[HADOOP-10851] NetgroupCache does not remove group memberships

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.4.1
• Fix Version/s: 2.6.0
• Component/s: security
• Target Version/s: 2.6.0
• Hadoop Flags: Reviewed
• Assignee: Benoy Antony
• Reporter: Benoy Antony
• Created: 16/Jul/14 19:14
• Updated: 01/Dec/14 03:09
• Resolved: 12/Aug/14 22:33

Description

NetgroupCache is used by GroupMappingServiceProvider implementations based on net groups.
But it has a serious flaw in that once a user to group membership is established, it remains forever even if user is actually removed from the netgroup and cache is cleared. It is cleared only if the server is restarted.

To reproduce this:

• Cache a group with a set of users.
• Test membership correctness.
• Clear cache, remove a user from the group and cache the group again
• Expected result : user’s groups should not include the group from which he/she is removed.
• Actual result : user’s groups includes the group from which he/she was removed.

It is also noted that NetgroupCache has concurrency issues and a separate jira is filed to rectify them.

Issue Links

• is required by: HADOOP-10852 NetgroupCache is not thread-safe