CDH localhost:7180 页面无法打开

有时会遇到CDH集群的7180页面无法访问，通过命令查看服务发现：

 service --status-all
 cloudera-scm-server dead but pid file exists

删除pid文件：　

 rm -rf /var/run/cloudera-scm-server 　

然后启动服务cloudera-scm-server时会遇到过一段时间自己挂掉，并返回cloudera-scm-server dead but pid file exists的问题，主要是在cloudera-scm-server-db没有正常启动的情况，表现为如下情况：

 [root@gyvm- data]# service cloudera-scm-server start
 Starting cloudera-scm-server:                              [  OK  ]
 [root@gyvm- data]#
 [root@gyvm- data]# service cloudera-scm-server status
 cloudera-scm-server (pid  ) is running...
 [root@gyvm- data]# service cloudera-scm-server status
 cloudera-scm-server (pid  ) is running...
 [root@gyvm- data]# service cloudera-scm-server status
 cloudera-scm-server (pid  ) is running...
 [root@gyvm- data]# service cloudera-scm-server status
 cloudera-scm-server dead but pid file exists  

这时候想要完整重启cloudera-scm server-db/server，发现cloudera-scm-server-db无法重启

 [root@gyvm- data]# service cloudera-scm-server-db stop
 waiting for server to shut down............................................................... failed
 pg_ctl: server does not shut down

无法停止server-db的原因是残留了一个pid文件，status显示不正确，删除该文件，通过status查看，server-db其实已经停止了。

 [root@gyvm- data]# cd /var/lib/cloudera-scm-server-db/data
 [root@gyvm- data]# service cloudera-scm-server-db status
 pg_ctl: server is running (PID: )
 /usr/bin/postgres "-D" "/var/lib/cloudera-scm-server-db/data"
 [root@gyvm- data]# rm postmaster.pid
 rm: remove regular file `postmaster.pid'? y
 [root@gyvm- data]# service cloudera-scm-server-db status
 pg_ctl: no server running  

再次开启server-db，成功，启动server，成功。

 [root@gyvm- data]# service cloudera-scm-server-db start
 DB initialization done.
 waiting for server to start.... done
 server started
 [root@gyvm- data]# service cloudera-scm-server start
 Starting cloudera-scm-server:                              [  OK  ]  

【结论】

　　究其原因，是cloudera-server-db没有正常启动，但是残留了pid文件postmaster.pid，所以查看cloudera-server-db状态时，显示有误，返回cloudera-server-db是启动的状态。在此基础上，每次启动cloudera-server就会失败。

转自：http://blog.csdn.net/c1990/article/details/54706330