Here are some other random ideas: For the log rotation problem I normally write to a named pipe and have cronolog or multilog read from that named pipe:
http://cronolog.org/ http://cr.yp.to/daemontools/multilog.html I also have cronolog or multilog monitored with daemontools's supervise program or runit's runsv since cronolog will exit if you run out of disk space (and cause all writers to block which effectively creates a denial of service). In general, I use supervise or runsv to monitor all my daemon's, it is also a much easier interface for dealing with daemon's in my opinion. For graceful server shutdown I would agree with other people that doing it via signals would be easiest. I don't know enough about existing Lua signal library implementations, but in general you need to be careful in C about what functions get executed in your signal handlers. So for example, libev's signal handling facilities uses the "self pipe trick" so that your signal handles are ran in the "normal" flow of the event loop. Anyways, the easiest thing I can think of to do is to write a simple Lua C extension that handles SIGHUP and updates a userdata. Then at the end of your request processing, check the userdata to see if a signal was received and if so, then exit/respawn. Of course, the only problem with this solution is that you don't get a "timely" shutdown since your only checking the state variable at the end of processing a request. To overcome this, ideally you would check the accept() system call to see if it errors with EINTR and if so, then check the userdata to see if we got interrupted because of our SIGHUP handler and if so, then shutdown immediately. http://linux.die.net/man/2/accept Unfortunately, it looks like you would need to hack lua sockets for that though: https://github.com/LuaDist/luasocket/blob/master/src/usocket.c#L190 Cheers, -Brian On Sat, Apr 9, 2011 at 11:59 PM, Alexander Gladysh <aglad...@gmail.com> wrote: > Hi, list! > > Here is a simple question that I do not know a good answer for: > > I have a simple WSAPI-based HTTP service (running under > nginx/spawn+fcgi/multiwatch/luajit2b5). > > Aside of serving some data over HTTP, this service writes some data to > a log file for each request. > > I forked this service N times. Each fork does not and should not know > about other's existence. > > Now I rotated the log file. How do I tell the WSAPI service to let go > old log file and open a new one? > > * * * > > Note that my problem is more broad than that — for example I want to > tell all forks to shut down etc., but we may concentrate on the issue > at hand first. > > I have some possible solutions in mind (and actually do employ one of > them), but, since the question is so simple, I will wait until others > will suggest something. I like none of the options that I see. > > Alexander. > > -- Brian Maher >> Glory to God << _______________________________________________ Kepler-Project mailing list Kepler-Project@lists.luaforge.net http://lists.luaforge.net/cgi-bin/mailman/listinfo/kepler-project http://www.keplerproject.org/
