Laurent Bercot wrote:
If all this fuss is about socket activation, then you can simply forget it altogether. Jonathan was simply mentioning socket activation as an alternative to real dependency management, as in "that's what some people do". I don't think he implied it was a good idea. Only Lennart says it's a good idea. Or people who blindly repeat what Lennart says.
Actually, I carefully wrote "opening server sockets early", talking about the specific mechanism that is employed to weaken client ordering dependencies upon servers.
As to whether opening server sockets early is a good idea: I'm not in a hurry to naysay. It achieves the stated effect. Arguably, indeed, it can be described as *what the system already does* if one has a lot of daemontools-style services spawned through UCSPI toolsets. They all start up early and in parallel, opening the sockets very first thing with something like tcpserver or tcp-socket-listen and *then* progressing to starting the main server program, thereby allowing clients to connect and block (rather than fail to connect and abend over and over) in parallel. So it would be possibly a bit rich for me to agree that this is a Lennartism. Especially given that I have machines that do this and have had since before systemd was a twinkle in upstart's eye. (-:
