Tablestore provides zone-redundant storage to ensure high data availability and data center-level disaster recovery. When you store data in an instance created in a region that supports zone-redundant storage, Tablestore continues to provide strongly consistent services even if a data center becomes unavailable due to a network outage, power failure, or disaster.
Redundancy types
Tablestore provides two redundancy types: locally redundant storage and zone-redundant storage. If your business requires higher availability, you can create an instance in a region that supports zone-redundant storage to store and use your data.
When you create a new instance in a region that supports zone-redundant storage, the redundancy type is set to zone-redundant storage by default. You cannot select or change the redundancy type.
Locally redundant storage
Locally redundant storage uses a data redundancy mechanism within a single Availability Zone (AZ). It stores redundant copies of your data on multiple devices across different physical locations in the same AZ. This ensures data durability and availability if one or more hardware devices fail within the AZ.
Data in locally redundant storage is stored in a specific AZ. If the AZ becomes unavailable or all hardware devices in the AZ fail at the same time, the data becomes inaccessible.
Zone-redundant storage
Zone-redundant storage uses a data redundancy mechanism across multiple AZs. It stores redundant copies of your data across multiple AZs in the same region. If an AZ becomes unavailable, zone-redundant storage ensures that data remains accessible.
Zone-redundant storage provides data center-level disaster recovery. When an AZ in a region becomes unavailable, Tablestore continues to provide strongly consistent services. The failover process is transparent to users, with no service interruptions or data loss. This meets the strict requirements of critical business systems for a recovery time objective (RTO) and a recovery point objective (RPO) of zero.
Comparison of redundancy types
Locally redundant storage and zone-redundant storage differ in data durability, service availability, and supported regions. The following table describes the differences.
Dimension | Locally redundant storage | Zone-redundant storage |
Data durability | 99.999999999% (eleven 9s) | 99.9999999999% (twelve 9s) |
Service availability | 99.9% | 99.99% |
Supported regions | China (Qingdao), China (Hohhot), China (Guangzhou), China (Chengdu), Malaysia (Kuala Lumpur), Philippines (Manila), Thailand (Bangkok), UK (London), US (Silicon Valley), US (Virginia), UAE (Dubai), SAU (Riyadh - Partner Region) | China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Ulanqab), China (Shenzhen), China (Hong Kong), Japan (Tokyo), Singapore, Indonesia (Jakarta), Germany (Frankfurt) |
Notes
Each instance has only one redundancy type. You can view the redundancy type for an instance in the Tablestore console.
The redundancy type of a search index is independent of the instance's redundancy type. In regions that support zone-redundant storage, all search indexes use zone-redundant storage.
Billing
Using the zone-redundant storage feature for an instance does not affect the existing billing rules.
Related operations
To prevent important data from becoming unavailable due to accidental deletion or malicious modification, you can use the data backup feature to back up table data in an instance. For more information, see Backup and recovery.