Re: increasing HA

Hi Jehan-Guillaume,

Thanks for your opinion.

At first glance, i may use for automatic failover PAF, a proxy HAproxy and
for fencincg, i am a bit disappointed, i don't know what to do/use

How about you, do you have any preference about tools/solutions to use ?

now, I am aware that i will have to check and document limitation/risk...

Le mer. 5 sept. 2018 à 11:38, Jehan-Guillaume (ioguix) de Rorthais <
ioguix(at)free(dot)fr> a écrit :

> Hi all,
>
> On Tue, 4 Sep 2018 15:09:51 +0000
> ROS Didier <didier(dot)ros(at)edf(dot)fr> wrote:
>
> > Hi
> > I have made a lot of PostgreSQL High Availability tests
> (more
> > than 20 by solution) and the two following products respond well to the
> need :
> >
> > (1) Repmgr (2ndQuadrant)
> >
> > (2) Pglookout (aiven)
>
> Both solutions use a simple and naive implementation, which makes them
> easy to
> use and admin. However, it gives the responsibilities to the admin to deal
> with
> fencing, which is a mandatory piece in almost all kind of DB cluster if you
> want to cover most of the failure cases and avoid split brain.
>
> So yes, they are simple, because complexity is left to the admin skills. It
> kind of require you rewrote and test yourself part of the fencing stack of
> Pacemaker. Good luck.
>
> And I'm not speaking about watchdog here, which I just fail to imagine how
> the
> admin could implement it himself.
>
> Just consider how messy it is to deal with "logical fencing" when
> considering
> doing it with pgbouncer.
>
> In short: if you are ready to spend many dev/admin hours to build a safe HA
> cluster for your DB and set strict requirements, those are fine.
>
> > About PAF, the product is hard to install and set up . It need a linux
> > cluster and a system engineers team to use it.
>
> Indeed, Pacemaker has a steep learning cuve and documentation still
> requires
> some improvement. But HA is not an easy subject. Just look at RHEL or Suse
> requirements before their team accept to support your DB cluster (spoiler:
> fencing).
>
> Whatever solution you pick, you must **know and document** its limitations
> and
> risks.
>