Configure database flags

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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 desired functionality. 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

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. Scroll down 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 do not 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 Terraform resource.

cloud_sql/mysql_instance_flags/main.tf 
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"
  }
  deletion_protection = false # set to true to prevent destruction of the resource
}

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

REST v1

To set a flag for an existing database:

Before using any of the request data, make the following replacements:

  • project-id: The project ID
  • instance-id: The instance ID

HTTP method and URL: 

PATCH https://sqladmin.googleapis.com/v1/projects/project-id/instances/instance-id

Request JSON body: 

{
  "settings":
  {
    "databaseFlags":
    [
      {
        "name": "flag_name",
        "value": "flag_value"
      }
    ]
  }
}

To send your request, expand one of these options:

You should receive a JSON response similar to the following:

For example, to set the general_log flag for an existing database use:

Before using any of the request data, make the following replacements:

  • project-id: The project ID
  • instance-id: The instance ID

HTTP method and URL: 

PATCH https://sqladmin.googleapis.com/v1/projects/project-id/instances/instance-id

Request JSON body: 

{
  "settings":
  {
    "databaseFlags":
    [
      {
        "name": "general_log",
        "value": "on"
      }
    ]
  }
}

To send your request, expand one of these options:

You should receive a JSON response similar to the following:

If there are existing flags configured for the database, modify the previous command to include them. The PATCH command overwrites the existing flags with the ones specified in the request.

REST v1beta4

To set a flag for an existing database:

Before using any of the request data, make the following replacements:

  • project-id: The project ID
  • instance-id: The instance ID

HTTP method and URL: 

PATCH https://sqladmin.googleapis.com/sql/v1beta4/projects/project-id/instances/instance-id

Request JSON body: 

{
  "settings":
  {
    "databaseFlags":
    [
      {
        "name": "flag_name",
        "value": "flag_value"
      }
    ]
  }
}

To send your request, expand one of these options:

You should receive a JSON response similar to the following:

For example, to set the general_log flag for an existing database use:

Before using any of the request data, make the following replacements:

  • project-id: The project ID
  • instance-id: The instance ID

HTTP method and URL: 

PATCH https://sqladmin.googleapis.com/sql/v1beta4/projects/project-id/instances/instance-id

Request JSON body: 

{
  "settings":
  {
    "databaseFlags":
    [
      {
        "name": "general_log",
        "value": "on"
      }
    ]
  }
}

To send your request, expand one of these options:

You should receive a JSON response similar to the following:

If there are existing flags configured for the database, modify the previous command to include them. The PATCH command overwrites the existing flags with the ones specified in the request.

Clear all flags to their default values

Console

  1. In the Google Cloud console, select the project that contains the Cloud SQL instance for which you want to clear all flags.
  2. Open the instance and click Edit.
  3. Open the Database flags section.
  4. Click the X next to all of the flags shown.
  5. Click Save to save your changes.

gcloud

Clear all flags to their default values on an instance:

gcloud sql instances patch INSTANCE_NAME \
--clear-database-flags

You are prompted to confirm that the instance will be restarted.

REST v1

To clear all flags for an existing instance:

Before using any of the request data, make the following replacements:

  • project-id: The project ID
  • instance-id: The instance ID

HTTP method and URL: 

PATCH https://sqladmin.googleapis.com/v1/projects/project-id/instances/instance-id

Request JSON body: 

{
  "settings":
  {
    "databaseFlags": []
  }
}

To send your request, expand one of these options:

You should receive a JSON response similar to the following:

REST v1beta4

To clear all flags for an existing instance:

Before using any of the request data, make the following replacements:

  • project-id: The project ID
  • instance-id: The instance ID

HTTP method and URL: 

PATCH https://sqladmin.googleapis.com/sql/v1beta4/projects/project-id/instances/instance-id

Request JSON body: 

{
  "settings":
  {
    "databaseFlags": []
  }
}

To send your request, expand one of these options:

You should receive a JSON response similar to the following:

View current values of database flags

To view all current values of the MySQL system variables, log into your instance with the mysql client and enter the following statement:

 SHOW VARIABLES;

Note that you can change the value only for supported flags (as listed below).

Determine which database flags have been set for an instance

To see which flags have been set for a Cloud SQL instance:

Console

  1. In the Google Cloud console, select the project that contains the Cloud SQL instance for which you want to see the database flags that have been set.
  2. Select the instance to open its Instance Overview page.

    The database flags that have been set are listed under the Database flags section.

gcloud

Get the instance state:

gcloud sql instances describe INSTANCE_NAME

In the output, database flags are listed under the settings as the collection databaseFlags. For more information about the representation of the flags in the output, see Instances Resource Representation.

REST v1

To list flags configured for an instance:

Before using any of the request data, make the following replacements:

  • project-id: The project ID
  • instance-id: The instance ID

HTTP method and URL: 

GET https://sqladmin.googleapis.com/v1/projects/project-id/instances/instance-id

To send your request, expand one of these options:

You should receive a JSON response similar to the following:

In the output, look for the databaseFlags field.

REST v1beta4

To list flags configured for an instance:

Before using any of the request data, make the following replacements:

  • project-id: The project ID
  • instance-id: The instance ID

HTTP method and URL: 

GET https://sqladmin.googleapis.com/sql/v1beta4/projects/project-id/instances/instance-id

To send your request, expand one of these options:

You should receive a JSON response similar to the following:

In the output, look for the databaseFlags field.

Flags managed by Cloud SQL

Cloud SQL adjusts certain system flags depending on the instance machine type.

innodb_buffer_pool_instances
  • 1 for db-f1-micro and db-g1-small.
  • 1 if RAM < 7.5 GB.
  • 2 if 7.5 GB <= RAM < 13 GB.
  • 4 if 13 GB <= RAM < 26 GB.
  • 8 if RAM >= 26 GB.

Supported flags

The flags supported in Cloud SQL are the most commonly requested flags for MySQL. Flags not mentioned below are not supported.

For a given flag, Cloud SQL might support a different value or range from the corresponding MySQL parameter or option.

The flags apply to all versions of MySQL supported by Cloud SQL except where noted.

