Data Replication Overview

Scenarios

A fault in data storage can severely impact services. Therefore, backup and disaster recovery (DR) are critical to data storage. To ensure backup and DR, you can replicate data between buckets (either in the same region or across different regions).

Data replication falls into the following types: cross-region replication within an account, cross-region replication across accounts, same-region replication within an account, and same-region replication across accounts.

The following source and destination buckets are all Huawei Cloud OBS buckets.

• Cross-region replication within an account: Replicate data from bucket A in one region to bucket B in another region under the same account. For details, see Cross-Region Replication Within an Account Using OBS.

  

• Cross-region replication across accounts: Replicate data from bucket A in one region to bucket B in another region across accounts. For details, see Cross-Region Replication Across Accounts Using OMS.

  

• Same-region replication within an account: Replicate data from bucket A to bucket B within the same region under the same account. For details, see Same-Region Replication Within an Account Using OMS.

  

• Same-region replication across accounts: Replicate data from bucket A to bucket B within the same region across accounts. For details, see Same-Region Replication Across Accounts Using OMS.

  

Content Replicated

When data is replicated, it may often have features such as versioning, lifecycle rules, server-side encryption, and WORM retention policies. The following explains how these features affect replication, specifically, which data will be replicated and which will not.

Billing for Data Replication

• When you use the OMS console or APIs to migrate data, OBS APIs of both the source and destination ends are invoked to handle data upload and download. You will be billed for the API requests and data download traffic. For details, see OMS Billing. In addition, you will be billed for storing the objects in the destination bucket. For details, see Storage Costs.
• When you use the OBS console, APIs, or obsutil to replicate data across regions, you will be billed for requests, traffic, and storage. For details, see Table 4.

  Table 4 Billing for data replication across regions

  Action	Billing Item	Description	Billing Mode
  Replicate data across regions	Requests	You are billed for the number of successfully replicated objects. Successfully replicating one object creates a copy request. For details, see Copying Objects. For non-multipart objects, replicating an object creates a GET request to the source bucket and a PUT request to the destination bucket; deleting an object from the source bucket creates a DELETE request to the destination bucket. For multipart objects, replicating each part creates a GET request to the source bucket and a PUT request to the destination bucket. For details about how requests are billed, see Requests.	Pay-per-use
  	Data transfer	Traffic generated when you replicate data from the source bucket to the destination bucket in another region. Billing only applies to the data transferred out of the source bucket. If objects are encrypted using server-side encryption, the cost of their cross-region replication traffic is calculated based on the length of the plaintext for SSE-KMS and SSE-OBS.	Pay-per-use
  	Storage space	Space occupied by the replicated objects in the destination bucket If you have specified another storage class for object copies in the destination bucket, these copies are billed based on the new storage class. If objects are encrypted using server-side encryption, their storage cost is calculated based on the length of the ciphertext.	Pay-per-use Resource packages
  Synchronize existing objects	Requests	You are billed for the number of existing objects that are successfully replicated to the destination bucket. Billing applies to the number of objects that are successfully replicated. You are also billed for listing the existing objects.	Pay-per-use
  	Data transfer	Traffic generated when OBS replicates existing objects to the destination bucket in another region. Billing only applies to the data transferred out of the source bucket. If historical objects are encrypted using server-side encryption, the cost of their cross-region replication traffic is calculated based on the length of the plaintext for SSE-KMS and SSE-OBS.	Pay-per-use
  	Storage space	Space occupied by the replicated objects in the destination bucket If you have specified another storage class for object copies in the destination bucket, these copies are billed based on the new storage class. If historical objects are encrypted using server-side encryption, their storage cost is calculated based on the length of the ciphertext.	Pay-per-use Resource packages

• When you use OBS APIs, OBS SDKs, OBS Browser+, or obsutil to replicate data within the same region, you will be billed for requests and storage. For details, see Table 5.

  Table 5 Billing for data replication in the same region

  Action	Billing Item	Description	Billing Mode
  Replicate data in the same region	Requests	You are billed for the number of successfully replicated objects. Successfully replicating one object creates a copy request. For details, see Copying Objects. To learn about the request billing, see Requests.	Pay-per-use
  	Data transfer	Free, because data in the same region is replicated over an intranet.	N/A
  	Storage space	Storage space occupied by objects stored in the destination bucket. If you have specified another storage class for object copies in the destination bucket, these copies are billed based on the new storage class.	Pay-per-use Resource packages