Upgrade the database major version in-place

This page describes how to upgrade the database major version by upgrading your Cloud SQL instance in-place rather than by migrating data.

Introduction

Database software providers periodically release new major versions that contain new features, performance improvements, and security enhancements. Cloud SQL intakes new versions after they're released. Once Cloud SQL offers support for a new major version, you can upgrade your instances to keep your database updated.

You can upgrade the database version of an instance in-place or by migrating data. In-place upgrades are a simpler way to upgrade your instance's major version. You don't need to migrate data or change application connection strings. With in-place upgrades, you can retain the name, IP address, and other settings of your current instance after the upgrade. In-place upgrades don't require you to move data files and can be completed faster. In some cases, the downtime is shorter than what migrating your data entails.

The Cloud SQL for the PostgreSQL in-place upgrade operation uses the pg_upgrade utility.

Plan a major version upgrade

  1. Choose a target major version.

    See the list of versions that Cloud SQL supports.

  2. Consider the features offered in each database major version and address incompatibilities.

    New major versions introduce incompatible changes that might require you to modify the application code, the schema, or the database settings. Before you can upgrade your database instance, review the release notes of your target major version to determine the incompatibilities that you need to address. If you're skipping major versions, address the incompatibilities listed for each version that you're skipping.

  3. Test the upgrade with a dry run.

    Perform a dry run of the end-to-end upgrade process in a test environment before you upgrade the production database. You can clone your instance to create an identical copy of the data on which to test the upgrade process.

    In addition to validating that the upgrade completes successfully, run tests to ensure that the application behaves as expected on the upgraded database. If you haven't enabled automatic storage increases, take note of the disk storage used by the upgraded dry run instance to determine whether you need to increase the storage capacity for the production instance before upgrading.

  4. Decide on a time to upgrade.

    Upgrading requires the instance to become unavailable for a period of time. Plan to upgrade during a time period when database activity is low.

Prepare for a major version upgrade

Before you upgrade, complete the following steps.

  1. Check the LC_COLLATE value for each of your databases. The character set for each database must be en_US.UTF8.

    If the LC_COLLATE value for each database isn't en_US.UTF8, then the major version upgrade fails. To fix this, if any of your databases has a character set other than en_US.UTF8, then change the LC_COLLATE value for these databases to en_US.UTF8 before you perform the upgrade.

    To change the encoding of a database:

    1. Dump your database.
    2. Drop your database.
    3. Create a new database with the different encoding (for this example, en_US.UTF8).
    4. Reload your data.
  2. Manage your read replicas.

    Cloud SQL for PostgreSQL does not support cross-version replication, which means that you cannot upgrade the primary instance while the instance is replicating to the read replicas. Before upgrading, either disable replication for each read replica or delete the read replicas.

  3. If Cloud SQL is the logical replication source, disable pglogical extension replication as follows. You can enable it again after the upgrade. If Cloud SQL is the logical replication target, these steps are not required.
    1. Disable the subscription and disconnect the replica from the provider by using the following command:
      SELECT * FROM pglogical.alter_subscription_disable(subscription_name name, immediate bool);
      

      Replace name with the name of the existing subscription.

      Set the value of the immediate parameter to true if the subscription needs to be disabled immediately. By default, the value is false and the subscription is disabled only after the current transaction ends.

      For example:

      postgres=> SELECT * FROM pglogical.alter_subscription_disable('test_sub', true);
       alter_subscription_disable
      ----------------------------
       t
      (1 row)
      
    2. Drop the replication slot by connecting to the publisher or the Cloud SQL primary instance and running the following command:
      SELECT pg_drop_replication_slot(slot_name) FROM pg_replication_slots
        WHERE slot_name IN (SELECT slot_name FROM pg_replication_slots);

      For example:

      postgres=> SELECT pg_drop_replication_slot(slot_name) FROM pg_replication_slots
      postgres->    WHERE slot_name IN (SELECT slot_name FROM pg_replication_slots);
      -[ RECORD 1 ]------------+-
      pg_drop_replication_slot |
      
      postgres=>
      
  4. Manage your remaining PostgreSQL extensions.

    Most extensions work on the upgraded database major version. Drop any extensions that are no longer supported in your target version. For example, drop the chkpass extension if you're upgrading to PostgreSQL 11 or more recent versions.

