Re: [PATCH] Master promotion with SIGURG (CoW optimization)

[Jean Boussier <jean.boussier@shopify.com>]

> (fully quoting original message for archival purposes, original
> was sent privately)

Sorry for this. Again our company laptops got locked down recently
and now I'm just struggling with shitty mail clients I don't know how to use.


> I don't think Ruby 2.3+ is even necessary, just yet, nor kgio.
> None of these new code paths should be exception-intensive to be
> a performance problem.

True.


> > If anything, the reliable timeout is the number one reason why I still
> > believe unicorn
> > is the superior server out there.
>
> /me hides under a desk :<
>
> Honestly, you have no idea how embarrased I am of that (mis)feature.

It's a bit off topic, but really you shouldn't. A proper timeout mechanism
is absolutely essential to ensure resiliency of the service.

Unless your app is really trivial, it's pretty much impossible to ensure
that all your endpoints will always complete in a reasonable amount
of time, even more so when you have malicious actors trying to DOS
you, or some bugs in database clients and such.

Killing these stuck workers allows to keep the service healthy until the
problem is fixed. The only thing we changed is that we first send SIGTERM
so that we can report the backtrace and other debug data.

> send pipes or any other IO objects across.

Oh, that's what I missed, that makes sense. I'll try the C wrapper
to send both the message and the IO at the same time.

Thanks again, I'll likely get back to you next week with a patch.