PolarDB:Restore a cluster to a point in time

Usage notes

• The restored cluster inherits the data and accounts from the source cluster, but not its parameter settings.

• The available restoration time range depends on the Log Retention Period (Days) setting. By default, you can restore to any point within the last 7 days.

Procedure

1. Log on to the PolarDB console. In the left-side navigation pane, click Clusters. Select the region where your cluster is located, and then click the cluster ID to view its details page.

2. In the navigation pane, choose Settings and Management > Backup and Restoration.

3. Perform a point-in-time restoration.

   • To restore data within the same region:

     On the Backup and Restoration page, click Point-in-time Restoration.

   • To restore data across regions:

     1. On the Backup and Restoration page, select the region that contains the data you want to restore.

     2. Click Point-in-time Restoration.

4. On the configuration page, select the Commodity Type for the new cluster.

   • Subscription: A prepaid billing method where you pay for compute resources in advance.

   • Pay-as-you-go: A postpaid billing method where you are charged for the compute resources you use.

   • Serverless: Charges include costs for compute nodes, storage capacity, backup storage that exceeds the free quota, and optional SQL Explorer. For more information, see Serverless pricing.

   This operation creates a new cluster and does not affect the original cluster. Point-in-time restoration recovers data from the backups and redo logs of the original cluster into the new cluster. The data and running status of the original cluster remain unchanged.