A | B | C | D | E | F | G | H | I | L | M | N | O | P | Q | R | S | T | U | W

Cloud SQL Flag Type
Acceptable Values and Notes		 Restart
Required?
activate_all_roles_on_login boolean
on | off
default: off
No
auto_increment_increment integer
1 ... 65535		 No
auto_increment_offset integer
1 ... 65535		 No
automatic_sp_privileges boolean
on | off
default: on 		No
back_log integer
1 ... 65535
default: max_connections
Yes
binlog_cache_size integer
4096 ... 9223372036854775807		 No
binlog_expire_logs_seconds integer
0 or 86400 (1 day) ... 4294967295 (max value)
Default is 2592000, which equals 30 days.

See the Tips section for more information about this flag.

 No
binlog_group_commit_sync_delay 0 ... 1000000

Supported in MySQL 5.7, 8.0

Default is 0.

 No
binlog_group_commit_sync_no_delay_count 0 ... 1000000

Supported in MySQL 5.7, 8.0

Default is 0.

 No
binlog_row_image enumeration
full (default), minimal, or noblob		 No
binlog_row_metadata enumeration
full or minimal (default)		 No
binlog_row_value_options string
PARTIAL_JSON		 No
binlog_rows_query_log_events boolean
on | off
default: off 		No
binlog_stmt_cache_size 4096 ... 9223372036854775807 No
binlog_transaction_dependency_history_size integer

For information about how to use this flag and its acceptable values, see Configuring parallel replication.

 No
binlog_transaction_dependency_tracking enumeration

For information about how to use this flag and its acceptable values, see Configuring parallel replication.

 No
block_encryption_mode string
aes-keylen-mode
default: aes-128-ECB
No
bulk_insert_buffer_size integer
0 ... 4294967295
default: 8388608		 No
character_set_server string
utf8 or utf8mb4 (recommended)		 Yes
cloudsql_allow_analyze_table boolean on | off
default: off
No
cloudsql_mysql_audit_data_masking_cmds string
"", dql, dml, ddl, dcl, show, call, create_udf, drop_function, create_procedure, create_function, drop_procedure, alter_procedure, alter_function, create_trigger, drop_trigger, create_event, alter_event, drop_event, create_db, drop_db, alter_db, create_user, drop_user, rename_user, alter_user, create_table, create_index, alter_table, drop_table, drop_index, create_view, drop_view, rename_table, update, insert, insert_select, delete, truncate, replace, replace_select, delete_multi, update_multi, load, select, call_procedure, connect, disconnect, grant, revoke, revoke_all, show_triggers, show_create_proc, show_create_func, show_procedure_code, show_function_code, show_create_event, show_events, show_create_trigger, show_grants, show_binlog_events, show_relaylog_events

default: create_user, alter_user, grant, and update 		No
cloudsql_mysql_audit_data_masking_regex string
max_string_length: 2048
default: Click here. 		No
cloudsql_mysql_audit_log_write_period integer
0...5000 milliseconds
default: 500 milliseconds 		No
cloudsql_mysql_audit_max_query_length integer
-1...1073741824
default: -1 		No
completion_type enumeration
NO_CHAIN (default), CHAIN, or RELEASE		 No
concurrent_insert enumeration
NEVER, AUTO (default), or ALWAYS		 No
connect_timeout integer
2 ... 31536000
default: 10		 No
cte_max_recursion_depth integer
0 ... 4294967295
default: 1000		 No
default_authentication_plugin string
mysql_native_password|caching_sha2_password
Yes
default_password_lifetime integer 0...65535
default: 0
No
default_time_zone string
There are two ways to specify timezones: as timezone offsets and timezone names. For example, +00:00 is the timezone offset for London (which is in the UTC timezone), and Europe/London is its timezone name.

You use values to specify timezone offsets, from -12:59 to +13:00. Leading zeros are required.

When using timezone names, automatic adjustment to daylight saving time is supported. When using timezone offsets, it isn't supported. See a list of timezone names that Cloud SQL for MySQL supports. You must update this flag manually, on the primary instance and on all read replicas, to account for it.

To set the timezone without causing a restart of the Cloud SQL instance, use the set time_zone=timezone_offset or timezone_name command with the init_connect flag.

 Yes
default_week_format integer
0 ... 7
default: 0		 No
delay_key_write enumeration
OFF, ON (default), or ALL		 No
disconnect_on_expired_password boolean on | off
default: on
Yes
div_precision_increment integer
0 ... 30
default: 4		 No
end_markers_in_json boolean
on | off
default: off 		No
eq_range_index_dive_limit integer
0 ... 2147483647		 No
event_scheduler boolean
on | off

If you are using the Event Scheduler, configure your instance with an activation policy of ALWAYS to ensure that scheduled events run.

See the Tips section for more information about this flag.

 No
expire_logs_days integer
0 ... 99
Default is 0, which means no automatic removal.

See the Tips section for more information about this flag.

 No
explicit_defaults_for_timestamp boolean
on | off		 Yes
flush_time integer
0 ... 31536000
default: 0		 No
ft_max_word_len integer
10 ... 252		 Yes
ft_min_word_len integer
1 ... 16		 Yes
ft_query_expansion_limit integer
0 ... 1000		 Yes
general_log boolean
on | off

See the Tips section for more information about general logs.

 No
generated_random_password_length integer 5-255
default: 20
No
group_concat_max_len integer
4 ... 17179869184		 No
gtid_executed_compression_period integer
0 ... 4294967295
default (up to version 8.0.22): 1000
default (version 8.0.23+): 0 		No
histogram_generation_max_mem_size integer
1000000 ... 4294967295
default: 20000000 		No
init_connect string No
innodb_adaptive_hash_index boolean
on | off		 No
innodb_adaptive_hash_index_parts integer
1 ... 512		 Yes
innodb_adaptive_max_sleep_delay integer
0 ... 1000000		 No
innodb_autoextend_increment integer
1 ... 1000		 No
innodb_autoinc_lock_mode integer
0 ... 2		 Yes
innodb_buffer_pool_chunk_size integer
1048576 ... (innodb_buffer_pool_size/innodb_buffer_pool_instances)

This flag value is dependent on innodb_buffer_pool_size and innodb_buffer_pool_instances. MySQL can auto-tune the value of innodb_buffer_pool_chunk_size based on these two flags.

Yes
innodb_buffer_pool_dump_pct integer
1 ... 100
Default: 25		 No
innodb_buffer_pool_dump_at_shutdown boolean
on | off		 No
innodb_buffer_pool_instances integer
1 ... 64		 Yes
innodb_buffer_pool_load_at_startup boolean
on | off		 Yes
innodb_buffer_pool_size integer

Setting this flag for MySQL 5.6 requires a restart. See the Tips section for more information about this flag.

