From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [212.224.123.68]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.proxmox.com (Postfix) with ESMTPS id 165668A9D4 for ; Fri, 21 Oct 2022 09:59:53 +0200 (CEST) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id EF2F21E9F4 for ; Fri, 21 Oct 2022 09:59:52 +0200 (CEST) Received: from proxmox-new.maurer-it.com (proxmox-new.maurer-it.com [94.136.29.106]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by firstgate.proxmox.com (Proxmox) with ESMTPS for ; Fri, 21 Oct 2022 09:59:52 +0200 (CEST) Received: from proxmox-new.maurer-it.com (localhost.localdomain [127.0.0.1]) by proxmox-new.maurer-it.com (Proxmox) with ESMTP id C6C5544AF9 for ; Fri, 21 Oct 2022 09:59:51 +0200 (CEST) Message-ID: Date: Fri, 21 Oct 2022 09:59:50 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.3.0 Content-Language: en-US To: Thomas Lamprecht , Proxmox VE development discussion References: <20221020071704.46578-1-s.sterz@proxmox.com> <47cbf07a-d82f-618e-7d11-28d49ebdffb6@proxmox.com> <8f6f8f15-31bd-f6c5-44e3-09b64e749761@proxmox.com> From: Stefan Sterz In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-SPAM-LEVEL: Spam detection results: 0 AWL -0.110 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment NICE_REPLY_A -0.001 Looks like a legit reply (A) SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: Re: [pve-devel] [PATCH manager v3 1/2] api: ceph: add applications of each pool to the lspools endpoint X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 21 Oct 2022 07:59:53 -0000 On 10/21/22 09:04, Thomas Lamprecht wrote: > Am 21/10/2022 um 08:57 schrieb Stefan Sterz: >>> out of interest: how expensive is this, did you check the overhead? >>> >> do you want a specific metric? in my (admittedly small) test setup >> (three vm cluster with 4 cores and 4Gib RAM) it is barely noticeable. >> the api call takes between 18 and 25ms in both cases for me. >> > > I mean, with a handful of pools you probably won't (or really should not) > see any difference >50 ms, that would make it a hard case arguing. > > Just wondered if many pools (e.g., [10, 100, 1000]) actually increase this > O(n) or if that falls in the noise of the rados monitor query overhead. > > I don't expect that is significant, just wondered if you already checked > and got some info on that. ok so from what i can tell this is probably O(n) as it iterates once over all pools, but that info should be in memory and not too bad imo (and since this is lspools there are some other calls here that are likely in O(n)). however, even if this rados command takes too long, it will time out after 5 seconds and then no applications will be included in the response. which is just the previous behavior and imo "safe". some more detail below: technically, one may argue this call is in O(n*m*k), with n being the number of pools, m the number of applications and k the number of metadata keys for the application. but m and k are very like very small if not zero (e.g. for a default rbd pool m is one and k would be zero). so more like O(n). at least if i am reading this right: https://github.com/smithfarm/ceph/blob/v17.0.0/src/mon/OSDMonitor.cc#L6876-L6956