There is one (responsible for sending SMS) service(daemon) in Ubuntu 20.04, it is single-threaded, how can run multiple copies of this service(daemon), or make it multi-threaded?
Otherwise, for each project, I create one server with this service, which affects resources.
the thought of Docker or lxd/lxc comes to mind.
One possible solution is to create few different config files and make the daemon listen on different port or use different socket (file).
Also is possible to run containers.
In both case you will need loadbalancer if you want to unify the communication from point of view of the client