Cloudera Manager 常见异常

1. Cloudera Management Service服务全部无法启动

观察到的现象：

（1）cm service 组件无法启动，启动时服务请求超时终止；（2）主机信息也无法获取到，一直提示“无法与服务端取得联系”（3）cm-server日志中提示“Authentication failure for user: '__cloudera_internal_user__mgmt-EVENTSERVER-95d257fb4b0322939118ac4012bb8d4e' from 10.21.48.82” 组件权限认证失败。

猜到到可能的原因：

（1）scm-agent与scm-server服务连接异常；

（2）mysql数据库连接异常，用户认证失败；

cloudera-scm-server 日志信息：

2019-01-29 08:44:10,188 INFO 780911426@scm-web-776:com.cloudera.server.web.cmf.AuthenticationFailureEventListener: Authentication failure for user: '__cloudera_internal_user__mgmt-EVENTSERVER-95d257fb4b0322939118ac4012bb8d4e' from 10.21.48.82
2019-01-29 08:44:10,194 INFO 416547936@scm-web-773:com.cloudera.server.web.cmf.AuthenticationFailureEventListener: Authentication failure for user: '__cloudera_internal_user__mgmt-HOSTMONITOR-95d257fb4b0322939118ac4012bb8d4e' from 10.21.48.82
2019-01-29 08:44:11,181 INFO 416547936@scm-web-773:com.cloudera.server.web.cmf.AuthenticationFailureEventListener: Authentication failure for user: '__cloudera_internal_user__mgmt-SERVICEMONITOR-95d257fb4b0322939118ac4012bb8d4e' from 10.21.48.82

cloudera-scm-agent 日志信息：

[02/Jan/2019 16:20:21 +0000] 28617 MainThread agent        ERROR    Heartbeating to 10.21.48.82:7182 failed.
Traceback (most recent call last):
  File "/usr/lib64/cmf/agent/build/env/lib/python2.6/site-packages/cmf-5.14.0-py2.6.egg/cmf/agent.py", line 1419, in _send_heartbeat
    self.master_port)
  File "/usr/lib64/cmf/agent/build/env/lib/python2.6/site-packages/avro-1.6.3-py2.6.egg/avro/ipc.py", line 469, in __init__
    self.conn.connect()
  File "/usr/lib64/python2.6/httplib.py", line 742, in connect
    self.timeout)
  File "/usr/lib64/python2.6/socket.py", line 567, in create_connection
    raise error, msg
error: [Errno 111] Connection refused

最后定位到了问题，是由于scm-agent连接scm-server的配置之前做过调整，导致scm-agent一直无法与scm-server取得联系，修改scm-agent的连接信息，主要server_host和server_port都要确认下（之前修改了server_host连接还是无法正常取得联系）。

修改scm-agent端所在的配置文件 /etc/cloudera-scm-agent/config.ini ：

[General]
# Hostname of the CM server.
server_host=10.21.48.82

# Port that the CM server is listening on.
server_port=7182

 修改后，问题解决，cm service正常启动。

Tips：定位问题要从整个系统架构层面去思考，熟悉架构的整体运行逻辑，猜测问题可能出现的环节，不要过早地陷入局部思维，然后就是一定要学会看log。