mha

mha.go

package main

import (
	"database/sql"
	"fmt"
	"log"
	"time"

	_ "github.com/go-sql-driver/mysql"
)

// MySQL主从关系
var (
	master = "root:baidu@123@tcp(10.0.0.235:3306)/"
)

// DBWrapper 包装数据库客户端
type DBWrapper struct {
	dsn string
	db  *sql.DB
}

func (dbw *DBWrapper) prepare() error {
	db, err := sql.Open("mysql", dbw.dsn)
	if err != nil {
		return err
	}
	dbw.db = db
	return nil
}

func (dbw *DBWrapper) destroy() {
	if dbw.db != nil {
		dbw.db.Close()
	}
}

func (dbw *DBWrapper) exec(sql string) (sql.Result, error) {
	err := dbw.prepare()
	if err != nil {
		return nil, err
	}
	defer dbw.destroy()

	return dbw.db.Exec(sql)
}

func (dbw *DBWrapper) query(sql string) (*sql.Rows, error) {
	err := dbw.prepare()
	if err != nil {
		return nil, err
	}
	defer dbw.destroy()

	return dbw.db.Query(sql)
}

func main() {
	wrapper := &DBWrapper{dsn: master}
	failTimes := 0
	for {
		// 探测Master存活
		rows, err := wrapper.query("SELECT 1")
		if err != nil {
			failTimes++
			log.Printf("Master探测连续失败%d次,错误:%v\n", failTimes, err)
		} else {
			rows.Close()
			failTimes = 0
		}

		// 未到达failover阈值
		if failTimes < 10 {
			time.Sleep(1 * time.Second)
			continue
		}

		// 触发failover流程
		fmt.Println("Master failover开始执行!")
		// 实现具体的 failover 逻辑...
		break
	}
}