hadoop2 - Hadoop "failed on connection exception: java.net.ConnectException: Connection refused"

Question

我正在尝试在本地模式下运行 Hadoop 命令。我在 Mac OS X 10.10.5 上运行，将文件放入 HDFS 时遇到错误。以下是我的 Hadoop 命令的错误消息:

 $ sudo hadoop fs -put HG00103.mapped.ILLUMINA.bwa.GBR.low_coverage.20120522.bam /usr/ds/genomics
    Password:
    15/09/25 10:10:50 WARN util.NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
    put: Call From BlueMeanie/10.0.1.5 to localhost:9000 failed on connection exception: java.net.ConnectException: Connection refused; For more details see:  http://wiki.apache.org/hadoop/ConnectionRefused

以下是我的系统的详细信息:

$ java -version
java version "1.8.0_05"
Java(TM) SE Runtime Environment (build 1.8.0_05-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.5-b02, mixed mode)

$ hadoop version
Hadoop 2.3.0
Subversion http://svn.apache.org/repos/asf/hadoop/common -r 1567123
Compiled by jenkins on 2014-02-11T13:40Z
Compiled with protoc 2.5.0
From source with checksum dfe46336fbc6a044bc124392ec06b85
This command was run using /Users/davidlaxer/hadoop-`2.3.0/share/hadoop/common/hadoop-common-2.3.0.jar`

$ cat /etc/hosts
##
# Host Database
#
# localhost is used to configure the loopback interface
# when the system is booting.  Do not change this entry.
##
127.0.0.1   localhost
10.0.1.5    BlueMeanie
255.255.255.255 broadcasthost
::1 localhost
fe80::1%lo0 localhost

$ telnet 10.1.1.5 9000
Trying 10.1.1.5...
^C
$ telnet localhost 9000
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
Trying fe80::1...
telnet: connect to address fe80::1: Connection refused
telnet: Unable to connect to remote host

$ env | grep HADOOP
HADOOP_HOME=/Users/dbl/hadoop-2.3.0/
HADOOP_CONF_DIR=/Users/dbl/hadoop-2.3.0/etc

$ cat core_site.xml

<configuration>
    <property>
        <name>fs.defaultFS</name>
        <value>hdfs://localhost:9000</value>
    </property>
</configuration>

$ cat hdfs-site.xml 
<configuration>
    <property>
        <name>dfs.replication</name>
        <value>1</value>
    </property>
</configuration>
$ cat yarn_site.xml 
<configuration>
    <property>
        <name>yarn.nodemanager.aux-services</name>
        <value>mapreduce_shuffle</value>
    </property>
</configuration>
$ cat mapred_site.xml 
<configuration>
    <property>
        <name>mapreduce.framework.name</name>
        <value>yarn</value>
    </property>
</configuration>

