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 Submissions
NodesOccupied Map Slots
Occupied Reduce SlotsReserved Map Slots
Reserved Reduce SlotsMap Task Capacity
Reduce Task CapacityAvg. Tasks/Node
Blacklisted NodesGraylisted Nodes
Excluded Nodes

0 0 01
0 0
0 02
2 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。