After I launch Locust without the web UI:
$ locust -f locust_files/my_locust_file.py --no-web -c 1000 -r 100
is it possible to change the number of users or hatch rate programmatically during the execution?
No.. that is not possible.. Locust requires the number of virtual users and hatch rate to be defined at test startup.
In Locust, can I modify the number of users and hatch rate after I start the test?