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 D9B84185CE for ; Fri, 24 Apr 2015 21:28:40 +0000 (UTC) Received: (qmail 80129 invoked by uid 500); 24 Apr 2015 21:28:39 -0000 Delivered-To: apmail-hadoop-hdfs-issues-archive@hadoop.apache.org Received: (qmail 80024 invoked by uid 500); 24 Apr 2015 21:28:39 -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 79678 invoked by uid 99); 24 Apr 2015 21:28:39 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 24 Apr 2015 21:28:39 +0000 Date: Fri, 24 Apr 2015 21:28:39 +0000 (UTC) From: "feng xu (JIRA)" To: hdfs-issues@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Created] (HDFS-8246) Get HDFS file name based on block pool id and block id MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 feng xu created HDFS-8246: ----------------------------- Summary: Get HDFS file name based on block pool id and block i= d Key: HDFS-8246 URL: https://issues.apache.org/jira/browse/HDFS-8246 Project: Hadoop HDFS Issue Type: New Feature Components: HDFS, hdfs-client, namenode Reporter: feng xu This feature provides HDFS shell command and C/Java API to retrieve HDFS fi= le name based on block pool id and block id. 1. The Java API in class DistributedFileSystem public String getFileName(String poolId, long blockId) throws IOException 2. The C API in hdfs.c char* hdfsGetFileName(hdfsFS fs, const char* poolId, int64_t blockId) 3. The HDFS shell command=20 hdfs dfs [generic options] -fn This feature is useful if you have HDFS block file name in local file syste= m and want to find out the related HDFS file name in HDFS name space (http= ://stackoverflow.com/questions/10881449/how-to-find-file-from-blockname-in-= hdfs-hadoop). Each HDFS block file name in local file system contains both= block pool id and block id, for sample HDFS block file name /hdfs/1/hadoop= /hdfs/data/current/BP-97622798-10.3.11.84-1428081035160/current/finalized/s= ubdir0/subdir0/blk_1073741825, the block pool id is BP-97622798-10.3.11.84= -1428081035160 and the block id is 1073741825. The block pool id is unique= ly related to a HDFS name node/name space, and the block id is uniquely re= lated to a HDFS file within a HDFS name node/name space, so the combination= of block pool id and a block id is uniquely related a HDFS file name.=20 The shell command and C/Java API do not map the block pool id to name node,= so it=E2=80=99s user=E2=80=99s responsibility to talk to the correct name = node in federation environment that has multiple name nodes. The block pool= id is used by name node to check if the user is talking with the correct n= ame node. The implementation is straightforward. The client request to get HDFS file = name reaches the new method String getFileName(String poolId, long blockId)= in FSNamesystem in name node through RPC, and the new method does the fol= lowings, (1)=09Validate the block pool id. (2)=09Create Block based on the block id. (3)=09Get BlockInfoContiguous from Block. (4)=09Get BlockCollection from BlockInfoContiguous. (5)=09Get file name from BlockCollection. -- This message was sent by Atlassian JIRA (v6.3.4#6332)