On 25/09/2015 09:26, Jaromil wrote:
What I'm particularly interested is something to do process monitoring and respawning for a certain group of daemons
Just supervise the daemons you want to supervise, and don't supervise the ones you don't want to. But really, there's no reason *not* to supervise every daemon on your system: even if you're not using the respawning mechanism, it gives you a reproducible environment to start them (without 40 lines of boilerplate) as well as a nice, race-free interface to send them signals - no .pid files. The only reason why supervision is not more widespread is inertia. There's a huge historical collection of sysv-rc-like scripts that does not play well with supervision, and rewriting them requires a tremendous effort. But I'm hopeful: since the init wars, people have realized that some work was necessary. There are initiatives to develop collections of supervision scripts already. And daemon authors have started putting in the effort to write systemd .service files, when supervision scripts are easier, so there's no reason they can't be convinced.
I wish to have something that is not a lousy shell-script (and of course not a monster of office-suite dimensions taking over the whole setup) to notice the crash, save the logs aside and restart the daemon - and fast.
That's exactly what a supervision suite does. You could already do it with daemontools in 1998! :P Nowadays, supervision suites are a dime a dozen. Of course, I'm advertising s6, the one I wrote - but it is honestly more featureful than the other ones, and, I like to think, correctly maintained.
It has been since the times of Icecast1 (pre-kh) that I need something like that, been using restartd for a quick setup, but it does not handle dependencies.. now wondering if s6-rc does it.
s6 does it. s6-rc is not a supervision suite, it's a service manager working on top of s6. The distinction is important: - booting a machine (s6-linux-init), - supervising processes (s6), and - managing services (s6-rc) are not the same job, even if they are somewhat related. It's the confusion between those three jobs that led to the birth of mediocre software like sysvinit (I'm not hating: we didn't know better at the time), and later on, of abominations like systemd (I *am* hating). But yes, if all you need is process supervision, s6, or any other supervision suite, is what you need. If you need dependency management, especially between oneshots and longruns, then s6-rc can do it.
In general I'd be incline to use s6 more because the whole suite Laurent is developing seems very minimal and... no-bullshit (Gandi's tm)
It's Gandi's motto (I like those guys, my VPS is hosted by them, I have a few of their T-shirts), it's the suckless philosophy, and it's mine. I like to think it's also the philosophy of Devuan people, who voluntarily rejected the biggest bullshit of the decade. -- Laurent _______________________________________________ Dng mailing list Dng@lists.dyne.org https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
