我们通过 Cloudera Manager 启用 Namenode 高可用性，使用
Cloudera Manager >> HDFS >> Action > Enable High Availability >> Selected Stand By Namenode & Journal Nodes Then nameservice1
一旦整个过程完成，然后部署客户端配置。
通过列出 HDFS 目录（hadoop fs -ls /）然后手动故障转移到备用名称节点并再次列出 HDFS 目录（hadoop fs -ls /）从客户端计算机进行测试。这个测试很完美。
但是当我使用以下命令运行 hadoop sleep 作业时，它失败了
$ hadoop jar /opt/cloudera/parcels/CDH-4.6.0-1.cdh4.6.0.p0.26/lib/hadoop-0.20-mapreduce/hadoop-examples.jar sleep -m 1 -r 0
java.lang.IllegalArgumentException: java.net.UnknownHostException: nameservice1
at org.apache.hadoop.security.SecurityUtil.buildTokenService(SecurityUtil.java:414)
at org.apache.hadoop.hdfs.NameNodeProxies.createNonHAProxy(NameNodeProxies.java:164)
at org.apache.hadoop.hdfs.NameNodeProxies.createProxy(NameNodeProxies.java:129)
at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:448)
at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:410)
at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:128)
at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2308)
at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:87)
at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2342)
at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2324)
at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:351)
at org.apache.hadoop.fs.Path.getFileSystem(Path.java:194)
at org.apache.hadoop.mapreduce.JobSubmissionFiles.getStagingDir(JobSubmissionFiles.java:103)
at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:980)
at org.apache.hadoop.mapred.JobClient$2.run(JobClient.java:974)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:416)
at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1438)
at org.apache.hadoop.mapred.JobClient.submitJobInternal(JobClient.java:974)
at org.apache.hadoop.mapred.JobClient.submitJob(JobClient.java:948)
at org.apache.hadoop.mapred.JobClient.runJob(JobClient.java:1410)
at org.apache.hadoop.examples.SleepJob.run(SleepJob.java:174)
at org.apache.hadoop.examples.SleepJob.run(SleepJob.java:237)
at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
at org.apache.hadoop.examples.SleepJob.main(SleepJob.java:165)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:622)
at org.apache.hadoop.util.ProgramDriver$ProgramDescription.invoke(ProgramDriver.java:72)
at org.apache.hadoop.util.ProgramDriver.driver(ProgramDriver.java:144)
at org.apache.hadoop.examples.ExampleDriver.main(ExampleDriver.java:64)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:622)
at org.apache.hadoop.util.RunJar.main(RunJar.java:208)
Caused by: java.net.UnknownHostException: nameservice1
... 37 more
我不知道为什么即使在部署客户端配置之后它也无法解析 nameservice1。
当我用谷歌搜索这个问题时，我发现这个问题只有一个解决方案
在配置条目中添加以下条目以修复问题 dfs.nameservices=nameservice1 dfs.ha.namenodes.nameservice1=namenode1,namenode2 dfs.namenode.rpc-address.nameservice1.namenode1=ip-10-118-137-215.ec2 .internal:8020 dfs.namenode.rpc-address.nameservice1.namenode2=ip-10-12-122-210.ec2.internal:8020 dfs.client.failover.proxy.provider.nameservice1=org.apache.hadoop.hdfs .server.namenode.ha.ConfiguredFailoverProxyProvider
我的印象是 Cloudera Manager 会处理它。我检查了客户端是否有此配置和配置（/var/run/cloudera-scm-agent/process/1998-deploy-client-config/hadoop-conf/hdfs-site.xml）。
还有一些配置文件的更多细节：
[11:22:37 root@datasci01.dev:~]# ls -l /etc/hadoop/conf.cloudera.*
/etc/hadoop/conf.cloudera.hdfs:
total 16
-rw-r--r-- 1 root root 943 Jul 31 09:33 core-site.xml
-rw-r--r-- 1 root root 2546 Jul 31 09:33 hadoop-env.sh
-rw-r--r-- 1 root root 1577 Jul 31 09:33 hdfs-site.xml
-rw-r--r-- 1 root root 314 Jul 31 09:33 log4j.properties
/etc/hadoop/conf.cloudera.hdfs1:
total 20
-rwxr-xr-x 1 root root 233 Sep 5 2013 container-executor.cfg
-rw-r--r-- 1 root root 1890 May 21 15:48 core-site.xml
-rw-r--r-- 1 root root 2546 May 21 15:48 hadoop-env.sh
-rw-r--r-- 1 root root 1577 May 21 15:48 hdfs-site.xml
-rw-r--r-- 1 root root 314 May 21 15:48 log4j.properties
/etc/hadoop/conf.cloudera.mapreduce:
total 20
-rw-r--r-- 1 root root 1032 Jul 31 09:33 core-site.xml
-rw-r--r-- 1 root root 2775 Jul 31 09:33 hadoop-env.sh
-rw-r--r-- 1 root root 1450 Jul 31 09:33 hdfs-site.xml
-rw-r--r-- 1 root root 314 Jul 31 09:33 log4j.properties
-rw-r--r-- 1 root root 2446 Jul 31 09:33 mapred-site.xml
/etc/hadoop/conf.cloudera.mapreduce1:
total 24
-rwxr-xr-x 1 root root 233 Sep 5 2013 container-executor.cfg
-rw-r--r-- 1 root root 1979 May 16 12:20 core-site.xml
-rw-r--r-- 1 root root 2775 May 16 12:20 hadoop-env.sh
-rw-r--r-- 1 root root 1450 May 16 12:20 hdfs-site.xml
-rw-r--r-- 1 root root 314 May 16 12:20 log4j.properties
-rw-r--r-- 1 root root 2446 May 16 12:20 mapred-site.xml
[11:23:12 root@datasci01.dev:~]#
我怀疑 /etc/hadoop/conf.cloudera.hdfs1 和 /etc/hadoop/conf.cloudera.mapreduce1 中的旧配置存在问题，但不确定。
看起来 /etc/hadoop/conf/* 从未更新
# ls -l /etc/hadoop/conf/
total 24
-rwxr-xr-x 1 root root 233 Sep 5 2013 container-executor.cfg
-rw-r--r-- 1 root root 1979 May 16 12:20 core-site.xml
-rw-r--r-- 1 root root 2775 May 16 12:20 hadoop-env.sh
-rw-r--r-- 1 root root 1450 May 16 12:20 hdfs-site.xml
-rw-r--r-- 1 root root 314 May 16 12:20 log4j.properties
-rw-r--r-- 1 root root 2446 May 16 12:20 mapred-site.xml
有人对这个问题有任何想法吗？