hadoop非HA安裝，解決defalutFS（eg：beh）問題
報錯如下：
（1）修改core-site.xml :
<property>
<name>fs.defaultFS</name>
<value>hdfs://beh/</value>
</property>
為如下：（因為不修改，hdfs dfs -ls / 會無法檢視，報錯UnknownHostException: beh）
<property>
<name>fs.defaultFS</name>
<value>hdfs://****:9000/</value>
</property>
修改為如上之後（hdfs dfs -ls / 可以檢視，但是執行yarn 測試樣例 wordcount無法得到yarn資源，且任務所在節點的nodemanager直接掛掉，檢視nodemanager日誌，發現如下報錯）
注：wordcount測試樣例：hadoop jar /opt/beh/core/hadoop/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.6.0-cdh5.13.1.jar wordcount /wkz/in/hadooptest /wkz/out
FATAL org.apache.hadoop.yarn.event.AsyncDispatcher: Error in dispatcher thread
java.lang.IllegalArgumentException: java.net.UnknownHostException: beh
at org.apache.hadoop.security.SecurityUtil.buildTokenService(SecurityUtil.java:406)
at org.apache.hadoop.hdfs.NameNodeProxies.createNonHAProxy(NameNodeProxies.java:310)
at org.apache.hadoop.hdfs.NameNodeProxies.createProxy(NameNodeProxies.java:176)
at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:735)
at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:678)
at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:158)
at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2816)
at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:98)
at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2853)
at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2835)
at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:387)
at org.apache.hadoop.fs.Path.getFileSystem(Path.java:296)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.logaggregation.LogAggregationService.g
etFileSystem(LogAggregationService.java:181)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.logaggregation.LogAggregationService.v
erifyAndCreateRemoteLogDir(LogAggregationService.java:188)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.logaggregation.LogAggregationService.i
nitApp(LogAggregationService.java:336)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.logaggregation.LogAggregationService.h
andle(LogAggregationService.java:463)
at org.apache.hadoop.yarn.server.nodemanager.containermanager.logaggregation.LogAggregationService.h
andle(LogAggregationService.java:68)
at org.apache.hadoop.yarn.event.AsyncDispatcher.dispatch(AsyncDispatcher.java:182)
at org.apache.hadoop.yarn.event.AsyncDispatcher$1.run(AsyncDispatcher.java:109)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.net.UnknownHostException: beh
... 20 more
（2）出現如上錯誤後，還原core-site.xml 為：
<property>
<name>fs.defaultFS</name>
<value>hdfs://beh/</value>
</property>
執行wordcount測試樣例：
hadoop jar /opt/beh/core/hadoop/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.6.0-cdh5.13.1.jar wordcount hdfs://****:9000/wkz/in/hadooptest hdfs://****:9000/wkz/out
直接報錯，報錯找不到截圖了，只能大概描述下：
第一：還是有java.net.UnknownHostException: beh
第二：mapreduce.framework.name錯誤
後來做了如下修改：（去掉beh有關的所有，東西，eg：dfs.namenode.rpc-address.beh變為dfs.namenode.rpc-address）
hdfs-site.xml
<configuration>
<!--
<property>
<name>dfs.nameservices</name>
<value>beh</value>
</property>
-->
<property>
<name>dfs.namenode.rpc-address</name>
<value>*****9000</value>
</property>
<property>
<name>dfs.namenode.http-address</name>
<value>******:50070</value>
</property>
<property>
<name>dfs.namenode.name.dir</name>
<value>/data01/dsjdev/testname</value>
</property>
<property>
<name>dfs.datanode.data.dir</name>
<value>/data01/dsjdev/testdn</value>
</property>
<property>
<name>dfs.block.size</name>
<value>134217728</value>
</property>
<property>
<name>dfs.datanode.handler.count</name>
<value>20</value>
</property>
<property>
<name>dfs.namenode.handler.count</name>
<value>20</value>
</property>
<property>
<name>dfs.datanode.max.xcievers</name>
<value>131072</value>
</property>
<property>
<name>dfs.datanode.socket.write.timeout</name>
<value>0</value>
</property>
<property>
<name>dfs.socket.timeout</name>
<value>180000</value>
</property>
<property>
<name>dfs.replication</name>
<value>2</value>
</property>
<property>
<name>mapred.child.env</name>
<value>JAVA_LIBRARY_PATH=$HADOOP_HOME/lib/native</value>
</property>
</configuration>
core-site.xml
<configuration>
<property>
<name>fs.defaultFS</name>
<value>hdfs://******:9000/</value>
</property>
<property>
<name>hadoop.tmp.dir</name>
<value>/data01/dsjdev/testnn</value>
</property>
<property>
<name>io.file.buffer.size</name>
<value>131072</value>
</property>
<property>
<name>io.compression.codecs</name>
<value>org.apache.hadoop.io.compress.DefaultCodec,org.apache.hadoop.io.compress.GzipCodec,org.apache.hadoop.io.compress.BZip2Codec,org.apache.hadoop.io.compress.SnappyCodec</value>
</property>
<property>
<name>fs.trash.interval</name>
<value>10080</value>
<description>Number of minutes between trash checkpoints.