    Update PostGIS and related extensions manually to the latest version.

Upgrade the database major version in-place

When you initiate an upgrade operation, Cloud SQL first checks the configuration of your instance to ensure that it's compatible for an upgrade. After verifying your configuration, Cloud SQL makes your instance unavailable, makes a pre-upgrade backup, performs the upgrade, makes your instance available, and makes a post-upgrade backup.

Console

  1. In the Google Cloud console, go to the Cloud SQL Instances page.

    Go to Cloud SQL Instances

  2. To open the Overview page of an instance, click the instance name.
  3. Click Edit.
  4. In the Instance info section, click the Upgrade button and confirm that you want to go to the upgrade page.
  5. On the Choose a database version page, click the Database version for upgrade list and select one of the available database major versions.
  6. Click Continue.
  7. In the Instance ID box, enter the name of the instance and then click the Start upgrade button.
The operation takes several minutes to complete.

Verify that the upgraded database major version appears below the instance name on the instance Overview page.

gcloud

  1. Start the upgrade.

    Use the gcloud beta sql instances patch command with the --database-version flag.

    Before running the command, replace the following:

    • INSTANCE_NAME: The name of the instance.
    • DATABASE_VERSION: The enum for the database major version, which must be greater than the current version. See the available database version enums.
    gcloud beta sql instances patch INSTANCE_NAME \
    --database-version=DATABASE_VERSION
    

    Major version upgrades take several minutes to complete. You might see a message indicating that the operation is taking longer than expected. You can either ignore this message or run the gcloud sql operations wait command to dismiss the message.

  2. Get the upgrade operation name.

    Use the gcloud sql operations list command with the --instance flag.

    Before running the command, replace the INSTANCE_NAME variable with the name of the instance.

    gcloud sql operations list --instance=INSTANCE_NAME
    
  3. Monitor the status of the upgrade.

    Use the gcloud sql operations describe command.

    Before running the command, replace the OPERATION variable with the upgrade operation name retrieved in the previous step.

    gcloud sql operations describe OPERATION
    

REST v1

  1. Start the in-place upgrade.

    Use a PATCH request with the instances:patch method.

    Before using any of the request data, replace these variables:

    • project_id: The ID of the project.
    • instance_name: The name of the instance.

    HTTP method and URL:

    POST https://sqladmin.googleapis.com/sql/v1/projects/project-id/instances/instance_name
    

    Request JSON body:

    {
      "databaseVersion": enum DATABASE_VERSION
    }
    

    Replace DATABASE_VERSION with the enum for the database major version, which must be greater than the current version. See the available database version enums.

    Send your request using curl or PowerShell. See Edit instances.

  2. Get the upgrade operation name.

    Use a GET request with the operations.list method after replacing project_id with the ID of the project.

    HTTP method and URL:

    GET https://sqladmin.googleapis.com/sql/v1/projects/project-id/operations
    
  3. Monitor the status of the upgrade.

    Use a GET request with the operations.get method after replacing the following variables:

    • project_id: The ID of the project.
    • operation_name: The upgrade operation name retrieved in the previous step.

    HTTP method and URL:

    GET https://sqladmin.googleapis.com/sql/v1/projects/project-id/operation/operation_name
    

When you place an in-place upgrade request, Cloud SQL first performs a pre-upgrade check. If Cloud SQL determines that your instance isn't ready for an upgrade, your upgrade request fails with a message suggesting how you can address the issue. See also Troubleshoot a major version upgrade.