5. Configure the following parameters.

   Parameter	Description
   Cloned By	Select Restore to Point in Time.
   Region	Select the destination region for the restoration. Note If cross-region backup is enabled, you can restore data to the source region or the destination region. If cross-region backup is disabled, the destination region is the same as the source cluster's region by default and does not need to be selected.
   Point in Time	Select the point in time to which you want to restore the data. Note The available time range depends on the Log Retention Period (Days) setting. The default is 7 days.
   Primary Zone	Select the primary availability zone for the cluster. Note In a region with multiple availability zones, PolarDB automatically replicates data to a secondary availability zone for disaster recovery.
   Minimum Read-only Nodes	Minimum Read-only Nodes: The minimum number of read-only nodes. Valid values: 0 to 15. Maximum Read-only Nodes: The maximum number of read-only nodes. Valid values: 0 to 15. Note The number of read-only nodes automatically scales up or down within the specified range based on the workload. For more information about the scaling policy, see Auto scaling. To ensure high availability for your serverless cluster, we recommend setting Minimum Read-only Nodes to 1. Minimum PCUs per Node: The minimum number of PCUs for each node in the cluster. Valid values: 0.25 to 31 PCUs. Maximum PCUs per Node: The maximum number of PCUs for each node in the cluster. Valid values: 1 to 32 PCUs. Note Serverless uses PCUs as the unit for per-second billing and resource scaling. One PCU is equivalent to approximately 1 vCPU core and 2 GB of memory. The PCUs of a node dynamically scale within the specified range, with a minimum scaling step of 0.5 PCU. Example: If you set Minimum PCUs per Node to 2 and Maximum PCUs per Node to 16, the default specification for each node in the serverless cluster is 2 PCUs (about 2 vCPU cores and 4 GB of memory). When the system detects an increase in workload, it automatically scales up the PCUs of the primary node or read-only nodes. However, the number of PCUs cannot exceed 16. Note These parameters are available only when Product Type is set to Serverless.
   Maximum Read-only Nodes
   Minimum PCUs per Node
   Maximum PCUs per Node
   Network Type	This parameter is fixed to VPC and cannot be changed.
   VPC	Select the VPC and vSwitch for the cluster. We recommend that you select the same VPC and vSwitch as the source cluster. Note To achieve optimal performance, make sure that your PolarDB cluster and the ECS instances that you want to connect to are in the same VPC. Otherwise, they cannot communicate over the internal network.
   vSwitch
   Compatibility	This parameter is fixed to the compatibility version of the source cluster and cannot be changed. For example, if the source cluster is fully compatible with MySQL 8.0, the compatibility for the new cluster is also fixed to MySQL 8.0.
   Minor Version	Select 8.0.1 or 8.0.2. Note This parameter is available only when Compatibility is set to MySQL 8.0.
   Edition	This parameter is fixed to the edition of the source cluster and cannot be changed. For example, if the source cluster is Cluster Edition, the new cluster is also Cluster Edition. For more information, see Enterprise editions.
   Database Type	PolarDB for MySQL Cluster Edition supports two resource types: General Specification and Dedicated Specification. Dedicated: Each cluster exclusively uses its allocated compute resources, ensuring stable and reliable performance. General-purpose: Different clusters on the same server share idle compute resources, offering higher cost-effectiveness through resource multiplexing. For a detailed comparison of the two resource types, see How to choose between general-purpose and dedicated resource types.
   CPU Architecture	This parameter is fixed to the CPU architecture of the source cluster and cannot be changed.
   Node Specifications	Select a Node Specifications. Different specifications offer different maximum storage capacities and performance levels. For more information, see Enterprise Edition compute node specifications. Note To ensure the stability of the restored cluster, we recommend that you select a Node Specifications that is equal to or higher than that of the source cluster.
   Nodes	If the source cluster is Cluster Edition, the system displays two nodes (one read-write node and one read-only node) by default. You can choose to create two nodes or a single read-write node. If the source cluster is Multi-master Cluster (Limitless) Edition, the system creates two primary nodes with the same specifications by default. You do not need to configure this parameter.
   PolarProxy type	PolarDB provides two PolarProxy types: Standard Enterprise Edition and Dedicated Enterprise Edition. Standard Enterprise Edition: Used with the general-purpose resource type. It shares physical CPU resources and provides intelligent, second-level elastic scaling based on the workload. Dedicated Enterprise Edition: Used with the dedicated resource type. It uses dedicated physical CPU resources for better performance stability. Note PolarProxy Enterprise Edition is currently free of charge. The future billing policy is to be determined.
   Enable No-activity Suspension	If you choose to Enable No-activity Suspension, you must set the Detection Period for No-activity Suspension. The valid range is 5 minutes to 24 hours. Note These parameters are available only when Product Type is set to Serverless.
   Enable hot standby cluster	PolarDB provides multiple high availability modes. After you enable the hot standby storage cluster feature for a PolarDB cluster, a hot standby storage cluster is created in the secondary zone of the region in which the PolarDB cluster resides or in a different data center in the same zone. The hot standby storage cluster has independent storage resources. Whether the hot standby storage cluster has independent compute resources varies based on the high availability mode. When the PolarDB cluster in the primary zone fails, the hot standby storage cluster immediately takes over and handles read and write operations and storage tasks. Note For more information about the hot standby storage cluster and related solutions, see High availability modes (hot standby clusters). Rules for changing high availability modes: You cannot directly change the high availability mode of a cluster from Double Zones (Hot Standby Storage Cluster Enabled) or Double Zones (Hot Standby Storage and Compute Clusters Enabled) to Single Zone (Hot Standby Storage Cluster Disabled). For such change of the high availability mode, we recommend that you purchase a new cluster and select the Single Zone (Hot Standby Storage Cluster Disabled) high availability mode for the cluster. Then, migrate the existing cluster to the new cluster by using Data Transmission Service (DTS). For information about how to migrate an existing cluster to a new cluster, see Migration between PolarDB for MySQL clusters. You can select the Three Zones high availability mode only when you purchase a new cluster. You cannot change the high availability mode of a cluster from Three Zones to other high availability modes and vice versa. You can manually change the high availability mode of a cluster from Single Zone (Hot Standby Storage Cluster Disabled) to a different high availability mode. For more information, see High availability modes (hot standby clusters).
