Michael Fischer <[email protected]> wrote: > Hi everyone, > > While writing a script to determine the success or failure of a > Unicorn reload attempt (without having to parse a log), I noticed that > Unicorn doesn't preserve the timestamp of its pid file. In other > words, instead of renaming pidfile to pidfile.oldbin (and then back > again if the reload failed), it creates a new pid file for each master > phase change. > > This means we cannot simply compare the mtime of the current pidfile > against the time the USR2 signal was given in order to make a > reasonable conclusion. > > I tried another method, which was to look at the start time of the > process as reported by ps(1), but on Linux, that time does not come > from the wall clock: it's derived from the number of jiffies since > system boot. So it's not guaranteed to be accurate, especially if the > wall clock was incorrect at system boot. > > Are there any other methods anyone can suggest? Otherwise, a change > to Unicorn's behavior with respect to pid file maintenance would be > kindly appreciated.
I read and stash the value of the pid file before issuing any USR2. Later, you can issue "kill -0 $old_pid" after sending SIGQUIT to ensure it's dead. Checking the mtime of the pidfile is really bizarre... OTOH, there's times when users accidentally remove a pid file and regenerate by hand it from ps(1), too... _______________________________________________ Unicorn mailing list - [email protected] http://rubyforge.org/mailman/listinfo/mongrel-unicorn Do not quote signatures (like this one) or top post when replying
