Promote a migration job

For continuous migrations, you can initiate the promotion process when you are ready to cut over your applications to the destination databases. Promoting the migration job disconnects the destination instance from the source, transforms it into an independent standalone primary database instance so you can you resume automated backups, configure point-in-time recovery (PITR), and create read replicas.

You can promote a migration job or promote selected databases from a migration job.

  1. Stop all writes, running scripts, and client connections to the source database. The downtime period begins here.
  2. Wait until the replication delay metric is at or close to zero. This means that the migration job has processed all outstanding changes.

    You can promote a migration even if the replication delay isn't at zero. This can reduce the database downtime, but may affect the accuracy of the data in the destination.

  3. Perform the promote action:

    Console

    1. In the Google Cloud console, go to the Migration jobs page.

      Go to Migration jobs

    2. On the Jobs tab, click the display name of the migration job that you want to promote.

      The migration job details page opens.

    3. Perform one of the following promote actions:

      • If you want to promote all databases included in the migration, on the migration job's toolbar, click Promote.

        The promote migration job dialog appears.

      • If you want to promote only specific databases, select them using the checkboxes next to the database names and on the Databases tab, click Promote.

        The dialog with a number of databases that you want to promote appears.

    4. In the dialog, ensure that no errors are displayed, and then click Promote.

    gcloud

    Before using any of the command data below, make the following replacements:

    • MIGRATION_JOB_ID with your migration job identifier.

      If you don't know the identifier, you can use the gcloud database-migration migration-jobs list command to list all migration jobs in a given region and view their identifiers.

    • REGION with the identifier of the region where your connection profile is saved.

    Execute the following command:

    Linux, macOS, or Cloud Shell

    gcloud database-migration migration-jobs \
promote MIGRATION_JOB_ID \
  --region=REGION

    Windows (PowerShell)

    gcloud database-migration migration-jobs `
promote MIGRATION_JOB_ID `
  --region=REGION

    Windows (cmd.exe)

    gcloud database-migration migration-jobs ^
promote MIGRATION_JOB_ID ^
  --region=REGION

    Result

    The action is performed in an asynchronous manner. As such, this command returns an Operation entity that represents a long-running operation: 

    done: false
metadata:
  '@type': type.googleapis.com/google.cloud.clouddms.v1.OperationMetadata
  apiVersion: v1
  createTime: '2024-02-20T12:20:24.493106418Z'
  requestedCancellation: false
  target: MIGRATION_JOB_ID
  verb: start
name: OPERATION_ID

    To see if your operation is successful, you can query the returned operation object, or check the status of the migration job:

  4. The destination instance or the databases that you selected are promoted. The destination instance is disconnected from the source, becomes an independent standalone primary instance, and is ready for full application traffic. The migration job status changes to Completed.
  5. (Optional) For sources that use the pg_cron extension: The pg_cron extension (or any cron settings associated with the extension) isn't migrated by Database Migration Service, but it is supported in Cloud SQL for PostgreSQL destinations. If you use the pg_cron extension in your source databases, you can re-install it on your destination instance.
  6. You can now connect your application to the Cloud SQL instance and delete the migration job.