Kill a malformed user's job from UI/API in web.py

I have a web app(built on on web.py), say My_Cool_App where a user triggers a job and sometimes right after triggering the job, the user realizes that the machine on which the job is running against suddenly went down - and would ideally like to kill this specific job, since it is wasteful, otherwise.

In the past, I had to kill it from the web app directly on the machine where it runs. I can design an API that does the following.

Question : How do I kill this pid, without having to re-start the app ? Is there an identifier that's assigned to a "specific" user's run ?

http://my_machine_dns:7091/My_Cool_App?pid_to_kill=user_enters_pid_or_equivalent_here

I can see that I can kill a session & probably re-start My_Cool_App, but that would ALSO kill other user's job if the app goes down. Suggestions ?