This can cause FileSystem already closed issues or leave FileSystem objects open when they should be discarded.
Using hdfs FileSystem.newInstance does not gaurantee a new instance.
Commit 1668411 from Mark Miller in branch 'dev/trunk'
[ https://svn.apache.org/r1668411 ]
SOLR-7284: HdfsUpdateLog is using hdfs FileSystem.get without turning off the cache.
SOLR-7286: Using HDFS's FileSystem.newInstance does not guarantee a new instance.
Commit 1672108 from Mark Miller in branch 'dev/branches/lucene_solr_5_1'
[ https://svn.apache.org/r1672108 ]
Commit 1672109 from Mark Miller in branch 'dev/branches/branch_5x'
[ https://svn.apache.org/r1672109 ]
Bulk close after 5.1 release