有趣的单机单节点现象

建立了hadoop的伪分布，但总是上传0node文档，即空的文本，关了防火墙，安全模式，又没有出什么错，start的都有，jps也没问题
于是只能断开主从节点的链接，返回单机单节点，在单机单节点下有现象如下：
一、[root@hadoop conf]# start-all.sh
starting namenode, logging to /usr/lib/hadoop/hadoop-1.2.1/libexec/../logs/hadoop-sp-namenode-hadoop.master.out
localhost: starting datanode, logging to /usr/lib/hadoop/hadoop-1.2.1/libexec/../logs/hadoop-root-datanode-hadoop.master.out
localhost: starting secondarynamenode, logging to /usr/lib/hadoop/hadoop-1.2.1/libexec/../logs/hadoop-root-secondarynamenode-hadoop.master.out
starting jobtracker, logging to /usr/lib/hadoop/hadoop-1.2.1/libexec/../logs/hadoop-sp-jobtracker-hadoop.master.out
localhost: starting tasktracker, logging to /usr/lib/hadoop/hadoop-1.2.1/libexec/../logs/hadoop-root-tasktracker-hadoop.master.out


二、[root@hadoop conf]# jps
12155 JobTracker
12258 TaskTracker
12074 SecondaryNameNode
11338 
11967 DataNode
11863 NameNode
12317 Jps


三、[root@hadoop conf]# jps
12155 JobTracker
12258 TaskTracker
12074 SecondaryNameNode
12370 Jps
11338 
11863 NameNode


四、
[root@hadoop conf]# hadoop dfsadmin -report
Configured Capacity: 0 (0 KB)
Present Capacity: 0 (0 KB)
DFS Remaining: 0 (0 KB)
DFS Used: 0 (0 KB)
DFS Used%: ?%
Under replicated blocks: 0
Blocks with corrupt replicas: 0
Missing blocks: 0


-------------------------------------------------
Datanodes available: 0 (0 total, 0 dead)


五、
localhost:50070
Cluster Summary
8 files and directories, 0 blocks = 8 total. Heap Size is 31.32 MB / 966.69 MB (3%)
Configured Capacity :0 KB
DFS Used : 0 KB
Non DFS Used :0 KB
DFS Remaining :0 KB
DFS Used% : 100 %
DFS Remaining% :0 %
Live Nodes : 0
Dead Nodes : 0
Decommissioning Nodes :0
Number of Under-Replicated Blocks :0


There are no datanodes in the cluster 


六、locahost：50030
Cluster Summary (Heap Size is 15.25 MB/966.69 MB)
Running Map Tasks Running Reduce TasksTotal SubmissionsNodesOccupied Map SlotsOccupied Reduce SlotsReserved Map SlotsReserved Reduce SlotsMap Task CapacityReduce Task CapacityAvg. Tasks/NodeBlacklisted NodesGraylisted NodesExcluded Nodes
0 0 010 0 0 022 4.00 0 0 0


七、logs/datanode-log日志：hadoop-root-datanode-hadoop.master.log
STARTUP_MSG: Starting DataNode
STARTUP_MSG:   host = java.net.UnknownHostException: hadoop.master: hadoop.master: Name or service not known
STARTUP_MSG:   args = []
STARTUP_MSG:   version = 1.2.1
STARTUP_MSG:   build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.2 -r 1503152; compiled by 'mattf' on Mon Jul 22 15:23:09 PDT 2013
STARTUP_MSG:   java = 1.7.0_45
************************************************************/
2016-04-29 05:55:51,536 INFO org.apache.hadoop.metrics2.impl.MetricsConfig: loaded properties from hadoop-metrics2.properties
2016-04-29 05:55:51,589 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source MetricsSystem,sub=Stats registered.hadoop-root-datanode-hadoop.master.log


