Building a Go MySQL Driver for Seata AT Mode: A Practical Guide

Background

In April 2020 a Go distributed‑transaction framework called Seata‑Golang was started. The Java Seata AT mode proxies the DataSource and intercepts SQL to capture before/after snapshots for rollback. The goal for the Go client was to achieve the same functionality with minimal code intrusion.

Using database/sql in Go

Go developers obtain a database handle with sql.Open("mysql", dsn). Transactions are started via db.Begin() or db.BeginTx(ctx, &sql.TxOptions{}), returning a tx object. Queries use tx.Query, modifications use tx.Exec, and the transaction is finished with tx.Commit() or tx.Rollback().

Design Decision

Embedding AT parameters in the DSN would break driver design, so the AT proxy is placed above the database/sql layer. The proxy wraps objects created by database/sql and implements the same Tx interface, adding a custom Begin() method. This preserves the familiar API while providing Seata‑Golang functionality.

Tx Interface

type Tx interface {
  Commit() error
  Rollback() error
}

Driver Details

Do not set interpolateParams=true in the DSN . The driver only handles the Binary protocol; enabling this forces the Text protocol, which is unsupported.

Joining a global transaction : call db.BeginTx(ctx, driver.TxOptions) and embed the XID in the context using mysql.XID.

Initialization : before using the driver, initialize the Seata‑Golang client and register the MySQL driver.

config.InitConf(configPath)
client.NewRpcClient()
mysql.InitDataResourceManager()
mysql.RegisterResource(config.GetATConfig().DSN)

Example Usage

ctx := context.WithValue(context.Background(), mysql.XID, c.Request.Header.Get("XID"))
tx, err := dao.BeginTx(ctx, &sql.TxOptions{
    Isolation: sql.LevelDefault,
    ReadOnly: false,
})

References

Source code (beta): https://github.com/opentrx/mysql

Sample usage: https://github.com/opentrx/seata-go-samples