From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lj1-f196.google.com (mail-lj1-f196.google.com [209.85.208.196]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by dev.tarantool.org (Postfix) with ESMTPS id E9D50469710 for ; Tue, 19 May 2020 22:39:50 +0300 (MSK) Received: by mail-lj1-f196.google.com with SMTP id w10so1073487ljo.0 for ; Tue, 19 May 2020 12:39:50 -0700 (PDT) Date: Tue, 19 May 2020 22:39:48 +0300 From: Konstantin Osipov Message-ID: <20200519193948.GA12955@atlas> References: <670c3876e58a7cfa14d45db1dc074a10dd034759.1586808463.git.korablev@tarantool.org> <20200413221229.GA3462@atlas> <20200514021155.GB18509@tarantool.org> <20200514065608.GA12581@atlas> <20200519191006.GB13813@tarantool.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200519191006.GB13813@tarantool.org> Subject: Re: [Tarantool-patches] [PATCH 2/2] vinyl: skip invalid upserts during squash List-Id: Tarantool development patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Nikita Pettik Cc: tarantool-patches@dev.tarantool.org, v.shpilevoy@tarantool.org * Nikita Pettik [20/05/19 22:10]: > On 14 May 09:56, Konstantin Osipov wrote: > > * Nikita Pettik [20/05/14 09:50]: > > > On 14 Apr 01:12, Konstantin Osipov wrote: > > > > * Nikita Pettik [20/04/14 00:57]: > > > > > > Finally, let's double check there are no issues with the used > > > > format - can it become obsolete by the time it's used, e.g. if > > > > there is an online/non-blocking schema change that happened in tx > > > > thread (compaction is running in the write thread)? > > > > > > Upserts are supported only by primary index. Meanwhile vinyl does > > > not support altering primary index of non-empty space. Am I missing > > > something? > > > > I mean the space format object itself. Squashing is happening in a > > different thread, the > > > > > Seems like you've cut sentence. Could you please suggest exact > test scenario? We already have similar test in vinyl/errinj.test.lua: 1. Memtable dump is started. 2. Space is altered. 3. The format object is gone. 4. Memtable dump uses the old format object for upsert squashing. Similar with compaction: 1. Compaction starts and uses the existing format objects 2. It uses the format object for upsert squashing 3. Space is altered and format is changed 4. We report a squash failure/suppress failure. This is both related to memory liveness issues (e.g. we may use a freed format object, which isn't the case because we refcount them at start of dump/compaction), but also correctness issues: we accept data which is no longer acceptable according to the new format, or report/skip data which shouldn't be skipped. -- Konstantin Osipov, Moscow, Russia