From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from [87.239.111.99] (localhost [127.0.0.1]) by dev.tarantool.org (Postfix) with ESMTP id 794ED6EC40; Wed, 7 Jul 2021 00:19:47 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 dev.tarantool.org 794ED6EC40 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=tarantool.org; s=dev; t=1625606387; bh=NIUhBUzRRQAemGffCIUBQaqMLGPA4e8HEE0k+pnxfok=; h=To:References:Date:In-Reply-To:Subject:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=ir8clOT+YPvjVJAYitAU1EwnPNm+FgMr8H8q2UqtM7EzUB4gXtK74SywF8NO/yqZd bDDvMFkDGzmvINkHHH9Bc7TArP6Zu6nEUtLGVn+a3iE374WrDPMMg2vCI3R8T3cLCJ Gbehsfq8Fty+Qeob0vjnFvogCbzxh+cKCLWm7/VY= Received: from smtpng3.i.mail.ru (smtpng3.i.mail.ru [94.100.177.149]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id 984216EC40 for ; Wed, 7 Jul 2021 00:19:45 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 dev.tarantool.org 984216EC40 Received: by smtpng3.m.smailru.net with esmtpa (envelope-from ) id 1m0sTo-000593-Mq; Wed, 07 Jul 2021 00:19:45 +0300 To: Oleg Babin , tarantool-patches@dev.tarantool.org, yaroslav.dynnikov@tarantool.org References: <6d8c2a728366edf5b0d208aeed9e027f870aa699.1625177222.git.v.shpilevoy@tarantool.org> <900c73e7-9824-ad3c-88f8-aa07b0382986@tarantool.org> <07f4dc34-0453-ce22-747e-6c50a2bcac12@tarantool.org> <7aa15d86-2ec9-c517-5553-e37f7370f49b@tarantool.org> Message-ID: <5156b7dd-13e6-7457-491d-4d66f42eb615@tarantool.org> Date: Tue, 6 Jul 2021 23:19:43 +0200 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <7aa15d86-2ec9-c517-5553-e37f7370f49b@tarantool.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit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eAau8CL7WIMRKs4sN3D3tLDjz0dLbV79QFUyzQ2Ujvy7cMT6pYYqY16iZVKkSc3dCLJ7zSJH7+u4VD18S7Vl4ZUrpaVfd2+vE6kuoey4m4VkSEu530nj6fImhcD4MUrOEAnl0W826KZ9Q+tr5ycPtXkTV4k65bRjmOUUP8cvGozZ33TWg5HZplvhhXbhDGzqmQDTd6OAevLeAnq3Ra9uf7zvY2zzsIhlcp/Y7m53TZgf2aB4JOg4gkr2biojwWhFrYo6Pn0i3feZrkkleA== X-Mailru-Sender: 689FA8AB762F7393C37E3C1AEC41BA5D88B1A54254B5C49F138E17CE3FF5C6213841015FED1DE5223CC9A89AB576DD93FB559BB5D741EB963CF37A108A312F5C27E8A8C3839CE0E267EA787935ED9F1B X-Mras: Ok Subject: Re: [Tarantool-patches] [PATCH vshard 5/6] router: introduce automatic master discovery X-BeenThere: tarantool-patches@dev.tarantool.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Vladislav Shpilevoy via Tarantool-patches Reply-To: Vladislav Shpilevoy Errors-To: tarantool-patches-bounces@dev.tarantool.org Sender: "Tarantool-patches" >>> And we even don't have exposed replicaset_wait_connected/replicaset_wait_master >>> >>> to call it before master will be known. As result several seconds we will get failed requests. >> I didn't expose them yet because I am very reluctant towards exposing >> anything until there is an explicit request from a user. Don't want to >> overload the API. >> >>> Also I saw TODO in test that "RO requests should be able to go to replicas" and I expect questions >>> >>> about RTO 0 on read requests from our customers. >> What do you mean as "RTO 0 on read requests"? >> > We faced it when developed CRUD module. To perform requests we need to know space schema. > > But all remote schema changes are visible only after request that triggers schema refetch. > > And we had working cluster but the first portion of requests failed because of outdated schema. > > > Will we have something similar when we doesn't discover master yet but have replicas and our > > read requests will fail? If it's so please file at least an issue to fix it. Yes, I understand now. Right, you might have failures, I am afraid. Depending on your timeout. If there is no master, your request will try to wait for a master's appearance during the given timeout. It won't fail immediately. But sometimes it does not even need to wait - it can simply go to a working replica right away if there is one. I mentioned it in XXX comments in the patch. I created a ticket: https://github.com/tarantool/vshard/issues/288.