From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mp0 ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by ms11 with LMTPS id wGu7GFei+F/WZQAA0tVLHw (envelope-from ) for ; Fri, 08 Jan 2021 18:20:07 +0000 Received: from aspmx1.migadu.com ([2001:41d0:2:4a6f::]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) by mp0 with LMTPS id GD2MFFei+F/wTwAA1q6Kng (envelope-from ) for ; Fri, 08 Jan 2021 18:20:07 +0000 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by aspmx1.migadu.com (Postfix) with ESMTPS id C27379402AF for ; Fri, 8 Jan 2021 18:20:06 +0000 (UTC) Received: from localhost ([::1]:38282 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kxwMn-0003O2-Ox for larch@yhetil.org; Fri, 08 Jan 2021 13:20:05 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:53180) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kxwMa-0003No-3m for guix-devel@gnu.org; Fri, 08 Jan 2021 13:19:52 -0500 Received: from fencepost.gnu.org ([2001:470:142:3::e]:43281) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kxwMY-0006Bx-Cm; Fri, 08 Jan 2021 13:19:50 -0500 Received: from [2a01:e0a:19b:d9a0:d54b:f4e5:4687:8012] (port=35886 helo=cervin) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1kxwMU-0003qv-UM; Fri, 08 Jan 2021 13:19:49 -0500 From: Mathieu Othacehe To: Pierre Neidhardt Subject: Re: Cuirass logo - artwork. References: <87bldzu64t.fsf@gnu.org> <87sg7bzrj8.fsf@ambrevar.xyz> Date: Fri, 08 Jan 2021 19:19:45 +0100 In-Reply-To: <87sg7bzrj8.fsf@ambrevar.xyz> (Pierre Neidhardt's message of "Fri, 08 Jan 2021 10:50:19 +0100") Message-ID: <87a6tjqoji.fsf@gnu.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: guix-devel@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: guix-devel@gnu.org Errors-To: guix-devel-bounces+larch=yhetil.org@gnu.org Sender: "Guix-devel" X-Migadu-Flow: FLOW_IN X-Migadu-Spam-Score: -2.85 Authentication-Results: aspmx1.migadu.com; dkim=none; dmarc=pass (policy=none) header.from=gnu.org; spf=pass (aspmx1.migadu.com: domain of guix-devel-bounces@gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=guix-devel-bounces@gnu.org X-Migadu-Queue-Id: C27379402AF X-Spam-Score: -2.85 X-Migadu-Scanner: scn0.migadu.com X-TUID: 98NPDyzkzOQ7 Hello Pierre, > - Why is it called "Cuirass"? :p No idea, you would have to ask Mathieu Lirzin about it! > - Why the move to PostgreSQL? At first I thought that all the performance issues we had were caused by unoptimized SQL queries. Turns out it was only half of the problem. As we have multiple processes accessing the database (cuirass, cuirass-web, cuirass-send-events and now remote-server), we are falling into the architecture model that is very badly supported by SQLite: many readers and many readers across several processes[1]. I also noticed that SQLite doesn't handle I/O pressure on the hard drive the database is sitting on. I had to mount the database file on a tmpfs directory to get around this issue[2]. Finally, SQLite doesn't offer any real monitoring solution, requires periodical vacuuming and is really hard to configure[3]. As stated on SQLite website: "SQLite does not compete with client/server databases. SQLite competes with fopen()." I've been running Cuirass using a PostgreSQL database, and without any particular tuning everything works smooth, which makes me regret to have waited so long to leap the breach. Thanks for you interest, Mathieu [1]: https://softwareengineering.stackexchange.com/questions/340550/why-are-concurrent-writes-not-allowed-on-an-sqlite-database [2]: https://issues.guix.gnu.org/43850 [3]: https://wiki.mozilla.org/Performance/Avoid_SQLite_In_Your_Next_Firefox_Feature