Just happened to me with great surprise, that a Rails 3.2 served with unicorn 4.3.1 did not reload after a USR2 signal. In particular, this deploy was introducing ActiveAdmin. The admin routes kept sending me 404 until I did a full stop and start. So what are the cases in which the USR2 signal is not enough to reload the app?
on 2012-09-19 23:33
on 2012-09-21 00:26
We have had this same problem: we have a "hot deploy" system that deploys the new code, and then sends the USR2 signal to the master unicorn to restart. About 20% of the time (very rough estimate, no real research into that number) the unicorn master does not restart (though, annoyingly, the deploy still acts like it succeeded). They respond to KILL or QUIT but not USR2. Edit: we are running Rails 3.0 and Unicorn 4.3.1
on 2012-10-11 10:14
In this case, you just pass the old PID to kill kill -s QUIT 23820 or you can take advantage of the fact this old PID is stored a known file (referenced in your error message) alongside the "current" PID, and execute: kill -s QUIT `cat /home/user/app.git/tmp/unicorn.pid.oldbin` Openwave has a highly experienced Ruby Rails Development team