No
innodb_change_buffer_max_size integer
0 ... 50		 No
innodb_change_buffering string

Options: none, inserts, deletes, changes, purges, all.

 No
innodb_checksum_algorithm string

Options: crc32, strict_crc32, innodb, strict_innod, none, strict_none.

No
innodb_cmp_per_index_enabled boolean
on | off		 No
innodb_commit_concurrency integer
0 ... 1000		 Yes
innodb_compression_failure_threshold_pct integer
0 ... 100		 No
innodb_compression_level integer
0 ... 9		 No
innodb_compression_pad_pct_max integer
0 ... 75		 No
innodb_concurrency_tickets integer
1 ... 4294967295		 No
innodb_deadlock_detect boolean
on | off

Supported in MySQL 5.7 and 8.0.

Default: on

 No
innodb_disable_sort_file_cache boolean
on | off		 No
innodb_doublewrite_batch_size integer
0 ... 256
Default: 0		 Yes
innodb_doublewrite_files integer
2 ... 128		 Yes
innodb_doublewrite_pages integer
4 ... 512
Default: 64		 Yes
innodb_file_per_table boolean
on | off

See the Tips section for more information about this flag.

 No
innodb_fill_factor integer
10 ... 100		 No
innodb_flush_log_at_trx_commit integer
1, 2
Default: 1.

See the Tips section for more information about this flag.

 No
innodb_flush_neighbors enumeration
0 ... 2

Supported in MySQL 5.6, 5.7, and 8.0.

Default values:

  • MySQL 5.6: 1
  • MySQL 5.7: 1
  • MySQL 8.0: 0

    		•  No
    innodb_flush_sync boolean
    on | off    		 No
    innodb_ft_cache_size integer
    1600000 ... 80000000    		 Yes
    innodb_ft_enable_diag_print boolean
    on | off    		 No
    innodb_ft_enable_stopword boolean
    on | off    		 No
    innodb_ft_max_token_size integer
    10 ... 252

    Supported only in MySQL 5.6 and later versions.

    		 Yes
    innodb_ft_min_token_size integer
    0 ... 16

    Supported only in MySQL 5.6 and later versions.

    		 Yes
    innodb_ft_num_word_optimize integer
    1000 ... 10000    		 No
    innodb_ft_result_cache_limit integer
    1000000 ... 4294967295    		 No
    innodb_ft_server_stopword_table string

    Supported only in MySQL 5.6 and later versions.

    		 No
    innodb_ft_sort_pll_degree integer
    1 ... 32    		 Yes
    innodb_ft_total_cache_size integer
    32000000 ... 1600000000    		 Yes
    innodb_ft_user_stopword_table string No
    innodb_io_capacity integer
    100 ... 100000
    Default: 5000

    Supported in MySQL 5.6, 5.7, and 8.0.

    To learn more about configuring the disk performance, see the E2 VMs table in Configure disks to meet performance requirements.

    		No
    innodb_io_capacity_max integer
    100 ... 100000
    Default: 10000

    Supported in MySQL 5.6, 5.7, and 8.0.

    To learn more about configuring the disk performance, see the E2 VMs table in Configure disks to meet performance requirements.

    		 No
    innodb_large_prefix boolean
    on | off

    Supported only in MySQL 5.6.

    		 No
    innodb_lock_wait_timeout integer
    1 ... 1073741824    		 No
    innodb_log_buffer_size integer
    262144 ... 4294967295    		 Yes
    innodb_log_checksums boolean
    on | off
    default: on    		 No
    innodb_log_compressed_pages boolean
    on | off
    default: on    		 No
    innodb_log_file_size integer
    MySQL 5.6: 1048576 ... 274877906944
    MySQL 5.7: 4194304 ... 274877906944     		Yes
    innodb_log_spin_cpu_abs_lwm integer
    0 ... 4294967295
    default: 80    		 No
    innodb_log_spin_cpu_pct_hwm integer
    0 ... 100
    default: 50    		 No
    innodb_log_wait_for_flush_spin_hwm integer
    0 ... 4294967295
    default: 400    		 No
    innodb_log_write_ahead_size integer
    512 ... 65536
    default: 8192    		 No
    innodb_lru_scan_depth integer
    100 ... 9223372036854775807    		 No
    innodb_max_dirty_pages_pct float
    0 ... 99.99
    default: 90    		 No
    innodb_max_dirty_pages_pct_lwm float
    0 ... 99.99
    default: 10    		 No
    innodb_max_purge_lag integer
    0 ... 4294967295
    default: 0    		 No
    innodb_max_undo_log_size integer
    10485760 ... 9223372036854775807
    default: 1073741824    		 No
    innodb_max_purge_lag_delay integer
    0 ... 10000000
    default: 0    		 No
    innodb_monitor_disable string No
    innodb_monitor_enable string No
    innodb_monitor_reset string
    counter, module, pattern, all    		 No
    innodb_monitor_reset_all enumeration
    Valid values: counter, module, pattern, all    		 No
    innodb_old_blocks_pct integer
    5 ... 95    		 No
    innodb_old_blocks_time integer
    0 ... 4294967295    		 No
    innodb_online_alter_log_max_size integer
    65536 ... 9223372036854775807    		 No
    innodb_open_files integer
    100 ... 2147483647
    default:
    MySQL 5.7: 2000
    MySQL 8.0: 4000     		≥ 8.0.28: No
    ≤ 8.0.27: Yes
    innodb_optimize_fulltext_only boolean
    on | off    		 No
    innodb_page_cleaners integer
    1 ... 64
    Supported in MySQL 5.7 and 8.0. Default: 4. For version 5.7, the default is 32.    		 Yes
    innodb_parallel_read_threads integer
    1 ... 256
    default: 4    		 No
    innodb_print_all_deadlocks boolean
    on | off
    default: off    		 No
    innodb_print_ddl_logs boolean
    on | off    		 No
    innodb_purge_batch_size integer
    1 ... 5000
    default: 300    		 No
    innodb_purge_rseg_truncate_frequency integer
    1 ... 128
    default: 128    		 No
    innodb_purge_threads 1 ... 32

    Supported in MySQL 5.6, 5.7, 8.0

    Default is 1.

