Thanks Chris. Information you provided is very much helpful.. On 20 Feb 2016 12:18 am, "Chris Nauroth" <[email protected]> wrote:
> Hello Shashi, > > HDFS itself doesn't have any knowledge of membership of users in groups. > The user and group field of an HDFS file or directory are just arbitrary > strings. For consulting a user's group memberships, HDFS runs a group > mapping provider [1]. This is pluggable, but the common case is either > querying the underlying OS directly or querying an LDAP server. > > For a given username, you can check what HDFS thinks its group memberships > are by running the "hdfs groups" command [2]. For example: > > > hdfs groups chris > chris : staff everyone localaccounts _appserverusr admin _appserveradm > _lpadmin _appstore _lpoperator _developer com.apple.access_screensharing > com.apple.access_ssh > > However, there is no way to query a list of all users in a group through > HDFS. HDFS doesn't have a use case for this kind of query, so it doesn't > implement one. For that, I'd expect you'd need to query directly whatever > your group membership infrastructure is (i.e. run the "groups" command at > the OS layer or query an LDAP server). > > I hope this helps. > > --Chris Nauroth > > [1] > http://hadoop.apache.org/docs/r2.7.2/hadoop-project-dist/hadoop-hdfs/HdfsPermissionsGuide.html#Group_Mapping > [2] > http://hadoop.apache.org/docs/r2.7.2/hadoop-project-dist/hadoop-hdfs/HDFSCommands.html#groups > > > From: Shashi Vishwakarma <[email protected]> > Date: Thursday, February 18, 2016 at 11:29 PM > To: "[email protected]" <[email protected]> > Subject: Get member list of group in HDFS using Java/Script > > Hi > > I need to find how many users belong to particular group in HDFS using > Java/Script. > > Let's say I have a directory /user/data in HDFS and it belongs to a group > 'abc' . > > I need to find how may other users belongs to 'abc' group. > > Can anyone suggest something. > > Thanks >
