[ACCUMULO-2831] HDFS Configuration classloader not correct when using VFSClassLoader

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.6.0
• Fix Version/s: 1.5.2, 1.6.1, 1.7.0
• Component/s: start
• Labels: classloader
• Assignee: Dave Marion
• Reporter: Dave Marion
• Created: 22/May/14 00:39
• Updated: 24/May/14 00:35
• Resolved: 22/May/14 01:15

Description

When using hdfs to load jars with the VFS classloader, the Hadoop FileSystem object is created before the VFS classloader. The FileSystem object and associated Configuration object are cached by the DFS Client and use the thread context classloader at the time of creation, which is not the VFS class loader. This leads to Accumulo classes not being found when they are loaded via the Configuration object, such as when WAL recovery is performed. The WAL is read using a SequenceFile$Reader object, which tries to load the Key and Value classes for the SequenceFile using WritableName.getClass(String, Configuration)