Current HDFS updates the modification time of a file when the file is created. We would like to update the modification time of the file when the file is closed after being written to. This helps HDFS Raid to detect file changes more aggressively.
1. Made changes to closeFile@/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java;
2. Added unit test to testTimesAtClose@/org/apache/hadoop/hdfs/TestSetTimes.java.