Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qFWV5-0006dd-TO for pgsql-hackers@arkaria.postgresql.org; Sat, 01 Jul 2023 09:02:40 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.92) (envelope-from ) id 1qFWV2-0001Xw-Iy for pgsql-hackers@arkaria.postgresql.org; Sat, 01 Jul 2023 09:02:36 +0000 Received: from magus.postgresql.org ([2a02:c0:301:0:ffff::29]) by malur.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qFWV2-0001Xn-7F for pgsql-hackers@lists.postgresql.org; Sat, 01 Jul 2023 09:02:36 +0000 Received: from forwardcorp1b.mail.yandex.net ([2a02:6b8:c02:900:1:45:d181:df01]) by magus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1qFWUu-001Xb2-Gq for pgsql-hackers@postgresql.org; Sat, 01 Jul 2023 09:02:35 +0000 Received: from mail-nwsmtp-smtp-corp-main-11.iva.yp-c.yandex.net (mail-nwsmtp-smtp-corp-main-11.iva.yp-c.yandex.net [IPv6:2a02:6b8:c0c:2c24:0:640:73f8:0]) by forwardcorp1b.mail.yandex.net (Yandex) with ESMTP id C8C43606FE; Sat, 1 Jul 2023 12:02:25 +0300 (MSK) Received: from smtpclient.apple (unknown [2a02:6b8:b081:b591::1:3a]) by mail-nwsmtp-smtp-corp-main-11.iva.yp-c.yandex.net (smtpcorp/Yandex) with ESMTPSA id N2LV5k0Om8c0-CIfS7S38; Sat, 01 Jul 2023 12:02:25 +0300 X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1688202145; bh=lUy4bX9gnWA8GdJPXdWoTEvC0ounhvh9JW8Or6kksbU=; h=References:To:Cc:In-Reply-To:Date:From:Message-Id:Subject; b=vXVgLEupQaQGmdvRgA6zc7P6cq4fg32il4HhR+08qpq/8l3VkZ2Ey2sjJ6hflphdP c4+WnFhgZa4AgX44ciGBdOITXy35x0TWVpQ7SbKdM5XoNgj0abcaGPAzd4yiZkdi7D B+A5l4cv8rj9AfykQqAnxYIhTwy7b9wWSM06FaIs= Authentication-Results: mail-nwsmtp-smtp-corp-main-11.iva.yp-c.yandex.net; dkim=pass header.i=@yandex-team.ru From: "Andrey M. Borodin" Message-Id: <206B487C-B20E-4140-9C25-C6694CE7D4D4@yandex-team.ru> Content-Type: multipart/alternative; boundary="Apple-Mail=_48A0E217-3F2E-4D2F-BC0A-2BBEC5A0D1D2" Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3696.120.41.1.2\)) Subject: Re: pg_upgrade instructions involving "rsync --size-only" might lead to standby corruption? Date: Sat, 1 Jul 2023 14:02:23 +0500 In-Reply-To: Cc: Bruce Momjian , Nikolay Samokhvalov , pgsql-hackers , Stephen Frost To: Robert Haas References: X-Mailer: Apple Mail (2.3696.120.41.1.2) List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk --Apple-Mail=_48A0E217-3F2E-4D2F-BC0A-2BBEC5A0D1D2 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Fast upgrade of highly available cluster is a vital part of being = industry-acceptable solution for any data management system. Because the = cluster is required to be highly available. Without this documented technique upgrade of 1Tb cluster would last many = hours, not seconds. There are industry concerns about scalability beyond tens of terabytes = per cluster, but such downtime would significantly lower that boundary. > On 1 Jul 2023, at 01:16, Robert Haas wrote: >=20 > If somebody > wants to write a reliable tool for this to ship as part of PostgreSQL, > well and good. IMV that's a good idea. We could teach pg_upgrade or some new tool to do = that reliably. The tricky part is that the tool must stop-start standby = remotely... Best regards, Andrey Borodin.= --Apple-Mail=_48A0E217-3F2E-4D2F-BC0A-2BBEC5A0D1D2 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii Fast = upgrade of highly available cluster is a vital part of being = industry-acceptable solution for any data management system. Because the = cluster is required to be highly available.

Without this documented technique = upgrade of 1Tb cluster would last many hours, not seconds.
There are industry concerns about scalability beyond tens of = terabytes per cluster, but such downtime would significantly lower that = boundary.

On 1 Jul 2023, at 01:16, Robert Haas <robertmhaas@gmail.com> wrote:

 If = somebody
wants to = write a reliable tool for this to ship as part of PostgreSQL,
well and = good.

IMV that's a good idea. We could teach pg_upgrade or some new = tool to do that reliably. The tricky part is that the tool must = stop-start standby remotely...


Best= regards, Andrey Borodin.
= --Apple-Mail=_48A0E217-3F2E-4D2F-BC0A-2BBEC5A0D1D2--