[HADOOP-9357] Fallback to default authority if not specified in FileContext

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Invalid
• Affects Version/s: 2.0.0-alpha
• Target Version/s: 2.1.0-beta
• Hadoop Flags: Incompatible change, Reviewed
• Assignee: Andrew Wang
• Reporter: Andrew Wang
• Created: 04/Mar/13 18:40
• Updated: 06/Mar/17 22:33
• Resolved: 06/Mar/17 22:33

Description

Currently, FileContext adheres rather strictly to RFC2396 when it comes to parsing absolute URIs (URIs with a scheme). If a user asks for a URI like "hdfs:///tmp", FileContext will error while FileSystem will add the authority of the default FS (e.g. turn it into "hdfs://defaultNN:port/tmp").

This is technically correct, but FileSystem's behavior is nicer for users and okay based on 5.2.3 in the RFC, so lets do it in FileContext too:

For backwards
compatibility, an implementation may work around such references
by removing the scheme if it matches that of the base URI and the
scheme is known to always use the  syntax.  The parser
can then continue with the steps below for the remainder of the
reference components.  Validating parsers should mark such a
misformed relative reference as an error.

Issue Links

• breaks: YARN-516 TestContainerLocalizer.testContainerLocalizerMain is failing
• is related to: HDFS-4653 4 unit tests in TestFcHdfsSymlink failed on trunk