我从这里下载了CDH 4.5快速启动vm。每个服务看起来都很好，除了以下错误是在我打开活动选项卡查看mapreduce活动后看到的：
The Activity Monitor server (activitymonitor (localhost)) is unavailable or not responding to connections.
在我尝试重新启动活动监视器服务后，问题仍然存在，然后我在日志中发现以下错误消息。有人能帮忙看看吗？
11:24:35.862 PM WARN org.mortbay.log
failed SelectChannelConnector@localhost.localdomain:9999: java.net.BindException: Address already in use
11:24:35.864 PM WARN org.mortbay.log
failed Server@59cc2f42: java.net.BindException: Address already in use
11:24:35.869 PM ERROR com.cloudera.cmon.firehose.Main
Failed to start Firehose
com.cloudera.enterprise.EnterpriseServiceException: java.net.BindException: Address already in use
at com.cloudera.cmon.firehose.AgentMessageService.startService(AgentMessageService.java:144)
at com.cloudera.enterprise.EnterpriseService.start(EnterpriseService.java:71)
at com.cloudera.enterprise.EnterpriseService.start(EnterpriseService.java:68)
at com.cloudera.cmon.firehose.Main.main(Main.java:371)
Caused by: java.net.BindException: Address already in use
at sun.nio.ch.Net.bind(Native Method)
at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:126)
at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:59)
at org.mortbay.jetty.nio.SelectChannelConnector.open(SelectChannelConnector.java:216)
at org.mortbay.jetty.nio.SelectChannelConnector.doStart(SelectChannelConnector.java:315)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.Server.doStart(Server.java:235)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at com.cloudera.cmon.firehose.AgentMessageService.startService(AgentMessageService.java:142)
... 3 more
"java.net.BindException:Address already in use"明确表示端口9999已被其他服务占用。你必须检查服务的PID并停止它：
lsof-p|grep LISTEN|grep 9999
使用PID终止服务，或者如果您知道服务，则优雅地停止