You could try this on your laptop, but you would find that your computer will not really be able to create 10,000 requests to a temp server (or anyplace) at the same time. Most modern machines top out around 1000 or so simultaneous connections.
You can create something in code that will certainly do this one connection after another, but this is not the same as a true load test where you ramp up and ramp down the number of requests per second. You will quickly find that this is IO and connection-bound and not a true test for your application.
Your best bet, if you are trying to benchmark/stress your server, is to put your server on a box or service that is internet accessible like nodejitsu or nodester (both free services) and then use another service (free or otherwise) to hit your server's URL. You don't say if this is what you're doing, but this is the usual way to do load and stress testing.
Two companies that I have used in the past are Load Impact and Blitz.io to get the number of simultaneous user requests to your server. for 10,000 users you will need to pay a bit but it's not too large a fee.
You may also want to look into the libraries from New Relic to help you monitor the server/service itself and how it behaves under stress. They have some great capabilities in helping find bottlenecks in applications.
This may be a bit more than what you were looking for, but I hope that it's helpful. If I am off the mark, let me know and I'll be happy to amend this to be closer to what it is you are looking for.
fun2function is called from yourtempServer, and should make calls totempServer. Am I right ? If I am, it doesn't make sense...