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

Cluster Edition

  • Overview

    Cluster Edition uses an architecture where computing is decoupled from storage. The number of database compute nodes can be dynamically scaled from 2 up to 16. All compute nodes are dedicated nodes. Therefore, resources are isolated among the nodes. The PolarDB for MySQL database engine consists of multiple database nodes. PolarProxy works as a database proxy and is deployed on top of the database engine. PolarProxy supports features such as read/write splitting and load balancing. PolarDB for MySQL PolarProxy provides 2 to 10 cluster endpoints. The dynamic scaling of storage capacity in Cluster Edition does not affect your services. Each cluster supports a maximum of 100 TB storage. You are charged for the storage that you use. For more information, see Billable items. Cluster Edition allows you to deploy a cluster across multiple zones and perform a failover across zones. If a zone becomes unavailable, you can switch database services to another zone within 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 requires only about 5 minutes to add nodes for horizontal scaling. This does not affect your services. For more information, see Add or remove read-only nodes.

    For more information about Cluster Edition, see Architecture.

  • Scenarios

    Cluster Edition is the recommended product edition of PolarDB for MySQL. It supports features such as fast data backup, Restore data, and Global Database Network (GDN) free of charge. It also supports elastic scaling and parallel queries for enterprises. We recommend that you use this edition in your production environments.

  • Supported kernel versions

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

  • Node specifications and pricing

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

Single node

  • Overview

    Single Node uses nodes of the burstable performance type and shares resources in a computing resource pool. This improves computing resource usage. The architecture of Single Node also saves resource costs because no proxy is required. Similar to Cluster Edition, dynamic scaling of storage capacity in Single Node does not affect your services. You are charged for the storage that you use. PolarDB clusters of the Single Node edition do not synchronize logs. This reduces the overhead of synchronizing and parsing redo logs, and improves performance.

  • Scenarios

    Single Node is cost-effective and is the optimal choice for testing and personal use. This edition can be used by startups as the starter product.

  • Supported kernel versions

    Single Node supports three kernel versions: PolarDB for MySQL 5.6, 5.7, and 8.0.

  • Node specifications and pricing

    Single Node supports only the node specification of 4-Core 8 GB (Burstable Performance). For more information, see Billable items.

Archive database

  • Overview

    Archive Database provides a high compression ratio and uses X-Engine as the default storage engine. PolarDB Archive Database provides a large storage capacity and allows you to store archived data at a low cost. X-Engine uses log-structured merge-tree (LSM tree) and the Zstandard (ZSTD) data compression algorithm to increase the data compression ratio. Compared with InnoDB, X-Engine allows you to save up to 70% on storage space. By default, a Archive Database cluster uses one dedicated node. This saves the costs on PolarProxy and reduces the overhead for synchronizing redo logs. However, Archive Database has limits, especially the limits on the compatibility with MySQL. This is because X-Engine has some limits on features. For more information, see Limits.

  • Scenarios

    Archive Database is used to store archived data and provides a high data compression ratio. It is applicable to services that do not have high requirements for computing but need to store archived data, such as DingTalk messages.

  • Supported kernel versions

    Only PolarDB for MySQL 8.0 is supported.

  • Node specifications and pricing

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

Comparisons

  • Features such as elastic upgrades and downgrades, GDNs, performance optimization, and kernels
    Feature Cluster Edition Single Node Archive Database
    Change specifications 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
    Autonomy center Supported Not supported Not supported
    Performance Insight Supported Not supported Not supported
    Slow SQL queries Supported Not supported Not supported
  • Data migration or synchronization
    • Clone a cluster. For more information, see Clone a cluster.
      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.
      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.
      Edition New cluster
      Cluster Edition Single Node Archive Database
      ApsaraDB RDS for MySQL 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.
      Edition New cluster
      Cluster Edition Single Node Archive Database
      ApsaraDB RDS for MySQL 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
    Item Cluster Edition Single Node Archive Database
    Specifications of compute nodes Supports eight dedicated specifications. Supports only the node specification of 4-Core 8 GB (Burstable Performance). Supports seven dedicated node specifications.
    Billable items A serverless architecture is used for storage. Therefore, you do not need to specify the storage capacity when you purchase clusters. The storage capacity of the clusters is automatically increased when the amount of data increases. You are only charged for the storage that you use. You can view the storage that you have used on the Overview page of a cluster in the console.
    Storage plan Supported
  • Transparent data encryption (TDE). For more information, see Configure TDE.
    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.
    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.
    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 number.

FAQ

  • Can I change the product edition to another one?
    Yes, cluster editions can be changed. The following table describes which editions can be changed.
    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 do 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. However, Single Node and Archive Database can ensure high service availability and high data reliability by using new technologies, such as computing scheduling within seconds and distributed multi-replica storage.