PaaS only

Overview of the split database solution

Last update: April 16, 2024

CREATED FOR:

  • Experienced
  • Admin
  • Developer
NOTE
This feature is available for Adobe Commerce instances only.
IMPORTANT
The split database feature was deprecated in version 2.4.2 of Adobe Commerce. See Revert from a split database to a single database.

Adobe Commerce offers several scalability advantages, including the ability to use three separate master databases for different functional areas of the Commerce application.

Checkout, orders, and product data can each use a separate master database that you can optionally replicate. This separation independently scales load from website checkouts, order management activities, website browsing, and merchandising activities, depending on your needs. These changes provide considerable flexibility in how the database tier can be scaled.

INFO
Adobe Commerce on cloud infrastructure does not support this feature.

The ResourceConnections class provides the unified MySQL database connection to the Commerce application. For queries to the master databases, we implement the Command Query Responsibility Segregation (CQRS) database pattern. This pattern handles the logic for routing the read and write queries to the appropriate databases. Developers do not need to know which configuration is being used and there are no separate read and write database connections.

If you set up optional database replication, you get the following advantages:

  • Data backup
  • Data analysis without affecting the master database
  • Scalability

MySQL databases replicate asynchronously, which means slaves do not need to be connected permanently to receive updates from the master.

The following figure shows how this feature works.

Adobe Commerce uses different databases to store tables

In Magento Open Source, only one master database is used.

Adobe Commerce uses three master databases and a configurable number of slave databases for replication. Adobe Commerce has a single interface for database connections, resulting in faster performance and better scalability.

Configuration options

Because of the way the split database performance solution is designed, your custom code and installed components cannot do any of the following:

  • Write directly to the database (instead, you must use the Adobe Commerce database interface)
  • Use JOINs that affect the sales or quote databases
  • Use foreign keys to tables in the checkout, sales, or main databases
WARNING
Contact component developers to verify whether their components do any of the preceding. If so, you must choose only one of the following:
  • Ask the component developers to update their components.
  • Use the components as-is without the split database solution.
  • Remove the components so you can use the split database solution.

This also means you can either:

  • Configure the split database solution before putting Commerce into production.

    Adobe recommends configuring split databases as soon as possible after you install the Commerce software.

  • Manually configure the split database solution.

    You must perform this task if you have already installed components or if Commerce is already in production. (Do not update a production system; make the updates in a development system and synchronize the changes after you have tested them.)

    WARNING
    You must back up the two additional database instances manually. Commerce backs up only the main database instance. The magento setup:backup --db command and Admin options do not back up the additional tables.