If zero, the trash feature is disabled.
</description>
</property>
</configuration>
yarn-site.xml
<configuration>
<property>
<name>yarn.nodemanager.aux-services</name>
<value>mapreduce_shuffle</value>
</property>
<property>
<name>yarn.nodemanager.aux-services.mapreduce.shuffle.class</name>
<value>org.apache.hadoop.mapred.ShuffleHandler</value>
</property>
<property>
<name>yarn.nodemanager.local-dirs</name>
<value>/data01/dsjdev/testnn_local_dir</value>
</property>
<property>
<name>yarn.nodemanager.log-dirs</name>
<value>/data01/dsjdev/testnn_log_dir</value>
</property>
<property>
<name>yarn.log-aggregation-enable</name>
<value>true</value>
</property>
<property>
<description>Where to aggregate logs</description>
<name>yarn.nodemanager.remote-app-log-dir</name>
<value>hdfs://******:9000/var/log/hadoop-yarn/apps</value>
</property>
<property>
<name>yarn.resourcemanager.connect.retry-interval.ms</name>
<value>2000</value>
</property>
<property>
<name>yarn.resourcemanager.cluster-id</name>
<value>beh</value>
</property>
<property>
<name>yarn.resourcemanager.scheduler.class</name>
<value>org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler</value>
</property>
<property>
<name>yarn.app.mapreduce.am.scheduler.connection.wait.interval-ms</name>
<value>5000</value>
</property>
<property>
<name>yarn.resourcemanager.address</name>
<value>******:23140</value>
</property>
<property>
<name>yarn.resourcemanager.scheduler.address</name>
<value>******:23130</value>
</property>
<property>
<name>yarn.resourcemanager.webapp.https.address</name>
<value>******:23189</value>
</property>
<property>
<name>yarn.resourcemanager.webapp.address</name>
<value>******:23188</value>
</property>
<property>
<name>yarn.resourcemanager.resource-tracker.address</name>
<value>******:23125</value>
</property>
<property>
<name>yarn.resourcemanager.admin.address</name>
<value>******:23141</value>
</property>
<property>
<description>Address where the localizer IPC is.</description>
<name>yarn.nodemanager.localizer.address</name>
<value>0.0.0.0:23344</value>
</property>
<property>
<description>NM Webapp address.</description>
<name>yarn.nodemanager.webapp.address</name>
<value>0.0.0.0:23999</value>
</property>
<property>
<name>mapreduce.shuffle.port</name>
<value>23080</value>
</property>
<property>
<name>yarn.nodemanager.resource.memory-mb</name>
<value>10240</value>
</property>
<property>
<name>yarn.scheduler.minimum-allocation-mb</name>
<value>6144</value>
</property>
<property>
<name>yarn.nodemanager.resource.cpu-vcores</name>
<value>2</value>
<description>number of all the cpu cores</description>
</property>
</configuration>
mapred-site.xml
<configuration>
<property>
<name>mapreduce.framework.name</name>
<value>yarn</value>
</property>
<property>
<name>mapreduce.jobhistory.address</name>
<value>*****:10020</value>
</property>
<property>
<name>mapreduce.jobhistory.webapp.address</name>
<value>*****:19888</value>
</property>
<property>
<name>yarn.app.mapreduce.am.staging-dir</name>
<value>/data01/dsjdev/hadoop-yarn/staging</value>
</property>
<property>
<name>mapred.child.java.opts</name>
<value>-Xmx2g</value>
</property>
<property>
<name>io.sort.mb</name>
<value>512</value>
</property>
<property>
<name>io.sort.factor</name>
<value>20</value>
</property>
<property>
<name>mapred.job.reuse.jvm.num.tasks</name>
<value>-1</value>
</property>
<property>
<name>mapreduce.reduce.shuffle.parallelcopies</name>
<value>20</value>
</property>
<property>
<name>mapred.output.compress</name>
<value>true</value>
</property>
<property>
<name>mapred.output.compression.codec</name>
<value>org.apache.hadoop.io.compress.SnappyCodec</value>
</property>
<property>
<name>mapreduce.map.output.compress</name>
<value>true</value>
</property>
<property>
<name>mapreduce.map.output.compress.codec</name>
<value>org.apache.hadoop.io.compress.SnappyCodec</value>
</property>
<property>
<name>mapred.output.compression.type</name>
<value>BLOCK</value>
</property>
<property>
<name>mapreduce.cluster.local.dir</name>
<value>/data01/dsjdev/testmapred/local</value>
</property>
</configuration>
修改後重啟hadoop，一切正常