PHP Database Sharding: Scaling Guide

To achieve database sharding expansion, you can follow the steps below:

1. Preparing to scale up servers: To begin, new servers need to be prepared in order to scale up the database shards. Make sure that the servers have the appropriate database software installed and are of the same version and configuration as the existing shard servers.
2. Set up a new server: Configure the database on the new server, including installing database software, adjusting configuration files, and configuring the network. Ensure that the new server can communicate properly with the existing shard servers.
3. Data Migration: Moving some data from existing shard servers to a new server. You can export data from the existing server to the new server using database backup and restore tools like mysqldump and mysqlimport commands.
4. Update the application: Update the database connection information in the application’s configuration file by adding the address and port of the new server to the connection pool. Make sure the application can connect to the new server.
5. Database synchronization: Start the database service on the new server and establish master-slave synchronization with the existing shard server. The data on the existing server can be synchronized in real time to the new server using the database’s built-in replication feature.
6. Testing and verification: Perform some test operations on the new server to ensure the reading and writing capability of the database is functioning properly. Utilize stress testing tools to test and examine the performance and stability of the database.
7. Expansion completed: If the new server can operate properly and pass the testing, then the expansion is considered complete. You can continue to repeat the above steps, adding more servers to the database shard in order to achieve a larger scale of expansion.

It is important to note that when scaling out a database sharding system, it is vital to ensure that the application’s code and logic can properly handle the reading, writing, and querying of sharded data. Additionally, one must also consider load balancing and fault recovery mechanisms between the database shards to ensure the stability and reliability of the database.