var showMem = function() {  
         var mem = process.memoryUsage();  
         var format = function(bytes) {  
              return (bytes/1024/1024).toFixed(2)+'MB';  
         };  
         console.log('Process: heapTotal '+format(mem.heapTotal) + ' heapUsed ' + format(mem.heapUsed) + ' rss ' + format(mem.rss));  
         console.log('----------------------------------------');  
    };  
      
    var useMem = function () {  
         var size = 20*1024*1024;  
         var arr = new Array(size);  
         for (var i=0;i<size;i++) {  
              arr[i] = 0;  
         }  
         return arr;  
    };  
      
    var total = [];  
      
    for (var j=0;j<15;j++) {  
         showMem();  
         total.push(useMem());  
    }  
    showMem();