> ## Documentation Index > Fetch the complete documentation index at: https://kb.hosting.com/llms.txt > Use this file to discover all available pages before exploring further. # Drupal performance and MySQL transaction isolation levels > This article discusses a warning message that Drupal displays about performance and MySQL transaction isolation levels, and how to resolve it. This article discusses a warning message that Drupal displays about performance and MySQL transaction isolation levels, and how to resolve it. ## About the Drupal warning message After you install Drupal, you may see the following warning message on the **Status report** page of the administration interface: ```` Transaction isolation level REPEATABLE-READ The recommended level for Drupal is "READ COMMITTED". See the setting MySQL transaction isolation level page for more information. ```![Drupal - Admin interface - Transaction isolation level](https://static.hosting.com/kb/kb-drupal-transaction-isolation-level.png) By default, MySQL uses the **REPEATABLE READ** isolation level. According to the [Drupal documentation](https://www.drupal.org/docs/getting-started/system-requirements/setting-the-mysql-transaction-isolation-level), however, this level can cause deadlocks on database tables, leading to poor site performance. ## Determining the current transaction isolation level To determine the current transaction isolation level enabled on your account, follow these steps: 1. Log in to your account [using SSH](/docs/using-ssh-secure-shell). 2. At the command prompt, log in to MySQL by typing the following command. Replace **_username_** with your username: ```bash mysql -u username -p ```` 3. At the prompt, type the following command: ```bash theme={null} SHOW variables WHERE variable_name LIKE "%_isolation"; ``` 4. Examine the command output: * If the isolation level is set to **REPEATABLE READ**, you receive the following output: ``` +------ ---------+-----------------+ | Variable_name | Value           | +---------------+-----------------+ | tx_isolation  | REPEATABLE-READ | +---------------+-----------------+ 1 row in set (0.001 sec) ``` * If the isolation level is set to **READ COMMITTED**, you receive the following output: ``` +---------------+----------------+ | Variable_name | Value          | +---------------+----------------+ | tx_isolation  | READ-COMMITTED | +---------------+----------------+ 1 row in set (0.001 sec) ``` The procedure to change the transaction isolation level depends on the type of hosting account you have. ### Shared, reseller, and Turbo Web hosting accounts **Important** The following procedure applies to Drupal 10. To change the transaction isolation level on these types of hosting accounts, follow these steps: 1. Open the Drupal *settings.php* file in your preferred text editor. > 📘 Note > > By default, this file is located in the *sites/default* directory. 2. In the *settings.php* file, locate the database connection array. This array is usually near the end of the file and looks similar to the following: ``` $databases['default']['default'] = array (   'database' = 'example_drup123',   'username' = 'example_drup123',   'password' = 'example-password',   'prefix' = 'drom_',   'host' = 'localhost',   'port' = '3306',   'isolation_level' = '',   'driver' = 'mysql', ); ``` 3. Change the **isolation\_level** line as follows: ``` 'isolation_level' = 'READ COMMITTED', ``` For example, the database connection array should now look like: ``` $databases['default']['default'] = array (   'database' = 'example_drup123',   'username' = 'example_drup123',   'password' = 'example-password',   'prefix' = 'drom_',   'host' = 'localhost',   'port' = '3306',   'isolation_level' = 'READ COMMITTED',   'driver' = 'mysql', ); ``` 4. Save your changes to the *settings.php* file and exit the text editor. 5. Log in to Drupal as the administrator, and then go to the **Status report** page. The transaction isolation level warning message should be gone. ### VPS and Dedicated servers How you change the transaction isolation level on a VPS or Dedicated server depends on whether or not you have root access: * If you **do not have** root access to the server, please open a support ticket on the Hosting Panel at [https://my.hosting.com](https://my.hosting.com) and we will assist you. * If you **do have** root access to the server, you can change the isolation level yourself. To do this, follow these steps: 1. As the root user, open the */etc/my.cnf* file in your preferred text editor. 2. Locate the **\[mysqld]** section. 3. Copy the following line, and then paste it into the */etc/my.cnf* file in the **\[mysqld]** section: ``` transaction_isolation="READ-COMMITTED" ``` 4. Save your changes to the */etc/my.cnf* file, and then exit the text editor. 5. Type the following command to restart the MySQL service: ```bash theme={null} systemctl restart mysqld ``` 6. The isolation level is now set to **READ COMMITTED**. To verify this, follow the procedure described in the **Determining the current transaction isolation level** section above. ## More information * To view the official Drupal documentation, please visit [https://www.drupal.org/documentation](https://www.drupal.org/documentation). * For more information about transaction isolation levels and how they affect Drupal performance, please visit [https://www.drupal.org/docs/getting-started/system-requirements/setting-the-mysql-transaction-isolation-level](https://www.drupal.org/docs/getting-started/system-requirements/setting-the-mysql-transaction-isolation-level). ## Related articles * [Configuring Drupal to use memcached](/docs/configuring-drupal-to-use-memcached) * [Configuring Drupal to use Redis](/docs/configuring-drupal-to-use-redis) * [Configuring the Drupal cron routine](/docs/configuring-the-drupal-cron-routine) * [Enabling caching for Drupal on Turbo servers](/docs/enabling-caching-for-drupal-on-turbo-web-hosting) * [Identifying and avoiding harmful Drupal modules](/docs/identifying-and-avoiding-harmful-drupal-modules) * [Optimizing Drupal](/docs/optimizing-drupal) * [Optimizing Drupal database usage](/docs/optimizing-drupal-database-usage) * [Troubleshooting Drupal](/docs/troubleshooting-drupal)