my code keeps using setinterval to fetch redis data (redis is on another server). Dozens of people access the network outflow bandwidth (bit/s) of the redis server at the same time.
whether there should be a cache or what dozens of people access at the same time causes dozens of links to request more REDIS users to increase bandwidth exponentially

   //  
    io.sockets.on("connection", function (socket) {  
      
        //console.log("...");  
        //  
        onlineCountPP;  
        var domain = socket.handshake.headers.origin;

        if(typeof domain == "undefined"){
            return;
        }

        
            
            socket.volatile.emit("onlinenums", {polotime: res[2]});  
        });



            
        });
               
      
        }
        
        var once = setTimeout(refresh,100);
        
        var tweets = setInterval(refresh, 2000);  
        
      
        console.log(":"+onlineCount);  
        //  
        socket.on("disconnect", function() {  
            clearInterval(tweets);
            if(onlineCount > 0 ){  
                //  
                onlineCount--;  
                console.log(":"+onlineCount);  
            }  
        });  
    });  

    


      
    //HTTP3000  
    app.listen(3000, function(){  
        console.log("listening on *:3000");  
    });