PolarDB for MySQL supports three different editions: Cluster Edition, Single Node, and Archive Database. This topic describes these three editions.

Cluster Edition

  • Overview

    Cluster Edition uses an architecture where computing is decoupled from storage. At the computing layer, the number of database nodes can be dynamically scaled from 2 to a maximum of 16. All the compute nodes use the dedicated specifications. Therefore, resources are isolated among the nodes. Multiple database nodes constitute the database engine layer of PolarDB for MySQL. The PolarProxy layer that supports features, such as read/write splitting and load balancing, resides over the database engine layer. PolarDB for MySQL provides 2 to 10 Internet-facing cluster endpoints over the PolarProxy layer. The dynamic scale-out of storage capacity in Cluster Edition does not affect your business. Each cluster supports a maximum of 100 TB storage capacity. You are charged for the used storage space. For more information, see Specifications and pricing. Cluster Edition allows you to distribute data across multiple zones, and supports zone-level disaster recovery. If a zone becomes unavailable, you can switch database services to another zone within a few minutes. For more information, see Deploy a cluster across zones and change the primary zone. Cluster Edition also supports the dynamic scale-out and scale-in of multiple nodes. It takes only about 5 minutes to add nodes for horizontal scale-out. This does not affect your business. For more information, see Add or remove read-only nodes.

    For more information about Cluster Edition, see Architecture.

  • Scenarios

    Cluster Edition is the main edition that is recommended in PolarDB for MySQL. This edition provides features for free, such as fast data backup, Restore data, and global database network (GDN) deployment. It also provides enterprise-class features, such as rapid elastic upgrades and downgrades and acceleration of parallel queries. We recommend that you use this edition in production environments.

  • Supported kernel versions

    Cluster Edition supports three kernel versions: PolarDB for MySQL 5.6, 5.7, and 8.0.

  • Node specifications and pricing

    Cluster Edition supports eight types of dedicated node specifications. For more information, see Billable items.

Single Node

  • Overview

    Single Node adopts the burstable performance specification, and shares resources in a computing resource pool. This improves resource utilization. The Single Node architecture also saves resource costs because it requires no proxy. Single Node is the same as Cluster Edition in the following aspects: The dynamic scale-out of storage capacity does not affect your business. You are charged for the used storage space. In addition, a Single Node cluster does not need to synchronize logs. This saves overheads of synchronizing and parsing redo logs. The cluster also delivers good performance.

  • Scenarios

    Cost-effective Single Node is the optimal choice for individuals to use for testing and learning. Startups can also use this edition as an entry-level product.

  • Supported kernel versions

    Single Node supports two versions: PolarDB for MySQL 5.6 and 8.0.

  • Node specifications and pricing

    Single Node supports only the burstable performance node specification: 4 cores and 8 GB. For more information, see Billable items.

Archive Database

  • Overview

    Archive Database replaces InnoDB with X-Engine and uses X-Engine as the default storage engine. X-Engine improves the data compression ratio by using the log-structured merge-tree (LSM tree) that is in a hierarchical architecture and the Zstandard (ZSTD) compression algorithm. Compared with InnoDB that serves as the storage engine, X-Engine can save up to 70% of storage capacity. By default, Archive Database uses only one compute node that has dedicated computing specifications. This saves costs at the PolarProxy layer and overheads of synchronizing redo logs. However, Archive Database has some limits, particularly the limits on the compatibility with MySQL, because this edition adopts X-Engine. For more information about the limits, see Limits.

  • Scenarios

    Archive Database is positioned as an archive database that has the high data compression ratio. This edition is applicable to business where computing requirements are low, but archived data, such as messages in DingTalk, must be stored.

  • Supported kernel versions

    Archive Database supports PolarDB for MySQL 8.0.

  • Node specifications and pricing

    Archive Database supports seven types of dedicated node specifications. For more information, see Billable items.

