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 AlloyDB for PostgreSQL cluster from the source and transforms it into an independent standalone primary cluster so you can direct application traffic to the cluster.

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

    You can promote a migration even if the replication delay isn't at zero. This can reduce database cutover time, but might affect data currency 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. On the migration job toolbar, click Promote.

      The promote migration job dialog 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 migration job 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: promote
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 AlloyDB for PostgreSQL cluster is promoted. The destination cluster is disconnected from the source, becomes an independent standalone primary cluster, and is ready for full application traffic. The migration job status changes to Completed.
  5. (Optional) Re-install extensions: If your source database used extensions that aren't migrated by Database Migration Service (such as pg_cron), re-install and configure those extensions on your destination cluster.
  6. You can now connect your applications to the AlloyDB for PostgreSQL cluster and delete the completed migration job.