This is Hadoop 2.0, but using the separate MR1 package (hadoop-2.0.0-mr1-cdh4.1.3), not yarn. I formatted the namenode ("./bin/hadoop namenode -format") and saw no errors in the shell or in the logs/[namenode].log file (in fact, simply formatting the namenode doesn't even create the log file yet). I believe that merely formatting the namenode shouldn't leave any persistent java processes running, so I wouldn't expect "ps aux | grep java" to show anything, which of course it doesn't.
I then started the namenode with "./bin/hadoop-daemon.sh start namenode". This produces the log file and still shows no errors. The final entry in the log is: 2013-02-19 19:15:19,477 INFO org.apache.hadoop.ipc.Server: Starting Socket Reader #1 for port 9000 Curiously, I still don't see any java processes running and netstat doesn't show any obvious 9000 listeners. I get this: $ netstat -a -t --numeric-ports -p (Not all processes could be identified, non-owned process info will not be shown, you would have to be root to see it all.) Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 localhost:25 *:* LISTEN - tcp 0 0 *:22 *:* LISTEN - tcp 0 0 ip-13-0-177-11:60765 ec2-50-19-38-112.compute:22 ESTABLISHED 23591/ssh tcp 0 0 ip-13-0-177-11:22 13.0.177.165:56984 ESTABLISHED - tcp 0 0 ip-13-0-177-11:22 13.0.177.165:38081 ESTABLISHED - tcp 0 0 *:22 *:* LISTEN - Note that ip-13-0-177-11 is the current machine (it is also specified as the master in /etc/hosts and is indicated via localhost in fs.default.name on port 9000 (fs.default.name = "hdfs://localhost:9000")). So, at this point, I'm beginning to get confused because I don't see a java namenode process and I don't see a port 9000 listener...but still haven't seen any blatant error messages. Next, I try "hadoop fs -ls /". I then get the shell error I have been wrestling with recently: ls: Call From ip-13-0-177-11/127.0.0.1 to localhost:9000 failed on connection exception: java.net.ConnectException: Connection refused; For more details see: http://wiki.apache.org/hadoop/ConnectionRefused Furthermore, this last step adds the following entry to the namenode log file: 2013-02-19 19:15:20,434 WARN org.apache.hadoop.hdfs.server.blockmanagement.BlockManager: ReplicationMonitor thread received InterruptedException. java.lang.InterruptedException: sleep interrupted at java.lang.Thread.sleep(Native Method) at org.apache.hadoop.hdfs.server.blockmanagement.BlockManager$ReplicationMonitor.run(BlockManager.java:3025) at java.lang.Thread.run(Thread.java:679) 2013-02-19 19:15:20,438 WARN org.apache.hadoop.hdfs.server.blockmanagement.DecommissionManager: Monitor interrupted: java.lang.InterruptedException: sleep interrupted 2013-02-19 19:15:20,442 INFO org.apache.hadoop.hdfs.server.namenode.FSNamesystem: Stopping services started for active state 2013-02-19 19:15:20,442 INFO org.apache.hadoop.hdfs.server.namenode.FSNamesystem: Stopping services started for standby state 2013-02-19 19:15:20,442 INFO org.apache.hadoop.ipc.Server: Stopping server on 9000 2013-02-19 19:15:20,444 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Stopping NameNode metrics system... 2013-02-19 19:15:20,444 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: NameNode metrics system stopped. 2013-02-19 19:15:20,445 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: NameNode metrics system shutdown complete. 2013-02-19 19:15:20,445 FATAL org.apache.hadoop.hdfs.server.namenode.NameNode: Exception in namenode join java.io.FileNotFoundException: webapps/hdfs not found in CLASSPATH at org.apache.hadoop.http.HttpServer.getWebAppsPath(HttpServer.java:560) at org.apache.hadoop.http.HttpServer.<init>(HttpServer.java:247) at org.apache.hadoop.http.HttpServer.<init>(HttpServer.java:171) at org.apache.hadoop.hdfs.server.namenode.NameNodeHttpServer$1.<init>(NameNodeHttpServer.java:89) at org.apache.hadoop.hdfs.server.namenode.NameNodeHttpServer.start(NameNodeHttpServer.java:87) at org.apache.hadoop.hdfs.server.namenode.NameNode.startHttpServer(NameNode.java:547) at org.apache.hadoop.hdfs.server.namenode.NameNode.startCommonServices(NameNode.java:480) at org.apache.hadoop.hdfs.server.namenode.NameNode.initialize(NameNode.java:443) at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:608) at org.apache.hadoop.hdfs.server.namenode.NameNode.<init>(NameNode.java:589) at org.apache.hadoop.hdfs.server.namenode.NameNode.createNameNode(NameNode.java:1140) at org.apache.hadoop.hdfs.server.namenode.NameNode.main(NameNode.java:1204) 2013-02-19 19:15:20,447 INFO org.apache.hadoop.util.ExitUtil: Exiting with status 1 2013-02-19 19:15:20,474 INFO org.apache.hadoop.hdfs.server.namenode.NameNode: SHUTDOWN_MSG: /************************************************************ SHUTDOWN_MSG: Shutting down NameNode at ip-13-0-177-11/127.0.0.1 ************************************************************/ This is particularly confusing because, while the hadoop-2.0.0-mr1-cdh4.1.3/ dir does have a webapps/ dir, there is no "hdfs" file or dir in that webapps/. It contains job/, static/, and task/. If I start over from a freshly formatted namenode and take a slightly different approach -- if I try to start the datanode immediately after starting the namenode -- once again it fails, and in a very similar way. This time the command to start the datanode has two effects: the namenode log still can't find webapps/hdfs, just as shown above, and also, there is now a datanode log file, and it likewise can't find webapps/datanode ("java.io.FileNotFoundException: webapps/datanode not found in CLASSPATH") so I get two very similar errors at once, one on the namenode and one on the datanode. This webapps/ dir business makes no sense since the files (or directories) the logs claim to be looking for inside webapps/ ("hdfs" and "datanode") don't exist! Thoughts? ________________________________________________________________________________ Keith Wiley kwi...@keithwiley.com keithwiley.com music.keithwiley.com "It's a fine line between meticulous and obsessive-compulsive and a slippery rope between obsessive-compulsive and debilitatingly slow." -- Keith Wiley ________________________________________________________________________________