It is a set of independent computing units interconnected through a high-speed network. To the user, the cluster is an independent server. The cluster can be flexibly scheduled with high reliability, high availability, and scalability.
The metrics refer to certain types of data obtained through collection, push, and other methods, such as CPU usage and disk usage. BCM stores them, which can be used to display trend graphs and information, and to configure alarm policies.
The metric, also known as index, is a standard to measure the status or condition of the system in an aspect, such as the performance of the system, service or program. The metrics generate a series of data points as time goes on. BCE provides a series of metrics by default for cloud services, such as BCC, RDS, etc., and auxiliary facilities automatically publish these metric data points to BCM. Users can also customize a series of metrics, and use BCM API or bcm-tool tools to publish their data points to BCM, and then retrieve data or statistical data of these data points according to certain filtering conditions.
The listener is used to forward the user request to the backend server and return its response to the user. The listener is configured with a listening protocol and a listening port, and forwards the request to the port of the backend server according to the forwarding rule. The listener also provides the health check function of the backend server.
A service that checks the running status of the back-end server instance. It checks the path and server port specified by the user. When a problem occurs on the back-end server instance, it stops distributing requests to it and performs subsequent checks until the instance returns to normal.
Authentication and authorization are two separate concepts, but these two operations are closely related. Authentication is to get the identity of the user, while authorization is to determine whether the user has the authority to operate. Therefore, authorization is a judgment after authentication. IAM uses policies to determine privileges. User policies are similar to roles in RBAC. It defines a collection of resources and operations. In the scenario where the server needs to be authorized, it passes the authorization context (operator, operational resources and operations) to IAM. IAM performs the corresponding authorization operation according to the configuration of the policy, and finally returns the result of whether the user has privilege.
When there is no free space in physical memory, some space on the disk is used as virtual memory.
An IAM user is a kind of object identity with certain identity credentials, and it usually corresponds one-to-one to a certain person or an application. IAM role is a virtual identity, which is associated with a set of privileges. There is no certain identity credential, and it must be associated with an entity identity before it can be used.
Each BCC in the scaling group is called as one node. The scaling group is scaled up or down by increase or decrease of the number of nodes. One scaling group contains N nodes, and the user can configure the maximum and minimum numbers of nodes for the scaling up.
You can aggregate data points over a period of time, such as the sum, average, maximum, and minimum values every 10 minutes.