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 1nLgl7-0006MY-1l for pgsql-hackers@arkaria.postgresql.org; Sun, 20 Feb 2022 07:35:53 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.92) (envelope-from ) id 1nLgkY-0001qy-OM for pgsql-hackers@arkaria.postgresql.org; Sun, 20 Feb 2022 07:35:18 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nLgkY-0001qU-C1 for pgsql-hackers@lists.postgresql.org; Sun, 20 Feb 2022 07:35:18 +0000 Received: from forwardcorp1p.mail.yandex.net ([2a02:6b8:0:1472:2741:0:8b6:217]) by makus.postgresql.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nLgkS-0006we-MV for pgsql-hackers@postgresql.org; Sun, 20 Feb 2022 07:35:16 +0000 Received: from myt5-4c5921969858.qloud-c.yandex.net (myt5-4c5921969858.qloud-c.yandex.net [IPv6:2a02:6b8:c12:3b1a:0:640:4c59:2196]) by forwardcorp1p.mail.yandex.net (Yandex) with ESMTP id 670F42E0971; Sun, 20 Feb 2022 10:35:08 +0300 (MSK) Received: from myt5-70c90f7d6d7d.qloud-c.yandex.net (myt5-70c90f7d6d7d.qloud-c.yandex.net [2a02:6b8:c12:3e2c:0:640:70c9:f7d]) by myt5-4c5921969858.qloud-c.yandex.net (mxbackcorp/Yandex) with ESMTP id aVbvbzeNku-Z7HaJ7QQ; Sun, 20 Feb 2022 10:35:08 +0300 X-Yandex-Fwd: 2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1645342508; bh=+bQ0Od0Pi77m42G8VRQR+1HnoGT1kMU3lYzOc9GPyxU=; h=Message-Id:References:Date:Subject:Cc:To:In-Reply-To:From; b=rkNmgjVjNAugKDkjJb2XuD7bg+7DGglkkiGGmXysJ0HVsm2O2wpjYq0QWFqSswsEZ UlBqLlqvPKtibBJuYDFCH7nfk65jy2g+wZoxp+NP6GuY49E7ttzAD/gBND+v2OSPao vlUR1De7x/Yn7fiWUHhXBTYzyoZ9U02BnhpA1BtA= Authentication-Results: myt5-4c5921969858.qloud-c.yandex.net; dkim=pass header.i=@yandex-team.ru Received: from smtpclient.apple (dynamic-vpn.dhcp.yndx.net [2a02:6b8:b081:a505::1:2e]) by myt5-70c90f7d6d7d.qloud-c.yandex.net (smtpcorp/Yandex) with ESMTPSA id oBxnA44sQb-Z6HGa1c3; Sun, 20 Feb 2022 10:35:07 +0300 (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client certificate not present) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 15.0 \(3693.60.0.1.1\)) Subject: Re: MultiXact\SLRU buffers configuration From: Andrey Borodin In-Reply-To: <20220219214223.w4bmhiozeimcqhzb@alap3.anarazel.de> Date: Sun, 20 Feb 2022 12:35:06 +0500 Cc: Thomas Munro , Gilles Darold , Tomas Vondra , Tomas Vondra , Alexander Korotkov , Anastasia Lubennikova , Daniel Gustafsson , Kyotaro Horiguchi , pgsql-hackers Content-Transfer-Encoding: quoted-printable Message-Id: <01FF6FFC-7379-43EA-B04A-673C98ABFAAF@yandex-team.ru> References: <27D90FFC-B897-4BC5-B4F5-9047B9886AA3@yandex-team.ru> <15CA416B-3446-462D-902B-4883DD3ADEE6@yandex-team.ru> <3130B767-FEB7-4F18-AE90-DD95B4367316@yandex-team.ru> <20220219214223.w4bmhiozeimcqhzb@alap3.anarazel.de> To: Andres Freund X-Mailer: Apple Mail (2.3693.60.0.1.1) List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk > On 20 Feb 2022, at 02:42, Andres Freund wrote: >=20 > On 2022-02-20 10:38:53 +1300, Thomas Munro wrote: >> Back to this patch: assuming we can settle on a good-enough-for-now >> replacement algorithm, do we want to add this set of 7 GUCs? Does >> anyone else want to weigh in on that? >=20 > I'm -0.2 on it, given that we have a better path forward. That=E2=80=99s a really good path forward, but it's discussed at least = for 3.5 years[0]. And guaranteed not to be there until 2023. Gilles, = Shawn, Dmitry expressed their opinion in lines with that the patch =E2=80=9C= is a must-have=E2=80=9D referring to real pathological performance = degradation inflicted by SLRU cache starvation. And I can remember dozen = of other incidents that would not happen if the patch was applied, e.g. = this post is referring to the patch as a cure [1]. Best regards, Andrey Borodin. [0] = https://www.postgresql.org/message-id/flat/20180814213500.GA74618%4060f81d= c409fc.ant.amazon.com [1] = https://about.gitlab.com/blog/2021/09/29/why-we-spent-the-last-month-elimi= nating-postgresql-subtransactions/#what-can-we-do-about-getting-rid-of-nes= sie=09=