This topic describes the causes for errors in reading data from the source Logstore and the troubleshooting methods.

After the data transformation engine is started, it reads data from the source Logstore in streaming mode. That is, the data transformation engine continuously reads data from the source Logstore during the data transformation process.Errors in reading data from the source Logstore
Errors may occur in this step because of inaccessibility to the source Logstore. The possible causes are as follows:
  • The configurations of the source Logstore are incorrect.
  • The source Logstore information is changed.
  • A network error occurs.
Error impact:
  • If an error occurs in this step, the data transformation task will keep retrying until data reading succeeds or is manually stopped. If the retry succeeds, the data transformation task works properly.
  • If an error is returned after some data has been read, the data transformation task saves the breakpoint and keeps retrying. After the retry succeeds, it continues reading from the breakpoint without losing any logs or generating any duplicate logs.

Common errors and troubleshooting methods

  • An invalid AccessKey is configured for the source Logstore.

    The AccessKey ID or AccessKey secret may be invalid.

    • Error log:
      # The specified AccessKey ID is invalid.
      {
        "errorCode": "Unauthorized", 
        "errorMessage": "AccessKeyId not found: LTAIL3gUus8AEu11"
      }
      # The specified AccessKey secret is invalid.
      { 
        "errorCode": "SignatureNotMatch", 
        "errorMessage": "signature uJfAJbc0ji04gb+cXhh0qWtajpM= not match"
      }
    • Troubleshooting method:

      Check the data transformation rule to make sure that the specified AccessKey ID and AccessKey secret of the source Logstore are valid and correct.

  • The source Logstore information is changed.
    The configurations of the source Logstore are correct, and some transformation tasks may have been performed. However, the source Logstore information has changed during data transformation. As a result, you fail to access the source Logstore based on the existing configurations.
    • Error log:
      The information of the source Logstore may have the following changes:
      • The source Logstore is deleted. In this case, the following error message is returned:
        {
          "errorMessage": "Logstore [logstore_name] does not exist."
        }
      • The AccessKey ID or AccessKey secret of the source Logstore is changed. In this case, the following error message is returned:
        # The specified AccessKey ID is invalid.
        {
          "errorCode": "Unauthorized", 
          "errorMessage": "AccessKeyId not found: LTAIL3gUus8AEu11"
        }
        # The specified AccessKey secret is invalid.
        { 
          "errorCode": "SignatureNotMatch", 
          "errorMessage": "signature uJfAJbc0ji04gb+cXhh0qWtajpM= not match"
        }
    • Troubleshooting method:
      • Check whether the source Logstore is deleted.
      • Check whether the AccessKey ID or AccessKey secret of the source Logstore is changed.
  • A network error occurs.
    • Error log:
      {
        "errorCode": "LogRequestError",
        "errorMessage": "HTTPConnectionPool(host='your_host', port=80): Max retries exceeded with url: your_url (Caused by NewConnectionError: Failed to establish a new connection: [Errno 11001] getaddrinfo failed'"
      }
    • Troubleshooting method:

      Check whether the network is properly connected.

  • No data is read from the source Logstore.

    This is not an error and no error message is returned. For more information, see Troubleshoot common errors.