org.apache.hadoop.security
Class Groups

java.lang.Object
  org.apache.hadoop.security.Groups

public class Groups
extends Object

A user-to-groups mapping service. Groups allows for server to get the various group memberships of a given user via the getGroups(String) call, thus ensuring a consistent user-to-groups mapping and protects against vagaries of different mappings on servers and clients in a Hadoop cluster.

Constructor Summary

Groups(Configuration conf)

Method Summary

void	cacheGroupsAdd(List<String> groups)
List<String>	getGroups(String user) Get the group memberships of a given user.
static Groups	getUserToGroupsMappingService() Get the groups being used to map user-to-groups.
static Groups	getUserToGroupsMappingService(Configuration conf)
void	refresh() Refresh all user-to-groups mappings.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Groups

public Groups(Configuration conf)

Method Detail

getGroups

public List<String> getGroups(String user)
                       throws IOException

Get the group memberships of a given user.

Parameters:

user - User's name

Returns:

the group memberships of the user

Throws:

IOException

refresh

public void refresh()

Refresh all user-to-groups mappings.

cacheGroupsAdd

public void cacheGroupsAdd(List<String> groups)

getUserToGroupsMappingService

public static Groups getUserToGroupsMappingService()

Get the groups being used to map user-to-groups.

Returns:

the groups being used to map user-to-groups.

getUserToGroupsMappingService

public static Groups getUserToGroupsMappingService(Configuration conf)