When you use Data Online Migration, you are charged only for the data traffic that is generated by data uploads, data downloads, and API calls. This topic describes the billing items of Data Online Migration.

Online migration process

The online migration process includes the following steps:
  1. Retrieve the details of data to be migrated: Data Online Migration overwrites or skips the source files based on the File Overwrite Method that you specified when you created a migration job.
  2. Migrate data: Data Online Migration migrates data from the source data address to the destination data address.
  3. Check data integrity: Data Online Migration compares migrated data with the source data to ensure data integrity.
  4. Generate migration logs: Data Online Migration generates and pushes migration logs to the destination data address after you click Generate Migration Report.

Number of API requests

API requests are required when you compare files at the source and destination data addresses, migrate data to the destination data address, and check data integrity. The number of API requests varies depending on different scenarios. This section describes the number of API requests when a single file is migrated.
Notice
  • API requests incur fees only when the data source is Object Storage Service (OSS) or a third-party cloud service. When you migrate data from Apsara File Storage NAS, HTTP/HTTPS endpoints, and Elastic Compute Service (ECS) instances, you are not charged for making API requests to access these data sources.
  • The following API requests apply only to a successful migration job.
  • If you need to migrate a file that has different names at the source data address and destination data address, make the following API requests:
    • Source-side API requests
      • Call the GetMeta API operation to compare data before migration.
      • Call the GetObject API operation to migrate data.
    • Destination-side API requests
      • Call the GetMeta API operation to compare data before migration.
      • Call the PutObject API operation to migrate data.
        Notice If the size of a file exceeds 150 MB, the file is split into multiple parts before it is uploaded. The size of each part is less than or equal to 50 MB. The number of API requests depends on the amount of data you want to migrate. For example, a file of 150 MB is split into three parts. Therefore, three PutObject requests are made.
      • Call the GetMeta API operation to check data integrity after migration.
  • If you need to migrate a file that has the same name at the source data address and destination data address, make the following API requests:
    • Source-side API requests
      • Call the GetMeta API operation to compare data before migration.
      • Call the GetObject API operation to migrate data.
    • Destination-side API requests
      • Call the GetMeta API operation to compare data before migration.
      • Call the PutObject API operation to migrate data.
        Notice If the size of a file exceeds 150 MB, the file is split into multiple parts before it is uploaded. The size of each part is less than or equal to 50 MB. The number of API requests depends on the amount of data you want to migrate. For example, a file of 150 MB is split into three parts. Therefore, three PutObject requests are made.
      • Call the GetMeta API operation to check data integrity after migration.
  • If you do not need to migrate a file that has the same name at the source data address and destination data address, make the following API requests:
    • Source-side API requests
      • Call the GetMeta API operation to compare data before migration.
    • Destination-side API requests
      • Call the GetMeta API operation to compare data before migration.
      • Call the GetMeta API operation to check data integrity after migration.
Example: Assume that you need to migrate 1,000 files and the size of each file is less than 150 MB. Among the 1,000 files, 500 files have a unique name. Among these 500 files, 300 files that have the same name at the source and destination data addresses need to be migrated to the destination data address. The other 200 files that have the same name at the source and destination data addresses do not need to be migrated to the destination data address. If the migration job succeeds, the total number of API requests are calculated by using the following formula:
  • Total number of API requests that are made for the source data address 
    500*2+300*2+200*1=1800
  • Total number of API requests that are made for the destination data address 
    500*3+300*3+200*2=2800
Note For information about charges incurred by API requests, contact your cloud service provider. For information about the billing items and methods of OSS, see Overview.

Traffic fees for download and upload

Fees are incurred when data is downloaded from the source data address and uploaded to Object Storage Service (OSS). Traffic fees vary depending on different scenarios.
Notice
  • Traffic fees are generated only when the data source is OSS or a third-party cloud service. When you migrate data from Apsara File Storage NAS, HTTP/HTTPS endpoints, and Elastic Compute Service (ECS) instances, you are not charged for downloading data.
  • The following billing items apply only to a successful migration job.
  • Migrate data from a third-party cloud service.

    Fees are incurred for downloading data at the source data address. The traffic depends on the amount of data that you want to download. You are charged by the cloud service provider that owns the source data address. You are not charged for uploading data to OSS.

  • Migrate data from an OSS endpoint to another OSS endpoint over the Alibaba Cloud internal network.

    No fees are incurred because the data upload or download is performed over the Alibaba Cloud internal network.

  • Migrate data from an OSS endpoint to another OSS endpoint over the Internet.

    Fees are incurred for downloading data from the source data address. The traffic depends on the amount of data that you want to download. You are charged by OSS. You are not charged for uploading data to OSS.