Thank you both. So what both of you were saying which will be true is that is order to start and synchronize the cluster, I will have to format both nodes at the same time ok.
I was working on the master node without the second node and did not format before trying to start the second one. I reformatted the cluster with both nodes connected and it worked. But I have a question. If I want to add a third node and my current cluster is populated with some tables, will I have to format it again in order to add the node? On Wed, Mar 13, 2013 at 10:34 AM, Mohammad Tariq <[email protected]> wrote: > Hello Cyril, > > This is because your datanode has a different namespaceID from the > one which master(namenode) actually has. Have you formatted the HDFS > recently? Were you able to format it properly? Everytime you format HDFS, > NameNode generates new namespaceID, which should be same in both NameNodes > and DataNodes otherwise it won't be able to reach NameNode. > > Warm Regards, > Tariq > https://mtariq.jux.com/ > cloudfront.blogspot.com > > > On Wed, Mar 13, 2013 at 7:57 PM, Cyril Bogus <[email protected]> wrote: > >> I am trying to start the datanode on the slave node but when I check the >> dfs I only have one node. >> >> When I check the logs on the slave node I find the following output. >> >> 2013-03-13 10:22:14,608 INFO >> org.apache.hadoop.hdfs.server.datanode.DataNode: STARTUP_MSG: >> /************************************************************ >> STARTUP_MSG: Starting DataNode >> STARTUP_MSG: host = Owner-5/127.0.1.1 >> STARTUP_MSG: args = [] >> STARTUP_MSG: version = 1.0.4 >> STARTUP_MSG: build = >> https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.0 -r >> 1393290; compiled by 'hortonfo' on Wed Oct 3 05:13:58 UTC 2012 >> ************************************************************/ >> 2013-03-13 10:22:15,086 INFO >> org.apache.hadoop.metrics2.impl.MetricsConfig: loaded properties from >> hadoop-metrics2.properties >> 2013-03-13 10:22:15,121 INFO >> org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source >> MetricsSystem,sub=Stats registered. >> 2013-03-13 10:22:15,123 INFO >> org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Scheduled snapshot >> period at 10 second(s). >> 2013-03-13 10:22:15,123 INFO >> org.apache.hadoop.metrics2.impl.MetricsSystemImpl: DataNode metrics system >> started >> 2013-03-13 10:22:15,662 INFO >> org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source ugi >> registered. >> 2013-03-13 10:22:15,686 WARN >> org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Source name ugi already >> exists! >> 2013-03-13 10:22:19,730 ERROR >> org.apache.hadoop.hdfs.server.datanode.DataNode: java.io.IOException: >> Incompatible namespaceIDs in /home/hadoop/hdfs/data: namenode namespaceID = >> 1683708441; datanode namespaceID = 606666501 >> at >> org.apache.hadoop.hdfs.server.datanode.DataStorage.doTransition(DataStorage.java:232) >> at >> org.apache.hadoop.hdfs.server.datanode.DataStorage.recoverTransitionRead(DataStorage.java:147) >> at >> org.apache.hadoop.hdfs.server.datanode.DataNode.startDataNode(DataNode.java:385) >> at >> org.apache.hadoop.hdfs.server.datanode.DataNode.<init>(DataNode.java:299) >> at >> org.apache.hadoop.hdfs.server.datanode.DataNode.makeInstance(DataNode.java:1582) >> at >> org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:1521) >> at >> org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:1539) >> at >> org.apache.hadoop.hdfs.server.datanode.DataNode.secureMain(DataNode.java:1665) >> at >> org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:1682) >> >> 2013-03-13 10:22:19,731 INFO >> org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG: >> /************************************************************ >> SHUTDOWN_MSG: Shutting down DataNode at Owner-5/127.0.1.1 >> ************************************************************/ >> >> Thank you for any insights. >> >> Cyril >> > >
