AWS DMS Serverless premigration.

AWS DMS Serverless includes pre-migration assessment capabilities that help identify potential issues before starting your database migration. By running a pre-migration assessment, you can detect and resolve configuration problems or compatibility issues that might prevent successful serverless replication. For more information see Individual assessments.

Unlike AWS DMS Standard, AWS DMS Serverless automatically stores pre-migration assessment results in a system-managed Amazon S3 bucket, eliminating the need for you to specify a custom bucket.

AWS DMS Serverless provides the following optional settings to support pre-migration assessment:

• ResultLocationFolder: The folder within an Amazon S3 bucket where you want AWS DMS to store the results of this assessment run.

• ResultEncryptionMode: The supported values are SSE_KMS and SSE_S3. If these values are not provided, then the files are not encrypted at rest. For more information, see Creating AWS KMS keys to encrypt Amazon S3 target objects.

• ResultKmsKeyArn: The ARN of a customer KMS encryption key that you specify when you set ResultEncryptionMode to SSE_KMS.

• IncludeOnly: A space-separated list of names for specific individual assessments that you want to include. These names come from the default list of individual assessments that AWS DMS supports for the associated migration.

• Exclude: A space-separated list of names for specific individual assessments that you want to exclude. These names come from the default list of individual assessments that AWS DMS supports for the associated migration.

• FailOnAssessmentFailure: A configurable setting you can set to true (the default setting) or false. Use this setting to to stop the replication from starting automatically if the assessment fails. This can help you evaluate the issue that is preventing the replication from running successfully.

Using KMS key to encrypt files

To configure SSE-KMS for DMS Serverless premigration assessment with a customer-managed key, add a policy statement that grants the DMS service-linked role on your KMS key, enabling secure encryption and decryption of data during the assessment process. You must configure the kms:GenerateDataKey and kms:Decrypt permissions. See the example below:

{
      "Sid": "AccessForDMSServerlessPremigration",
      "Effect": "Allow",
      "Principal": {
        "AWS": "arn:aws:iam::<CustomerAccountId>:role/aws-service-role/dms.amazonaws.com/AWSServiceRoleForDMSServerless"
      },
      "Action": [
        "kms:Decrypt",
        "kms:GenerateDataKey*"
      ],
      "Resource": "*"
    }

Limitations

Serverless premigrations has the following limitations:

• AWS DMS Serverless retains only the most recent pre-migration assessment results when you call the describe-replications API. While older assessment runs are removed from the immediate display, the corresponding result files remain accessible in the S3 results bucket.

• Custom S3 buckets cannot be chosen to store the assessment results.

• Transformations on remap schema, table, columns are not supported by preflight.