1、软件环境
| RHEL6 | 角色 | jdk-8u45 |
| hadoop-2.8.1.tar.gz | | ssh |
| xx.xx.xx.xx ip地址 | NN | hadoop1 |
| xx.xx.xx.xx ip地址 | DN | hadoop2 |
| xx.xx.xx.xx ip地址 | DN | hadoop3 |
| xx.xx.xx.xx ip地址 | DN | hadoop4 |
| xx.xx.xx.xx ip地址 | DN | hadoop5 |
本次涉及伪分布式部署只是要主机hadoop1
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2、启动密钥互信问题
HDFS启动
[hadoop@hadoop01 hadoop]$ ./sbin/start-dfs.sh
Starting namenodes on [hadoop01]
The authenticity of host 'hadoop01 (172.16.18.133)' can't be established.
RSA key fingerprint is 8f:e7:6c:ca:6e:40:78:b8:df:6a:b4:ca:52:c7:01:4b.
Are you sure you want to continue connecting (yes/no)? yes
hadoop01: Warning: Permanently added 'hadoop01' (RSA) to the list of known hosts.
hadoop01: chown: changing ownership of `/opt/software/hadoop-2.8.1/logs': Operation not permitted
hadoop01: starting namenode, logging to /opt/software/hadoop-2.8.1/logs/hadoop-hadoop-namenode-hadoop01.out
hadoop01: /opt/software/hadoop-2.8.1/sbin/hadoop-daemon.sh: line 159:
/opt/software/hadoop-2.8.1/logs/hadoop-hadoop-namenode-hadoop01.out: Permission denied
启动如果有交互输入密码，不输入报错权限限制，这是因为我们没有配置互信，
伪分布式即便在同一台机器上面我们也需要配置ssh登陆互信。
非root用户公钥文件权限必须是600权限（root除外）
在hadoop用户配置ssh免密码登陆
[hadoop@hadoop01 .ssh]$ cat id_rsa.pub > authorized_keys
[hadoop@hadoop01 .ssh]$ chmod 600 authorized_keys [hadoop@hadoop01 hadoop]$ ssh hadoop01 date
[hadoop@hadoop01 .ssh]$ [hadoop@hadoop01 hadoop]$ ./sbin/start-dfs.sh
Starting namenodes on [hadoop01]
hadoop01: starting namenode, logging to /opt/software/hadoop-2.8.1/logs/hadoop-hadoop-namenode-hadoop01.out
hadoop01: starting datanode, logging to /opt/software/hadoop-2.8.1/logs/hadoop-hadoop-datanode-hadoop01.out
Starting secondary namenodes [hadoop01]
hadoop01: starting secondarynamenode, logging to /opt/software/hadoop-2.8.1/logs/hadoop-hadoop-secondarynamenode-hadoop01.out
[hadoop@hadoop01 hadoop]$ jps
1761 Jps
1622 SecondaryNameNode
1388 DataNode
1276 NameNode |
3、进程process information unavailable 问题
分两种情况：1、进程不存在，且process information unavailable
2、进程存在 报process information unavailable
对于第一种情况：
[hadoop@hadoop01 sbin]$ jps
3108 DataNode
4315 Jps
4156 SecondaryNameNode
2990 NameNode [hadoop@hadoop01 hsperfdata_hadoop]$ ls
5295 5415 5640
[hadoop@hadoop01 hsperfdata_hadoop]$ ll
total 96
-rw------- 1 hadoop hadoop 32768 Apr 27 09:35 5295
-rw------- 1 hadoop hadoop 32768 Apr 27 09:35 5415
-rw------- 1 hadoop hadoop 32768 Apr 27 09:35 5640
[hadoop@hadoop01 hsperfdata_hadoop]$ pwd
/tmp/hsperfdata_hadoop /tmp/hsperfdata_hadoop 里面记录jps显示的进程号，如果此时jps看到报错 [hadoop@hadoop01 tmp]$ jps
3330 SecondaryNameNode -- process information unavailable
3108 DataNode -- process information unavailable
3525 Jps
2990 NameNode -- process information unavailable 查询异常进程是否存在 [hadoop@hadoop01 tmp]$ ps -ef |grep 3330
hadoop 3845 2776 0 09:29 pts/6 00:00:00 grep 3330 |
对于进程不存在了，ok去/tmp/hsperfdata_xxx删除文件， 直接重新启动进程。。
jps查询的是当前用户的 hsperfdata_当前用户/文件
[root@hadoop01 ~]# jps
7153 -- process information unavailable
8133 -- process information unavailable
7495 -- process information unavailable
8489 Jps
[root@hadoop01 ~]# ps -ef |grep 7153 ---查看异常进程存在
hadoop 7153 1 2 09:47 ? 00:00:17 /usr/java/jdk1.8.0_45/bin/java -Dproc_namenode -Xmx1000m -Djava.net.preferIPv4Stack=true -Dhadoop.log.dir=/opt/software/hadoop-2.8.1/logs -Dhadoop.log.file=hadoop.log -Dhadoop.home.dir=/opt/software/hadoop-2.8.1 -Dhadoop.id.str=hadoop -Dhadoop.root.logger=INFO,console -Djava.library.path=/opt/software/hadoop-2.8.1/lib/native -Dhadoop.policy.file=hadoop-policy.xml -Djava.net.preferIPv4Stack=true -Djava.net.preferIPv4Stack=true -Djava.net.preferIPv4Stack=true -Dhadoop.log.dir=/opt/software/hadoop-2.8.1/logs -Dhadoop.log.file=hadoop-hadoop-namenode-hadoop01.log -Dhadoop.home.dir=/opt/software/hadoop-2.8.1 -Dhadoop.id.str=hadoop -Dhadoop.root.logger=INFO,RFA -Djava.library.path=/opt/software/hadoop-2.8.1/lib/native -Dhadoop.policy.file=hadoop-policy.xml -Djava.net.preferIPv4Stack=true -Dhadoop.security.logger=INFO,RFAS -Dhdfs.audit.logger=INFO,NullAppender -Dhadoop.security.logger=INFO,RFAS -Dhdfs.audit.logger=INFO,NullAppender -Dhadoop.security.logger=INFO,RFAS -Dhdfs.audit.logger=INFO,NullAppender -Dhadoop.security.logger=INFO,RFAS org.apache.hadoop.hdfs.server.namenode.NameNode
root 8505 2752 0 09:58 pts/6 00:00:00 grep 7153 假如存在，当前用户查看就是process information unavailable ，这时候查看是否进程是否存在，当前用户 ps –ef |grep 进程号，看进程运行用户，不是切换用户
[hadoop@hadoop01 hadoop]$ jps -----切换hadoop用户查看进程
7153 NameNode
8516 Jps
8133 DataNode
7495 SecondaryNameNode 切换用户发现进程都正常。
这个情况是查看的用户不对，hadoop查看jps不是运行用户查看，这个情况是不需要进行任何处理，服务运行正常
|
总结：对应process information unavailable报错，处理：
1.查看进程是否存在 （进程不存在，删/tmp/hsperfdata_xxx,重新启动进程）
2.如果进程存在，查看存在的进程运行用户，如果不是当前用户 切换用户后重新运行jps
文章题目：大数据之---hadoop问题排查汇总终极篇---持续更新中
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http://scjbc.cn/article/pghsdi.html
