HTTP keep-alive in node.js

Question

I am trying to set-up a HTTP client to keep the underlying connection open (keep-alive) in node.js, but it seems that the behaviour does not correspond to the docs (http://n

Answer 1

If I'm not mistaken the connection pool was implemented in 0.12.

So if you want to have a connection pool prior 0.12 you can simply use the request module:

var request = require('request')
request.get('www.twilio.com', {forever: true}, function (err, res, body) {});

If you are using node 0.12+ and you want to use the HTTP core module directly, then you can use this to initialize your agent:

var agent = new http.Agent({
  keepAlive: true,
  maxSockets: 1,
  keepAliveMsecs: 3000
})

Notice the keepAlive: true property, that is required to keep the socket open.

You can pass an agent to the request module as well, again that works only on 0.12+ otherwise it defaults to internal pool implementation.

Answer 2

The below worked for me in meteor which uses the npm module for keepaliveagent

var agent = new KeepAliveAgent({ maxSockets: 1 });

var options = {
  agent:agent,
  headers: {"Connection":"Keep-Alive"}
}

try {
  var client = Soap.createClient(url);

  var result = client.myfirstfunction(args,options);

//process result
  result = client.mysecondfunction(args,options);

}

Both the method calls returns data in one socket connection. You pass the options in each method call

Answer 3

I guess it should work on node 0.12+. You may also want to use a different agent for this purpose. For example keep-alive-agent can do what you want:

var KeepAliveAgent = require('keep-alive-agent'),
    agent = new KeepAliveAgent();