[HDFS-7367] HDFS short-circuit read cannot negotiate shared memory slot and file descriptors when SASL is enabled on DataTransferProtocol.

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.6.0
• Component/s: hdfs-client
• Target Version/s: 2.6.0
• Hadoop Flags: Reviewed
• Assignee: Chris Nauroth
• Reporter: Chris Nauroth
• Created: 06/Nov/14 00:46
• Updated: 01/Dec/14 03:10
• Resolved: 06/Nov/14 04:35

Description

When both short-circuit read and SASL on DataTransferProtocol are enabled, the server side tries to negotiate SASL on the operation to allocate a new shared memory slot. However, the transport for this operation is the Unix domain socket (not TCP), and the client always assumes that Unix domain socket traffic is trustworthy. The end result is that the server side still attempts SASL negotiation, and it fails with an exception while erroneously trying to parse the domain socket address as if it were a network address. The read succeeds, but only because we fallback to a read through the DataNode TCP server. It's not a short-circuit read.

Issue Links

• relates to: HDFS-2856 Fix block protocol so that Datanodes don't require root or jsvc