    		 Yes
    innodb_random_read_ahead boolean
    on | off    		 No
    innodb_read_ahead_threshold integer
    0 ... 64    		 No
    innodb_read_io_threads integer
    1 ... 64     		Yes
    innodb_replication_delay integer
    0 ... 4294967295    		 No
    innodb_rollback_on_timeout boolean
    on | off    		 Yes
    innodb_rollback_segments integer
    1 ... 128    		 No
    innodb_segment_reserve_factor float
    .03 ... 40
    default: 12.5    		 No
    innodb_sort_buffer_size integer
    65536 ... 67108864    		 Yes
    innodb_spin_wait_delay integer
    MySQL 5.7: 0 ... 1000000
    MySQL 8.0.13+: 0 ... 1000
    default: 6    		 No
    innodb_stats_auto_recalc boolean
    on | off    		 No
    innodb_stats_include_delete_marked boolean
    on | off
    default: off    		 No
    innodb_stats_method enumeration
    nulls_equal | nulls_unequal | nulls_ignored    		 No
    innodb_stats_on_metadata boolean
    on | off    		 No
    innodb_stats_persistent boolean
    on | off    		 No
    innodb_stats_persistent_sample_pages integer
    1 ... 9223372036854775807    		 No
    innodb_stats_sample_pages integer
    1 ... 9223372036854775807    		 No
    innodb_stats_transient_sample_pages integer
    1 ... 9223372036854775807    		 No
    innodb_status_output boolean
    on | off    		 No
    innodb_status_output_locks boolean
    on | off    		 No
    innodb_strict_mode boolean
    on | off    		 No
    innodb_sync_array_size 1 ... 1024

    Supported in MySQL 5.6, 5.7, 8.0

    Default is 1.

    		 Yes
    innodb_sync_spin_loops integer
    0 ... 4294967295
    default: 30    		 No
    innodb_table_locks boolean
    on | off
    default: on    		 No
    innodb_thread_concurrency integer
    0 ... 1000    		 No
    innodb_thread_sleep_delay integer
    0 ... 1000000    		 No
    innodb_undo_log_truncate boolean
    on | off
    default: on    		 No
    innodb_use_native_aio boolean
    on | off
    default: on    		 Yes
    innodb_write_io_threads integer
    1 ... 64    		 Yes
    interactive_timeout integer
    1 ... 31536000    		 No
    internal_tmp_disk_storage_engine enumeration
    INNODB | MYISAM
    Default: INNODB
    This flag is used for MySQL 5.7 only.    		 No
    internal_tmp_mem_storage_engine enumeration
    MEMORY, TempTable
    This flag is used for MySQL 8.0 only.    		 No
    join_buffer_size integer
    128 ... 9223372036854775807    		 No
    key_buffer_size integer
    0 ... 4294967295
    default: 8388608    		 No
    key_cache_age_threshold integer
    100 ... 9223372036854775807
    default: 300    		 No
    key_cache_block_size integer
    512 ... 16384
    default: 1024    		 No
    key_cache_division_limit integer
    1 ... 100
    default: 100    		 No
    local_infile boolean
    on | off    		 No
    lock_wait_timeout integer
    1 ... 31536000    		 No
    log_bin_trust_function_creators boolean
    on | off    		 No
    log_output set
    FILE | TABLE | NONE    		 No
    log_error_verbosity integer
    1 ... 3
    default:
    MySQL 5.7: 3
    MySQL 8.0: 2    		 No
    log_queries_not_using_indexes boolean
    on | off    		 No
    log_slow_admin_statements boolean
    on | off
    default: off    		 No
    log_slow_extra boolean
    on | off
    default: off    		 No
    log_throttle_queries_not_using_indexes integer
    0 ... 9223372036854775807    		 No
    log_timestamps string
    "UTC | SYSTEM"
    default: UTC    		 No
    long_query_time float
    0 ... 30000000

    Cloud SQL provides the ability to set this flag to less than 1 if needed.

    If the log_queries_not_using_indexes flag is also enabled, you may see queries with less than the time specified here.

    		 No
    lower_case_table_names 5.7 | 8.0 integer
    0 or 1
    Default: 0

    If you use the default value of 0 for this flag, table and database names are case sensitive. When set to 1, table and database names are case insensitive.

    For MySQL 5.7 instances, you can change the value of this flag at any time. If you do, make sure that you understand how the change affects your existing tables and databases.

    For MySQL 8.0 instances, you can set the value of this flag to a desired value only while an instance is being created. After you set this value, you can't change it. Also, for an existing instance, you can't change the value of this flag.

    When creating read replicas for MySQL 5.7 or MySQL 8.0 instances, the replica inherits this flag value from the primary.

    		Yes
    mandatory_roles string role name
    default: empty string
    		No
    max_allowed_packet integer
    16384 ... 1073741824

    This value must be a multiple of 1024, if sql_mode=TRADITIONAL or sql_mode=STRICT_ALL_TABLES.

    		 No
    max_binlog_cache_size integer
    4096 ... 4294967296
    default: 4294967296    		 No
    max_binlog_size integer
    4096 ... 1073741824    		 No
    max_binlog_stmt_cache_size integer
    4096 ... 4294967296
    default: 4294967296    		 No
    max_connect_errors integer
    1 ... 9223372036854775807
    default: 100    		 No
    max_connections integer
    1 ... 100000     		No
    max_digest_length integer
    0 ... 1048576    		 Yes
    max_error_count integer
    0 ... 65535
    default:
    MySQL 5.7 or lower: 64
    MySQL 8.0+: 1024    		 No
    max_execution_time integer
    0 ... 9223372036854775807    		 No
    max_heap_table_size integer
    16384 ... 67108864

    See the Tips section for more information about this flag.

