From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 27057 invoked from network); 11 Aug 2021 14:21:53 -0000 Received: from alyss.skarnet.org (95.142.172.232) by inbox.vuxu.org with ESMTPUTF8; 11 Aug 2021 14:21:53 -0000 Received: (qmail 28896 invoked by uid 89); 11 Aug 2021 14:22:17 -0000 Mailing-List: contact supervision-help@list.skarnet.org; run by ezmlm Sender: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Received: (qmail 28889 invoked from network); 11 Aug 2021 14:22:17 -0000 From: "Laurent Bercot" To: "Arjun D R" Subject: Re: S6 Queries Cc: supervision@list.skarnet.org Date: Wed, 11 Aug 2021 14:21:50 +0000 Message-Id: In-Reply-To: References: Reply-To: "Laurent Bercot" User-Agent: eM_Client/8.2.1473.0 Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedvtddrkedugdejgecutefuodetggdotffvucfrrhhofhhilhgvmecupfgfoffgtffkveetuefngfdpqfgfvfenuceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephffvufffkfgjfhhrfgggtgfgsehtqhertddtreejnecuhfhrohhmpedfnfgruhhrvghnthcuuegvrhgtohhtfdcuoehskhgrqdhsuhhpvghrvhhishhiohhnsehskhgrrhhnvghtrdhorhhgqeenucggtffrrghtthgvrhhnpedvgfevffeuleegvdektdffteegvdeiieefkeetgfeuheffheelheejhfevueeijeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhhouggvpehsmhhtphhouhht >Thanks Laurent for the detailed explanations. We did a bootup speed >comparison between S6 and systemd. S6 is able to boot up slightly faster >than systemd. Actual result is 4-4.5% faster but we were expecting >something near to 20%. >Ours is a bit complex setup with more than 140 services (includes a lot of >long run services and a lot of dependencies). The main advantage in system= d >is, it starts many critical processes very quickly since it has no >dependency to logging services. We collect the logs from journalctl and >store it in log files. Whereas in S6, the critical services start up is a >bit delayed since it has to depend on logging services which in turn >depends on other services (responsible for backing up the previous logs). Thank you for these numbers! Indeed they confirm my intuition: booting via s6 is a little faster than systemd, but nothing extraordinary, because s6-rc emphasizes reliability over speed. Your critical services may be slightly delayed, but you have the guarantee that you will not lose logs - whereas with systemd, if a piece of your logging system fails to start, your critical services may=20 already have produced some data that will vanish into the aether. Whether or not that's an acceptable risk is up to you. -- Laurent