Before using the CCSE, you need to understand the concepts associated with this product. This section introduces the basic concepts and brief descriptions of commonly used terms during CCSE operations to facilitate your understanding of the CCSE product.

Cluster

A cluster refers to the combination of cloud resources required to run containers, associating multiple server nodes, load balancing, private networks, and other cloud resources.

To set up a CCSE proprietary cluster, you need to create either one Master node (non-highly available) or three/five Master nodes (highly available), along with several Worker nodes. This allows for finer-grained control over the cluster infrastructure, but requires you to plan, maintain, and upgrade the server cluster yourself.

Node

A server (a virtual machine instance or a physical server) that has Docker Engine installed can be used for deploying and managing containers. The CCSE Agent program will be installed on the node and registered to a cluster.

Private Network VPC

A VPC is your own private network on the cloud. You have full control over your VPC, such as choosing the IP address range, configuring routing tables, and gateways. You can use eSurfing Cloud resources like cloud servers, cloud databases, and load balancing within your self-defined VPC.

Security Group

A security group is a form of virtual firewall with status detection and packet filtering capabilities. It is used to divide secure domains on the cloud. A security group is a logical group composed of instances within the same region that have the same security protection requirements and trust each other.

Application Directory

An application directory integrates Helm, delivers Helm-associated functions and expands on them with features like a graphical interface.

Orchestration Template

An orchestration template is a method of saving Kubernetes orchestration files in YAML format.

Kubernetes

Kubernetes is an open-source platform with portability and scalability. It is used to manage containerized workloads and services, facilitating declarative configuration and automation.

Container

Package applications along with technologies of runtime-dependent environment. A single node can run multiple containers.

Image

Container image is a standard format for packaging container applications, encapsulating the binary data of the application and all its software dependencies.

Image Registry

A container image repository is a repository used to store container images developed for Kubernetes and container-based applications.

Master Node

The master node serves as the administrator of the Kubernetes cluster. It operates services including the kube-apiserver, kube-scheduler, kube-controller-manager, etcd components, and container network-related components.

Worker Node

A worker node is a node in a Kubernetes cluster that carries the workload. It can be either a virtual or physical machine. Worker nodes manage the actual scheduling of Pods and facilitate communication with the master node. Services on a worker node include the Docker runtime environment, kubelet, Kube-Proxy, and other optional components.

Namespace

Namespaces provide virtual isolation within a Kubernetes cluster. A Kubernetes cluster initially includes three namespaces: the default namespace "default" and the system namespaces "kube-system" and "kube-public". In addition to this, administrators can create new namespaces to meet specific requirements.

Container Group (Pod)

A Pod is the smallest fundamental unit for deploying applications or services in Kubernetes. Each Pod encapsulates multiple (or just one) application containers, allocates storage resources, assigns a unique network IP, and offers options to manage and control the running of these containers.

Replication Controller (RC)

The RC ensures that a specific number of Pod replicas are running in the Kubernetes cluster at any time. By monitoring the running Pods, it maintains the specified number of Pod replicas within the cluster. The specified number can be multiple or just one. When there are fewer replicas than specified, the RC initiates new Pod replicas; when there are more than specified, the RC terminates the excess Pod replicas.

ReplicaSet (RS)

The RS is the upgraded version of the RC. The only difference lies in their support for selectors, as RS supports a wider variety of matching modes. Generally, an RS object is not used independently but serves as an ideal state parameter for Deployments.

Workload

A workload refers to the applications running on Kubernetes. Workloads include the following types:

Workload Type	Description
Stateless Workload (Deployment)	Deployment represents a single update operation to the Kubernetes cluster. It is suitable for running completely independent applications with the same functionalities.
Stateful Workload (StatefulSet)	StatefulSet supports orderly deployment, scaling, and rolling upgrades of applications. If you want to provide persistent storage for your workload using persistent volumes, the StatefulSet can be part of your solution.
DaemonSet	A DaemonSet ensures that a Pod is running on all (or some) nodes. Unlike Deployment, DaemonSet deploys defined Pods on specified nodes, ensuring that these nodes are running the Daemon Pod. Suitable for the deployment scenarios such as cluster logging and monitoring.
Job	A Job is a one-time task. You can use a Job to run multiple Pods in parallel.
CronJob	A CronJob schedules tasks to run periodically at specified periods. Suitable for tasks such as data backups or email sending.
Custom Resource Definition (CRD)	In the extensive Kubernetes ecosystem, you can add third-party workload resources through CRD. CRD enables you to define custom resources.

Cloud Container Service Engine (CCSE)

Terms