How to do performance WebSocket testing at home

Question

I have written WebSocket server and wanted to make performance test for it (how many users sending messages to every connected users can I handle at max on my PC). I use JMeter to do it. After running first test, it stopped after about 16500 samples and next test didn't even run. I think It's because my PC opened too many TCP connections (one TCP connection for one WebSocket connection).

So I'm interested in how can I test it at home? Is there a way to open something like "fake" TCP connections so I can have unlimited number of it?

Answer 1

Performance testing on scaled down environments doesn't make a lot of sense because you cannot extrapolate the results and predict how the performance will look like in the real production environment.

Of course you can use profiler tools and try optimizing your code however the code might behave differently in the production environment due to higher amount of resources available.

If you still want to proceed there are no "fake" connections you could use, but you can increase the limits on your operating system level. For MS Windows:

• Increase ephemeral ports range
• Decrease the maximum time the connection spends in TIME_WAIT state
• Increase the maximum number of network connections

From JMeter perspective

• make sure to check jmeter.log file for any suspicious entries
• if it "hangs" take a thread dump and see what threads are doing, maybe it worth setting reasonable timeouts
• follow JMeter Best Practices and recommendations from 9 Easy Solutions for a JMeter Load Test “Out of Memory” Failure
• if possible install JMeter and the system under test onto separate machines