如何在mongod服务器上同时运行5个以上的操作

Question

api.route('/allsearch')
    .post(function(req,res){
        var filters=req.body.everything;
        var filterid=req.body.filterId;
        var searchid=req.body.searchid;
        var zipgroup=req.body.zipgroup;
        var myObject = new Array();
        Searchfinal.update({searchfilterid:filterid},{$set:{consumed:0}}, function(err, resu){
            var asyncTasks = [];
            zipgroup.forEach(function(item){
              asyncTasks.push(function(callback){
                searchingalgo(item, filters, filterid,  function(pers){
                        myObject[item] = pers;
                  callback();
                });
              });
            });
            Async.parallel(asyncTasks, function(){

            });         //getdata function 
                res.json({ 
                    suceess: true,
                    message: 'Precess Started'
                    });

        });
    });

zipgroup是一个拉链数组，请求的格式如

{"everything":{"zip":37664,"radius":10,"GENDER":"","HH_INCOME":"","NET_WORTH":"","OCC_OCCUP":"","ac":"ADULTS_F_18_24":true},"child":"","HH_INCOME_VALUE":""},"searchid":"56acf3517f690df311344b14","filterId":"56acf3547f690df311344b15","zipgroup":["37615"," 37663"," 37662"," 37669"," 37664"," 37617"," 37660"," 37645"," 37665"," 24290"," 24258"," 37615"," 37265"," 24230"," 14258"]}

问题是它一次只运行5个进程，不超过5个。

> db.currentOp().inprog.length
5

这是shell上的输出