    		 No
    max_join_size integer
    16 ... 9223372036854775807    		 No
    max_length_for_sort_data integer
    4 ... 8388608    		 No
    max_points_in_geometry integer
    3 ... 1048576    		 No
    max_prepared_stmt_count integer
    0 ... 1048576    		 No
    max_seeks_for_key integer
    1 ... 9223372036854775807    		 No
    max_sort_length integer
    4 ... 8388608    		 No
    max_sp_recursion_depth integer
    0 ... 255    		 No
    max_user_connections integer
    0 ... 4294967295    		 No
    max_write_lock_count integer
    1 ... 9223372036854775807    		 No
    min_examined_row_limit integer
    0 ... 4294967295
    default: 0    		 No
    net_buffer_length integer
    1024 ... 1048576
    default: 16384     		No
    net_read_timeout integer
    30 ... 4294967295    		 No
    net_retry_count integer
    10 ... 4294967295    		 No
    net_write_timeout integer
    60 ... 4294967295    		 No
    ngram_token_size integer
    1 ... 10
    default: 2     		Yes
    optimizer_prune_level integer
    0 ... 1    		 No
    optimizer_search_depth integer
    0 ... 62    		 No
    optimizer_trace_max_mem_size integer
    0 ... 9223372036854775807    		 No
    optimizer_trace_offset integer
    -9223372036854775808 ... 9223372036854775807    		 No
    parser_max_mem_size integer
    10000000 ... 9223372036854775807    		 No
    password_history integer 0-4294967295
    default: 0
    		No
    password_require_current boolean on | off
    default: off
    		No
    password_reuse_interval integer 0-4294967295
    default: 0
    		No
    performance_schema boolean
    on | off

    default: off, for MySQL 5.6, 5.7, 8.0 (< 8.0.26)

    default: on, for MySQL >= 8.0.26 and instance RAM greater than 15,360 Mib

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_accounts_size integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_digests_size integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_error_size integer
    0 ... 1048576    		 Yes
    performance_schema_events_stages_history_long_size integer
    -1 ... 1048576    		 Yes
    performance_schema_events_stages_history_size integer
    -1 ... 1024

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_events_statements_history_long_size integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_events_statements_history_size integer
    -1 ... 1024

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_events_transactions_history_long_size integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_events_transactions_history_size integer
    -1 ... 1024

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_events_waits_history_long_size integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_events_waits_history_size integer
    -1 ... 1024

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_hosts_size integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_cond_classes integer
    0 ... 256

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_cond_instances integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_digest_length integer
    0 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_digest_sample_age integer
    0 ... 1048576
    default: 60     		No
    performance_schema_max_file_classes integer
    0 ... 256

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_file_handles integer
    0 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_file_instances integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_index_stat integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_memory_classes integer
    0 ... 1024

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_metadata_locks integer
    -1 ... 104857600

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_mutex_classes integer
    0 ... 256

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_mutex_instances integer
    -1 ... 104857600

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_prepared_statements_instances integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_program_instances integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_rwlock_classes integer
    0 ... 256

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_rwlock_instances integer
    -1 ... 104857600

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_socket_classes integer
    0 ... 256

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_socket_instances integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_sql_text_length integer
    0 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_stage_classes integer
    0 ... 256

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_statement_classes integer
    0 ... 256

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_statement_stack integer
    1 ... 256

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_table_handles integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_table_instances integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_table_lock_stat integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_thread_classes integer
    0 ... 256

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_max_thread_instances integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_session_connect_attrs_size integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_setup_actors_size integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_setup_objects_size integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    performance_schema_users_size integer
    -1 ... 1048576

    See Tips section for more information about performance_schema flags.

    		 Yes
    preload_buffer_size integer
    1024 ... 1073741824
    default: 32768     		No
    query_alloc_block_size integer
    1024 ... 4294967295    		 No
    query_cache_limit integer
    0 ... 223338299392

    This flag is not available for MySQL 8.0 as the query cache is deprecated as of MySQL 5.7.20, and is removed in MySQL 8.0.

    		 No
    query_cache_min_res_unit integer
    0 ... 9223372036854775807

    This flag is not available for MySQL 8.0 as the query cache is deprecated as of MySQL 5.7.20, and is removed in MySQL 8.0.

    		 No
    query_cache_size integer
    0 ... 223338299392

    This flag is not available for MySQL 8.0 as the query cache is deprecated as of MySQL 5.7.20, and is removed in MySQL 8.0.

    		 No
    query_cache_type enumeration
    0 ... 2

    This flag is not available for MySQL 8.0 as the query cache is deprecated as of MySQL 5.7.20, and is removed in MySQL 8.0.

    		 Yes
    query_cache_wlock_invalidate boolean
    on | off

    This flag is not available for MySQL 8.0 as the query cache is deprecated as of MySQL 5.7.20, and is removed in MySQL 8.0.

    		 No
    query_prealloc_size integer
    8192 ... 9223372036854775807    		 No
    range_alloc_block_size integer
    4096 ... 4294967295    		 No
    range_optimizer_max_mem_size integer
    0 ... 9223372036854775807    		 No
    read_buffer_size integer
    8192 ... 2147483647    		 No
    read_only boolean
    on | off

    Has no effect for replicas.

    		 No
    read_rnd_buffer_size integer
    1 ... 2147483647    		 No
    regexp_stack_limit integer
    0 ... 2147483647    		 No
    regexp_time_limit integer
    0 ... 2147483647
    default: 32     		No
    rpl_read_size integer
    8192 ... 4294959104
    default: 8192     		No
    schema_definition_cache integer
    256 ... 524288
    default: 256     		No
    session_track_gtids string
    OFF | OWN_GTID | ALL_GTIDS
    default: OFF     		No
    session_track_schema boolean
    on | off
    default: on     		No
    session_track_state_change boolean
    on | off
    default: off     		No
    session_track_transaction_info string
    OFF | STATE | CHARACTERISTICS
    default: OFF     		No
    show_create_table_verbosity boolean
    on | off
    default: off     		No
    show_compatibility_56 boolean
    on | off

    Supported only in MySQL 5.7.

    		 No
    skip_show_database flag
    on | off    		 Yes
    slave_checkpoint_group integer
    32 ... 524280
    Default is 512.

    This flag doesn't affect replicas that don't have multithreading enabled.

    		 No
    slave_checkpoint_period integer
    1 ... 4294967295
    Default is 300.

    The unit is milliseconds.

    		 No
    slave_compressed_protocol boolean
    on | off     		No
    slave_net_timeout integer
    1 ... 31536000

    The unit is seconds.

    		 No
    slave_parallel_type enumeration

    For information about how to use this flag and its acceptable values, see Configuring parallel replication.

    		 No
    slave_parallel_workers integer

    For information about how to use this flag and its acceptable values, see Configuring parallel replication.

    		 No
    slave_preserve_commit_order boolean

    For information about how to use this flag and its acceptable values, see Configuring parallel replication.

    		 No
    slave_pending_jobs_size_max integer

    For information about how to use this flag and its acceptable values, see Configuring parallel replication.

