Return-Path: X-Original-To: apmail-hadoop-hdfs-issues-archive@minotaur.apache.org Delivered-To: apmail-hadoop-hdfs-issues-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id C78F818145 for ; Tue, 24 Nov 2015 03:41:11 +0000 (UTC) Received: (qmail 13662 invoked by uid 500); 24 Nov 2015 03:41:11 -0000 Delivered-To: apmail-hadoop-hdfs-issues-archive@hadoop.apache.org Received: (qmail 13555 invoked by uid 500); 24 Nov 2015 03:41:11 -0000 Mailing-List: contact hdfs-issues-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: hdfs-issues@hadoop.apache.org Delivered-To: mailing list hdfs-issues@hadoop.apache.org Received: (qmail 13441 invoked by uid 99); 24 Nov 2015 03:41:11 -0000 Received: from arcas.apache.org (HELO arcas) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 24 Nov 2015 03:41:11 +0000 Received: from arcas.apache.org (localhost [127.0.0.1]) by arcas (Postfix) with ESMTP id 335462C1F6D for ; Tue, 24 Nov 2015 03:41:11 +0000 (UTC) Date: Tue, 24 Nov 2015 03:41:11 +0000 (UTC) From: "Tsz Wo Nicholas Sze (JIRA)" To: hdfs-issues@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Updated] (HDFS-8674) Improve performance of postponed block scans MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/HDFS-8674?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Tsz Wo Nicholas Sze updated HDFS-8674: -------------------------------------- Component/s: (was: HDFS) namenode > Improve performance of postponed block scans > -------------------------------------------- > > Key: HDFS-8674 > URL: https://issues.apache.org/jira/browse/HDFS-8674 > Project: Hadoop HDFS > Issue Type: Improvement > Components: namenode > Affects Versions: 2.6.0 > Reporter: Daryn Sharp > Assignee: Daryn Sharp > Priority: Critical > Attachments: HDFS-8674.patch > > > When a standby goes active, it marks all nodes as "stale" which will cause block invalidations for over-replicated blocks to be queued until full block reports are received from the nodes with the block. The replication monitor scans the queue with O(N) runtime. It picks a random offset and iterates through the set to randomize blocks scanned. > The result is devastating when a cluster loses multiple nodes during a rolling upgrade. Re-replication occurs, the nodes come back, the excess block invalidations are postponed. Rescanning just 2k blocks out of millions of postponed blocks may take multiple seconds. During the scan, the write lock is held which stalls all other processing. -- This message was sent by Atlassian JIRA (v6.3.4#6332)