2016-04-29 05:56:11,625 ERROR org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Error getting localhost name. Using 'localhost'...
java.net.UnknownHostException: hadoop.master: hadoop.master: Name or service not known
at java.net.InetAddress.getLocalHost(InetAddress.java:1473)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.getHostname(MetricsSystemImpl.java:481)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.configureSystem(MetricsSystemImpl.java:412)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.configure(MetricsSystemImpl.java:408)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.start(MetricsSystemImpl.java:152)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.init(MetricsSystemImpl.java:133)
at org.apache.hadoop.metrics2.lib.DefaultMetricsSystem.init(DefaultMetricsSystem.java:40)
at org.apache.hadoop.metrics2.lib.DefaultMetricsSystem.initialize(DefaultMetricsSystem.java:50)
at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:1650)
at org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:1669)
at org.apache.hadoop.hdfs.server.datanode.DataNode.secureMain(DataNode.java:1795)
at org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:1812)
Caused by: java.net.UnknownHostException: hadoop.master: Name or service not known
at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
at java.net.InetAddress$1.lookupAllHostAddr(InetAddress.java:901)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1293)
at java.net.InetAddress.getLocalHost(InetAddress.java:1469)
... 11 more
2016-04-29 05:56:11,637 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Scheduled snapshot period at 10 second(s).
2016-04-29 05:56:11,637 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: DataNode metrics system started
2016-04-29 05:56:12,279 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source ugi registered.
2016-04-29 05:56:32,680 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG: 
/************************************************************
SHUTDOWN_MSG: Shutting down DataNode at java.net.UnknownHostException: hadoop.master: hadoop.master: Name or service not known
************************************************************/
2016-04-29 06:05:34,585 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: STARTUP_MSG: 
/************************************************************
STARTUP_MSG: Starting DataNode
STARTUP_MSG:   host = java.net.UnknownHostException: hadoop.master: hadoop.master: Name or service not known
STARTUP_MSG:   args = []
STARTUP_MSG:   version = 1.2.1
STARTUP_MSG:   build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.2 -r 1503152; compiled by 'mattf' on Mon Jul 22 15:23:09 PDT 2013
STARTUP_MSG:   java = 1.7.0_45
************************************************************/
2016-04-29 06:05:35,766 INFO org.apache.hadoop.metrics2.impl.MetricsConfig: loaded properties from hadoop-metrics2.properties
2016-04-29 06:05:35,928 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source MetricsSystem,sub=Stats registered.
2016-04-29 06:05:55,999 ERROR org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Error getting localhost name. Using 'localhost'...
java.net.UnknownHostException: hadoop.master: hadoop.master: Name or service not known
at java.net.InetAddress.getLocalHost(InetAddress.java:1473)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.getHostname(MetricsSystemImpl.java:481)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.configureSystem(MetricsSystemImpl.java:412)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.configure(MetricsSystemImpl.java:408)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.start(MetricsSystemImpl.java:152)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.init(MetricsSystemImpl.java:133)
at org.apache.hadoop.metrics2.lib.DefaultMetricsSystem.init(DefaultMetricsSystem.java:40)
at org.apache.hadoop.metrics2.lib.DefaultMetricsSystem.initialize(DefaultMetricsSystem.java:50)
at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:1650)
at org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:1669)
at org.apache.hadoop.hdfs.server.datanode.DataNode.secureMain(DataNode.java:1795)
at org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:1812)
Caused by: java.net.UnknownHostException: hadoop.master: Name or service not known
at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
at java.net.InetAddress$1.lookupAllHostAddr(InetAddress.java:901)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1293)
at java.net.InetAddress.getLocalHost(InetAddress.java:1469)
... 11 more
2016-04-29 06:05:56,022 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Scheduled snapshot period at 10 second(s).
2016-04-29 06:05:56,022 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: DataNode metrics system started
2016-04-29 06:05:57,242 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source ugi registered.
2016-04-29 06:06:20,016 ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: java.net.UnknownHostException: hadoop.master: hadoop.master: Name or service not known
at java.net.InetAddress.getLocalHost(InetAddress.java:1473)
at org.apache.hadoop.security.SecurityUtil.getLocalHostName(SecurityUtil.java:271)
at org.apache.hadoop.security.SecurityUtil.login(SecurityUtil.java:289)
at org.apache.hadoop.hdfs.server.datanode.DataNode.<init>(DataNode.java:313)
at org.apache.hadoop.hdfs.server.datanode.DataNode.makeInstance(DataNode.java:1712)
at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:1651)
at org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:1669)
at org.apache.hadoop.hdfs.server.datanode.DataNode.secureMain(DataNode.java:1795)
at org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:1812)
Caused by: java.net.UnknownHostException: hadoop.master: Name or service not known
at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
at java.net.InetAddress$1.lookupAllHostAddr(InetAddress.java:901)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1293)
at java.net.InetAddress.getLocalHost(InetAddress.java:1469)
... 8 more