Edition comparison

  • Features such as elastic upgrades and downgrades, GDNs, and kernels
    Feature Cluster Edition Single Node Archive Database
    Change configurations Supported Not supported Not supported
    Add or remove nodes Supported Not supported Not supported
    Switch over services between primary and read-only nodes Supported Not supported Not supported
    GDN Supported Not supported Not supported
    Parallel query Supported Not supported Not supported
    Cluster endpoint Supported Not supported Not supported
  • Data migration or synchronization feature
    • Clone a cluster. For more information, see Clone a cluster.
      Product edition Destination cluster
      Cluster Edition Single Node Archive Database
      Source cluster Cluster Edition Supported Not supported Not supported
      Single Node Not supported Supported Not supported
      Archive Database Not supported Not supported Supported
    • Restore a cluster from the recycle bin. For more information, see Cluster recycle bin.
      Product edition New cluster
      Cluster Edition Single Node Archive Database
      Deleted cluster Cluster Edition Supported Not supported Not supported
      Single Node Available soon Available soon Not supported
      Archive Database Not supported Not supported Available soon
    • Migrate data from ApsaraDB RDS for MySQL. For more information, see Create a PolarDB for MySQL cluster from an ApsaraDB RDS for MySQL instance.
      Product edition New cluster
      Cluster Edition Single Node Archive Database
      ApsaraDB RDS for MySQL edition Basic Edition Available soon Available soon Not supported
      High-availability Edition Supported Not supported Not supported
      Enterprise Edition Not supported Not supported Not supported
    • Clone data from ApsaraDB RDS for MySQL. For more information, see Create a PolarDB for MySQL cluster by using the Clone from RDS method.
      Product edition New cluster
      Cluster Edition Single Node Archive Database
      ApsaraDB RDS for MySQL edition Basic Edition Available soon Available soon Not supported
      High-availability Edition Supported Supported Not supported
      Enterprise Edition Not supported Not supported Not supported
  • Specifications and resource plans
    Comparison item Cluster Edition Single Node Archive Database
    Specifications of compute nodes Supports eight types of dedicated specifications. Supports only the burstable performance specification: 4 cores and 8 GB. Supports sevent types of dedicated specifications.
    Specifications and pricing The storage space of the three editions is provisioned in a serverless architecture. Therefore, you do not need to specify the storage capacity when you purchase clusters. The storage capacity of the clusters is automatically scaled out online as the amount of data increases. You are charged for only the storage space that is occupied by the actual amount of data. You can view the details about the Database Storage Usage on the Overview page of the cluster.
    • Mainland China: USD 0.00077/GB/hour
    • China (Hong Kong) and regions outside China: USD 0.00085/GB/hour
    Storage plan Supported.
  • Transparent data encryption (TDE). For more information, see Configure TDE.
    Product edition Version Support for TDE
    Cluster Edition 5.6 The revision version must be 5.6.1.0.21 or later.
    5.7 The revision version must be 5.7.1.0.3 or later.
    8.0 The revision version must be 8.0.1.1.1 or later.
    Single Node 5.6 The revision version must be 5.6.1.0.21 or later.
    8.0 The revision version must be 8.0.1.1.1 or later.
    Archive Database 8.0 Not supported.
    Note For more information about the revision version of each version of the clusters, see Query the kernel version.

FAQ

  • Can different editions be switched with each other?
    Yes, different editions can be switched with each other. The following table describes which editions can be switched.
    Product edition Destination edition
    Cluster Edition Single Node Archive Database
    Source edition Cluster Edition None Not supported Not supported
    Single Node Available soon None Not supported
    Archive Database Not supported Not supported None
  • How can the Single Node and Archive Database editions ensure service availability and data reliability?

    Single Node and Archive Database are database products that provide specific services based on a single compute node. Although only one node is available, Single Node and Archive Database can ensure high service availability and high data reliability by using technologies, such as computing scheduling within seconds and distributed multi-replica storage.