node.js - after get request, script does not return to console

Question

Here is a simple script

    var http = require(\"http\");

    http.get( WEBSITE, function(res) {
       console.log(\"Does not return\");
       return;
    })         


        

Answer 1

By "return to console" I'm assuming you mean that node exits and drops you back at a shell prompt.

In fact, node does eventually exit for all of those domains you listed. (You were just impatient.)

What you are seeing is the result of HTTP keep-alives. By default, node keeps the TCP connection open after a HTTP request completes. This makes subsequent requests to the same server faster. As long as a TCP connection is still open, node will not exit.

Eventually, either node or the server will close the idle connection (and thus node will exit). It's likely that Google and Facebook allow idle connections to live for longer amounts of time than Yahoo and Wikipedia.

If you want your script to make a request and exit as soon as it completes, you need to disable HTTP keep-alives. You can do this by disabling Agent support.

http.get({ host:'google.com', port:80, path:'/', agent:false }, function(res) {
   ...
});

Only disable the Agent if you need this specific functionality. In a normal, long-running app, disabling the Agent can cause many problems.

There are also some other approaches you can take to avoid keep-alives keeping node running.