Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1sy160-00DmMC-2f for pgsql-general@arkaria.postgresql.org; Tue, 08 Oct 2024 03:41:12 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.94.2) (envelope-from ) id 1sy15y-0028AB-Px for pgsql-general@arkaria.postgresql.org; Tue, 08 Oct 2024 03:41:10 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1sy15y-0028A2-EA for pgsql-general@lists.postgresql.org; Tue, 08 Oct 2024 03:41:10 +0000 Received: from mail.causa-arcana.com ([188.166.12.15]) by magus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1sy15u-00384K-3c for pgsql-general@lists.postgresql.org; Tue, 08 Oct 2024 03:41:09 +0000 Authentication-Results: OpenDMARC; dmarc=fail (p=reject dis=none) header.from=kotovalexarian.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kotovalexarian.com; s=default; t=1728358864; bh=3ZWcEBHZX/iYVot8vlkixlJcSXyclpaG+8GvXjCMEuY=; h=Date:From:To:Subject:In-Reply-To:References:From; b=X5roxkNXbh5kp0y5OJ2WUp8SBOAN3OmySciJf1awbonq7TB5jxHOp+oClf+90oevr 1Q7rVicTSX40lmX01Bf88t5Y7azVkKHDLEIK6pYw4IjwmpSmKqvsiUf3lbcEISrdfR dkmS9G0/95T1SFrmAM07K+hFFlMx83upcpg9ETLmN1Y+V7u7iPee1XmGXSPfRqnmyr g/5/A0YXNHNyQZbYxoXHZ/bH9vSa3z5NCo208ljGz5WlENajwzgMIGnRqqQElrPIWA +RHgGTBZ+iOpGcfXz/yLmvYFYyxqnnPUciXpG63AEj98ndwt1i3WhzlJS9yNbEF884 /5oL/LkT89l5g== Received: from [127.0.0.1] (unknown [91.151.138.154]) by mail.causa-arcana.com (Postfix) with ESMTPSA id 97C7F21 for ; Tue, 8 Oct 2024 03:41:04 +0000 (UTC) Date: Tue, 08 Oct 2024 07:41:00 +0400 From: me+postgres@kotovalexarian.com To: pgsql-general@lists.postgresql.org Subject: Re: Load balancing of write queries among health-checked nodes User-Agent: K-9 Mail for Android In-Reply-To: References: Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk Among PostgreSQL instances there is only one master=2E But yes, each server= may be considered master by the clients because it's Pgpool-II will redire= ct write queries to the actual master=2E Maybe it's even better to avoid th= is unnecessary traffic between servers and decide which Pgpool-II is in fro= nt of the master on the client side, but this is optional=2E Dnia 8 pa=C5=BAdziernika 2024 07:30:05 GMT+04:00, Ron Johnson napisa=C5=82/a: >On Mon, Oct 7, 2024 at 11:04=E2=80=AFPM wrote: > >> Hello=2E I have a PostgreSQL high availability cluster with Pgpool-II, = but I >> don't use the virtual IP feature so my clients don't know which node to >> send queries to=2E DNS round-robin is not a solution because it can't >> distinguish between healthy and dead nodes=2E >> >> I thought about having a Pgpool-II instance on each client (client >> Pgpool-II -> cluster Pgpool-II -> PostgreSQL), but AFAIK it can't >> distribute write queries=2E I also know that libpq may have multiple no= des to >> connect, but I need an advanced health check because a node may have >> connectivity but be separated from the whole cluster so it must be >> considered dead=2E >> > >Isn't that multi-master clustering? >