ApsaraDB for SelectDB:Service overview for beginners

Architecture and components

This section briefly describes the system architecture and components of the service to help you quickly understand the architecture, the purpose of each component, and the relationships among the components. For more information, see Service architecture.

Architecture

SelectDB is a modern real-time data warehousing service based on Apache Doris. It uses a new cloud-native architecture that supports compute-storage separation. Compute-storage separation is a new data architecture design paradigm. It decouples the computing layer from the storage layer to allow users to separately scale out computing and storage resources based on business requirements. This prevents resource waste, reduces costs, and improves the overall performance and security of the system.

Components

• Application system or client: An application system or a client is the service or tool that you use to access SelectDB.

• Instance:

  • An SelectDB instance is the basic unit that is used to manage computing resources.

  • Each instance can contain one or more backend (BE) clusters.

  • An SelectDB instance uses a cloud-native architecture that supports compute-storage separation. The architecture consists of the service layer, computing layer, and storage layer. Requests sent to instances are received at the service layer, which works similarly to the frontends (FEs) of Apache Doris. Requests sent to clusters are processed at the computing layer, which works similarly to the BEs of Apache Doris. Object Storage Service (OSS) is used as the storage layer for data storage.

• Cluster:

  • A cluster in SelectDB is a distributed system that contains one or more nodes. Each node contains computing resources and cache resources.

  • An instance contains one or more clusters.

  • Data can be written to or read from multiple clusters in the same instance and is shard among the clusters but computed separately. Therefore, an SelectDB instance with multiple clusters can be used in scenarios such as read/write isolation, online and offline business isolation, and production and test environment isolation.

• Storage: SelectDB uses OSS as the storage layer to persistently store data.

  Based on the high reliability of OSS, SelectDB does not need to maintain data replicas in distributed data warehouses. The low-cost feature of OSS reduces the unit storage cost of SelectDB by more than 90% when compared with traditional data warehouses.

Features

The following figure shows the core features of SelectDB. The information helps you more effectively evaluate whether ApsaraDB for SelectDB meets your business requirements.

Billing

The SelectDB service is charged. To ensure that you can appropriately use resources and prevent unnecessary costs, we recommend that you carefully read the following topics before you purchase an instance. These topics help you understand the billable items and select appropriate configurations for an instance.

• Billing overview

• Billable items and unit prices

• Billing method