    		 No
    slave_sql_verify_checksum boolean
    on | off     		No
    slave_transaction_retries integer
    0 ... 9223372036854775807
    		 No
    slow_launch_time Integer
    0 ... 31536000
    Default: 2    		 No
    slow_query_log boolean
    on | off

    See the Tips section for more information on slow query logs.

    		 No
    sort_buffer_size integer
    32768 ... 9223372036854775807    		 No
    sql_mode string

    See the Server SQL Modes in the MySQL documentation for allowed values, including combined modes, such as ANSI. NO_DIR_IN_CREATE is not supported.

    Cloud SQL for MySQL doesn't support empty values for the sql_mode flag. Instead of using an empty value, set this flag to the NO_ENGINE_SUBSTITUTION mode.

    		 No
    sql_require_primary_key boolean
    on | off
    Default: off    		 No
    stored_program_cache integer
    16 ... 524288    		 No
    stored_program_definition_cache integer
    256 ... 524288
    Default: 256    		 No
    sync_binlog integer
    0 ... 4294967295

    Supported only on read replicas and external server replicas in MySQL 5.7 and 8.0.

    The default setting of 1 enables the synchronization of the binary log to disk before transactions are committed.

    This flag is not supported on primary instances or legacy HA failover replicas. If a replica using this flag is promoted, the flag is removed.

    		 No
    sync_master_info integer
    0 ... 4294967295
    Default: 10000    		 No
    sync_relay_log integer
    0 ... 4294967295
    Default: 10000    		 No
    sync_relay_log_info integer
    0 ... 4294967295
    Default: 10000    		 No
    table_definition_cache integer
    400 ... 524288    		 No
    tablespace_definition_cache integer
    256 ... 524288
    Default: 256    		 No
    table_open_cache integer
    1 ... 524288    		 No
    table_open_cache_instances integer
    1 ... 64    		 Yes
    temptable_max_mmap integer
    0 ... 68719476736
    Default: 1073741824    		 No
    temptable_max_ram integer
    2097152 ... 68719476736
    Default: 1073741824    		 No
    thread_cache_size integer
    0 ... 16384    		 No
    thread_stack integer
    131072 ... 9223372036854775807    		 Yes
    tls_version String

    Version 5.7 to Version 8.0.27: TLSv1, TLSv1.1
    Version 8.0.28 or later: TLSv1.2
    		 Version 5.7: Yes

    Version 8.0 or later: No
    tmp_table_size integer
    1024 ... 67108864

    See the Tips section for more information about this flag.

    		 No
    transaction_alloc_block_size integer
    1024 ... 131072    		 No
    transaction_isolation enumeration
    READ-UNCOMMITTED | READ-COMMITTED | REPEATABLE-READ | SERIALIZABLE    		 Yes
    transaction_prealloc_size integer
    1024 ... 131072    		 No
    transaction_write_set_extraction enumeration

    For information about how to use this flag and its acceptable values, see Configuring parallel replication.

    		 No
    updatable_views_with_limit integer
    0 ... 1    		 No
    wait_timeout integer
    1 ... 31536000    		 No
    windowing_use_high_precision boolean
    on | off
    Default: on     		No

    Timezone names

    In this section, you'll learn about the time-zone names that Cloud SQL for MySQL supports.

    The table in this section displays the following:

