var mysql = require('mysql'),  Connection = require('mysql/lib/Connection.js');var pool = mysql.createPool({  host: '127.0.0.1',  database: 'myDB',  port: 3306,  user: 'root',  password: 'root',  debug: false,  connectionLimit: 3});var execPool = function() {  pool.getConnection(function(err, conn) {    transAutoRelease(conn);    conn.beginTransaction(function(err) {      if (err) throw err;      conn.query("INSERT INTO test(id,name,date,test) values(1,'123',now(),1)",        function(err, ret) {          if (err) {            console.error(err);            conn.rollback(function() {});          } else {            console.log(ret);            conn.query('UPDATE test set id=12321312 where id=1', function(err, ret) {              if (err) {                console.error(err);                conn.rollback(function() {                });              } else {                conn.commit(function() {                  console.log('success' + JSON.stringify(ret));                });              }            });          }        });    });  });}function after(fn, cb) { return function() {    fn.apply(this, arguments);    cb();  }}function transAutoRelease(conn) {  if (conn.commit == Connection.prototype.commit)    conn.commit = after(conn.commit, release);  if (conn.rollback == Connection.prototype.rollback)    conn.rollback = after(conn.rollback, release);  function release() {    if (conn) {      conn.release();    }  }}var intervalStartProcess = function() {  setInterval(function() {    execPool();  }, 1000);}for (var i = 5 - 1; i >= 0; i--) {  intervalStartProcess();}