前言：集群主节点根目录内存快爆了，开始清理主节点内存重启组件，发现Kerberos认证的角色用户都过期了，又重新生成了一下角色，在启动impala组件过程中，其中一个Impala Daemon组件启动失败。
集群版本：CDH6.3.2+CM6.3.1
查看Impala Daemon启动报错日志
上午11点22:12.422分 INFO java:188
Found configuration file file:/run/cloudera-scm-agent/process/1244-impala-IMPALAD/hive-conf/hive-site.xml
上午11点22:12.640分 INFO java:289
Reloading authorization policy file from:
上午11点22:12.692分 INFO java:212
Loading allocation file /var/run/cloudera-scm-agent/process/1244-impala-IMPALAD/impala-conf/fair-scheduler.xml
上午11点22:12.717分 INFO java:2662
resource-types.xml not found
上午11点22:12.718分 INFO java:419
Unable to find ‘resource-types.xml’.
上午11点22:12.747分 INFO java:165
Loading Llama configuration: /var/run/cloudera-scm-agent/process/1244-impala-IMPALAD/impala-conf/llama-site.xml
上午11点22:12.748分 INFO cc:382
System memory available: 15.51 GB (from physical mem)
上午11点22:12.748分 INFO cc:409
Using process memory limit: 256.00 MB (–mem_limit=268435456)
上午11点22:12.756分 INFO cc:262
Buffer pool limit: 217.59 MB
上午11点22:12.757分 WARN cc:132
It appears that OpenSSL has been previously initialized by code outside of Kudu. Please use kudu::client::DisableOpenSSLInitialization() to avoid potential crashes due to conflicting initialization.
上午11点22:12.759分 INFO cc:153
Registered KRPC service: impala.ControlService
上午11点22:12.759分 INFO cc:153
Registered KRPC service: impala.DataStreamService
上午11点22:12.765分 INFO cc:224
Starting webserver on 0.0.0.0:25000
上午11点22:12.765分 INFO cc:238
Document root: /opt/cloudera/parcels/CDH-6.3.2-1.cdh6.3.2.p5253.21605619/lib/impala
上午11点22:12.765分 INFO cc:370
Webserver: set_ports_option: cannot bind to 0.0.0.0:25000: 98 (地址已在使用)
上午11点22:12.766分 INFO cc:124
Webserver: Could not start on address 0.0.0.0:25000
@ 0xb4c589
@ 0x11d0f0c
@ 0xf539db
@ 0x1040fe6
@ 0xab5133
@ 0x7f90f2f5e554
@ 0xb11808
上午11点22:12.766分 FATAL cc:72
Webserver: Could not start on address 0.0.0.0:25000
. Impalad exiting.
Wrote minidump to /var/log/impala-minidumps/impalad/b022aa35-2e8f-4d88-c096a2b0-e936a03f.dmp
日志显示节点三上的25000被占用，导致impala Daemon启动报错
去后台查看端口号
[root@cloud03 conf]# netstat -anp|grep 25000
tcp 0 0 172.21.33.30:25000 172.21.33.30:25000 ESTABLISHED 1052/python2
端口 25000 已经被一个名为 python2 的进程占用了
终止该进程
[root@cloud03 conf]# kill -9 1052
[root@cloud03 conf]# netstat -anp|grep 25000
tcp 0 0 172.21.33.30:25000 172.21.33.30:25000 TIME_WAIT -
去cm界面上，重启停止的impala组件，启动成功。
