[HDFS-3907] Allow multiple users for local block readers

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0.0, 2.0.0-alpha
• Fix Version/s: 2.0.2-alpha
• Component/s: datanode
• Target Version/s: 1.3.0
• Hadoop Flags: Reviewed
• Assignee: Eli Collins
• Reporter: Eli Collins
• Created: 08/Sep/12 21:54
• Updated: 28/Sep/15 20:58
• Resolved: 10/Mar/15 04:13

Description

The dfs.block.local-path-access.user config added in HDFS-2246 only supports a single user, however as long as blocks are group readable by more than one user the feature could be used by multiple users, to support this we just need to allow both to be configured. In practice this allows us to also support HBase where the client (RS) runs as the hbase system user and the DN runs as hdfs system user. I think this should work secure as well since we're not using impersonation in the HBase case.

Issue Links

• relates to: HDFS-2246 Shortcut a local client reads to a Datanodes files directly