4 ms·

I'm a little concerned that these days to go-to answer for a crashing daemon is to have another daemon that watches it and restarts it. Who watches the watcher

I'm a little concerned that these days to go-to answer for a crashing daemon is to have another daemon that watches it and restarts it. Who watches the watchers? What happened to writing things that don't break?

nmcfarl 13y ago
Whenever I hear this complaint the first thing I think about is this Douglas Adams quote: The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair. Personally when doing operations related stuff I like to assume that everything will eventually break - though, hopefully not all at once.
- asdasf 13y ago
  That quote is entirely inapplicable though. It is in fact much easier to fix the simple, do one thing and do it well unix style applications. They are not hard to get at or repair. This is one area where I think the linux philosophy winning out over the unix philosophy has really cost us a lot.
  - jt884 13y ago
    I cannot abide this "X philosophy vs Y philosophy" nonsense. It's just imprecise, meaningless, appeal-to-authority drivel, the likes of which should be expected from used car salesmen, not engineers. Say what you mean, not what some other guy vaguely said 20 years ago.
rodgerd 13y ago
If your PID 1 is screwed, the ordering of syslogd/nginx restarts is the least of your worries.
jt884 13y ago
Oh please, spare us the fake concern. systemd is just an init daemon doing what init daemons should have been doing for a long time. The only reason sysvinit didn't do this is because it was a nasty rats nest of shell scripts with absolutely zero introspection capability. "Who watches the watchers" is such a silly question. Simple knowledge of the halting problem (and all other problems reducible to it) should inform you of how pointless it is to ask "what if" question like this. What if cosmic rays flip a critical bit in just the right way and cause the dialysis machine to explode? Who's gonna "watch" for that? Things DO break. Having the init daemon do whatever it can to assist is just good sense.
asdfaoeu 13y ago
http://0pointer.de/blog/projects/watchdog.html http://0pointer.de/blog/projects/watchdog.html

nmcfarl 13y ago

Whenever I hear this complaint the first thing I think about is this Douglas Adams quote: The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair. Personally when doing operations related stuff I like to assume that everything will eventually break - though, hopefully not all at once.

asdasf 13y ago
That quote is entirely inapplicable though. It is in fact much easier to fix the simple, do one thing and do it well unix style applications. They are not hard to get at or repair. This is one area where I think the linux philosophy winning out over the unix philosophy has really cost us a lot.
- jt884 13y ago
  I cannot abide this "X philosophy vs Y philosophy" nonsense. It's just imprecise, meaningless, appeal-to-authority drivel, the likes of which should be expected from used car salesmen, not engineers. Say what you mean, not what some other guy vaguely said 20 years ago.

rodgerd 13y ago

If your PID 1 is screwed, the ordering of syslogd/nginx restarts is the least of your worries.

jt884 13y ago

Oh please, spare us the fake concern. systemd is just an init daemon doing what init daemons should have been doing for a long time. The only reason sysvinit didn't do this is because it was a nasty rats nest of shell scripts with absolutely zero introspection capability. "Who watches the watchers" is such a silly question. Simple knowledge of the halting problem (and all other problems reducible to it) should inform you of how pointless it is to ask "what if" question like this. What if cosmic rays flip a critical bit in just the right way and cause the dialysis machine to explode? Who's gonna "watch" for that? Things DO break. Having the init daemon do whatever it can to assist is just good sense.

asdfaoeu 13y ago

http://0pointer.de/blog/projects/watchdog.html http://0pointer.de/blog/projects/watchdog.html