From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gnu.wildebeest.org (wildebeest.demon.nl [212.238.236.112]) by sourceware.org (Postfix) with ESMTPS id 24B563857C68 for ; Fri, 5 Feb 2021 22:09:54 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 24B563857C68 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=klomp.org Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=mark@klomp.org Received: from tarox.wildebeest.org (tarox.wildebeest.org [172.31.17.39]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by gnu.wildebeest.org (Postfix) with ESMTPSA id EDAFB30278CD; Fri, 5 Feb 2021 23:09:52 +0100 (CET) Received: by tarox.wildebeest.org (Postfix, from userid 1000) id CF2414000D41; Fri, 5 Feb 2021 23:09:52 +0100 (CET) Message-ID: Subject: Re: PATCH: PR27092 debuginfod improve low-memory operations From: Mark Wielaard To: "Frank Ch. Eigler" , elfutils-devel@sourceware.org Date: Fri, 05 Feb 2021 23:09:52 +0100 In-Reply-To: <57bb92a3e14dde7fa9c2121aef447b2ce796b0f6.camel@klomp.org> References: <20210205014532.GA8530@redhat.com> <57bb92a3e14dde7fa9c2121aef447b2ce796b0f6.camel@klomp.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Mailer: Evolution 3.28.5 (3.28.5-10.el7) Mime-Version: 1.0 X-Spam-Status: No, score=-5.6 required=5.0 tests=BAYES_00, KAM_DMARC_STATUS, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: elfutils-devel@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Elfutils-devel mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Feb 2021 22:09:55 -0000 Hi, Just for the list to have it archived. We did briefly discuss this on irc. The changes have already been pushed. On Fri, 2021-02-05 at 18:24 +0100, Mark Wielaard wrote: > On Thu, 2021-02-04 at 20:45 -0500, Frank Ch. Eigler via Elfutils- > devel wrote: =20 > > - New prometheus metrics to track filesystem freespace, and more > > details about some errors. >=20 > This part looks fine. >=20 > Maybe this is a general question about exposing metrics. But does this > help people who want to do denial of service attacks? I mean by seeing > what effect some queries might have on freespace/errors? >=20 > Not a showstopper, but maybe something to think about before > encouraging people to expose their metrics? yeah hypothetically, and yet at the same time one needs that info more to detect problems early > > - Frequent checking of $TMPDIR freespace, to trigger fdcache > > emergency flushes. >=20 > This too looks fine. >=20 > > - Switch to floating point prometheus metrics, to communicate > > fractions - and short time intervals - accurately. >=20 > You move all metrics to use doubles. Including the metrics that use > integral values using inc_metric (the threads, _total and _count ones). > I cannot tell how that looks on the Prometheus side. Isn't it better to > keep those as integrals? Aka maybe inc_metric shouldn't call through to > add_metric? Or maybe have two metric maps, one for counts and one for > values/durations? doubles are the native type for prometheus consumers, the textual form doesn't really matter (and ieee doubles propagate 40+bit integers exactly so that's okay) might tweak the formatting to add all the digits of precision rather than the c++ default, easily > All code changes look fine. Please feel free to push if you think my > questions above are a little silly :) The actual changes seem to do > what you intended. Cheers, Mark