    • Timezone name: The name that Cloud SQL for MySQL supports.
    • STD: The time-zone offset in standard time (STD).
    • DST: The time-zone offset in daylight savings time (DST).
    • Synonym names: The names for time zones that you may want to use, but they aren't supported by Cloud SQL for MySQL. If this situation occurs, then use the corresponding time-zone name.
    time-zone name STD DST Synonym names
    Africa/Cairo +02:00 +02:00 Egypt
    Africa/Casablanca +01:00 +00:00
    Africa/Harare +02:00 +02:00 Africa/Maputo
    Africa/Monrovia +00:00 +00:00
    Africa/Nairobi +03:00 +03:00 Africa/Addis_Ababa
    Africa/Asmera
    Africa/Dar_es_Salaam
    Africa/Djibouti
    Africa/Kampala
    Africa/Mogadishu
    Indian/Antananarivo
    Indian/Comoro
    Indian/Mayotte
    Africa/Tripoli +02:00 +02:00 Libya
    Africa/Windhoek +02:00 +02:00
    America/Araguaina −03:00 −03:00
    America/Asuncion −04:00 −03:00
    America/Bogota −05:00 −05:00
    America/Buenos_Aires −03:00 −03:00 America/Argentina/Buenos_Aires
    America/Caracas −04:00 −04:00
    America/Chicago −06:00 −05:00
    America/Chihuahua −07:00 −06:00 America/Ojinaga
    America/Cuiaba −04:00 −04:00
    America/Denver −07:00 −06:00 America/Shiprock
    Navajo
    MST7MDT
    US/Mountain
    America/Detroit −05:00 −04:00
    America/Fortaleza −03:00 −03:00
    America/Guatemala −06:00 −06:00
    America/Halifax −04:00 −03:00 Canada/Atlantic
    America/Los_Angeles −08:00 −07:00
    America/Manaus −04:00 −04:00 Brazil/West
    America/Matamoros −06:00 −05:00
    America/Mexico_City −06:00 −05:00
    America/Monterrey −06:00 −05:00
    America/Montevideo −03:00 −03:00
    America/New_York −05:00 −04:00
    America/Phoenix −07:00 −07:00 US/Arizona
    MST
    America/Creston
    America/Santiago −04:00 −03:00 Chile/Continental
    America/Sao_Paolo −03:00 −03:00
    America/Tijuana −08:00 −07:00 Mexico/BajaNorte
    America/Ensenada
    America/Santa_Isabel
    Asia/Amman +02:00 +03:00
    Asia/Ashgabat +05:00 +05:00 Asia/Ashkhabad
    Asia/Baghdad +03:00 +03:00
    Asia/Baku +04:00 +04:00
    Asia/Bangkok +07:00 +07:00 Asia/Phnom_Penh
    Asia/Vientiane
    Asia/Beirut +02:00 +03:00
    Asia/Calcutta +05:30 +05:30 Asia/Kolkata
    Asia/Damascus +02:00 +03:00
    Asia/Dhaka +06:00 +06:00 Asia/Dacca
    Asia/Irkutsk +08:00 +08:00
    Asia/Jerusalem +02:00 +03:00 Asia/Tel_Aviv
    Israel
    Asia/Kabul +04:30 +04:30
    Asia/Karachi +05:00 +05:00
    Asia/Kathmandu +05:45 +05:45 Asia/Katmandu
    Asia/Kolkata +05:30 +05:30
    Asia/Krasnoyarsk +07:00 +07:00
    Asia/Magadan +11:00 +11:00
    Asia/Muscat +04:00 +04:00 Asia/Dubai
    Asia/Novosibirsk +07:00 +07:00
    Asia/Riyadh +03:00 +03:00 Asia/Kuwait
    Antarctica/Syowa
    Asia/Aden
    Asia/Seoul +09:00 +09:00 ROK
    Asia/Shanghai +08:00 +08:00 Asia/Chongqing
    Asia/Chungking
    Asia/Harbin
    PRC
    Asia/Singapore +08:00 +08:00 Singapore
    Asia/Taipei +08:00 +08:00 ROC
    Asia/Tehran +03:30 +04:30 Iran
    Asia/Tokyo +09:00 +09:00 Japan
    Asia/Ulaanbaatar +08:00 +08:00 Asia/Ulan_Bator
    Asia/Vladivostok +10:00 +10:00
    Asia/Yakutsk +09:00 +09:00
    Asia/Yerevan +04:00 +04:00
    Atlantic/Azores −01:00 +00:00
    Australia/Adelaide +09:30 +10:30 Australia/South
    Australia/Brisbane +10:00 +10:00 Australia/Queensland
    Australia/Darwin +09:30 +09:30 Australia/North
    Australia/Hobart +10:00 +11:00 Australia/Currie
    Australia/Tasmania
    Australia/Perth +08:00 +08:00 Australia/West
    Australia/Sydney +10:00 +11:00 Australia/NSW
    Australia/ACT
    Australia/Canberra
    Brazil/East −03:00 −03:00 America/Sao_Paulo
    Canada/Newfoundland −03:30 −02:30 America/St_Johns
    Canada/Saskatchewan −06:00 −06:00 America/Regina
    Canada/Yukon −07:00 −07:00 America/Whitehorse
    Europe/Amsterdam +01:00 +02:00
    Europe/Athens +02:00 +03:00
    Europe/Dublin +01:00 +00:00 Eire
    Europe/Helsinki +02:00 +03:00 Europe/Mariehamn
    Europe/Istanbul +03:00 +03:00 Turkey
    Asia/Istanbul
    Europe/Kaliningrad +02:00 +02:00
    Europe/Madrid +01:00 +02:00
    Europe/Moscow +03:00 +03:00 W-SU
    Europe/Paris +01:00 +02:00 MET
    CET
    Europe/Prague +01:00 +02:00 Europe/Bratislava
    Europe/Sarajevo +01:00 +02:00 Europe/Belgrade
    Europe/Ljubljana
    Europe/Podgorica
    Europe/Skopje
    Europe/Zagreb
    Pacific/Auckland +12:00 +13:00 NZ
    Antarctica/McMurdo
    Antarctica/South_Pole
    Pacific/Fiji +12:00 +13:00
    Pacific/Guam +10:00 +10:00 Pacific/Saipan
    Pacific/Honolulu −10:00 −10:00 US/Hawaii
    Pacific/Johnston
    HST
    Pacific/Samoa −11:00 −11:00 Pacific/Pago_Pago
    US/Samoa
    US/Alaska −09:00 −08:00 America/Anchorage
    America/Juneau
    America/Metlakatla
    America/Nome
    America/Sitka
    America/Yakutat
    US/Central −06:00 −05:00 America/Chicago
    US/Eastern −05:00 −04:00 America/New_York
    US/East-Indiana −05:00 −04:00 America/Indiana/Indianapolis
    America/Indianapolis
    America/Fort_Wayne
    US/Mountain −07:00 −06:00 America/Denver
    US/Pacific −08:00 −07:00 America/Los_Angeles
    UTC +00:00 +00:00 Etc/UTC
    Etc/UCT
    Etc/Universal
    Etc/Zulu

    Timezone tables in Cloud SQL might need refreshing with the latest data. For example, a country might shift from a DST timezone offset to an STD offset or a country might introduce a new timezone.

    For every critical service agent (CSA) release for Cloud SQL, timezone tables are refreshed with the latest data. When this happens, during the non-maintenance window, the replica instances are refreshed. Primary instances are then refreshed during the maintenance window.

    You can either wait until the regular maintenance window for the CSA release or you can perform self service maintenance to refresh the timezone tables with the latest data. For more information about viewing the available maintenance versions, see Determine the target maintenance version.

    Tips for working with flags

    general_log, slow_query_log

    To make your general or slow query logs available, enable the corresponding flag and set the log_output flag to FILE. This makes the log output available using the Logs Viewer in the Google Cloud console. Note that Google Cloud's operations suite logging charges apply. To minimize instance storage cost, general and slow query logs on the instance disk are rotated when the log file is older than 24 hours (and no changes have been made within that duration) or greater than 100MB in size. Old log files are automatically deleted after the rotation.

    If the log_output is set to NONE, you can't access the logs. If you set log_output to TABLE, the log output is placed in a table in the mysql system database. It might consume a considerable amount of disk space. If this table becomes large, it can affect instance restart time or cause the instance to lose its SLA coverage. For this reason, the TABLE option is not recommended. In addition, the log content isn't available in Logs Explorer and it isn't rotated. If needed, you can truncate your log tables by using the API. For more information, see the instances.truncateLog reference page.

    expire_logs_days, binlog_expire_logs_seconds
    If you enable point-in-time recovery, the expiration period of your binary logs is determined by the lesser of your transaction log retention period and the values of these flags. You can use these flags to manage how long binary logs are stored on your replicas. For more information, see the transaction log retention page.
    innodb_buffer_pool_size

    The value of the innodb_buffer_pool_size is the size in bytes of the buffer pool. You cannot enable this flag on instances that have fewer than 3,840 MiB of RAM.

    This flag is not configurable for shared-core machine types (f1_micro and g1_small). Changing this flag on MySQL 5.6 requires a restart.

    In Cloud SQL, the default, minimum allowable, and maximum allowable values of the innodb_buffer_pool_size flag depend on the instance's memory. These values can be roughly calculated as a percentage of the instance's RAM. By default, the value of this flag is typically set close to the maximum allowable value. The maximum allowable allocation percentage increases with instance size. The minimum allowable value is usually about 20% of the instance's RAM.

