Apigee Edge supports Node.js version 0.10. In this version of Node, the default connection pool for outgoing http requests to a host is 5. This can be a significant bottleneck if you have many concurrent requests to the same host. This is a very well-known issue. Fortunately, there are some very simple solutions that will make your application more performant in these scenarios:

• Manually increase the connection pool:

    var http = require('http');    
    http.globalAgent.maxSockets = 100;
    // You could also set it to unlimited (Node v0.12 does by default):
    http.globalAgent.maxSockets = Infinity;

• Disable HTTP global Agent:

  var http = require('http'); 
  var req = http.request({        
    agent: false,    
    url: "",            
    ...    
  }, function (res) { ... });