adminWhat MySQL Does
MySQL is the database layer behind many WordPress websites. It stores structured data such as posts, pages, users, settings, comments, menus, plugin data and metadata.
Where MySQL Sits In The Stack
MySQL sits behind the application layer. Visitors do not connect to MySQL directly. WordPress connects to MySQL through PHP when it needs to read or write data.
How It Works
When a page loads, WordPress may ask MySQL for the post title, post content, author information, menu data, plugin settings and custom fields. MySQL returns the requested data, and WordPress uses that data to build the final page.
Why MySQL Matters
If MySQL fails, the website may show database connection errors, slow admin pages, failed imports, missing content or timeout errors.
Infrastructure Layer
Database
Difficulty Level
Beginner
Core Concept
MySQL stores the structured website data that WordPress needs to build pages, manage users and keep settings.
System Role
It is the database layer behind the application, supplying content and configuration when WordPress executes through PHP-FPM.
How It Works
WordPress uses PHP to send queries to MySQL. MySQL returns posts, metadata, options, users and plugin data. WordPress then builds the final HTML response.
Connected Components
WordPress, PHP-FPM, database user, database password, wp-config.php, MySQL service, storage, backup system, slow query logs.
Common Failure Points
Wrong database credentials, MySQL stopped, too many connections, slow queries, full disk, crashed tables, missing database backup, failed imports.
Verification Method
Check MySQL service status, verify database connection, inspect disk usage, test login from CLI, review slow queries and confirm backup restore process.
Basic Commands
systemctl status mysql;
mysql -u USER -p;
df -h;
mysqlcheck DATABASE_NAME;
tail -n 50 /var/log/mysql/error.log