Hi, I need to install hadoop on 16-node cluster. I have a couple of related questions: 1. I have installed hadoop on a shared directory, i.e., there is just one place where the whole hadoop installation files exist and all the 16 nodes use the same installation. Is that an issue or I need to install hadoop on each of these nodes in their local directory separately? 2. I installed hadoop-0.21 and after following the installation instructions, when i tried formatting, I get the following error:
************************************************************/ Re-format filesystem in /var/tmp/data/dfs/name ? (Y or N) Y 11/04/13 09:16:23 INFO namenode.FSNamesystem: defaultReplication = 3 11/04/13 09:16:23 INFO namenode.FSNamesystem: maxReplication = 512 11/04/13 09:16:23 INFO namenode.FSNamesystem: minReplication = 1 11/04/13 09:16:23 INFO namenode.FSNamesystem: maxReplicationStreams = 2 11/04/13 09:16:23 INFO namenode.FSNamesystem: shouldCheckForEnoughRacks = false 11/04/13 09:16:23 INFO security.Groups: Group mapping impl=org.apache.hadoop.security.ShellBasedUnixGroupsMapping; cacheTimeout=300000 11/04/13 09:16:23 INFO namenode.FSNamesystem: fsOwner=bus145 11/04/13 09:16:23 INFO namenode.FSNamesystem: supergroup=supergroup 11/04/13 09:16:23 INFO namenode.FSNamesystem: isPermissionEnabled=true 11/04/13 09:16:23 INFO namenode.FSNamesystem: isAccessTokenEnabled=false accessKeyUpdateInterval=0 min(s), accessTokenLifetime=0 min(s) 11/04/13 09:16:24 INFO common.Storage: Cannot lock storage /var/tmp/data/dfs/name. The directory is already locked. 11/04/13 09:16:24 ERROR namenode.NameNode: java.io.IOException: Cannot lock storage /var/tmp/data/dfs/name. The directory is already locked. at org.apache.hadoop.hdfs.server.common.Storage$StorageDirectory.lock(Storage.java:617) at org.apache.hadoop.hdfs.server.namenode.FSImage.format(FSImage.java:1426) at org.apache.hadoop.hdfs.server.namenode.FSImage.format(FSImage.java:1444) at org.apache.hadoop.hdfs.server.namenode.NameNode.format(NameNode.java:1242) at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1348) at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1368) 11/04/13 09:16:24 INFO namenode.NameNode: SHUTDOWN_MSG: /************************************************************ SHUTDOWN_MSG: Shutting down NameNode at inti79.cse.psu.edu/130.203.58.207 ************************************************************/ 3. I was using before hadoop-0.20, and formatting was working fine. 4. Also, when i do a bin/start-dfs.sh, am able to see the Namenode, Datanode up, however on bin/start-mapred.sh, am not able to see Jobtracker up on the master node, though Tasktracker seems to be up on slaves. Before upgrading to Hadoop-0.21, everything was working fine with hadoop-0.20 including running benchmarks and getting stats. Any suggestions in this regard is highly appreciated. Thanks, Bikash