Re: Reducing power consumption on idle servers

On Wed, 9 Mar 2022 at 01:16, Zheng Li <zhengli10(at)gmail(dot)com> wrote:

> > 1. Standardize the hibernation time at 60s, using a #define
> > HIBERNATE_DELAY_SEC 60
>
> I notice in patch 3 HIBERNATE_DELAY_SEC has been increased to 300
> seconds, what’s the reasoning behind it? Is longer hibernation delay
> better? If so can we set it to INT_MAX (the max timeout allowed by
> WaitLatch()) in which case a worker in hibernation only relies on
> wakeup? I think it would be nice to run experiments to verify that the
> patch reduces power consumption while varying the value of
> HIBERNATE_DELAY_SEC.

Setting it to INT_MAX would be the same as not allowing a timeout,
which changes a lot of current behavior and makes it less robust.

Waking once per minute is what we do in various cases, so 60sec is a
good choice.

In the case of logical rep launcher we currently use 300sec, so using
60s would decrease this.

I don't see much difference between power consumption with timeouts of
60s and 300s.

In the latest patch, I chose 300s. Does anyone have an opinion on the
value here?

--
Simon Riggs http://www.EnterpriseDB.com/