2016-04-29 06:06:20,021 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG: 
/************************************************************
SHUTDOWN_MSG: Shutting down DataNode at java.net.UnknownHostException: hadoop.master: hadoop.master: Name or service not known
************************************************************/
2016-04-29 06:08:59,408 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: STARTUP_MSG: 
/************************************************************
STARTUP_MSG: Starting DataNode
STARTUP_MSG:   host = java.net.UnknownHostException: hadoop.master: hadoop.master: Name or service not known
STARTUP_MSG:   args = []
STARTUP_MSG:   version = 1.2.1
STARTUP_MSG:   build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.2 -r 1503152; compiled by 'mattf' on Mon Jul 22 15:23:09 PDT 2013
STARTUP_MSG:   java = 1.7.0_45
************************************************************/
2016-04-29 06:09:00,562 INFO org.apache.hadoop.metrics2.impl.MetricsConfig: loaded properties from hadoop-metrics2.properties
2016-04-29 06:09:00,614 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source MetricsSystem,sub=Stats registered.
2016-04-29 06:09:20,640 ERROR org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Error getting localhost name. Using 'localhost'...
java.net.UnknownHostException: hadoop.master: hadoop.master: Name or service not known
at java.net.InetAddress.getLocalHost(InetAddress.java:1473)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.getHostname(MetricsSystemImpl.java:481)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.configureSystem(MetricsSystemImpl.java:412)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.configure(MetricsSystemImpl.java:408)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.start(MetricsSystemImpl.java:152)
at org.apache.hadoop.metrics2.impl.MetricsSystemImpl.init(MetricsSystemImpl.java:133)
at org.apache.hadoop.metrics2.lib.DefaultMetricsSystem.init(DefaultMetricsSystem.java:40)
at org.apache.hadoop.metrics2.lib.DefaultMetricsSystem.initialize(DefaultMetricsSystem.java:50)
at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:1650)
at org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:1669)
at org.apache.hadoop.hdfs.server.datanode.DataNode.secureMain(DataNode.java:1795)
at org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:1812)
Caused by: java.net.UnknownHostException: hadoop.master: Name or service not known
at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
at java.net.InetAddress$1.lookupAllHostAddr(InetAddress.java:901)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1293)
at java.net.InetAddress.getLocalHost(InetAddress.java:1469)
... 11 more
2016-04-29 06:09:20,667 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: Scheduled snapshot period at 10 second(s).
2016-04-29 06:09:20,667 INFO org.apache.hadoop.metrics2.impl.MetricsSystemImpl: DataNode metrics system started
2016-04-29 06:09:21,421 INFO org.apache.hadoop.metrics2.impl.MetricsSourceAdapter: MBean for source ugi registered.
2016-04-29 06:09:42,388 ERROR org.apache.hadoop.hdfs.server.datanode.DataNode: java.net.UnknownHostException: hadoop.master: hadoop.master: Name or service not known
at java.net.InetAddress.getLocalHost(InetAddress.java:1473)
at org.apache.hadoop.security.SecurityUtil.getLocalHostName(SecurityUtil.java:271)
at org.apache.hadoop.security.SecurityUtil.login(SecurityUtil.java:289)
at org.apache.hadoop.hdfs.server.datanode.DataNode.<init>(DataNode.java:313)
at org.apache.hadoop.hdfs.server.datanode.DataNode.makeInstance(DataNode.java:1712)
at org.apache.hadoop.hdfs.server.datanode.DataNode.instantiateDataNode(DataNode.java:1651)
at org.apache.hadoop.hdfs.server.datanode.DataNode.createDataNode(DataNode.java:1669)
at org.apache.hadoop.hdfs.server.datanode.DataNode.secureMain(DataNode.java:1795)
at org.apache.hadoop.hdfs.server.datanode.DataNode.main(DataNode.java:1812)
Caused by: java.net.UnknownHostException: hadoop.master: Name or service not known
at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
at java.net.InetAddress$1.lookupAllHostAddr(InetAddress.java:901)
at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1293)
at java.net.InetAddress.getLocalHost(InetAddress.java:1469)
... 8 more


2016-04-29 06:09:42,392 INFO org.apache.hadoop.hdfs.server.datanode.DataNode: SHUTDOWN_MSG: 
/************************************************************
SHUTDOWN_MSG: Shutting down DataNode at java.net.UnknownHostException: hadoop.master: hadoop.master: Name or service not known
************************************************************/


八、结果重启一遍什么事都没，正常运行。