[PATCH] add reload_delay directive

[Maxim Dounin]

Hello!

On Mon, Jun 19, 2017 at 11:09:58PM +0800, Peng Fang wrote:

> # HG changeset patch
> # User RocFang <fangpeng1986 at gmail.com>
> # Date 1497882783 0
> # Node ID 8b9e416ef7f9f8e7f96eaa53b479062683464481
> # Parent  a39bc74873faf9e5bea616561b43f6ecc55229f9
> Introduced reload_delay.
> 
> Previously, the master process will sleep 100ms before sending a
> SHUTDOWN signal to old worker processes when reload. This patch
> make the sleep time configurable, because in some scenarios, the
> new workers may spend more than 100ms to get ready. For example,
> the init_prcess hook of some 3rd modules may be time-consuming.

The sleep in question is intended to let OS some time to actually 
start the process, and not intended to allow time-consuming work 
to happen on a worker process start.

In general, no time-consuming operations are expected to be done 
during a worker process start.  Instead, time-consuming 
preparatory work is expected to happen in the context of the 
master process during configuration parsing and init module hooks.  
If a module does something time-consuming in the init process 
hook, it might be a good idea to change the module logic.

Unless there is something more specific than a "the init_prcess 
hook of some 3rd modules may be time-consuming", I would rather 
reject the patch, as it introduces unneeded user-level complexity 
by adding a directive, and encourages bad module writing practice.

Nevertheless, thank you for the patch.

-- 
Maxim Dounin
http://nginx.org/