From hdfs-issues-return-242870-archive-asf-public=cust-asf.ponee.io@hadoop.apache.org Thu Nov 15 19:30:06 2018 Return-Path: X-Original-To: archive-asf-public@cust-asf.ponee.io Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by mx-eu-01.ponee.io (Postfix) with SMTP id D1FCA180669 for ; Thu, 15 Nov 2018 19:30:05 +0100 (CET) Received: (qmail 45537 invoked by uid 500); 15 Nov 2018 18:30:04 -0000 Mailing-List: contact hdfs-issues-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Delivered-To: mailing list hdfs-issues@hadoop.apache.org Received: (qmail 45506 invoked by uid 99); 15 Nov 2018 18:30:04 -0000 Received: from pnap-us-west-generic-nat.apache.org (HELO spamd1-us-west.apache.org) (209.188.14.142) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 15 Nov 2018 18:30:04 +0000 Received: from localhost (localhost [127.0.0.1]) by spamd1-us-west.apache.org (ASF Mail Server at spamd1-us-west.apache.org) with ESMTP id 53AA6CD923 for ; Thu, 15 Nov 2018 18:30:04 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd1-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: -109.501 X-Spam-Level: X-Spam-Status: No, score=-109.501 tagged_above=-999 required=6.31 tests=[ENV_AND_HDR_SPF_MATCH=-0.5, KAM_ASCII_DIVIDERS=0.8, RCVD_IN_DNSWL_MED=-2.3, SPF_PASS=-0.001, USER_IN_DEF_SPF_WL=-7.5, USER_IN_WHITELIST=-100] autolearn=disabled Received: from mx1-lw-eu.apache.org ([10.40.0.8]) by localhost (spamd1-us-west.apache.org [10.40.0.7]) (amavisd-new, port 10024) with ESMTP id 2RVEIdgNNy16 for ; Thu, 15 Nov 2018 18:30:02 +0000 (UTC) Received: from mailrelay1-us-west.apache.org (mailrelay1-us-west.apache.org [209.188.14.139]) by mx1-lw-eu.apache.org (ASF Mail Server at mx1-lw-eu.apache.org) with ESMTP id C2C565F4A1 for ; Thu, 15 Nov 2018 18:30:01 +0000 (UTC) Received: from jira-lw-us.apache.org (unknown [207.244.88.139]) by mailrelay1-us-west.apache.org (ASF Mail Server at mailrelay1-us-west.apache.org) with ESMTP id 1E142E0177 for ; Thu, 15 Nov 2018 18:30:01 +0000 (UTC) Received: from jira-lw-us.apache.org (localhost [127.0.0.1]) by jira-lw-us.apache.org (ASF Mail Server at jira-lw-us.apache.org) with ESMTP id A693921357 for ; Thu, 15 Nov 2018 18:30:00 +0000 (UTC) Date: Thu, 15 Nov 2018 18:30:00 +0000 (UTC) From: "Bharat Viswanadham (JIRA)" To: hdfs-issues@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (HDDS-816) Create OM metrics for bucket, volume, keys MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/HDDS-816?page=3Dcom.atlassian.j= ira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=3D166884= 82#comment-16688482 ]=20 Bharat Viswanadham commented on HDDS-816: ----------------------------------------- Hi [~elek] The reason why we have not gone with rocksdb estimate number of keys is, li= ke if we take this value during OM start, and DB compaction is not done, st= ill we see the wrong value. Suppose, if we have a background thread, which = takes this values for every configured interval, it causes an impression to= admin that key count is=C2=A0varying continously somehow, without any user= action (like deletion, creation), and it will cause a panic to admin. And = also the estimates key count=C2=A0can also be an issue=C2=A0with this appro= ach because the calculation wibe estimatedate when below are happening on r= ocksdb. (comments from code of rocksdb) (1) there exist merge keys (2) keys are directly overwritten (3) deletion on non-existing keys =C2=A0 So, on our OM=C2=A0rocksb=C2=A02 and 3 can happen, so the estimate will be = mostly wrong. Even if we think after compaction we get this value, but afte= r some time background thread gets the estimate count value again and we wi= ll be wrong. And if we don't=C2=A0have background thread to update at the f= requent interval the behavior is unpredictable and it depends on rocksdb co= mpaction timing. So, I think missing the interval if OM is having unclean shutdown will be o= kay. And atleast we shall be accurate in the happy scenario. =C2=A0 =C2=A0 > Create OM metrics for bucket, volume, keys > ------------------------------------------ > > Key: HDDS-816 > URL: https://issues.apache.org/jira/browse/HDDS-816 > Project: Hadoop Distributed Data Store > Issue Type: Bug > Components: Ozone Manager > Reporter: Bharat Viswanadham > Assignee: Bharat Viswanadham > Priority: Major > Attachments: HDDS-816.00.patch, HDDS-816.01.patch, HDDS-816.03.pa= tch, Metrics for number of volumes, buckets, keys.pdf, Proposed Approach.pd= f > > > This Jira is used to create the following metrics in Ozone manager. > # number of volumes=C2=A0 > # number of=C2=A0buckets > # number of keys -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscribe@hadoop.apache.org For additional commands, e-mail: hdfs-issues-help@hadoop.apache.org