpenShift since the inception of the Kubernetes project in 2014. In 2017,

2809-561: Was inspired by Google's Borg cluster manager and based on Promise Theory . Many of its top contributors had previously worked on Borg; they codenamed Kubernetes " Project 7 " after the Star Trek ex- Borg character Seven of Nine and gave its logo a seven-spoked ship's wheel (designed by Tim Hockin). Unlike Borg, which was written in C++ , Kubernetes is written in the Go language. Kubernetes

#509490