If an IP tries to access an account and repeatedly fails logins, that user IP would be blocked at the server.
如果有一个IP试图通过某一帐户不断地访问并登录失败,那么服务器将锁定该用户IP。
3
When Transaction 2 (Tx2) wants access to the row that contains the balance for this account, Tx2 is blocked until Tx1 has updated the balance to 3000 and committed its changes.