Product editions

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.

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.

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

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

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.

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.

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

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

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.

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.

Archive Database supports PolarDB for MySQL 8.0.

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

• 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

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.