[MAPREDUCE-4562] Support for "FileSystemCounter" legacy counter group name for compatibility reasons is creating incorrect counter name

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.23.0, 0.23.1, 2.0.0-alpha
• Fix Version/s: 0.23.3, 2.0.2-alpha
• Hadoop Flags: Reviewed
• Assignee: Jarek Jarcec Cecho
• Reporter: Jarek Jarcec Cecho
• Created: 16/Aug/12 06:46
• Updated: 11/Oct/12 17:48
• Resolved: 16/Aug/12 13:35

Description

Hi Guys,
I was investigating issue in Sqoop project(http://sqoop.apache.org/). Problem is that we are reporting number of written filesystem bytes back to the user and on Hadoop 0.23/2.x we're always getting 0. I've noticed that there was some refactorization in FileSystem counter related code and found MAPREDUCE-3542 requesting backward compatibility.

Included patch seems to be adding counter "FileSystemCounter":

hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/counters/AbstractCounters.java:84

legacyMap.put("FileSystemCounter", FileSystemCounter.class.getName());

But it appears that original name is "FileSystemCounters" (Notice the plural "s" at the end of name):

src/mapred/org/apache/hadoop/mapred/Task.java:91 (0.20.2)

protected static final String FILESYSTEM_COUNTER_GROUP = "FileSystemCounters";

src/mapred/org/apache/hadoop/mapred/Task.java:109 (1.0.3)

protected static final String FILESYSTEM_COUNTER_GROUP = "FileSystemCounters";

I therefore believe that this counter should be renamed in order to provide backward compatibility. I might fix this discrepancy in Sqoop, but I believe that other projects/users might also be affected and therefore it would be better to fix it in upstream.