Distributed Relational Database Service (DRDS) is a lightweight (stateless), flexible, stable, and efficient middleware product independently developed by Alibaba Group to resolve scalability issues with single-host relational databases.
DRDS is primarily used for large-scale online data operations to operate, maintain and manage distributed databases throughout their entire lifecycle. Due to is compartmentalized structure, DRDS provides an efficient way to perform operations to meet the demand of the online services for relational databases.
Data reading, writing, and storage are distributed in clusters, and are not limited by the capacity of an individual server, allowing for unlimited connections to your services.
DRDS specifications can be flexibly upgraded and downgraded. DRDS storage can be scaled from the console. In addition, read/write splitting enhances the read capacity on a linear scale.
Database and table sharding allows for operations to be made to a small amount of data. Multiple sharding modes are available for different types of data. Certain SQL statements can be executed on multiple servers in parallel to further improve query performance.
The account management system in DRDS runs in a similar way to an account system on a single MySQL server. The API supports authentication and authorization to guarantee security for your business systems.
DRDS is primarily used to solve the following problems:
Bottleneck on single-host database capacity: As the data size and access volume keep increasing, single-host databases are faced with great challenges that cannot be completely resolved by upgrading the hardware.
Difficulties with expansion of single-host databases: Expansion of traditional databases often results in service interruption and is difficult to perform with no or slightly perceptible impact on the service.
High cost of traditional databases: When service data and access volume reach a certain level, traditional databases must rely on specific high-end storage devices and minicomputers to keep working, which leads to dramatic increase in the cost.
DRDS supports database/table sharding for RDS for MySQL instances. After creating a distributed database, select a sharding key based on which DRDS generates the sharding rules to accomplish horizontal data sharding.
Transparent Read and Write Separation
Read and write separation using RDS read-only instances or a MySQL slave database helps your application solve issues with transactions, read-only instances or slave database mounting, and specified master/slave access without interfering with the application. You can perform read and write separation on the DRDS console.
Smooth Expansion of Data Storage
When data storage capacity and traffic load reach the bottleneck, DRDS supports online storage capacity expansion without modifying the application. You can visually track the progress of the capacity expansion.
With DRDS instances, you can elastically expand service capabilities by changing the number of resources.
Distributed O&M Instruction
DRDS comes with our proprietary O&M instruction sets such as SHOW SLOW, TRACE, and SHOW NODE for distributed databases to help you identify and locate issues quickly.
DRDS supports the distributed and incremental DRDS sequence. With this feature, you can meet service requirements for primary or unique keys and specific scenarios when using distributed databases.
Database Account and Permission System
DRDS supports the standalone-like MySQL account and permission system to ensure the security of the account when used by different roles.
DRDS works with the distributed transaction kit GTS to support distributed transactions and ensure data consistency between distributed databases.
Monitoring and Alerting
DRDS supports real-time monitoring and alerting for core resource indicators and database instance indicators, such as instance CPU, network I/O, and active threads.
DRDS performs billing based on the specifications of the activated instance.
In Pay-As-You-Go mode, traffic is billed by the hour, with the fee deducted in real time. Within a billing cycle, a minimum rate of one hour is charged if your DRDS instance is used for less than one hour.
DRDS instances support upgrading and downgrading. You can perform the operation from the DRDS console. After the operation, your DRDS instance will be billed according to the new specification.
The billing time is usually within 1 hour after the end of the current billing cycle. For example, the bill for 10:00-11:00 is generated after 11:00 based on the system billing time. After the bill is generated, the fee is automatically deducted from your account balance.
The intranet traffic generated by using DRDS instances is free. That means no fee is charged for your data transfer between ECS and DRDS instances.
Delinquency Reminder and Suspension Policies
The system determines, based on the average amount payable over the last 24 hours for the DRDS service, whether the remaining account balance is sufficient to pay for the next three billing cycles. If the remaining account balance is insufficient, you will receive an SMS or email notification.
If the delinquency reminder feature is enabled, you will receive an SMS or email notification when your balance is less than your preset amount.
If the remaining account balance is less than the account payable on the previous bill, payment for the DRDS instance is considered overdue. You will receive an SMS or email notification within 24 hours, reminding you to renew your service. If you recharge within 24 hours after receiving the notification, your service is not suspended. During this period of time, Alibaba Cloud continues billing your account for the instance. We recommend that you pay off all the due bills as soon as possible so you can continue to use the instance.
Your Pay-As-You-Go instance is suspended and billing stops if you fail to renew your service within 24 hours. If you recharge your account and clear the overdue payment within the following three days, the suspended instance is re-activated automatically. If you fail to settle the outstanding bill within three days, it is deemed that you forfeit the instance, in which case the distributed configurations residing in the instance are deleted and are unrecoverable. You will receive an SMS or email notification one day prior to the release of the instance.
Highly Concurrent Real Time Transaction
Customer-oriented e-commerce, financial, O2O, and retail industries face challenges like large user bases, frequent sales events, and increasingly degraded responsiveness of databases for core transaction systems, which restrict business operations. By providing the linear horizontal expansion capability to improve data processing capabilities in real time and to accelerate access efficiency with a peak TPS over 1.5 million, DRDS can easily meet the requirements of highly concurrent real-time transaction scenarios.
Massive Data Storage and Access
Business data increases dramatically with the development of enterprise customers, which results in a database capacity bottleneck for databases on a single computer and restricts business development. DRDS can linearly expand storage space and currently supports a single database cluster hosting more than 200 MySQL instances for PB-level storage. DRDS applies to various mass data storage and access scenarios such as industrial manufacturing, smart home, and the Internet of vehicles.
Cost-effective Database Solutions
For government agencies, large enterprises, and banks, traditional business solutions depend on costly minicomputers and high-end storage devices to support mass data storage and highly concurrent database access and to expand service capabilities. DRDS provides cost-effective local database solutions using common servers with a performance that compares to that of the Alibaba Double 11 event.
Low Database O&M Costs
Startup enterprises suffer from poor technical accumulation, limited capital investment, quick business improvement, and highly risky database stability at the early stage. With Alibaba's long-term technical accumulation in distributed databases, DRDS provides an easy-to-use O&M system to lower technical O&M costs for enterprises and empower them with great database support capabilities for secured enterprise development.
Enterprises can use DRDS to back up their own databases to the cloud platforms for on-cloud data backup and disaster tolerance.
The Quick Start Guide describes how to buy a DRDS instance, create a DRDS database and related tables, and use a client to connect to the DRDS instance for database operation.
DRDS quick access flowchart: