From owner-freebsd-hackers@freebsd.org Tue May 23 22:31:05 2017 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id D7ED1D783BD for ; Tue, 23 May 2017 22:31:05 +0000 (UTC) (envelope-from rwmaillists@googlemail.com) Received: from mail-wm0-x244.google.com (mail-wm0-x244.google.com [IPv6:2a00:1450:400c:c09::244]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 69D681051 for ; Tue, 23 May 2017 22:31:05 +0000 (UTC) (envelope-from rwmaillists@googlemail.com) Received: by mail-wm0-x244.google.com with SMTP id k15so41621304wmh.3 for ; Tue, 23 May 2017 15:31:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20161025; h=date:from:to:subject:message-id:in-reply-to:references:mime-version :content-transfer-encoding; bh=l71OpBVdj9u1qdl8m7qR3tUOFVvqexWiAFIjhCPvAVA=; b=pFY+Ff38mfVsoT4t3QhmYDnLbxtnFiaNnjyQq85crHgOYIOB+gqlM6zHAD5D2SJy7+ 5KCJxwMq193JEBqskJtfXa5dY4Rr6NhG//5TBwe186X9jk240gTzJlp+cBh1mc0Df6pE 5dqWZkcHy72kLPyKbHnFVGXdvj+JHXuN0Vqeucve78lnDDHFaTRxmg7bv8/YOwP2EPVs K3Km8VAmg/XV2tJF6iS1uvCE3s95P/VQcn1cSC0+/jFL5VVx9zGrHpBJND4rtkMUTh+5 MCMW2fWHxvBFJO3T5fkHhMjS4oYS2sWDXyG5QYR5/zZrCbwyZhb01XKAZC0fHO3dtso1 vsaQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=l71OpBVdj9u1qdl8m7qR3tUOFVvqexWiAFIjhCPvAVA=; b=QKsH2YwI5rVtLd5RwGGBgkUY9Hm+hE8rznX1A7DxAp6J/nCq71Z70n+8MuoD2aV9J9 2wuP9jQ7lBVXNupVIiPN1+U/IobnY/BvVHWoGLR10bq/TbGzJfYe9v8d8FMntXH4RAOQ 0TxDtxK/2EWNfvxRUQoIBVaY7ZWmYG9bHBksPjimSgTmdl/hh4h6potakOSXNJVDXw96 tFSdNLKK9keDr0jp62JDc0WsaqCLR82DnJ920zbH3oNdP+tNF+z5keKxUbMTrtSTBMxB PVdukRZNZ4fP3xLFnoMuf0K4iV2mh/hKE6HDsIcO+y7GnLdBYhzXUbvpjEFNfvQNxncm rfew== X-Gm-Message-State: AODbwcA7ZU+TBVbRdQ+1wq2Y/HwfUIaFS+q6JOKyPEf9SQJrkKOJyGqX 8CuVtCDwjAif13Xd X-Received: by 10.223.161.194 with SMTP id v2mr19051539wrv.132.1495578663422; Tue, 23 May 2017 15:31:03 -0700 (PDT) Received: from gumby.homeunix.com ([81.17.24.158]) by smtp.gmail.com with ESMTPSA id w18sm1620251wmw.26.2017.05.23.15.31.01 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 23 May 2017 15:31:02 -0700 (PDT) Date: Tue, 23 May 2017 23:30:57 +0100 From: RW To: freebsd-hackers@freebsd.org Subject: Re: anti-dog-piling and ntpd leap files Message-ID: <20170523233057.59cd2393@gumby.homeunix.com> In-Reply-To: References: <20170522125307.76c9de6d@gumby.homeunix.com> <1104C7A7-5893-4602-9E34-5C212D987DAE@webweaving.org> <20170522143102.70035d8d@gumby.homeunix.com> X-Mailer: Claws Mail 3.15.0 (GTK+ 2.24.31; amd64-portbld-freebsd10.3) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 May 2017 22:31:05 -0000 On Mon, 22 May 2017 08:09:54 -0600 Alan Somers wrote: > On Mon, May 22, 2017 at 7:31 AM, RW via freebsd-hackers > wrote: > > That doesn't sound like a good idea. If they aren't backgrounded > > they'll block the rest of periodic daily for up to an hour. Not > > much of a problem on a server, but it would be when periodic is run > > from anacron at boot time. > > Actually, there are already many periodic scripts from ports that > include foreground sleeps, mostly notably 410.pkg-audit. I didn't know that and I think there is a POLA violation there because if you run "time periodic daily" from a terminal there is no warning that delays are being skipped. This happens in the new version too. > Do those > cause problems for anacron? I wouldn't think so, because anacron > knows to restart a job that didn't complete the last time it was run. It's more about knowing when they run. I have some local scripts that aren't entirely atomic, nothing catastrophic would happen if they were interrupted, but I'd rather they completed. I've been avoiding shutting down during what I thought was a very narrow window, but turns out to be 75 minutes wider than I thought. Another thing is that periodic tasks can be I/O and CPU intensive and some people may be good reason to get them out of the way at boot time, rather than have them randomly kick-in. The updated version is an improvement because the single delay can be configured, but you have to know it's there.