Hadoop2.7.3:启动hdfs和纱线后看不到DataNode/ResourceManager进程

Question

我使用的是mac和java版本：

$java -version
java version "1.8.0_111"
Java(TM) SE Runtime Environment (build 1.8.0_111-b14)
Java HotSpot(TM) 64-Bit Server VM (build 25.111-b14, mixed mode)

遵循以下链接：https://dtflaneur.wordpress.com/2015/10/02/installing-hadoop-on-mac-osx-el-capitan/

我首先根据需要安装hadoop、config ssh连接和xml文件，并且

start-dfs.sh
start-yarn.sh

屏幕输出如下：

$start-dfs.sh
17/05/06 09:58:32 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Starting namenodes on [localhost]
localhost: namenode running as process 74213. Stop it first.
localhost: starting datanode, logging to /usr/local/Cellar/hadoop/2.7.3/libexec/logs/hadoop-x-datanode-xdeMacBook-Pro.local.out
Starting secondary namenodes [0.0.0.0]
0.0.0.0: secondarynamenode running as process 74417. Stop it first.
17/05/06 09:58:39 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable

$start-dfs.sh
17/05/06 09:58:32 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Starting namenodes on [localhost]
localhost: namenode running as process 74213. Stop it first.
localhost: starting datanode, logging to /usr/local/Cellar/hadoop/2.7.3/libexec/logs/hadoop-x-datanode-xdeMacBook-Pro.local.out
Starting secondary namenodes [0.0.0.0]
0.0.0.0: secondarynamenode running as process 74417. Stop it first.
17/05/06 09:58:39 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable

然后使用jps，我看不到"DataNode“和"ResourceManager”。我认为DataNode是hdfs模块，ResourceManager是纱线模块：

$jps
74417 SecondaryNameNode
75120 Jps
74213 NameNode
74539 ResourceManager
74637 NodeManager

我可以列出hdfs文件：

$hdfs dfs -ls /
17/05/06 09:58:59 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
Found 1 items
drwxr-xr-x   - x supergroup          0 2017-05-05 23:50 /user

但是运行pi示例会引发异常：

$hadoop jar /usr/local/Cellar/hadoop/2.7.3/libexec/share/hadoop/mapreduce/hadoop-mapreduce-examples-2.7.3.jar pi 2 5
Number of Maps  = 2
Samples per Map = 5
17/05/06 10:19:48 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
17/05/06 10:19:49 WARN hdfs.DFSClient: DataStreamer Exception
org.apache.hadoop.ipc.RemoteException(java.io.IOException): File /user/x/QuasiMonteCarlo_1494037188550_135794067/in/part0 could only be replicated to 0 nodes instead of minReplication (=1).  There are 0 datanode(s) running and no node(s) are excluded in this operation.

我想知道我是否错过了任何配置，如何确保它们成功运行，以及如何检查或故障排除可能的失败原因？

谢谢。

Answer 1

我还在学习阶段。如果没有可用于读写的datanode，则会出现此错误。您可以使用此URL检查资源管理器：http://localhost:50070是否存在运行或不运行的任何数据节点。为了解决问题，您可以检查在hadoop安装目录下生成的日志。如果你能分享那些日志，我可以试着帮你。