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 1kxKdi-0008AN-Cz for pgsql-performance@arkaria.postgresql.org; Thu, 07 Jan 2021 02:03:02 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.92) (envelope-from ) id 1kxKdh-00042g-1A for pgsql-performance@arkaria.postgresql.org; Thu, 07 Jan 2021 02:03:01 +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 1kxKdg-00042Z-Qo for pgsql-performance@lists.postgresql.org; Thu, 07 Jan 2021 02:03:00 +0000 Received: from mail-wr1-x42e.google.com ([2a00:1450:4864:20::42e]) by makus.postgresql.org with esmtps (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1kxKdd-0005SH-OT for pgsql-performance@lists.postgresql.org; Thu, 07 Jan 2021 02:02:59 +0000 Received: by mail-wr1-x42e.google.com with SMTP id d26so4080258wrb.12 for ; Wed, 06 Jan 2021 18:02:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cybertec-at.20150623.gappssmtp.com; s=20150623; h=message-id:subject:from:to:date:in-reply-to:references:user-agent :mime-version:content-transfer-encoding; bh=Jkulo/IOKzHbxUUr2gpgUCwoIA4RGITcFhBcljT9teA=; b=z0LEjaVvwzdZGmUg8tQMHRahMq1KVAKLlwePJGIsZKax4Wlt5kot27C3n+FIRFOx42 ZEwzGMBySrpY0UR3YJyxVIMKd01MpqoF9S2zh22q4D4BfXkw3bqvpHRRVTJaWpatOzF6 +AWZf2WvZOi1MLmFFQLzcUNruJrN7CZDFyZT/hiTpd/ec+Ah+2HIEIVQSelx8WarZYY8 M/bxRvztvkZd/mzuL1eFOxsOzPxyso4O6NXKN5lGVjzjrCNtreA9Mp2+7e6iT9VdAbrt sy2+E95KHtInIOtVr1CDoch72THtpNR7bi5APHQt+a0mcv8Q4evPPHZxE9ypMl175RBk o3fQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:subject:from:to:date:in-reply-to :references:user-agent:mime-version:content-transfer-encoding; bh=Jkulo/IOKzHbxUUr2gpgUCwoIA4RGITcFhBcljT9teA=; b=ggbq461WIvvvzFFzb8KVRY9pjf7/ZKHx3+6elzShA3uzH8FjpWuyhI9kCA9TWG4hI9 77M8JprW5+LKC0dAVvza1tilNH7IOwZ5VJaIv9DSudvtU+xx2s1W9GrDAyxMnpzzLLEw x3Xs92ksT3mSVmCo0qzHQoxI3X22bgDW+fgcYZzZFSaYcZCspBHqzrzSDJ77m+zouBdW pz/4OgBeE2fX36f4/cZKXZfM7PRMA6bNBGoXQaCx2OTJjri64tX4+SI6MxW/ti2ctbB3 wiplgT52AcRFp/Tk+fIMKXOQDTQFqY4eDqIrnHcY+le8EFL2KuN3w125mQtuVtvf8AEh a/Mw== X-Gm-Message-State: AOAM533xsDxuvZ6F7ZY1SW87RXx7p9PUdAX/Vr8e8/VckTFXBdPdzuka S4WXF4K7ffgAczUzqv1Co9/PyUrgaqs2CA== X-Google-Smtp-Source: ABdhPJwQe0Cx8h7onysPZrG9gVVa4Doix2cnRl6pQG18M4kg1zUh00u0GaEmGNhAKXQpQFJ1ifvbmw== X-Received: by 2002:adf:bb0e:: with SMTP id r14mr6861262wrg.159.1609984974757; Wed, 06 Jan 2021 18:02:54 -0800 (PST) Received: from localhost.localdomain (178-190-179-204.adsl.highway.telekom.at. [178.190.179.204]) by smtp.gmail.com with ESMTPSA id l7sm5131184wme.4.2021.01.06.18.02.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 Jan 2021 18:02:54 -0800 (PST) Message-ID: <4f031716ed0a0175ffceffcb40c36c05f66685e3.camel@cybertec.at> Subject: Re: High COMMIT times From: Laurenz Albe To: Don Seiler , pgsql-performance@lists.postgresql.org Date: Thu, 07 Jan 2021 03:02:53 +0100 In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.36.5 (3.36.5-2.fc32) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Precedence: bulk On Wed, 2021-01-06 at 10:19 -0600, Don Seiler wrote: > This week we've noticed that we're starting to see spikes where COMMITs are taking much longer than usual. > Sometimes, quite a few seconds to finish. > > This is PostgreSQL 12.4 on Ubuntu 18.04, all running in MS Azure (*not* managed by them). Unless you are using WITH HOLD cursors on large result sets, this is very likely I/O overload. Use tools like "sar", "vmstat" and "iostat" to monitor your I/O load. Yours, Laurenz Albe -- Cybertec | https://www.cybertec-postgresql.com