Date: Wed, 16 Apr 2025 22:35:34 +0300
From: Konstantin Osipov <kostja.osipov@gmail.com>
To: Greg Sabino Mullane <htamfids@gmail.com>
Cc: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>,
	Andrey Borodin <x4mmm@yandex-team.ru>, Tom Lane <tgl@sss.pgh.pa.us>,
	Nikolay Samokhvalov <nik@postgres.ai>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: Built-in Raft replication
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* Greg Sabino Mullane <htamfids@gmail.com> [25/04/16 22:33]:
> > Users find it a waste of resources to deploy 3 big PostgreSQL instances
> > just for HA where 2 suffice even if they deploy 3 lightweight DCS
> > instances. Having only some of the nodes act as DCS and others purely
> > PostgreSQL nodes will reduce waste of resources.
> >
> 
> A big problem is that putting your DCS into Postgres means your whole
> system is now super-sensitive to IO/WAL-streaming issues, and a busy
> database doing database stuff is going to start affecting the DCS stuff.

Affecting in what way? Do you have a scenario in mind where an
external state provider would act differently (better)? 

> With three lightweight DCS servers, you don't really need to worry about
> how stressed the database servers are. In that way, I feel etcd et al. are
> adhering to the unix philosophy of "do one thing, and do it well."

-- 
Konstantin Osipov, Moscow, Russia