From mapreduce-issues-return-91976-archive-asf-public=cust-asf.ponee.io@hadoop.apache.org Tue Jun 12 23:04:03 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 48246180608 for ; Tue, 12 Jun 2018 23:04:03 +0200 (CEST) Received: (qmail 94456 invoked by uid 500); 12 Jun 2018 21:04:02 -0000 Mailing-List: contact mapreduce-issues-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Delivered-To: mailing list mapreduce-issues@hadoop.apache.org Received: (qmail 94445 invoked by uid 99); 12 Jun 2018 21:04:02 -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; Tue, 12 Jun 2018 21:04:02 +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 BEF53C828A for ; Tue, 12 Jun 2018 21:04:01 +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-us.apache.org ([10.40.0.8]) by localhost (spamd1-us-west.apache.org [10.40.0.7]) (amavisd-new, port 10024) with ESMTP id vjBP5Q6571du for ; Tue, 12 Jun 2018 21:04:01 +0000 (UTC) Received: from mailrelay1-us-west.apache.org (mailrelay1-us-west.apache.org [209.188.14.139]) by mx1-lw-us.apache.org (ASF Mail Server at mx1-lw-us.apache.org) with ESMTP id EA3AA5F19B for ; Tue, 12 Jun 2018 21:04:00 +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 79C51E031B for ; Tue, 12 Jun 2018 21:04:00 +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 34CF12109B for ; Tue, 12 Jun 2018 21:04:00 +0000 (UTC) Date: Tue, 12 Jun 2018 21:04:00 +0000 (UTC) From: "Arun Suresh (JIRA)" To: mapreduce-issues@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (MAPREDUCE-7101) Revisit behavior of JHS scan file behavior 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/MAPREDUCE-7101?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16510203#comment-16510203 ] Arun Suresh commented on MAPREDUCE-7101: ---------------------------------------- Thanks [~tmarquardt]. The patch looks good to me. +1 The comment describing the new field in JHAdminConfig is wrong - minor thing I can fix before committing. Given that this patch retains the default behavior, and specific cloud deployments can choose to always scan. Maybe a pluggable FS specific scan is probably a better long term solution, but I agree with [~leftnoteasy] and [~rohithsharma] that we should go ahead with the approach in this patch to unblock. > Revisit behavior of JHS scan file behavior > ------------------------------------------ > > Key: MAPREDUCE-7101 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-7101 > Project: Hadoop Map/Reduce > Issue Type: Bug > Reporter: Wangda Tan > Assignee: Thomas Marquardt > Priority: Critical > Attachments: MAPREDUCE-7101.001.patch > > > Currently, the JHS scan directory if the modification of *directory* changed: > {code} > public synchronized void scanIfNeeded(FileStatus fs) { > long newModTime = fs.getModificationTime(); > if (modTime != newModTime) { > <... omitted some logics ...> > // reset scanTime before scanning happens > scanTime = System.currentTimeMillis(); > Path p = fs.getPath(); > try { > scanIntermediateDirectory(p); > {code} > This logic relies on an assumption that, the directory's modification time will be updated if a file got placed under the directory. > However, the semantic of directory's modification time is not consistent in different FS implementations. For example, MAPREDUCE-6680 fixed some issues of truncated modification time. And HADOOP-12837 mentioned on S3, the directory's modification time is always 0. > I think we need to revisit behavior of this logic to make it to more robustly work on different file systems. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: mapreduce-issues-unsubscribe@hadoop.apache.org For additional commands, e-mail: mapreduce-issues-help@hadoop.apache.org