Hi Expert,
Below are my steps and is it a hadoop bug or did I miss any thing? Thanks!
Step:
[A] Upgrade
1. Install Hadoop 2.2.0 cluster
2. Stop Hadoop services
3. Replace 2.2.0 binaries with 2.4.1 binaries
4. Start datanodes: $HADOOP_HOME/sbin/hadoop-daemon.sh start datanode
5. Start namenode with option upgrade: $HADOOP_HOME/sbin/hadoop-daemon.sh
start namenode -upgrade
6. Start secondary namenode, tasktracker and jobtracker
Result:
Whole upgrade process could be completed successfully.
[B] Rollback
1. Stop all hadoop services
2. Replace 2.4.1 binaries with 2.2.0 binaries
3. Start datanodes: $HADOOP_HOME/sbin/hadoop-daemon.sh start datanode
4. Start namenode with option upgrade: $HADOOP_HOME/sbin/hadoop-daemon.sh
start namenode -rollback
Result:
Namenode service could be started
Datanodes failed with exception:
Issue: DataNode failed with following exception
2014-09-17 11:04:51,416 INFO
org.apache.hadoop.hdfs.server.common.Storage: Lock on
/hadoop/hdfs/data/in_use.lock acquired by nodename 817443@shihc071-public
2014-09-17 11:04:51,418 FATAL
org.apache.hadoop.hdfs.server.datanode.DataNode: Initialization failed for
block pool Block pool BP-977402492-9.181.64.185-1410497086460 (storage id )
service to hostname/ip:9000
org.apache.hadoop.hdfs.server.common.IncorrectVersionException:
Unexpected version of storage directory /hadoop/hdfs/data. Reported: -55.
Expecting = -47.
at
org.apache.hadoop.hdfs.server.common.Storage.setLayoutVersion(Storage.java:1082)
at
org.apache.hadoop.hdfs.server.datanode.DataStorage.setFieldsFromProperties(DataStorage.java:302)
at
org.apache.hadoop.hdfs.server.common.Storage.readProperties(Storage.java:921)