Automatic upgrade backups

When you perform a major version upgrade, Cloud SQL automatically makes two on-demand backups, called upgrade backups:

  • The first upgrade backup is the pre-upgrade backup, which is made immediately before starting the upgrade. You can use this backup to restore your database instance to its state on the previous version.
  • The second upgrade backup is the post-upgrade backup, which is made immediately after new writes are allowed to the upgraded database instance.

When you view your list of backups, the upgrade backups are listed with type On-demand. Upgrade backups are labeled so that you can identify them easily. For example, if you're upgrading from PostgreSQL 9.6 to PostgreSQL 13, your pre-upgrade backup is labeled Pre-upgrade backup, POSTGRES_9_6 to POSTGRES_13. and your post-upgrade backup Post-upgrade backup, POSTGRES_13 from POSTGRES_9_6.

As with other on-demand backups, upgrade backups persist until you delete them or delete the instance. If you have PITR enabled, you can't delete your upgrade backups while they're in your retention window. If you need to delete your upgrade backups, you'll need to disable PITR or wait until your upgrade backups are no longer in your retention window.

Complete the major version upgrade

Once you've finished upgrading your primary instance, perform the following steps to complete your upgrade:

  1. Enable pglogical replication if your instance used it before the upgrade. Doing this automatically creates the necessary replication slot.
    1. Drop the pglogical subscription on the destination replica by using the following command:
      select pglogical.drop_subscription(subscription_name name);
      

      Replace name with the name of the existing subscription.

      For example:

      postgres=> select pglogical.drop_subscription(subscription_name := 'test_sub');
      -[ RECORD 1 ]-----+--
      drop_subscription | 1
      
    2. Recreate the pglogical subscription on the destination (replica) by providing connection details as follows to the Cloud SQL primary instance:
      SELECT pglogical.create_subscription(
          subscription_name := 'test_sub',
          provider_dsn := 'host=primary-ip port=5432 dbname=postgres user=replication_user password=replicapassword'
      ); 

      For example:

      postgres=> SELECT pglogical.create_subscription(
      postgres(>     subscription_name := 'test_sub',
      postgres(>     provider_dsn := 'host=10.58.64.90 port=5432 dbname=postgres user=postgres password=postgres'
      postgres(> );
      -[ RECORD 1 ]-------+-----------
      create_subscription | 2769129391
      
    3. Check the status of the subscription by using the following command:
      SELECT * FROM pglogical.show_subscription_status('test_sub');
      
    4. Test the replication by performing write transactions and verifying that the changes are visible on the destination.
  2. Upgrade the read replicas.

    If you stopped replication to read replicas, upgrade them one by one. You can use any of the methods used to upgrade the primary instance. When you upgrade a replica, Cloud SQL recreates it preserving the IP addresses, refreshes it with the latest data from the primary, and restarts the replica.

    If you deleted your read replicas prior to upgrading your primary, you can create new read replicas, which will automatically be provisioned on the upgraded database version.

  3. Refresh the database statistics.

    Run ANALYZE on your primary instance to update the system statistics after the upgrade. Accurate statistics ensure that PostgreSQL's query planner processes queries optimally. Missing statistics can lead to bad query plans, which in turn might degrade performance and take up excessive memory.

  4. Perform acceptance tests.

    You should run tests to ensure that the upgraded system performs as expected.

Troubleshoot a major version upgrade

Cloud SQL returns an error message if you attempt an invalid upgrade command, for example, if your instance contains invalid database flags for the new version.

If your upgrade request fails, check the syntax of your upgrade request. If the request has a valid structure, try looking into the following suggestions.

View upgrade logs

If any issues occur with a valid upgrade request, Cloud SQL publishes error logs to projects/PROJECT_ID/logs/cloudsql.googleapis.com%2Fpostgres-upgrade.log. Each log entry contains a label with the instance identifier to help you identify the instance with the upgrade error. Look for such upgrade errors and resolve them.

To view error logs, follow these steps:

  1. In the Google Cloud console, go to the Cloud SQL Instances page.

    Go to Cloud SQL Instances

  2. To open the Overview page of an instance, click the instance name.
  3. In the Operations and logs pane of the instance Overview page, click the View PostgreSQL error logs link.

