ApsaraDB RDS and PolarDB

Alibaba Cloud provides fully managed relational database services through ApsaraDB RDS and PolarDB. These services handle provisioning, patching, backups, and high availability so you can focus on your application.

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ApsaraDB RDS

ApsaraDB RDS is a managed relational database service that supports multiple database engines:

Engine	Versions	Notes
MySQL	5.6, 5.7, 8.0	Most popular choice
PostgreSQL	10, 11, 12, 13, 14, 15	Advanced features, strong standards compliance
SQL Server	2012–2022	Enterprise and Web editions
MariaDB	10.3	MySQL-compatible alternative

Key Features

Automated Backups

RDS automatically backs up your database:

• Automatic backups — daily full backups and continuous transaction log backups
• Retention — configurable from 7 to 730 days
• Point-in-time recovery — restore to any second within the retention period

High Availability

RDS supports Primary/Standby deployments:

• The standby instance is in a different availability zone
• Synchronous data replication ensures zero data loss
• Automatic failover takes 30–60 seconds

Zone A                Zone B
┌──────────┐         ┌──────────┐
│ Primary  │ ──sync──│ Standby  │
│ Instance │         │ Instance │
└──────────┘         └──────────┘

Read Replicas

Offload read-heavy workloads to read replicas:

• Up to 5 read replicas per primary instance
• Asynchronous replication
• Independent connection strings for read scaling

Instance Types

Category	Description	Best For
General-purpose	Shared CPU and memory	Dev/test, small workloads
Dedicated	Dedicated CPU and memory	Production workloads
Dedicated Host	Exclusive physical server	Compliance, licensing

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PolarDB

PolarDB is Alibaba Cloud's next-generation relational database, built using a cloud-native architecture with shared storage.

Architecture

PolarDB separates compute and storage:

┌──────────┐  ┌──────────┐  ┌──────────┐
│ Writer   │  │ Reader 1 │  │ Reader 2 │
│ Node     │  │ Node     │  │ Node     │
└────┬─────┘  └────┬─────┘  └────┬─────┘
     │             │             │
     └─────────────┼─────────────┘
                   │
         ┌─────────┴─────────┐
         │   Shared Storage  │
         │   (up to 100 TB)  │
         └───────────────────┘

PolarDB Editions

Edition	Compatible With	Key Feature
PolarDB for MySQL	MySQL 5.6, 5.7, 8.0	Up to 6x throughput of MySQL
PolarDB for PostgreSQL	PostgreSQL 11, 14	Oracle-compatible features
PolarDB-X	Distributed MySQL	Horizontal sharding