Upgrading Executable on the Fly - wrong docs?

[Ruslan Ermilov]

On Sat, Feb 09, 2013 at 05:12:28PM -0500, piotr.dobrogost wrote:
> Hi!
> 
> After reading the section titled "Upgrading Executable on the Fly" in the
> docs (at http://nginx.org/en/docs/control.html) I have an impression the
> information given is wrong.
> In the first bullet one reads
> "Send the HUP signal to the old master process. The old process will start
> new worker processes without re-reading the configuration. (...)"
> then in the second and third bullet one reads
> "When the new master process exits, the old master process will start new
> worker processes."

The instructions in the bullets are not supposed to be executed in
a sequence.  Instead, they document two possible actions to perform:

1) Start old workers with old configuration, then gracefully stop new
   master/workers (bullet #1).

2) Stop new master/workers immediately (*).  Old master will restart
   workers automatically when new master exits (bullet #2).  (*) send
   KILL to new workers if they don't exit normally (bullet #3).

> If the old master process already started new worker processes after it had
> received the HUP signal then it means it didn't have to wait until the new
> master process exited, right? Doesn't this contradict the subsequent
> information that the old master process waits with starting new worker
> processes until after the new master process exited?

I can see where your confusion comes from.  How's this instead?

http://pp.nginx.com/ru/libxslt/en/docs/control.html#upgrade