We have android application associated with salesforce application. We are using REST & Standard API to push & download data to Salesforce.

Currently, our customer has 1000 users using the mobile app and its is working fine. But they want to scale to a10k users and we want to check if there will any performance issue. We want to check REST APIs using multiple mobile users (10000 mobile user).

We found a tool called Jmeter which is used for generating multiple  mobile users and calling REST API simultaneously. But its creates just one user replicates it to call rest of the user APIs.  

We would like to know a viable approach fo testing simultaneous authenticated users using REST APIs.

Our endpoint looks something like this: https://base_URL/services/apexrest/gfsurveys/surveysubmission/

We would like to know if this is the right approach to know what happens if 10,000 mobile users sync at once?

We have a client and have android application associated with salesforce application. We are using REST & Standard API to push & download data to Salesforce.
Currently, our customer has 1000 users using the mobile app and its is working fine. But they want to scale to a10k users and we want to check if there will any performance issue. We want to check REST APIs using multiple mobile users (10000 mobile user).
We found a tool called Jmeter which is used for generating multiple  mobile users and calling REST API simultaneously. But its creates just one user replicates it to call rest of the user APIs.  

How can we test multiple users simultaneously calling a REST API?

Our endpoint looks something like this: https://base_URL/services/apexrest/gfsurveys/surveysubmission/

We would like to know if this is the right approach to know what happens if 10,000 mobile users sync at once?