[HADOOP-8842] local file system behavior of mv into an empty directory is inconsistent with HDFS

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Won't Fix
• Affects Version/s: 0.20.2
• Assignee: Unassigned
• Reporter: Julien Le Dem
• Created: 25/Sep/12 17:32
• Updated: 14/Nov/18 10:56
• Resolved: 14/Nov/18 10:56

Description

moving into an empty directory replaces the directory instead.
See output of attached script to reproduce :

repro.sh

rm -rf local_fs_bug
mkdir local_fs_bug
hdfs -rmr local_fs_bug
hdfs -mkdir local_fs_bug

echo ">>> HDFS: normal behavior"
touch part-0000
hdfs -mkdir local_fs_bug/a
hdfs -copyFromLocal part-0000 local_fs_bug/a
hdfs -mkdir local_fs_bug/b
hdfs -mkdir local_fs_bug/b/c
echo "content of a: 1 part"
hdfs -ls local_fs_bug/a
echo "content of b/c: empty"
hdfs -ls local_fs_bug/b/c
echo "mv a b/c"
hdfs -mv local_fs_bug/a local_fs_bug/b/c
echo "resulting content of b/c"
hdfs -ls local_fs_bug/b/c
echo "a is moved inside of c"
echo
echo ">>> local fs: bug"
mkdir -p local_fs_bug/a
touch local_fs_bug/a/part-0000
mkdir -p local_fs_bug/b/c
echo "content of a: 1 part"
hdfs -fs local -ls local_fs_bug/a
echo "content of b/c: empty"
hdfs -fs local -ls local_fs_bug/b/c
echo "mv a b/c"
hdfs -fs local -mv local_fs_bug/a local_fs_bug/b/c
echo "resulting content of b/c"
hdfs -fs local -ls local_fs_bug/b/c
echo "bug: a replaces c"
echo
echo ">>> but it works if the destination is not empty"
mkdir local_fs_bug/a2
touch local_fs_bug/a2/part-0000
mkdir -p local_fs_bug/b2/c2
touch local_fs_bug/b2/c2/dummy
echo "content of a2: 1 part"
hdfs -fs local -ls local_fs_bug/a2
echo "content of b2/c2: 1 dummy file"
hdfs -fs local -ls local_fs_bug/b2/c2
echo "mv a2 b2/c2"
hdfs -fs local -mv local_fs_bug/a2 local_fs_bug/b2/c2
echo "resulting content of b/c"
hdfs -fs local -ls local_fs_bug/b2/c2
echo "a2 is moved inside of c2"

Output:

>>> HDFS: normal behavior
content of a: 1 part
Found 1 items
-rw-r--r--   3 julien g          0 2012-09-25 17:16 /user/julien/local_fs_bug/a/part-0000
content of b/c: empty
mv a b/c
resulting content of b/c
Found 1 items
drwxr-xr-x   - julien g          0 2012-09-25 17:16 /user/julien/local_fs_bug/b/c/a
a is moved inside of c

>>> local fs: bug
content of a: 1 part
12/09/25 17:16:34 WARN fs.FileSystem: "local" is a deprecated filesystem name. Use "file:///" instead.
Found 1 items
-rw-r--r--   1 julien g          0 2012-09-25 17:16 /home/julien/local_fs_bug/a/part-0000
content of b/c: empty
12/09/25 17:16:34 WARN fs.FileSystem: "local" is a deprecated filesystem name. Use "file:///" instead.
mv a b/c
12/09/25 17:16:35 WARN fs.FileSystem: "local" is a deprecated filesystem name. Use "file:///" instead.
resulting content of b/c
12/09/25 17:16:35 WARN fs.FileSystem: "local" is a deprecated filesystem name. Use "file:///" instead.
Found 1 items
-rw-r--r--   1 julien g          0 2012-09-25 17:16 /home/julien/local_fs_bug/b/c/part-0000
bug: a replaces c

>>> but it works if the destination is not empty
content of a2: 1 part
12/09/25 17:16:36 WARN fs.FileSystem: "local" is a deprecated filesystem name. Use "file:///" instead.
Found 1 items
-rw-r--r--   1 julien g          0 2012-09-25 17:16 /home/julien/local_fs_bug/a2/part-0000
content of b2/c2: 1 dummy file
12/09/25 17:16:37 WARN fs.FileSystem: "local" is a deprecated filesystem name. Use "file:///" instead.
Found 1 items
-rw-r--r--   1 julien g          0 2012-09-25 17:16 /home/julien/local_fs_bug/b2/c2/dummy
mv a2 b2/c2
12/09/25 17:16:37 WARN fs.FileSystem: "local" is a deprecated filesystem name. Use "file:///" instead.
resulting content of b/c
12/09/25 17:16:38 WARN fs.FileSystem: "local" is a deprecated filesystem name. Use "file:///" instead.
Found 2 items
drwxr-xr-x   - julien g       4096 2012-09-25 17:16 /home/julien/local_fs_bug/b2/c2/a2
-rw-r--r--   1 julien g          0 2012-09-25 17:16 /home/julien/local_fs_bug/b2/c2/dummy
a2 is moved inside of c2