HDFS Permission Control BSFS Implementation & HDFS Permission Control EMETTEUR 00 MOIS 2011

General Structure Zhe LI – BSFS Implementation 27 Feb 2013

Main Classes and Methods Namespace Manager NManager.class NWorker.class Namaspace.class Metadata.class File System Client BlobSeerFileSystem.class BSFSClient.class BSFSCachedOutput/InputStream.class BSFSOuput/InputStream.class Functions BSFSClient.sendRequest(): send a request to and transfer answer from server NWorker.processData(): encapsulate app request, enqueue the request NWorker.run(): Dequeue the request, call Namespace.process() Namespace.process(): execute file system operation Zhe LI – BSFS Implementation 27 Feb 2013

BSFSInput/OutputStream Working Process NManager Nworker Namespace Metadata Hadoop BlobSeerFileSystem BSFSClient BSFSInput/OutputStream BlobSeer Storage Zhe LI – BSFS Implementation 27 Feb 2013

Supported Operations Zhe LI – BSFS Implementation 27 Feb 2013 MKDIR: create a directory EXISTS: check if a directory or a file exists ISFILE: check if the path in a request points to a file RENAME: rename a file or a directory BLOBID: retrieve the Blob ID where a file is stored CREATE: create a file STATUS: retrieve the status of a file or a directory DELETE: delete files or directories in the file system LISTDIR: list the content in a directory SETSIZE: set the size of a file in its meta-data information Zhe LI – BSFS Implementation 27 Feb 2013

HDFS General Structure Hadoop DistributedFileSystem DFSClient NameNode DataNodes Zhe LI – HDFS Permisson Control 27 Feb 2013

HDFS Permission Control Permission Model POSIX: Users: Owner, Group, Others Operation: Read, Write, Execute Implemented in package: fs.permission AccessControlException.class: exception for access control related issues. ChomedParser.class: parse a permission mode, apply it against existing file. FsAction.class: definition of permission modes, i.e, EXECUTE(‘‘--x’’) FSPermission.class: a class to set file/directly permissions PermissionParser.class: a basic class for parsing chmod or umask PermissionStatus.class: store permission related information (user name, group name, etc.) Zhe LI – HDFS Permisson Control 27 Feb 2013

Related FS Operations Working Plan Zhe LI – HDFS Permisson Control CREATE: create a file with default permission SET PERMISSION: set permissions to a file or a directory MKDIR: create a directory with the given permission STATUS: retrieve the status of a file or a directory Working Plan Each of the three operations should take 3 to 5 days for coding, testing and debugging. Remove a patch on Hadoop code that changes the output path to BSFS uri, and integrate it in BSFS code. It should take 2 or 3 days for coding, testing and debugging Zhe LI – HDFS Permisson Control 27 Feb 2013