报错：Heartbeating to master:7182 failed.

报错背景：

 cloudera-scm-agent 可以启动并且存活，但是jps没有进程。

报错现象：

查看报错日志：/opt/cm-5.15.1/log/cloudera-scm-agent/cloudera-scm-agent.log

[29/Apr/2019 14:27:52 +0000] 10528 MainThread throttling_logger INFO     (14 skipped) Identified java component java8 with full version java version "1.8.0_191" Java(TM) SE Runtime Environment (build 1.8.0_191-b12) Java HotSpot(TM) 64-Bit Server VM (build 25.191-b12, mixed mode)  for requested version .
[29/Apr/2019 14:33:53 +0000] 10528 MainThread agent        ERROR    Heartbeating to master:7182 failed.
Traceback (most recent call last):
  File "/opt/cm-5.15.1/lib64/cmf/agent/build/env/lib/python2.7/site-packages/cmf-5.15.1-py2.7.egg/cmf/agent.py", line 1441, in _send_heartbeat
    response = self.requestor.request('heartbeat', heartbeat_data)
  File "/opt/cm-5.15.1/lib64/cmf/agent/build/env/lib/python2.7/site-packages/avro-1.6.3-py2.7.egg/avro/ipc.py", line 141, in request
    return self.issue_request(call_request, message_name, request_datum)
  File "/opt/cm-5.15.1/lib64/cmf/agent/build/env/lib/python2.7/site-packages/avro-1.6.3-py2.7.egg/avro/ipc.py", line 254, in issue_request
    call_response = self.transceiver.transceive(call_request)
  File "/opt/cm-5.15.1/lib64/cmf/agent/build/env/lib/python2.7/site-packages/avro-1.6.3-py2.7.egg/avro/ipc.py", line 483, in transceive
    result = self.read_framed_message()
  File "/opt/cm-5.15.1/lib64/cmf/agent/build/env/lib/python2.7/site-packages/avro-1.6.3-py2.7.egg/avro/ipc.py", line 487, in read_framed_message
    response = self.conn.getresponse()
  File "/usr/lib64/python2.7/httplib.py", line 1113, in getresponse
    response.begin()
  File "/usr/lib64/python2.7/httplib.py", line 444, in begin
    version, status, reason = self._read_status()
  File "/usr/lib64/python2.7/httplib.py", line 408, in _read_status
    raise BadStatusLine(line)
BadStatusLine: ''
[29/Apr/2019 14:34:08 +0000] 10528 MainThread agent        ERROR    Heartbeating to master:7182 failed.
Traceback (most recent call last):
  File "/opt/cm-5.15.1/lib64/cmf/agent/build/env/lib/python2.7/site-packages/cmf-5.15.1-py2.7.egg/cmf/agent.py", line 1435, in _send_heartbeat
    self.master_port)
  File "/opt/cm-5.15.1/lib64/cmf/agent/build/env/lib/python2.7/site-packages/avro-1.6.3-py2.7.egg/avro/ipc.py", line 469, in __init__
    self.conn.connect()
  File "/usr/lib64/python2.7/httplib.py", line 824, in connect
    self.timeout, self.source_address)
  File "/usr/lib64/python2.7/socket.py", line 571, in create_connection
    raise err
error: [Errno 111] Connection refused
[29/Apr/2019 14:34:08 +0000] 10528 MainThread agent        INFO     Stopping agent...

报错原因：

报错信息：ERROR    Heartbeating to master:7182 failed。

错误解释：向master节点的指定端口7180发送心跳检测失败。

首次启动Agent，它会生成一个uuid，路径为：/opt/cm-5.1.3/lib/cloudera-scm-agent/uuid,如果每台机器上的Agent的uuid都是一样，就会出现报错情况。

报错解决：

进入目录：cd /opt/cm-5.15.1/lib/cloudera-scm-agent/

删除uuid：rm -rf uuid

重启agent：/opt/cm-5.15.1/etc/init.d/cloudera-scm-agent restart