intro&deploy-nebula-operator-en

docs-2.0/nebula-operator/1.introduction-to-nebula-operator.md

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+# What is Nebula Operator
+
+## Concept of Nebula Operator
+
+Nebula Operator is a tool to automate the deployment, and operation and maintenance of [Nebula Graph](https://github.com/vesoft-inc/nebula) clusters on [Kubernetes](https://kubernetes.io). Building upon the excellent scalability mechanism of Kubernetes, Nebula Graph introduced its operation and maintenance knowledge into the Kubernetes system, which makes Nebula Graph a real [cloud-native graph database](https://www.nebula-cloud.io/).
+
+## How it works
+
+For resource types that do not exist within Kubernetes，you can register them by adding custom API objects. The common way is to use the [CustomResourceDefinition](https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/#customresourcedefinitions).
+
+Nebula Operator abstracts the deployment management of Nebula Graph clusters as a CRD. By combining multiple built-in API objects including StatefulSet, Service, and ConfigMap, the routine management and maintenance of a Nebula Graph cluster are coded as a control loop in the Kubernetes system. When a CR instance is submitted, Nebula Operator drives database clusters to the final state according to the control process.
+
+## Functionalities of Nebula Operator
+
+The following features are already available in Nebula Operator:
+
+- **Deploy and uninstall clusters**：Nebula Operator simplifies the process of deploying and uninstalling clusters for users. Nebula Operator allows you to quickly create, update, or delete a Nebula Graph cluster by simply providing the corresponding CR file. For more information, see [Deploy Nebula Graph Clusters with Kubectl](3.deploy-nebula-graph-cluster/3.1create-cluster-with-kubectl.md) or [Deploy Nebula Graph Clusters with Helm](3.deploy-nebula-graph-cluster/3.2create-cluster-with-helm.md).
+
+- **Scale clusters**：Nebula Operator calls Nebula Graph's native scaling interfaces in a control loop to implement the scaling logic. You can simply perform scaling operations with YAML configurations and ensure the stability of data. For more information, see [Scale clusters with Kubectl](3.deploy-nebula-graph-cluster/3.1create-cluster-with-kubectl.md#_3) or [Scale clusters with Helm](3.deploy-nebula-graph-cluster/3.2create-cluster-with-helm.md#_2).
+
+- **Self-Healing**：Nebula Operator calls the interface provided by Nebula Graph clusters to dynamically sense cluster service status. Once an exception is detected, Nebula Operator performs fault tolerance. For more information, see [Self-Healing](5.operator-failover.md).
+
+- **Balance Scheduling**: Based on the scheduler extension interface, the scheduler provided by Nebula Operator evenly distributes Pods in a Nebula Graph cluster across all nodes.
+
+## Limitations
+
+### Version limitations
+
+Nebula Operator does not support v1.x version of Nebula Graph. Nebula Operator version and the corresponding Nebula Graph version are as follows:
+
+| Nebula Operator version | Nebula Graph version |
+| ------------------- | ---------------- |
+| {{operator.release}}| {{nebula.release}} |
+
+### Functionality limitations
+
+Nebula Operator currently only support manual scaling of Nebula Graph clusters, and does not support automatic scaling of Nebula Graph clusters.