Migrate to managed disaster recovery

This page describes how to migrate from BigQuery cross-regionreplication to BigQuery managed disaster recovery.

Overview

BigQuerycross-regionreplication (CRR) and manageddisasterrecovery (DR) are both features designed toenhance data availability and disaster recovery capabilities. However, theyhandle regional outages in different ways. CRR doesn't allow promoting thesecondary replica if the primary region is unavailable. In contrast, DR offersmore comprehensive protection by allowing a failover to the secondary replicaeven if the primary region is unavailable. With CRR, only storage is replicated,while with DR both storage and compute capacity are replicated.

The following table describes the feature capabilities of CRR and DR:

Migration implications

The following sections provide an overview of the cost and capability changesthat occur when you migrate to DR.

Cost implications

Consider the following cost implications when you migrate from CRR to DR:

• DR only supports write access from the Enterprise Plus edition, whichincurs higher compute costs. You can read from any capacity model, so read costsfor existing jobs don't change.

• DR usesTurboreplication, whichincurs additional costs depending on the region pair.

• Storage prices are the same for both CRR and DR.

For more information about pricing, seePricing.

Capability implications

Consider the following capability implications when you migrate from CRR to DR:

• DR only supports failover at the reservation level. Any existing jobs thatrely on dataset-level failover fail.

• Only Enterprise Plus edition queries can write to the dataset once itis attached to the DR reservation. Any existing write jobs that don't use anEnterprise Plus edition for their compute capacity fail.

Before you begin

Before you begin the migration, familiarize yourself with the concepts incross-region replication and manageddisaster recovery.

To migrate to DR, you must have the following prerequisites:

• You have an active Google Cloud project with BigQuery enabled.

• You have created and replicated datasets with CRR.

• The datasets have the same primary and secondary locations you want to use forDR.

• You have the necessary permissions to work with DR. For more information aboutpermissions, seeBefore youbegin.

Migrate from CRR to DR

The following sections describe how to migrate your datasets from CRR to DR. Itassumes you have already configured your datasets for CRR.

Create a failover reservation

To enable disaster recovery, you must create a failover reservation in theprimary region. Configure your reservation with the appropriate primary andsecondary region. The primary and secondary regions should match the regions ofall the CRR datasets you intend to migrate to DR. To create a failoverreservation, choose one of the following options:

Attach the dataset to the reservation

Once you've created the failover reservation, attach your cross-region dataset, or datasets, to the reservation. This enables failover for all of the attached datasets. To attach the dataset to the reservation, choose one of the following options:

Verify the configuration

To verify the status of your configuration, query theINFORMATION_SCHEMA.SCHEMATA_REPLICASview.

PROJECT_ID.`region-REGION`.INFORMATION_SCHEMA.SCHEMATA_REPLICAS[_BY_PROJECT]

Verify that the datasets are attached to the correct reservation in the correctregions.

• Optional:PROJECT_ID: the ID of your Google Cloud project. If not specified, the default project is used.
• REGION: anydataset region name. For example,`region-us`.

  Note: You must usea region qualifier to queryINFORMATION_SCHEMA views. The location of the query execution must match the region of theINFORMATION_SCHEMA view.

Examples

The following example walks you through the steps to migrate from CRR to DR withpractical examples using GoogleSQL. For this example, assume thefollowing:

• You are working in a project namedmyproject.

• You have already created a dataset namedmydataset and configured it withCRR.

• The primary region ofmydataset isus-central1 and the secondary region isus-west1.

To begin migrating your dataset to DR, first create a reservation with theEnterprise Plus edition. In this example, the name of the reservationismyreservation.

CREATERESERVATION`myproject.region-us-central1.myreservation`OPTIONS(slot_capacity=0,edition=ENTERPRISE_PLUS,autoscale_max_slots=50,secondary_location='us-west-1');

Once the reservation is created, you can then attach the dataset to thereservation. The following example attaches the dataset to the reservation:

ALTERSCHEMA`myproject.mydataset`SETOPTIONS(failover_reservation='myproject.myreservation');

Then, verify that the dataset has been successfully attached.

SELECTfailover_reservation_project_id,failover_reservation_name,FROM`myproject`.`region-us-west1`.INFORMATION_SCHEMA.SCHEMATA_REPLICASWHEREschema_name='mydataset';

The results of this query should look similar to the following:

+---------------------------------+---------------------------+| failover_reservation_project_id | failover_reservation_name |+---------------------------------+---------------------------+| myproject                       | myreservation             || myproject                       | myreservation             |+---------------------------------+---------------------------+

What's next?

• For more information about cross-region replication, seeCross-region datasetreplication.

• For more information about managed disaster recovery, seeManaged disasterrecovery.