    The Logs Explorer page opens.

  4. View logs as follows:

    • To list all error logs in a project, select the log name in the Log name log filter.

      For more information on query filters, see Advanced queries.

    • To filter the upgrade error logs for a single instance, enter the following query in the Search all fields box, after replacing DATABASE_ID with the project ID followed by the instance name in this format: project_id:instance_name.

      resource.type="cloudsql_database"
      resource.labels.database_id="DATABASE_ID"
      logName : "projects/PROJECT_ID/logs/cloudsql.googleapis.com%2Fpostgres-upgrade.log"
      

      For example, to filter the upgrade error logs by an instance named shopping-db running in the project buylots, use the following query filter:

      resource.type="cloudsql_database"
      resource.labels.database_id="buylots:shopping-db"
      logName : "projects/buylots/logs/cloudsql.googleapis.com%2Fpostgres-upgrade.log"
      

Log entries with the pg_upgrade_dump prefix indicate that an upgrade error had occurred. For example:

pg_upgrade_dump: error: query failed: ERROR: out of shared memory
HINT: You might need to increase max_locks_per_transaction.

Additionally, log entries labeled with a .txt secondary filename, such as tables_using_sql_identifier.txt and loadable_libraries.txt, might list other errors that you might want to resolve before attempting the upgrade again.

Check the memory

If the instance has insufficient shared memory, you might see this error message: ERROR: out of shared memory. This error is more likely to occur if you have in excess of 10,000 tables.

Before you attempt an upgrade, set the value of the max_locks_per_transaction flag to approximately twice the number of tables in the instance. The instance is restarted when you change the value of this flag.

Check the connections capacity

If your instance has insufficient connection capacity, you might see this error message: ERROR: Insufficient connections.

We recommend that you increase the max_connections flag value by the number of databases in your instance. The instance is restarted when you change the value of this flag.

Restore to the previous major version

If your upgraded database system doesn't perform as expected, you might need to restore your instance to the previous version. You do so by restoring your pre-upgrade backup to a Cloud SQL recovery instance, which is a new instance running the pre-upgrade version.

To restore to the previous version, perform the following steps:

  1. Identify your pre-upgrade backup.

    See Automatic upgrade backups.

  2. Create a recovery instance.

    Create a new Cloud SQL instance using the major version that Cloud SQL was running when the pre-upgrade backup was made. Set the same flags and instance settings that the original instance uses.

  3. Restore your pre-upgrade backup.

    Restore your pre-upgrade backup to the recovery instance. This might take several minutes to complete.

  4. Add your read replicas.

    If you were using read replicas, add them individually.

  5. Connect your application.

    Having recovered your database system, update your application with details about the recovery instance and its read replicas. You can resume serving traffic on the pre-upgrade version of your database.

FAQs

The following questions might come up when upgrading the database major version.

Is my instance unavailable during an upgrade?
Yes. Your instance stays unavailable for a period of time for Cloud SQL to perform the upgrade.
How long does an upgrade take?
Upgrading a single instance typically takes less than 10 minutes. Your upgrade time might be longer if your instance hosts too many databases or tables, your databases are very large, or your instance configuration uses a small number of vCPUs or memory. If you have multiple instances that need to be upgraded, your total upgrade time increases proportionately.
Can I monitor each step in my upgrade process?
While Cloud SQL allows you to monitor whether an upgrade operation is still in progress, you are unable to track the individual steps in each upgrade.
Can I cancel my upgrade after I've started it?
No, you can't cancel an upgrade once it has started. If your upgrade fails, Cloud SQL automatically recovers your instance on the previous version.
What happens to my settings during an upgrade?
When you perform an in-place major version upgrade, Cloud SQL retains your database settings, including your instance name, IP address, flag values, and user data. If a certain flag or a flag value is no longer supported in your target version, Cloud SQL automatically removes the flag during the upgrade.

What's next