[interf4ce]

This is very interesting. I'm not sure what I'd use it for yet, but I imagine it could be useful for triggering ad hoc jobs over the network. Maybe have Home Assistant make a network call to kick off a daily back up when I leave the office at the end of a work day.

[urineaut]

A pretty nice use case I have for socket activation is for isolating containers or applications from the host network. The great thing about socket activation is that opened sockets carry over even if the application/container unshares into a different network namespace! It also works great with Podman pods with networking in the pod completely disabled and, as those are host sockets, does fully retain the connection info of peers (so logs are not just uselessly containing the gateway IP, depending on the container network config)

[kevinmgranger]

I believe its original motivation was just speeding up boot times by starting fewer services, even if you'd eventually want the service running. This was achieved in the past with xinetd, but systemd made the approach more popular for the masses.

[roryirvine]

inetd began to fall out of favour in the mid-late 90s as services became more heavyweight and startup times became longer (think of the initial crypto setup needed by sshd vs rsh/telnetd)

CPU speeds have increased & and i/o latency has decreased so much since then that startup times are generally imperceptible, so the pendulum has swung back to favouring socket activation.

The anti-systemd "traditionalists" never seem to acknowledge that history, though!