The NameNode uses 2 separate Log4J appenders for tracking state changes. The appenders are named "org.apache.hadoop.hdfs.StateChange" and "BlockStateChange". The intention of BlockStateChange is to separate more verbose block state change logging and allow it to be configured separately. In branch-2, there is some block state change logging that incorrectly goes to the "org.apache.hadoop.hdfs.StateChange" appender though. The bug is not present in trunk.