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PolarDB:What is PolarDB for Xscale?

Last Updated:Dec 17, 2025

PolarDB for Xscale (referred to as PolarDB-X) is a high-performance cloud-native distributed database product independently designed and developed by Alibaba Cloud. It is featured by high throughput, large storage capacity, low latency, easy scalability, and ultra-high availability.

Architecture

PolarDB-X adopts the design philosophy: The database architecture grow with your business. It uses the integrated centralized and distributed architecture that can be smoothly upgraded with business growth. This avoids high costs associated with changing databases or purchasing large databases directly. Leveraging cloud resources and containerized deployment capabilities, PolarDB-X uses an x86 CPU architecture and the shared-nothing architecture for separation of storage and compute resources. This allows you to plan layer capacity depending on business needs.

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Features

PolarDB-X follows the approaches of self-development and open ecosystem. It delivers distributed capabilities around MySQL open-source ecosystem to minimize learning and usage costs. It is fully compatible with the MySQL open-source ecosystem in multiple dimensions such as SQL syntax, transaction behaviors, and ecosystem tools. To migrate a self-managed MySQL database to PolarDB-X, only minimal code modifications are required for applications.

Feature

Description

Financial-grade high availability (RPO=0)

Transparent distribution

PolarDB-X provides an easy-to-use transparent distribution architecture:

  • By default, PolarDB-X uses a primary key for sharding. This way, you do not need to specify a partition key when you migrate business data to PolarDB-X.

    Note

    This feature can simplify the data migration process, but you still need to design primary keys reasonably based on business requirements to overcome performance bottlenecks.

  • PolarDB-X uses the self-developed X-Paxos protocol to achieve a zero recovery point objective (RPO) during a failover. Additionally, PolarDB-X leverages the TSO policy and distributed MVCC capability to ensure the isolation and consistency of distributed transactions.

  • PolarDB-X supports linear scaling and uses consistent hashing for partitioning. To mitigate hotspotting and achieve load balancing, PolarDB-X can offload requests from overburdened nodes. During a scale-out, PolarDB-X implements computation offloading while maintaining stringent data consistency. The scale-out of a PolarDB-X instance does not affect your business. PolarDB-X also supports parallel queries and throttling to ensure business continuity during scaling.

  • PolarDB-X provides binary logging to resolve the issues of data forwarding from compute nodes to data nodes in distributed databases. In distributed databases, if you restore nodes based on backup files that are created at different points in time, data inconsistency can occur. To resolve this issue, PolarDB-X ensures data consistency before backup and creates backup files based on the globally consistent data.

Integration of centralized and distributed architectures

  • PolarDB-X provides two editions: Standard Edition that is 100% compatible with the native MySQL and Enterprise Edition that is highly compatible with the native MySQL. For more information, see Compatibility with MySQL.

  • When growing business requires the distributed architecture, Standard Edition can be upgraded to Enterprise Edition without service interruption. After the upgrade, distributed components can automatically connect to the original data nodes for scaling without data migration or application modifications.

  • With integration at the kernel level, PolarDB-X optimizes the centralized architecture using distributed technology.

HTAP

PolarDB-X delivers one-stop experience. It implements cold data archiving (TTL), clustered columnar index (CCI), combination of row store nodes and column store nodes, cost-based optimizers for HTAP scenarios. It also supports vectorized operators and uses the self-developed SQL engine to accomplish HTAP queries.

Open-source ecosystem and multi-cloud deployment

To meet the business requirements of different industries, PolarDB-X provides four deployment modes: Alibaba Cloud public cloud, Apsara Stack, DBStack, and Lite edition.

  • Alibaba Cloud public cloud supports fast iteration of PolarDB-X and ensures the stability of PolarDB-X instances. You can deploy PolarDB-X instances on Alibaba Cloud public cloud in fully managed mode. PolarDB-X provides a high-performance cloud-native database service in 13 regions worldwide.

  • Apsara Stack supports core Alibaba cloud services to meet compliance requirements for security and isolation.

    Important

    PolarDB-X instances on Alibaba Cloud public cloud and Apsara Stack may vary depending on types of deployed resources.

  • DBStack is a lightweight platform for database management and supports core Alibaba cloud services. DBStack meets the business requirements for high-performance, high-availability, and cost-effective database solutions in diverse scenarios.

  • PolarDB-X Lite provides up-to-date features and allows you to use minimal resources to create a distributed database cluster.

Security and stability

  • PolarDB-X has passed several national-level security certifications. It is successfully applied in the core systems in industries that have higher security requirements, such as finance and telecommunications.

  • PolarDB-X provides all-round security measures, such as IP address whitelists and SSL, transparent data encryption (TDE), backup encryption, always-confidential, SQL Audit and tracing, three-role mode, and tag permissions.

  • PolarDB-X provides financial-grade high availability and disaster recovery. It achieves a zero recovery point objective (RPO) during a failover and supports deployment in three data centers across two regions. Therefore, it satisfies the level 5 disaster recovery standards of the finance industry.

Scenarios

Scenario

Description

Relevant feature of PolarDB-X

Process many transactions with low latency

Transactions are involved in Internet business. Transaction systems are one of the core components in information systems. Business continuity, transactional consistency, and system security are the fundamentals to ensure that transaction systems can run as expected. In the Internet era, transaction systems that can run with heavy load and low latency for a long time become the trend.

Store data in a centralized manner

This scenario is also referred to as data centralization or data collation. In this scenario, an operational data store (ODS) is used to store enterprise business data and aggregate data sources that are vertically split. This scenario requires databases that support highly concurrent write operations, mass storage, multidimensional queries, and low-cost data processing.

Implement the database and table sharding architecture

This scenario demands high throughput, high concurrency, robust stability, and distributed O&M capabilities (such as distributed DDL queries and scaling). Open-source components can be used to implement the database and table sharding architecture.

Transparent distribution

Transform databases from a traditional architecture to a distributed architecture

When the single-node database cannot process business workloads, or the performance of a single table is deteriorated and table maintenance becomes difficult due to the large amount of data, upgrade to the distributed architecture, application code migration, and data migration are required.

Implement modular disaster recovery

In industries such as finance and telecommunications, it is necessary to ensure the continuity of core services as workloads increase. To achieve this, the current architecture is transformed to a distributed one to create a modular framework. Each module processes its own business workloads, implementing data center-level fault isolation and active geo-redundancy.

Run HTAP queries

Business on the Internet tends to be real-time and intelligent. Therefore, you may need to perform HTAP queries in the same data source. To meet these requirements, databases must be easy-to-use and can ensure data consistency and security.

HTAP

Minimize business costs and enhance productivity

Business workloads tend to be stable. Databases need to be optimized to minimize business costs. The following features are required: one-click MySQL migration, data compression, and data merge.

Multi-cloud deployment for disaster recovery

Self-built cross-cloud disaster recovery is required to prevent vendor lock-in and enhance technological mastery and failure escape. A database is required to cater to diverse demands.

Open-source ecosystem and multi-cloud deployment