   Cross-zone strong consistency	Specifies whether to enable strong consistency across three availability zones.
   Storage Type	The storage type is inherited from the source cluster. If the source cluster uses ESSD, you can only select ESSD. If the source cluster uses PSL4 or PSL5, you can select either PSL4 or PSL5. ESSDs are ultra-high-performance disks built on a distributed block storage architecture with 25 Gigabit Ethernet and Remote Direct Memory Access (RDMA) support, delivering up to 1 million random read/write IOPS at low one-way latency. PL0 ESSD: A performance level (PL) 0 ESSD. PL1 ESSD: A PL1 ESSD delivers five times the IOPS and approximately twice the throughput of a PL0 ESSD. PL2 ESSD: A PL2 ESSD delivers approximately twice the IOPS and throughput of a PL1 ESSD. PL3 ESSD: A PL3 ESSD delivers up to 10 times the IOPS and 5 times the throughput of a PL2 ESSD. It is suitable for business scenarios that require extremely high concurrent I/O performance and stable, low read/write latency. AutoPL ESSD: Compared to PL0, PL1, PL2, and PL3 ESSDs, AutoPL ESSDs decouple IOPS from capacity, allowing for flexible configuration and on-demand adjustments. This reduces the overall Total Cost of Ownership (TCO). Important For more information about the performance of ESSD cloud disks, see ESSD cloud disks. When an ESSD cloud disk's storage space is full, it becomes read-only. To avoid business disruptions, you can enable automatic storage scaling for ESSD cloud disks. PSL4 and PSL5 are storage types that PolarDB provides for different business scenarios. The differences are as follows: Storage type Features Use cases PSL5 (PolarStore Level 5) This storage class was used in earlier versions of PolarDB and is the default for clusters purchased before June 7, 2022. It offers higher performance, reliability, and availability. Business-critical workloads that require high performance and reliability, such as finance, e-commerce, government services, and medium-to-large internet businesses. PSL4 (PolarStore Level 4) A new PolarDB storage class that uses Alibaba's proprietary smart-SSD technology. This technology compresses and decompresses data at the physical SSD layer, which reduces storage costs with a manageable performance impact. Cost-sensitive applications that prioritize high cost-effectiveness. Note Storage class conversion rules: Some product series support upgrading the storage class from PSL4 to PSL5. Downgrading the storage class is not supported. You cannot downgrade PSL5 storage to PSL4 storage. To switch from PSL5 storage to PSL4 storage, purchase a new cluster and migrate the data using either a migration tool like Data Transmission Service (DTS) or a major version upgrade.
   Storage Engine	PolarDB provides two engine types: InnoDB and InnoDB & X-Engine. InnoDB: The InnoDB storage engine. InnoDB & X-Engine: A hybrid engine that deploys both InnoDB and X-Engine. If you select this option, you can set the proportion of resources allocated to X-Engine. For more information, see Introduction to X-Engine. Note This parameter is not available for PolarDB for MySQL Standard Edition.
   Storage Billing Method	PolarDB supports two storage billing methods: Pay-as-you-go and Subscription. Pay-as-you-go: With this pay-as-you-go method, storage capacity scales automatically. You are charged only for the storage you use, without needing to specify a capacity at purchase. For more information, see Pay-as-you-go pricing. Subscription: This method requires you to purchase a specific amount of storage in advance. For more information, see Subscription pricing. Note When Billing Method is set to Subscription, you can set Storage Payment Method to Pay-as-you-go or Subscription. When Billing Method is set to Pay-as-you-go, storage is billed on a pay-as-you-go basis by default and this parameter cannot be configured.
   Storage Capacity	The amount of prepaid storage space for a Subscription cluster. The storage capacity ranges from 50 GB to 500 TB, adjustable in 10 GB increments. Note This parameter is available only when Storage Payment Method is set to Subscription.
   Storage Fee	You do not need to specify storage capacity at purchase. PolarDB charges you hourly for your actual usage.
   Enable binary logging	Specifies whether to enable binary logging. For more information, see Enable binary logging.
   Cluster Name	Enter a name for the cluster. The name must meet the following requirements: It cannot start with http:// or https://. It must be 2 to 256 characters long. If you leave this parameter empty, the system automatically generates a cluster name. You can change the name after the cluster is created.
   Inherit tags from source cluster	Specifies whether to inherit tags from the source cluster.
   Subscription duration	Select the subscription duration for the cluster. Note This parameter is available only when Billing Method is set to Subscription.
   Quantity	Select the number of clusters to purchase.

6. Review the cluster configuration, confirm the cost, and read the terms of service. Then, click Buy Now.

7. After the purchase is complete, the system takes 10 to 15 minutes to create the cluster. You can then view the newly created cluster in the cluster list on the PolarDB console.

   Note

   • When a node's status is Creating, the cluster is not yet ready for use. The cluster is ready only when its status changes to Running.

   • Make sure that you have selected the correct region in the upper-left corner of the console. Otherwise, you may not be able to see the cluster you created.

API reference