Amazonrds 简明教程
Amazon RDS - DB Instances
DB 实例是在云中运行的隔离数据库环境，其中可以包含多个用户创建的数据库。可以使用与访问独立数据库实例相同的客户端工具和应用程序来访问它。但是，对于单个客户帐户，您可以拥有哪种类型的 DB 实例以及可以拥有多少个实例存在限制。下图说明了根据您选择的许可证类型进行的不同组合。
A DB instance is an isolated database environment running in the cloud which can contain multiple user-created databases. It can be accessed using the same client tools and applications used to access a standalone database instance. But there is restriction on how many DB instances of what type you can have for a single customer account. The below diagram illustrates the different combinations based on the type of license you opt for.
每个 DB 实例都由客户提供的名称标识，称为 DB 实例标识符。对于给定的 AWS 区域，它对于客户来说是唯一的。
Each DB instance is identified by a customer supplied name called DB instance identifier. It is unique for the customer for a given AWS region.
DB Instance Classes
根据处理能力和存储空间要求，AWS 为 RDS 服务提供了各种实例类型。
Depending on the need of the processing power and memory requirement, there is a variety of instance classes offered by AWS for the RDS service.
Instance Class |
Number of Vcpu |
Memory Range in GB |
Bandwidth Range in Mbps |
Standard |
1 to 64 |
1.7 to 256 |
450 to 10000 |
Memory Optimized |
2 to 128 |
17.1 to 3904 |
500 to 14000 |
Burstable Performance |
1 to 8 |
1 to 32 |
Low to Moderate |
如果需要比存储空间要求更多的处理能力，可以选择配备更多虚拟 CPU 的标准实例类型。但在需要大量存储空间的情况下，可以选择配备适当的 VCPU 数量的内存优化类型。选择正确的类型不仅会影响处理速度，还会影响使用服务的成本。当处理要求极小并且数据大小不在 PB 级时，需要可突发性能类型。
When there is a need of more processing power than memory requirement you can choose the standard instance class with a higher number of virtual CPUs. But in the case of very high memory requirement you can choose Memory optimized class with appropriate number of VCPUs. Choosing a correct class not only impacts the speed of the processing but also the cost of using service. The burstable performance class is needed when you have a minimal processing requirement and the data size in not in peta bytes.
DB Instance Status
数据库实例状态表示数据库的运行状况。可从 AWS 控制台或使用 AWS CLI 命令 describe-db-instances 查看其值。以下介绍了数据库实例的重要状态值及其含义。
The DB Instance status indicates the health of the DB. It’s value can be seen from the AWS console or using AWS CLI command describe-db-instances. The important status values of DB instances and their meaning is described below.
DB Instance Status |
Meaning |
Is the Instance Billed? |
Creating |
The instance is being created. The instance is inaccessible while it is being created. |
No |
Deleting |
The instance is being deleted. |
No |
Failed |
The instance has failed and Amazon RDS can’t recover it. |
No |
Available |
The instance is healthy and available. |
Yes |
Backing-up |
The instance is currently being backed up. |
Yes |