From hdfs-issues-return-209383-archive-asf-public=cust-asf.ponee.io@hadoop.apache.org Mon Feb 5 09:32:05 2018 Return-Path: X-Original-To: archive-asf-public@eu.ponee.io Delivered-To: archive-asf-public@eu.ponee.io Received: from cust-asf.ponee.io (cust-asf.ponee.io [163.172.22.183]) by mx-eu-01.ponee.io (Postfix) with ESMTP id 97EDD180676 for ; Mon, 5 Feb 2018 09:32:05 +0100 (CET) Received: by cust-asf.ponee.io (Postfix) id 87152160C46; Mon, 5 Feb 2018 08:32:05 +0000 (UTC) Delivered-To: archive-asf-public@cust-asf.ponee.io Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by cust-asf.ponee.io (Postfix) with SMTP id CDFD0160C4B for ; Mon, 5 Feb 2018 09:32:04 +0100 (CET) Received: (qmail 9564 invoked by uid 500); 5 Feb 2018 08:32:03 -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 9548 invoked by uid 99); 5 Feb 2018 08:32:03 -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; Mon, 05 Feb 2018 08:32:03 +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 2675DC05DB for ; Mon, 5 Feb 2018 08:32:03 +0000 (UTC) X-Virus-Scanned: Debian amavisd-new at spamd1-us-west.apache.org X-Spam-Flag: NO X-Spam-Score: -109.511 X-Spam-Level: X-Spam-Status: No, score=-109.511 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, T_RP_MATCHES_RCVD=-0.01, 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 FIppyPZK47DQ for ; Mon, 5 Feb 2018 08:32:02 +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 60F3D5FB9B for ; Mon, 5 Feb 2018 08:32:01 +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 8EB5EE00B4 for ; Mon, 5 Feb 2018 08:32:00 +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 4FF4F21E83 for ; Mon, 5 Feb 2018 08:32:00 +0000 (UTC) Date: Mon, 5 Feb 2018 08:32:00 +0000 (UTC) From: "LiXin Ge (JIRA)" To: hdfs-issues@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Comment Edited] (HDFS-13086) Add a field about exception type to BlockOpResponseProto 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/HDFS-13086?page=3Dcom.atlassian= .jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=3D1635= 2126#comment-16352126 ]=20 LiXin Ge edited comment on HDFS-13086 at 2/5/18 8:31 AM: --------------------------------------------------------- As described in the [design document|https://issues.apache.org/jira/browse/= HDFS-347] of short-circuit read below, disable the SCR is a simple way to i= nteract with append, truncate, etc. operations. {quote}Interaction with other features (e.g. Append) We should investigate whether (and how) this feature will interact with ot= her ongoing work, in particular appends. If there is any complication, it s= hould be straightforward to simply disable the fast path for any blocks cur= rently under construction. Given that the primary benefit for the fast path= is in mapreduce jobs, and mapreduce jobs rarely run on under-construction = blocks, this seems reasonable and avoids a lot of complexity. {quote} Without a doubt that disable the SCR is a useful way to simplify the design= and make the SCR feature take wonderful effect at most of the time. But gi= ven that append may becomes a common case in some situation and SCR was dis= abled frequently(see details in=C2=A0HDFS-12528), then it doesn't fit the i= nitial target scene of *{{rarely run on under-construction blocks}}* and se= ems not so reasonable. The initial patch is attached, my=C2=A0initial ideas is add a=C2=A0excepti= on type to BlockOpResponseProto to=C2=A0identify various kinds of exception= s,=C2=A0but now that the main kind is FNFE, so I just add a status to=C2=A0= identify the specify case.=C2=A0I would be very grateful if I could get opi= nions from [~xiaochen] and [~cmccabe]. =C2=A0 was (Author: gelixin): As described in the design document of short-circuit read below, disable th= e SCR is a simple way to interact with append, truncate, etc. operations. {quote}Interaction with other features (e.g. Append) We should investigate whether (and how) this feature will interact with ot= her ongoing work, in particular appends. If there is any complication, it s= hould be straightforward to simply disable the fast path for any blocks cur= rently under construction. Given that the primary benefit for the fast path= is in mapreduce jobs, and mapreduce jobs rarely run on under-construction = blocks, this seems reasonable and avoids a lot of complexity. {quote} Without a doubt that disable the SCR is a useful way to simplify the design= and make the SCR feature take wonderful effect at most of the time. But gi= ven that append may becomes a common case in some situation and SCR was dis= abled frequently(see details in=C2=A0HDFS-12528), then it doesn't fit the i= nitial target scene of *{{rarely run on under-construction blocks}}* and se= ems not so reasonable. The initial patch is attached, my=C2=A0initial ideas is add a=C2=A0excepti= on type to BlockOpResponseProto to=C2=A0identify various kinds of exception= s,=C2=A0but now that the main kind is FNFE, so I just add a status to=C2=A0= identify the specify case.=C2=A0I would be very grateful if I could get opi= nions from [~xiaochen] and [~cmccabe]. =C2=A0 > Add a field about exception type to BlockOpResponseProto > -------------------------------------------------------- > > Key: HDFS-13086 > URL: https://issues.apache.org/jira/browse/HDFS-13086 > Project: Hadoop HDFS > Issue Type: Improvement > Affects Versions: 3.1.0 > Reporter: LiXin Ge > Assignee: LiXin Ge > Priority: Minor > Attachments: HDFS-13086.001.patch > > > When user re-read a file in the way of=C2=A0short-circuit reads, it may= =C2=A0come across unknown errors=C2=A0due to the reasons that=C2=A0the file= =C2=A0has been appended after the first read which changes it's meta file, = or the file has been moved away by the balancer. > Such=C2=A0unknown errors will unnecessary disable=C2=A0short-circuit read= s for 10 minutes.=C2=A0HDFS-12528=C2=A0Make the=C2=A0{{expireAfterWrite}}= =C2=A0of=C2=A0{{DomainSocketFactory$pathMap}}=C2=A0configurable to give use= r a choice of=C2=A0never disable the domain socket.=C2=A0 > We can=C2=A0go a step further that=C2=A0add a field about exception type = to BlockOpResponseProto, so that we can Ignore the acceptable FNFE and set = a appropriate disable time to handle the unacceptable exceptions=C2=A0when = different=C2=A0type of exception happens in the same cluster. -- 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