Configure database flags

This page describes how to configure database flags for Cloud SQL, and lists the flags that you can set for your instance. You use database flags for many operations, including adjusting MySQL parameters, adjusting options, and configuring and tuning an instance.

In some cases, setting one flag may require that you set another flag to fully enable the functionality you want to use. For example, to enable slow query logging, you must set both the slow_query_log flag to on and the log_output flag to FILE to make your logs available using the Google Cloud console Logs Explorer.

When you set, remove, or modify a flag for a database instance, the database might be restarted. The flag value is then persisted for the instance until you remove it. If the instance is the source of a replica, and the instance is restarted, the replica is also restarted to align with the current configuration of the instance.

Configure database flags

The following sections cover common flag management tasks.

Set a database flag

Console

  1. In the Google Cloud console, select the project that contains the Cloud SQL instance for which you want to set a database flag.
  2. Open the instance and click Edit.
  3. Go to the Flags section.
  4. To set a flag that has not been set on the instance before, click Add item, choose the flag from the drop-down menu, and set its value.
  5. Click Save to save your changes.
  6. Confirm your changes under Flags on the Overview page.

gcloud

Edit the instance:

gcloud sql instances patch INSTANCE_NAME --database-flags=FLAG1=VALUE1,FLAG2=VALUE2

This command will overwrite all database flags previously set. To keep those and add new ones, include the values for all flags you want set on the instance; any flag not specifically included is set to its default value. For flags that don't take a value, specify the flag name followed by an equals sign ("=").

For example, to set the general_log, skip_show_database, and wait_timeout flags, you can use the following command:

gcloud sql instances patch INSTANCE_NAME \
  --database-flags=general_log=on,skip_show_database=on,wait_timeout=200000

Terraform

To add database flags, use a 

resource "google_sql_database_instance" "instance" {
  database_version = "MYSQL_8_0"
  name             = "mysql-instance"
  region           = "us-central1"
  settings {
    database_flags {
      name  = "general_log"
      value = "on"
    }
    database_flags {
      name  = "skip_show_database"
      value = "on"
    }
    database_flags {
      name  = "wait_timeout"
      value = "200000"
    }
    disk_type = "PD_SSD"
    tier      = "db-n1-standard-2"
  }
  # set `deletion_protection` to true, will ensure that one cannot accidentally delete this instance by
  # use of Terraform whereas `deletion_protection_enabled` flag protects this instance at the GCP level.
  deletion_protection = false
}

Apply the changes

To apply your Terraform configuration in a Google Cloud project, complete the steps in the following sections.

Prepare Cloud Shell

  1. Launch Cloud Shell.

  2. Set the default Google Cloud project where you want to apply your Terraform configurations.

    You only need to run this command once per project, and you can run it in any directory.

    export GOOGLE_CLOUD_PROJECT=PROJECT_ID

    Environment variables are overridden if you set explicit values in the Terraform configuration file.

Prepare the directory

Each Terraform configuration file must have its own directory (also called a root module).

  1. In Cloud Shell, create a directory and a new file within that directory. The filename must have the .tf extension—for example main.tf. In this tutorial, the file is referred to as main.tf. 
    mkdir DIRECTORY && cd DIRECTORY && touch main.tf

  2. If you are following a tutorial, you can copy the sample code in each section or step.

    Copy the sample code into the newly created main.tf.

    Optionally, copy the code from GitHub. This is recommended when the Terraform snippet is part of an end-to-end solution.

  3. Review and modify the sample parameters to apply to your environment.
  4. Save your changes.
  5. Initialize Terraform. You only need to do this once per directory. 
    terraform init

    Optionally, to use the latest Google provider version, include the -upgrade option: 

    terraform init -upgrade

Apply the changes

  1. Review the configuration and verify that the resources that Terraform is going to create or update match your expectations: 
    terraform plan

    Make corrections to the configuration as necessary.

  2. Apply the Terraform configuration by running the following command and entering yes at the prompt: 
    terraform apply

    Wait until Terraform displays the "Apply complete!" message.

  3. Open your Google Cloud project to view the results. In the Google Cloud console, navigate to your resources in the UI to make sure that Terraform has created or updated them.

Delete the changes

To delete your changes, do the following:

  1. To disable deletion protection, in your Terraform configuration file set the deletion_protection argument to false. 
    deletion_protection =  "false"
  2. Apply the updated Terraform configuration by running the following command and entering yes at the prompt: 
    terraform apply

  1. Remove resources previously applied with your Terraform configuration by running the following command and entering yes at the prompt:

    terraform destroy