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 B010F10D01 for ; Tue, 16 Dec 2014 21:31:14 +0000 (UTC) Received: (qmail 6515 invoked by uid 500); 16 Dec 2014 21:31:14 -0000 Delivered-To: apmail-hadoop-hdfs-issues-archive@hadoop.apache.org Received: (qmail 6469 invoked by uid 500); 16 Dec 2014 21:31:14 -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 6451 invoked by uid 99); 16 Dec 2014 21:31:14 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 16 Dec 2014 21:31:14 +0000 Date: Tue, 16 Dec 2014 21:31:14 +0000 (UTC) From: "Haohui Mai (JIRA)" To: hdfs-issues@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (HDFS-7531) Improve the concurrent access on FsVolumeList 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-7531?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14248982#comment-14248982 ] Haohui Mai commented on HDFS-7531: ---------------------------------- Looks good to me. Just a minor nit: {code} - List blocksVolumeIds = new ArrayList(volumes.volumes.size()); + List blocksVolumeIds = new ArrayList(curVolumes.size()); {code} It can be simplified as {code} + List blocksVolumeIds = new ArrayList<>(curVolumes.size()); {code} Since we're on Java 7. > Improve the concurrent access on FsVolumeList > --------------------------------------------- > > Key: HDFS-7531 > URL: https://issues.apache.org/jira/browse/HDFS-7531 > Project: Hadoop HDFS > Issue Type: Improvement > Components: datanode > Affects Versions: 2.6.0 > Reporter: Lei (Eddy) Xu > Assignee: Lei (Eddy) Xu > Attachments: HDFS-7531.000.patch > > > {{FsVolumeList}} uses {{synchronized}} to protect the update on {{FsVolumeList#volumes}}, while various operations (e.g., {{checkDirs()}}, {{getAvailable()}}) iterate {{volumes}} without protection. > This JIRA proposes to use {{AtomicReference}} to encapture {{volumes}} to provide better concurrent access. -- This message was sent by Atlassian JIRA (v6.3.4#6332)