How does shardingjdbc work?
Sharding-JDBC is an open-source middleware developed in Java language to simplify the interaction between Java applications and distributed databases. It uses sharding to store data across multiple databases based on certain rules, achieving horizontal partitioning and distributed storage of data.
The working principle of Sharding-JDBC is as follows:
- Database sharding configuration: Specifying data sources and sharding rules, including sharding field, sharding algorithm, through configuration files or programmatically.
- SQL parsing and rewriting: when an application initiates a database operation request, Sharding-JDBC will analyze the SQL and rewrite it into multiple subqueries based on sharding rules.
- Database routing: Based on the sharding rules, Sharding-JDBC calculates the value of the sharding field to determine which data node should store the data.
- Managing connections and data read/write operations: Sharding-JDBC utilizes a connection pool to efficiently manage database connections and sends data to the appropriate data nodes for read and write operations.
- Sharding-JDBC supports distributed transaction processing by ensuring transaction consistency among multiple data nodes through a transaction coordinator, such as the XA protocol.
In a nutshell, Sharding-JDBC shards data according to sharding rules, rewriting and routing SQL queries to the corresponding data nodes, thereby achieving distributed storage and access of data. Additionally, it also offers features such as connection management and transaction processing, streamlining the interaction between Java applications and distributed databases.
