flume No configuration found for this host:al 怎么解决

bin/conf/avro-kafka.conf
SLF4J: Class path contains multiple SLF4J bindings.
SLF4J: Found binding in [jar:file:/home/sun/app/apache-flume-1.7.0-bin/lib/slf4j-log4j12-1.6.1.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/sun/app/hadoop-2.7.2/share/hadoop/common/lib/slf4j-log4j12-1.7.10.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: Found binding in [jar:file:/home/sun/app/hbase-1.1.2/lib/slf4j-log4j12-1.7.5.jar!/org/slf4j/impl/StaticLoggerBinder.class]
SLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
2017-10-24 18:18:53,836 (lifecycleSupervisor-1-0) [INFO - org.apache.flume.node.PollingPropertiesFileConfigurationProvider.start(PollingPropertiesFileConfigurationProvider.java:62)] Configuration provider starting
2017-10-24 18:18:53,875 (conf-file-poller-0) [INFO - org.apache.flume.node.PollingPropertiesFileConfigurationProvider$FileWatcherRunnable.run(PollingPropertiesFileConfigurationProvider.java:134)] Reloading configuration file:/home/sun/app/apache-flume-1.7.0-bin/conf/avro-kafka.conf
2017-10-24 18:18:53,908 (conf-file-poller-0) [INFO - org.apache.flume.conf.FlumeConfiguration$AgentConfiguration.addProperty(FlumeConfiguration.java:1016)] Processing:k1
2017-10-24 18:18:53,918 (conf-file-poller-0) [INFO - org.apache.flume.conf.FlumeConfiguration$AgentConfiguration.addProperty(FlumeConfiguration.java:1016)] Processing:k1
2017-10-24 18:18:53,923 (conf-file-poller-0) [INFO - org.apache.flume.conf.FlumeConfiguration$AgentConfiguration.addProperty(FlumeConfiguration.java:930)] Added sinks: k1 Agent: a1
2017-10-24 18:18:53,924 (conf-file-poller-0) [INFO - org.apache.flume.conf.FlumeConfiguration$AgentConfiguration.addProperty(FlumeConfiguration.java:1016)] Processing:k1
2017-10-24 18:18:53,924 (conf-file-poller-0) [INFO - org.apache.flume.conf.FlumeConfiguration$AgentConfiguration.addProperty(FlumeConfiguration.java:1016)] Processing:k1
2017-10-24 18:18:53,925 (conf-file-poller-0) [INFO - org.apache.flume.conf.FlumeConfiguration$AgentConfiguration.addProperty(FlumeConfiguration.java:1016)] Processing:k1
2017-10-24 18:18:53,926 (conf-file-poller-0) [INFO - org.apache.flume.conf.FlumeConfiguration$AgentConfiguration.addProperty(FlumeConfiguration.java:1016)] Processing:k1
2017-10-24 18:18:53,926 (conf-file-poller-0) [INFO - org.apache.flume.conf.FlumeConfiguration$AgentConfiguration.addProperty(FlumeConfiguration.java:1016)] Processing:k1
2017-10-24 18:18:53,989 (conf-file-poller-0) [INFO - org.apache.flume.conf.FlumeConfiguration.validateConfiguration(FlumeConfiguration.java:140)] Post-validation flume configuration contains configuration for agents: [a1]
2017-10-24 18:18:53,989 (conf-file-poller-0) [WARN - org.apache.flume.node.AbstractConfigurationProvider.getConfiguration(AbstractConfigurationProvider.java:135)] No configuration found for this host:al
2017-10-24 18:18:54,009 (conf-file-poller-0) [INFO - org.apache.flume.node.Application.startAllComponents(Application.java:137)] Starting new configuration:{ sourceRunners:{} sinkRunners:{} channels:{} }
^C2017-10-24 18:19:10,880 (agent-shutdown-hook) [INFO - org.apache.flume.lifecycle.LifecycleSupervisor.stop(LifecycleSupervisor.java:78)] Stopping lifecycle supervisor 10
2017-10-24 18:19:10,896 (agent-shutdown-hook) [INFO - org.apache.flume.node.PollingPropertiesFileConfigurationProvider.stop(PollingPropertiesFileConfigurationProvider.java:84)] Configuration provider stopping


a1.sources = r1
a1.channels = c1
a1.sinks = k1

#source
a1.sources.r1.type = avro
a1.sources.r1.channels = c1
a1.sources.r1.bind =192.168.10.23
a1.sources.r1.port = 9999

#channel
a1.channels.c1.type = file
a1.channels.c1.checkpointDir = /home/sun/data/flume/checkpoint
a1.channels.c1.dataDirs = /home/sun/data/flume/data  
a1.channels.c1.maxFileSize = 104857600
a1.channels.c1.capacity = 90000000
a1.channels.c1.keep-alive = 60


#sink
a1.sinks.k1.type = org.apache.flume.sink.kafka.KafkaSink
a1.sinks.k1.topic = SunTopic1
a1.sinks.k1.brokerList =192.168.10.21:9092,192.168.10.22:9092,192.168.10.23:9092   #改为域名也是报一样的错误
a1.sinks.k1.requiredAcks = 1
a1.sinks.k1.kafka.producer.type = sync
a1.sinks.k1.batchSize = 1
a1.sinks.k1.channel =c1

#a1.sinks.k1.type = logger
#a1.sinks.k1.channel = c1

No configuration found for this host:al
al被视为hostname，其实他只是一个代理而已。
先检测hosts的配置，然后看看自己如何启动的。