How to increase max number of connections to Whois server in Node?

Question

How to increase max number of connections to Whois server in Node?

I'm querying a Whois server for information on a lot of domains. Here is my request code:

checkDomain (domain, callback) ->
    client = net.connect {port: 43, host: 'whois.examplenic.com'}, ->
        client.write domain + '.com' + '\r\n'

        client.on 'data', (data) ->
            ... do something with data ...

I first had some code that fired checkDomain sequentially. Then I decided to try 2 at a time and that doubled performance. But after 4, performance didn't increase at all. Which means that the number of connections is limited to 4 either by Node or the Whois server. Is there a way I can tell?

Thanks

javascript
node.js
coffeescript
connections

Answer 1

You can try your code with different Whois servers. If the performance differs, that would point to a server-dependent bottleneck; if it is the same, that would point to a Node bottleneck. I very much doubt Node would have any problem with just 4 concurrent connections, so it is much more likely you're seeing a server-dependent bottleneck; but you asked for a way to tell so here you go.