$ sbin/start-dfs.sh
Starting namenodes on [2015-09-25 16:36:54,540 WARN  [main] util.NativeCodeLoader (NativeCodeLoader.java:<clinit>(62)) - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
localhost]
[main]: ssh: Could not resolve hostname [main]: nodename nor servname provided, or not known
-: ssh: Could not resolve hostname -: nodename nor servname provided, or not known
Unable: ssh: Could not resolve hostname Unable: nodename nor servname provided, or not known
native-hadoop: ssh: Could not resolve hostname native-hadoop: nodename nor servname provided, or not known
load: ssh: Could not resolve hostname load: nodename nor servname provided, or not known
to: ssh: Could not resolve hostname to: nodename nor servname provided, or not known
for: ssh: Could not resolve hostname for: nodename nor servname provided, or not known
16:36:54,540: ssh: Could not resolve hostname 16:36:54,540: nodename nor servname provided, or not known
your: ssh: Could not resolve hostname your: nodename nor servname provided, or not known
platform...: ssh: Could not resolve hostname platform...: nodename nor servname provided, or not known
using: ssh: Could not resolve hostname using: nodename nor servname provided, or not known
builtin-java: ssh: Could not resolve hostname builtin-java: nodename nor servname provided, or not known
where: ssh: Could not resolve hostname where: nodename nor servname provided, or not known
applicable: ssh: Could not resolve hostname applicable: nodename nor servname provided, or not known
localhost: namenode running as process 99664. Stop it first.
2015-09-25: ssh: Could not resolve hostname 2015-09-25: nodename nor servname provided, or not known
WARN: ssh: Could not resolve hostname WARN: nodename nor servname provided, or not known
library: ssh: Could not resolve hostname library: nodename nor servname provided, or not known
classes: ssh: Could not resolve hostname classes: nodename nor servname provided, or not known
(NativeCodeLoader.java:<clinit>(62)): ssh: connect to host (NativeCodeLoader.java:<clinit>(62)) port 22: Operation timed out
util.NativeCodeLoader: ssh: connect to host util.NativeCodeLoader port 22: Operation timed out
cat: /Users/davidlaxer/hadoop-2.3.0/etc/hadoop/conf/slaves: No such file or directory
Starting secondary namenodes [2015-09-25 16:39:26,863 WARN  [main] util.NativeCodeLoader (NativeCodeLoader.java:<clinit>(62)) - Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
0.0.0.0]
WARN: ssh: Could not resolve hostname WARN: nodename nor servname provided, or not known
[main]: ssh: Could not resolve hostname [main]: nodename nor servname provided, or not known
Unable: ssh: Could not resolve hostname Unable: nodename nor servname provided, or not known
to: ssh: Could not resolve hostname to: nodename nor servname provided, or not known
-: ssh: Could not resolve hostname -: nodename nor servname provided, or not known
native-hadoop: ssh: Could not resolve hostname native-hadoop: nodename nor servname provided, or not known
library: ssh: Could not resolve hostname library: nodename nor servname provided, or not known
for: ssh: Could not resolve hostname for: nodename nor servname provided, or not known
your: ssh: Could not resolve hostname your: nodename nor servname provided, or not known
platform...: ssh: Could not resolve hostname platform...: nodename nor servname provided, or not known
16:39:26,863: ssh: Could not resolve hostname 16:39:26,863: nodename nor servname provided, or not known
using: ssh: Could not resolve hostname using: nodename nor servname provided, or not known
builtin-java: ssh: Could not resolve hostname builtin-java: nodename nor servname provided, or not known
classes: ssh: Could not resolve hostname classes: nodename nor servname provided, or not known
where: ssh: Could not resolve hostname where: nodename nor servname provided, or not known
applicable: ssh: Could not resolve hostname applicable: nodename nor servname provided, or not known
0.0.0.0: secondarynamenode running as process 99006. Stop it first.
2015-09-25: ssh: Could not resolve hostname 2015-09-25: nodename nor servname provided, or not known
load: ssh: Could not resolve hostname load: nodename nor servname provided, or not known
(NativeCodeLoader.java:<clinit>(62)): ssh: connect to host (NativeCodeLoader.java:<clinit>(62)) port 22: Operation timed out
util.NativeCodeLoader: ssh: connect to host util.NativeCodeLoader port 22: Operation timed out

Answer 1

在单节点模式下良好运行不需要启动Namenode、Datanode等。

<强> Single Node or Standalone 开箱即用使用标准hadoop安装，要求您设置fs.defaultFS 至 file:/// ，表示您的本地文件系统。

<小时/>

如果你想运行pseudo distributed (我猜你想从你的配置和你运行 start-dfs.sh 的事实中获得)你还必须记住，守护进程之间的通信是通过 ssh 执行的。所以你需要:

• 编辑您的 shd_config文件(安装 ssh 和后支持shd_config up)
• 添加端口 9000(我相信是端口 8020)。

然后，重新启动ssh并检查是否可以连接到 localhost通过ssh 。这可能就是启动 Namenode 和 Datanode 时出现的奇怪消息的全部内容。