Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1u3FVL-00Cr39-2a for pgsql-performance@arkaria.postgresql.org; Fri, 11 Apr 2025 14:37:15 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.94.2) (envelope-from ) id 1u3FVI-00AWlT-1T for pgsql-performance@arkaria.postgresql.org; Fri, 11 Apr 2025 14:37:12 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1u3FVH-00AWkw-NR for pgsql-performance@lists.postgresql.org; Fri, 11 Apr 2025 14:37:12 +0000 Received: from mail-yw1-x112b.google.com ([2607:f8b0:4864:20::112b]) by makus.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.96) (envelope-from ) id 1u3FVG-004FjA-1d for pgsql-performance@lists.postgresql.org; Fri, 11 Apr 2025 14:37:11 +0000 Received: by mail-yw1-x112b.google.com with SMTP id 00721157ae682-6fee63b9139so19487267b3.1 for ; Fri, 11 Apr 2025 07:37:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1744382229; x=1744987029; darn=lists.postgresql.org; h=to:subject:message-id:date:from:mime-version:from:to:cc:subject :date:message-id:reply-to; bh=2KsFPHYBCycGzO3RcOyC+tkdgBFURqfNln0V3iGLrcw=; b=S9xIO9Ca2Wi6H+3Cg0UnfMjYfF2XdtFPd+zOpwoUpuvKJoJwlPPR+l32bBteNwibiv Jt3Uxb1nFGWUvH9vwgF3kIjIJbr/ChXOOolZeymRW2Dy6TCubf68+PALx9Dxloi3mrn7 n+v9tfD0NRQYLdbpbQ7zJ6UZ13U7/k5BU20lg6/6qulEZtFsfDhowuzZ6dId9Vk8JLwH /agmSl8TiDdxeUqQLJ2vKAewRgrSUs+/1ym7bLkSNJNsWmh+czxsm4Z/XCn4xWqlHWuR FXn6oHsAMUOnRYS2F3efCntyTer/VfEy0KUaiKYgwGTZgl33pD9LcwUneUUGHH3gOoox AEmw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1744382229; x=1744987029; h=to:subject:message-id:date:from:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=2KsFPHYBCycGzO3RcOyC+tkdgBFURqfNln0V3iGLrcw=; b=HkhhbaIFD/sfZo/GLViY9JvWWnUnh5A8YMpkNJvV+lQ0yMW3jl+NYjEvfV5e6i247L 07UGUMAMTf+AeHt0ukG+4q8OU5v+J4Q0HfLj03CgrnTksIXA2iUZoipR8899GdKfIHEr D6ZE1E0rE1Cy8yjcDI4T+sLDgCp6lMXkIl8KycMDEljbTUg7abe7EtI9W9aufoKn4b9t cPE/9195SQdJ/NCarzIJTV8f1VnExiccKn5Le2C7sSETq1omdVzQzROCW1nLvmF5VtC4 c4tVYccImksFlfaFH0tUSj37U+8UPcvHM7FNMuQgLuTZzoG2r/JgZmYANWsQOYtDNrJa SpjA== X-Gm-Message-State: AOJu0Yw/tFPMk8qTT/AKGi+EG35qY/WMZ1MgvI+LEdyHX1Pq8QA87WzA EyoCW6s++u+mP/0/V1SQe9mKvOnDlHis1jGKnkLozQSKz2rVTpmZ3Oeh5aYVs3TgXxB+S9J8x7q TpBUKEUw/xZGP+qbc6Rfx9U/FQ+vl2w== X-Gm-Gg: ASbGncsiDOs4L4QO8E2O5NmczEarqJ0jswtqUxIMzEZ5o4PziqjVhtSq7IVvXuHIZrY oMji6vSa7ZKyX4CXt6oKd+Sx8nleHWpQkYKKFI5K2C+aK/qfj4x5motGedUr49A6AafP0n9AuPV wYvep7Rdn1vO1nfzUKW1uxU93tHeJY9zovSw== X-Google-Smtp-Source: AGHT+IFR3VqBLteUV3B/mdHj0YHn95rXN1G8nezy3TiqiqASZg5TkvPESrOVl6F6aUCEb0g0o1B9qkCmmKEPu27n5vQ= X-Received: by 2002:a81:b205:0:b0:6fd:33a1:f4b with SMTP id 00721157ae682-70549e484cemr91137097b3.4.1744382229441; Fri, 11 Apr 2025 07:37:09 -0700 (PDT) MIME-Version: 1.0 From: James Pang Date: Fri, 11 Apr 2025 22:36:57 +0800 X-Gm-Features: ATxdqUGuAk3_aM7FVZfd3EmJjLqNYrxbD1Dc48SLsvQClg9b6SaKUvjE6B0GWBw Message-ID: Subject: many sessions wait on LWlock WALWrite suddenly To: pgsql-performance@lists.postgresql.org Content-Type: multipart/alternative; boundary="00000000000023784a063281a3fa" List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk --00000000000023784a063281a3fa Content-Type: text/plain; charset="UTF-8" pgv14.8 , during peak time, we suddenly see hundreds of active sessions waiting on LWlock WALWrite at the same time, but we did not find any issue on storage . any suggestions ? Thanks, James --00000000000023784a063281a3fa Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
=C2=A0 =C2=A0pgv14.8 , during peak time, we suddenly see h= undreds of active sessions waiting on LWlock=C2=A0 WALWrite at the same tim= e, but we did not find any issue on storage .
any suggestions ?=C2=A0

Thanks,

James
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