This topic describes the common causes of a migration failure that may occur when you use Data Online Migration to migrate data and related solutions.

If a migration job fails, you can view the list of files that fail to be migrated to analyze the causes of the failure and troubleshoot the issue. On the Migration Jobs page, find a failed job, click Manage in the Operation column, and then click Retry to migrate failed files.

The following section describes the common causes of a migration failure and solutions:

Case 1: The "because downloader gets input stream failed" error message is displayed.

  • Symptom
    When you migrate data from Baidu Object Storage (BOS) to Alibaba Cloud Object Storage Service (OSS), the migration fails.
    • The following error message is displayed for the files that fail to be migrated.1
    • The following error message is recorded in the log file of BOS.1
  • Cause

    BOS sets traffic throttling on the source data address due to a large number of requests.

  • Solution
    Contact Baidu customer service to remove traffic throttling or retry after you set traffic throttling for the migration job.
    Important The following cloud service providers have set traffic throttling that may result in a migration failure:
    • BOS: You can contact Baidu customer service to remove traffic throttling or set traffic throttling for the migration job.
    • Qiniu Cloud: Traffic and concurrency limits are set by Qiniu Cloud-Integrated CDN (FUSION) for test endpoints. We recommend that you separate large amounts of data into multiple collections and migrate these collections one by one or use accelerated domains.
    • UPYUN: UPYUN sets traffic throttling for scenarios in which you download large amounts of data. When you migrate large amounts of data, we recommend that you contact UPYUN customer service to remove traffic throttling or use CDN.

Case 2: The "check size failed" error message is displayed.

  • Symptom
    When you migrate third-party data to OSS, the following error message is displayed for the files that fail to be migrated. 2
  • Cause

    The last modification time of files at the source data address is later than the last modification time of files at the destination data address. A file verification error occurs if you update source files after these files have been migrated to the destination bucket.

  • Solution

    Migrate the updated source files.

Case 3: The "premature end of content-length delimited message body" error message is displayed.

  • Symptom
    When you migrate third-party data to OSS, the following error message is displayed for the files that fail to be migrated. 3
  • Cause

    A connection that is used to send or receive data is closed by OSS. If the interval between two uploads exceeds 1 minute, the connection that is used to upload data is closed by OSS. Generally, the error is caused by network issues such as high network latency.

  • Solution

    Retry the migration job.

Case 4: The "check content-length failed" error message is displayed.

  • Symptom
    When you migrate third-party data to OSS, the following error message is displayed for the files that fail to be migrated. 4
  • Cause

    The source and destination data addresses have files with the same name. The last modification time of the file at the destination data address is later than the last modification time of the file at the source data address. The file is disregarded during the migration. However, an error may occur when the system checks the file after the migration job is complete.

  • Solution
    • If you need to migrate the file, you can retry the migration after you delete the file at the destination data address or modify the file name.
    • If you do not need to migrate the file, you can ignore the error.

Case 5: The "http status code 403" error message is displayed.

  • Symptom
    When you migrate data between OSS buckets, the following error message is displayed for the files that fail to be migrated. 5
  • Cause

    Insufficient permissions are granted. When you create data addresses, you must use an account that has the read permissions on the source data address and the write permissions on the destination data address. After a migration job is started, an error occurs if you modify the permissions of the account or the access permissions of OSS buckets, such as modifying the policies for OSS buckets.

  • Solution

    Retry the migration after you restore the permissions of the account.

Case 6: The "The operation is not valid for the object's state" error message is displayed.

  • Symptom
    When you migrate data between OSS buckets, the following error message is displayed for the files that fail to be migrated. 6
  • Cause

    Data Online Migration does not allow you to migrate archive files. The error occurs when archive files exist at the source data address.

  • Solution
    • If you need to migrate archive files, retry the migration after you change the file type to Standard.
    • If you do not need to migrate the files, ignore this error.

Case 7: The "check usermeta failed" error message is displayed.

  • Symptom
    When you migrate data from BOS to OSS, the following error message is returned:
    check usermeta failed
  • Cause

    The HTTP header or user metadata of a file contains special characters that cannot be identified during the migration.

  • Solution
    • Retry the migration after you modify the HTTP header or user metadata of the file.
    • Manually migrate the file that fails to be migrated.

Case 8: The "It is timeout to check the data source, please make sure all the parameters are correct and retry later" error message is displayed.

  • Symptom

    When you migrate data from Apsara File Storage NAS (NAS) to OSS, the migration job status is displayed as Invalid. Move the pointer over the 1 icon. The following error message is displayed: It is timeout to check the data source, please make sure all the parameters are correct and retry later.

  • Cause

    The IP address of the elastic network interface (ENI) used for migration cannot access the NAS file system in the virtual private cloud (VPC).

  • Solution

    Check whether access control or security groups are configured for the NAS file system. IP addresses used for migration are dynamic and random. You must authorize all IP addresses in the VPC to access the NAS file system.