From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f49.google.com (mail-ot1-f49.google.com [209.85.210.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 69B114A1E for ; Mon, 23 Sep 2024 01:26:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.49 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727054804; cv=none; b=PGGDGpnTsZMJ2xegHFPQvhgnvdK1fZPbcXGkYlc4kfQ264WnqrsaGwBKDD+1i2PPytzVXV66hSU30aKypuksvQm1+2h//Z/r+KCMgYd++p5SlWZRjmTHFpv8+L+muINKAA8c3C+WEIK0MLXJWs4rEhA9WW/0iwAZIf7de1Wxbe8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727054804; c=relaxed/simple; bh=8XlFApG6FPadMKvs9/6z33AE5+MsK/EP6PD6mz7amhk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=gqFJYpsZ2CCg8tPprN/n0mK6fvG9gryDlru8xM2XjIxt6g7TCF3DN60EcTf/D123pQJJMoRsawD/kWhqqcG1I2hXjdxNXXdyK5IMkbvsGIgz00gIQ5YrJ+juBiM43vSc6h19anujyTZ6ym2r1/AKNOa+E8bRXMb45M98+VQFQnQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=BG32wn08; arc=none smtp.client-ip=209.85.210.49 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="BG32wn08" Received: by mail-ot1-f49.google.com with SMTP id 46e09a7af769-7124395ca86so1470936a34.0 for ; Sun, 22 Sep 2024 18:26:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1727054802; x=1727659602; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=M4PgJ9J3iZt3sbxQnDGUQkK7yNo/JBGNON6+5QU6N4s=; b=BG32wn08bJUBjE56SBoIUCiL0vq8PcddMKhmPIrdwwaQmYNdEXkqJJnW154MAXFvPe JGVOCkichhBM9Qj+IP/XYd0mLOJchWT+83OFHbptd5Fz+N3dZFmOLNRaeQIig+cb3gp3 Ybm3nNQ0O4xzhWG0pdycj+p52zDrHzy1J5fbFI9K5BSfgjlNAW4i9DHU0OW7Ae84vIDR U10TVQEpE73onTvnsW5/IyrjtggNKdJik3e0uYkqMbfeibel1vhMRgkXdKTDS3PxDnsq 7wmqu5C29vLPWuyHIomfmQ6lWwqXKRlWGufJmvhK6M+fmQki2rC3eEAc+I92hRQ4qJbD rWVA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1727054802; x=1727659602; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=M4PgJ9J3iZt3sbxQnDGUQkK7yNo/JBGNON6+5QU6N4s=; b=QNqVqXMgGicdSXcgPtPsY7/9b+9My/glbReITptPMESFqYoYTukzPawQUA3CcUqV4G N1UTJnVTlN4ddl6L+AJOOw+zjMPIV2ncuD+XyECjIKDMuivzI+kN3VUVpnAxXoYueIug sCzbKbEJNO2K3Bh1f+W8pNkEiKtcJbRLKLSj4B9NM+9UCJLatX4a5hJm3CZKpEgNmSMT 7lNchvOwShZNrqol6RBVRxiop8OSpAmCjGQjOEld6n8/dXi0c5mv/i1Mlz+5W8bk6B3r 80Wu0jIIxsrfR+mgY87PGcwRu6ulK7s9e2U3x+SmdfAgrb2M9S7FxO135o393gWiY7ZC aSPg== X-Gm-Message-State: AOJu0YxJdsNjc3CxyRUWf1PF12Oz1rdHYlWPMGE0qvEQpIHsNpANOqrI g3ZQzN87DV95drl5EuBjyhyjR5GW9yQ7Pbm4eRKUvZLQBOLKWqckfC+pKw== X-Google-Smtp-Source: AGHT+IF77L0UcwMpoyIH+zsEwvrPrfl95CodjY6IIynV4C2+xxLIqC7e6yUhGU/XDUbVvnQIUC47Pw== X-Received: by 2002:a05:6830:2a14:b0:703:5fbe:e0ca with SMTP id 46e09a7af769-713923abdd1mr7106764a34.4.1727054802509; Sun, 22 Sep 2024 18:26:42 -0700 (PDT) Received: from ?IPV6:2600:1700:60ba:9810:1803:188e:65b0:6321? ([2600:1700:60ba:9810:1803:188e:65b0:6321]) by smtp.gmail.com with ESMTPSA id 46e09a7af769-71389b4a157sm1968651a34.2.2024.09.22.18.26.41 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 22 Sep 2024 18:26:41 -0700 (PDT) Message-ID: <91bf8c63-b2fc-48ca-a6de-37a576ddc1b1@gmail.com> Date: Sun, 22 Sep 2024 21:26:40 -0400 Precedence: bulk X-Mailing-List: git@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Prefetch maintenance might lead to thundering herd issues To: Shubham Kanodia Cc: git@vger.kernel.org, Patrick Steinhardt References: Content-Language: en-US From: Derrick Stolee In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 9/22/24 2:40 PM, Shubham Kanodia wrote: > On Sat, Sep 21, 2024 at 1:20 AM Derrick Stolee wrote: >> This is already handled by using a random minute of the hour, as >> implemented in 9b43399057 (maintenance: use random minute in cron >> scheduler, 2023-08-10), for example. There are similar uses for >> systemd, launchctl, and schtasks schedulers (look for uses of >> the get_random_minute() method). > Ah, thanks for pointing that out. It wasn't really clear from the > multiple examples and cron expressions on the git > maintenance documentation page (which have examples such as `0 1-23 * > * *` for hourly). I should've looked > more deeply into the implementation. > > Perhaps adding a line to the existing doc might be of help? What do > you think about adding a line to the > section on scheduling — I do think a doc change would help. Please submit it as a patch for review! Thanks, -Stolee