Tablestore provides the zone-redundant storage (ZRS) feature for disaster recovery of instance data in data centers. You can store your data in Tablestore instances that support ZRS. This way, data consistency can be ensured even if a data center is unavailable due to a network interruption, power failure, or disaster event. The ZRS feature ensures high data availability and disaster recovery.
Redundancy types
Tablestore provides two redundancy types: locally redundant storage (LRS) and ZRS. If your business requires higher availability, we recommend that you store your data in a region that supports ZRS.
LRS
LRS stores multiple copies of your data on multiple devices of different facilities in the same zone. LRS ensures data durability and availability in case of a hardware failure.
LRS stores copies of data in a specific zone. If the zone becomes unavailable, data in the zone is inaccessible.
ZRS
ZRS stores multiple copies of your data in multiple zones of the same region. If one of the zones is unavailable, your data is still accessible.
ZRS provides disaster recovery at the data center level. If a data center is unavailable due to a network interruption, power failure, or disaster event, Tablestore can still ensure data consistency. The entire fault handling process is user-imperceptible and can be performed without service interruption and data loss. It can also meet the requirements of key business systems for a recovery point objective (RPO) of 0 and a recovery time objective (RTO) of 0.
Differences between LRS and ZRS
LRS and ZRS differ in data durability, service availability, and instance types. The following table compares LRS and ZRS.
Dimension | LRS | ZRS |
Data durability | 99.999999999% (11 nines) | 99.9999999999% (12 nines) |
Service availability | 99.9% | 99.99% |
Instance type |
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Regions that support ZRS and regions that support redundancy type upgrade for existing instances
The following table describes, by instance type, the regions that support ZRS and those that support redundancy type upgrade for existing instances.
For more information about instances, see Instance.
Instance type | Region that supports ZRS | Region that supports redundancy type upgrade for existing instances |
High-performance instance | China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Ulanqab), China (Shenzhen), China (Hong Kong), and Singapore | China (Hangzhou), China (Shanghai), China (Hong Kong), and Singapore |
Capacity instance | China (Hong Kong) | N/A |
Redundancy type upgrade for existing instances
Tablestore can automatically upgrade the redundancy type of high-performance instances in the following regions from LRS to ZRS: China (Hangzhou), China (Shanghai), China (Hong Kong), and Singapore. For more information about the upgrade, see the upgrade announcements of Tablestore.
If you have any concern about the performance issues that may be caused due to the default upgrade, submit a ticket or contact us.
Usage notes
By default, the instance you create in a region that supports ZRS is of the ZRS type.
An instance can be of the LRS or ZRS type. The actual redundancy type that is displayed in the Tablestore console prevails.
Create a ZRS instance
Log on to the Tablestore console.
In the top navigation bar, select a resource group and a region that supports ZRS.
The instance types that the region supports are displayed in the console.
Click Create Instance.
On the On-demand tab of the Billing Method dialog box, specify an instance name, set the Instance Type parameter to High-performance, and then enter a description in the Instance Description field based on your business requirements.
Click OK.
After you create a high-performance instance, you can view the status of the instance on the Overview page. If ZRS is displayed in the Redundancy Type column for the instance, the instance is of the ZRS type.
Billing rules
The ZRS feature of an instance does not affect the existing billing rules of the instance.
Other operations
To prevent operations such as accidental deletion and malicious tampering from affecting the availability of important data, you can use the data backup feature to back up the table data in an instance. For more information, see Overview.