position api always returns 400 Bad Request for valid data

Hi, I'm working on test in JMeter for Traccar API and I've occured an issue.

My test plan involves sending requests from 1500 users every 15 seconds for 5 minutes, what gives us 100 requests per second and 30000 requests per 5 minutes. Unfortunately every time server stops retreiving data at some point(mostly after 10k+ requests) and starts responding with 400 Bad Request for each request. What is interesting, other endopints works fine. To fix it I need to restart my service, and after that the same requests passes with 200 response code, but after starting test plan problem occurs again.

I'm working on Windows and I set some keys to configure port connection limits, but without any result.
I'm also using every time 5055 port to send the data, maybe this is the problem?
I have to run such a test scenario, is there any solution to do it?

Thanks for help

1. Are you sure you are sending correct "accept" header with your request?
2. Why are you sending such excessive amount of requests? Are you aware of WebSocket option? Is it not working in your case?

I figuret it out. My problem was about manually adding devices. For some reason system did not recognized devices i was adding this way. I guess devices needs to be associated with some user. I've fixed it in other way, by dropping database.ignoreUnknown and adding in configuration file those lines:

<entry key='database.registerUnknown'>true</entry>
<entry key='database.registerUnknown.defaultGroupId'>1</entry>

Reffering to the second question, our company will be working on application, wich will be storing data about devices and I had to test your system on the maximum anticipated load.

Thank you for quick reply

My point was that the way you plan to use API is incorrect. You should use WebSocket instead of polling server.

Yes, you're right. To be true I don't know so much about using WebSocket's in jMeter, but I will read about it.

Thanks for help