I’m new to Docker Swarm so I’m not sure whether I should run a service in replicated or global mode?

The application within the service on initialisation creates a unique password (valid only for that app) and it’s stored in it’s own volume.

At the moment I’m creating the service with a unique name for each one such as service-1 and service-2 even though they’re running the same software. I could end up with 100 or more of these.

But then how would this approach affect updating the software when an update is released?

So is it best to run as replicated or global? And any thoughts about software updates would be most welcome.