Basic Cluster Information

Kubernetes is an open source container orchestration engine for automating deployment, scaling, and management of containerized applications.

For developers, Kubernetes is a cluster operating system. Kubernetes provides service discovery, scaling, load balancing, self-healing, and even leader election, freeing developers from infrastructure-related configurations.

Cluster Network

A cluster network can be divided into three network types:

Node network: IP addresses are assigned to nodes in a cluster.
Container network: IP addresses are assigned to containers in a cluster for communication. Currently, multiple container network models are supported, and each model has its own working mechanism.
Service network: A Service is a Kubernetes object used to access containers. Each Service has a static IP address.

When you create a cluster, select a proper CIDR block for each network. Ensure that the CIDR blocks do not conflict with each other and have sufficient available IP addresses. You cannot change the container network model after the cluster is created. Plan the container network model properly in advance.

You are advised to learn about the cluster network and container network models before creating a cluster. For details, see Container Network Models.

Master Nodes and Cluster Scale

When you create a cluster on CCE, you can have one or three master nodes. Three master nodes will be deployed in a cluster for HA.

The master node specifications decide the number of nodes that can be managed by a cluster. You can select the cluster management scale, for example, 50 or 200 nodes.

Cluster Lifecycle

**Table 1** Cluster status
Status	Description
Creating	A cluster is being created and is requesting for cloud resources.
Running	A cluster is running properly.
Hibernating	A cluster is hibernating.
Awaking	A cluster is being woken up.
Upgrading	A cluster is being upgraded.
Resizing	The cluster flavor is being changed.
Unavailable	A cluster is unavailable.
Deleting	A cluster is being deleted.