This topic describes the instance types that are supported by PolarDB-X instances.

PolarDB-X provides the following instance families: general-purpose, dedicated, and dedicated host.

  • Dedicated: The computing resources of a server such as CPU cores that are allocated to each PolarDB-X instance are exclusive to the instance. This improves performance stability.
  • General-purpose: Idle computing resources such as CPU cores are shared among PolarDB-X instances on the same server. This improves cost-effectiveness.
  • Dedicated host: Each PolarDB-X instance exclusively occupies the allocated computing resources, such as CPU cores. Data nodes exclusively occupy the IOPS resources of the entire host.

General-purpose instance family

Instance family Instance type CPU and memory specifications Maximum storage Maximum number of connections Maximum IOPS
General-purpose polarx.x4.medium.2e 2 CPU cores, 8 GB memory 3072GB 20000 4000
General-purpose polarx.x4.large.2e 4 CPU cores, 16 GB memory 3072GB 20000 7000
General-purpose polarx.x4.xlarge.2e 8 CPU cores, 32 GB memory 3072GB 20000 12000
General-purpose polarx.x4.2xlarge.2e 16 CPU cores, 64 GB memory 3072GB 20000 14000

Dedicated instance family

Instance family Instance type CPU and memory specifications Maximum storage Maximum number of connections Maximum IOPS
Dedicated polarx.x8.large.2e 4 CPU cores, 32 GB memory 3072GB 20000 9000
Dedicated polarx.x8.xlarge.2e 8 CPU cores, 64 GB memory 3072GB 20000 18000
Dedicated polarx.x8.2xlarge.2e 16 CPU cores, 128 GB memory 3072GB 20000 36000
Dedicated polarx.x8.4xlarge.2e 32 CPU cores, 128 GB memory 3072GB 20000 36000
Dedicated polarx.x8.4xlarge.2e 32 CPU cores, 256 GB memory 3072GB 20000 72000

Dedicated host instance families

Instance family Instance type CPU and memory specifications Maximum storage Maximum number of connections Maximum IOPS
Dedicated host polarx.st.8xlarge.25 60 CPU cores, 470 GB memory 6144GB 20000 120000
Dedicated host polarx.st.12xlarge.25 90 CPU cores, 720 GB memory 6144GB 20000 140000

Description

  • Data nodes support the general-purpose, dedicated, and dedicated host instance families. Compute nodes support only the general-purpose and dedicated instance families.
  • The instance types that are listed in this topic specify the specifications for single nodes. A PolarDB-X instance consists of at least two nodes to ensure high availability. Each performance and capacity metric of an instance can be calculated based on the following formula: Capacity units of an instance = Capacity unit per node × Number of nodes.
  • The instance type that specifies 2 CPU cores and 8 GB memory provides the basic specifications that are required in tests, trials, and light-load scenarios. We recommend that you do not use this instance type in a heavy-load production environment. We recommend that you use a dedicated instance type that specifies 8 CPU cores and 32 GB memory or higher in a production environment.
  • When you create a PolarDB-X instance, you can select node specifications for the primary instance. Then, each time you create a read-only instance for the primary instance, the read-only instance uses the same node specifications and contains the same number of nodes as the primary instance by default.
  • The maximum number of IOPS is a theoretical value. The maximum number of connections is the maximum number of connections that can be established from applications to each compute node.