On Fri, Oct 17, 2003 at 11:53:18AM +0200, Erich Schubert wrote: > minit is already really small. All it does is running processes and > restarting them when they die. There seems to be little difference > between what i can do with minit and with multiple runsv. > And yes, i do know about shared memory. > I admit that runsvdir has some nice features - like something similar to > runlevels, but way easier to understand. > Just change the symlink to the new runlevel and it will terminate > services not in the new runlevel, while starting new services. Nice! > > But i don't see why i need that many processes: [...]
As I already said in my last mail: modularity. Consider a multi-user server system, and you want to provide one or more users with their own personal service management. You can run additional instances of the runsvdir program under the uid and gid of the user as a service, so he can manage his own daemon processes with a guaranteed process state, logging, and supervision. Or use the runsv program to provide him with just a single service facility. On the other hand consider an embedded device, e.g. a kiosk system. You possibly don't want to use runsvdir and runsv at all, but run an X-server as the only service daemon on the system, running a gui application. If X exits the system shuts down. I could think of more scenarios. Each of the separated programs perform certain tasks: runit: clean process state, process 1 duties; runsvdir: privilege separation, service management, last-resort-log; runsv: user interface, supervision, logging. Running them in a process hierarchy makes it possible to recombine these features differently. I cannot see what's wrong with having some more processes running, very small ones which sleep most of the time. They don't hurt the system. Regards, Gerrit. -- Open projects at http://smarden.org/pape/.
