How to kill a Background worker and Its metadata

I've created a background worker and I am using Postgresql-9.4. This bgworker handles the job queue dynamically and goes to sleep if there is no job to process within the next 1 hour. 

Now, I want to have a mechanism to wake the bgworker up in case if someone adds a new job while the bgworker is in sleep mode. So to do it, I have created a trigger which initially removes the existing background worker and then registers a new one. I am using the following two queries inside it:

select pg_terminate_backend(pid of bgworker);

select worker_spi1_launch(1);

I am retrieving the pid from pg_Stat_activity. The maximum number of background worker that can run simultaneously is equal to 8.  I think even if I call pg_terminate_backend the metadata of the background worker is not being deleted and as a result after 8 insert operations I am not able to register a background worker. Please suggest what can be done here. 

Best, 

Akash