Flume客户端无法连接服务端

问题现象

安装Flume客户端并设置Avro Sink与服务端通信，发现无法连接Flume服务端。

原因分析

1. 服务端配置错误，监测端口启动失败，例如服务端Avro Source配置了错误的IP，或者已经被占用了的端口。
   查看Flume运行日志：

   2016-08-31 17:28:42,092 | ERROR | [lifecycleSupervisor-1-9] |  Unable to start EventDrivenSourceRunner: { source:Avro source avro_source: { bindAddress: 10.120.205.7, port: 21154 } } - Exception follows.  | org.apache.flume.lifecycle.LifecycleSupervisor$MonitorRunnable.run(LifecycleSupervisor.java:253)
   java.lang.RuntimeException: org.jboss.netty.channel.ChannelException: Failed to bind to: /192.168.205.7:21154

2. 若采用了加密传输，证书或密码错误。

   2016-08-31 17:15:59,593 | ERROR | [conf-file-poller-0] |  Source avro_source has been removed due to an error during configuration  | org.apache.flume.node.AbstractConfigurationProvider.loadSources(AbstractConfigurationProvider.java:388)
   org.apache.flume.FlumeException: Avro source configured with invalid keystore: /opt/Bigdata/MRS_XXX/install/FusionInsight-Flume-1.9.0/flume/conf/flume_sChat.jks

3. 客户端与服务端通信异常。

   PING 192.168.85.55 (10.120.85.55) 56(84) bytes of data.
   From 192.168.85.50 icmp_seq=1 Destination Host Unreachable
   From 192.168.85.50 icmp_seq=2 Destination Host Unreachable
   From 192.168.85.50 icmp_seq=3 Destination Host Unreachable
   From 192.168.85.50 icmp_seq=4 Destination Host Unreachable

解决办法

1. 设置为正确的IP，必须为本机的IP，如果端口被占用，重新配置一个空闲的端口。
2. 配置正确的证书路径。
3. 联系网络管理员，恢复网络。