    Approximate values for this flag:

    Instance RAM RangeMin %Default %Max %
    0 - 4.0GB of RAM~34%
    4.0GB - 7.5GB~20%~34%~34%
    7.5GB - 12GB~20%~52%~52%
    12GB - 24GB~20%~67%~67%
    24GB and above~20%~72%~72%

    Your exact values may vary. To calculate the current value for your instance, you can run the query:

      show global variables like 'innodb_buffer_pool_size'

    For reference, the minimum allowable, default, and maximum allowable values are provided for the machine types below.

    Machine type Instance RAM (GB) Min (GB)
    (% of total)    		 Default (GB)
    (% of total)    		 Max (GB)
    (% of total)
    db-f1-micro 0.6 - 0.053 -
    db-g1-small 1.7 - 0.625 -
    db-custom-1-3840 3.75 0.875
    (23%)    		 1.375
    (37%)    		 1.375
    (37%)
    db-custom-2-7680 7.5 1.5
    (20%)    		 4
    (53%)    		 4
    (53%)
    db-custom-4-15360 15 3
    (20%)    		 10.5
    (70%)    		 10.5
    (70%)
    db-custom-8-30720 30 6
    (20%)    		 22
    (73%)    		 22
    (73%)
    db-custom-16-61440 60 12
    (20%)    		 44
    (73%)    		 44
    (73%)
    db-custom-32-122880 120 24
    (20%)    		 87
    (73%)    		 87
    (73%)
    db-custom-64-245760 240 48
    (20%)    		 173
    (72%)    		 173
    (72%)
    db-custom-96-368640 360 72
    (20%)    		 260
    (72%)    		 260
    (72%)
    db-custom-2-13312 13 3
    (23%)    		 9
    (69%)    		 9
    (69%)
    db-custom-4-26624 26 6
    (23%)    		 19
    (73%)    		 19
    (73%)
    db-custom-8-53248 52 11
    (21%)    		 38
    (73%)    		 38
    (73%)
    db-custom-16-106496 104 21
    (20%)    		 75
    (72%)    		 75
    (72%)
    db-custom-32-212992 208 42
    (20%)    		 150
    (72%)    		 150
    (72%)
    db-custom-64-425984 416 84
    (20%)    		 300
    (72%)    		 300
    (72%)
    db-custom-96-638976 624 125
    (20%)    		 450
    (72%)    		 450
    (72%)

    innodb_file_per_table

    For all MySQL versions 5.6 and higher, the default value is ON.

    innodb_flush_log_at_trx_commit
    If you need higher performance, we recommend setting the value to 2. Cloud SQL does not support setting the value for this flag to 0. If you set the flag value to 2, you must either disable the binary log on the replica, or set sync_binlog to a value other than 1.

    You can only enable this flag for read replicas and external server replicas. For external server replicas, this flag must be set to the default value of 1 for full ACID compliance. You cannot enable this flag on primary instances or failover replicas.

    max_heap_table_size, tmp_table_size

    Exhausting the available instance memory can occur when you set tmp_table_size and max_heap_table_size too high for the number of concurrent queries the instance processes. Exhausting the memory results in an instance crash and restart.

    For more information about working with these flags, see How MySQL Uses Internal Temporary Tables and The MEMORY Storage Engine.

    performance_schema

    You can't enable this flag on instances that have less than 15,360 MiB of RAM. If you enable this flag, you can't change your machine type to a size that does not support the flag; you must first disable this flag.

    event_scheduler
    MySQL Events, also known as scheduled events, are tasks that you can schedule. Scheduled events are a group of one or more SQL statements that are set to execute at one or more specified intervals. The default value for MySQL 5.7 is OFF and the default value for MySQL 8.0 is ON. To learn more about the event_scheduler flag, see event_scheduler.

    If the event_scheduler flag is set to ON for a read replica, it can cause errors based on the type of statements defined in the events:

    • If your scheduled event is a write event on a read replica, it causes an error as read replicas are read only. See Read Replicas for more information.
    • If your scheduled event contains a stop operation, such as kill, event_scheduler applies it to the replica. This stops the replication and delete the replica.
    To avoid such errors, set the event_scheduler flag to OFF when creating replicas.

    For more information on how to enable or disable event_scheduler, see Configure database flags.

    System flags changed in Cloud SQL

    All other database system flags that are not listed in the supported flags section are called managed flags. For certain managed flags, Cloud SQL sets the flag to a value other than the default setting to ensure Cloud SQL instances run reliably. You can't change the values on these system flags.

    Managed flags with a non-default setting are listed below.

    Variable Name Setting in Cloud SQL. Notes
    binlog_format ROW Differs in MySQL 5.6 only
    binlog_error_action ABORT_SERVER Differs in MySQL 5.6 only
    innodb_doublewrite_pages 64 Applies to MySQL 8.0.26 and above
    innodb_file_format Barracuda Differs in MySQL 5.6 only
    innodb_flush_method O_DIRECT
    innodb_flush_neighbors 0 (in MySQL 5.6) and 2 (in MySQL 5.7 and 8.0)
    innodb_io_capacity 5000
    innodb_buffer_pool_instances
    Size of Instance
    (first match)     		innodb_buffer_pool_instances
    < 1024 1
    < 2048 1
    < 7680 1
    < 13312 2
    < 26624 4
    default 8
    memlock true
    skip_name_resolve ON
    relay_log_info_repository TABLE
    relay_log_recovery ON
    slave_net_timeout 30
    master_info_repository TABLE
    rpl_semi_sync_master_enabled 1
    rpl_semi_sync_master_timeout 3000
    innodb_page_cleaners 8 Differs in MySQL 5.7, 8.0 only
    admin_address 127.0.0.1 Differs in MySQL 8.0 only
    create_admin_listener_thread ON
    port-open-timeout 120 Differs in MySQL 8.0 only
    innodb_io_capacity_max 10000

    Troubleshooting

    Issue Troubleshooting
    After enabling a flag the instance loops between panicking and crashing. Contact customer support to request flag removal followed by a hard drain. This forces the instance t restart on a different host with a fresh configuration without the undesired flag or setting.
    You see the error message Bad syntax for dict arg when trying to set a flag. Complex parameter values, such as comma-separated lists, require special treatment when used with gcloud commands.

    What's next