分布式服务数据一致性-redis篇

client := goredislib.NewClient(&goredislib.Options{
   Addr: "10.211.55.6:6379",
})
pool := goredis.NewPool(client) // or, pool := redigo.NewPool(...)
rs := redsync.New(pool)

//根据需求设置锁名称
mutexName := "goods-1"
var wg sync.WaitGroup
wg.Add(20)
//根据需求设置锁
mutexName := "goods-1"
var wg sync.WaitGroup
wg.Add(20)
for i := 0; i < 20; i++ {
   go func() {
      defer wg.Done()
      var goods Goods
      mutex := rs.NewMutex(mutexName)
      fmt.Println("开始获取锁")
      if err := mutex.Lock(); err != nil {
         fmt.Println("获取锁异常")
         panic(err)
      }
      fmt.Println("获取锁成功")
      db.Where(Goods{ProductId: 1}).First(&goods)
      result := db.Model(&Goods{}).Where("product_id=?", 1).Updates(Goods{Inventory: goods.Inventory - 1})
      if result.RowsAffected == 0 {
         fmt.Println("更新失败")
      }
      fmt.Println("开始释放锁")
      if ok, err := mutex.Unlock(); !ok || err != nil {
         panic("unlock failed")
      }
      fmt.Println("锁释放成功")
   }()
}
wg.Wait()Copy

redis 127.0.0.1:6379> SETNX KEY_NAME VALUECopy

func (m *Mutex) acquire(ctx context.Context, pool redis.Pool, value string) (bool, error) {
   conn, err := pool.Get(ctx)
   if err != nil {
      return false, err
   }
   defer conn.Close()
   reply, err := conn.SetNX(m.name, value, m.expiry)  //过期时间为8秒
   if err != nil {
      return false, err
   }
   return reply, nil
}Copy

var touchScript = redis.NewScript(1, `
   if redis.call("GET", KEYS[1]) == ARGV[1] then
      return redis.call("PEXPIRE", KEYS[1], ARGV[2])
   else
      return 0
   end
`)Copy