Understanding Resource Usage
Quick explanations on how your server resources are used by the store and visitors. You can monitor these under Server Metrics.
In general terms, Webserver resource usage increases with more traffic and/or more plugins.
CPU and Memory
CPU and Memory usage on Webserver are usually correlated and are used by WordPress, plugins, themes, and backend processes like image optimization.
In general terms, MySQL resource usage increases with more products, customers and orders. Spikes happen with major data changes, like importing or bulk updating.
Updating the database with large datasets usually increases CPU usage due to the computation of database relations. Or, in other words, when you are importing products, customers, or orders, or cleaning up the database.
Visitors on your store do not have a significant impact on the database, as normal reading or writing into the database is not resource-intensive.
Used for fast access to frequently used data, like when buyers add products to cart, wishlist, or go to checkout. Also used for search. Database memory does increase with an increase in checkouts or add-to-carts.