Re: BUG #15187: When use huge page, there may be a lot of hanged connections with status startup or authentication

On 2018-05-06 23:45:17 +0800, chenhj wrote:
> >>
> >>Chen, have you disabled transparent hugepages and zone reclaim?
> >>
> >>Greetings,
> >>
> >>Andres Freund>>c) Depend on huge page >huge_page=on, happen(no matter transparent_hugepage is [always] or [never]) >huge_page=off, not happen
> >
> >When disable transparent hugepages ,this problem also occurs.
> >Aboud zone reclaim,I will see it later.
> >What I doubt is that this problem does not occurs at PostgreSQL 9.6.2 (I tested 10.2 and 9.6.2 on the same machine)
> >d) Depend on PostgreSQL Version
> >PostgreSQL 10.2 happen
> >PostgreSQL 9.6 not happen
> >Chen Huajun
> The problem occurs whether vm.zone_reclaim_mode is set to 0 or 1.
>
> In addition, what needs to be corrected is that even huge_pages=off is problematic.
>
> Huge_pages = on SQL execution is a very slow , and with hangd connections in startup and auth state.
>

You'd probably need to provide a few perf profiles to get further
insight.

Greetings,

Andres Freund