org.apache.thrift7.transport.TTransportException: java.net.ConnectException: Connection timed out

storm诡异问题查找：

一个经常容易报的异常：

Exception in thread "main" org.apache.thrift7.transport.TTransportException: java.net.ConnectException: Connection timed out
	at org.apache.thrift7.transport.TSocket.open(TSocket.java:183)
	at org.apache.thrift7.transport.TFramedTransport.open(TFramedTransport.java:81)
	at backtype.storm.thrift$nimbus_client_and_conn.invoke(thrift.clj:75)
	at backtype.storm.command.list$_main.invoke(list.clj:22)
	at clojure.lang.AFn.applyToHelper(AFn.java:159)
	at clojure.lang.AFn.applyTo(AFn.java:151)
	at backtype.storm.command.list.main(Unknown Source)
Caused by: java.net.ConnectException: Connection timed out
	at java.net.PlainSocketImpl.socketConnect(Native Method)
	at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
	at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
	at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
	at java.net.Socket.connect(Socket.java:579)
	at org.apache.thrift7.transport.TSocket.open(TSocket.java:178)
	... 6 more
Exception in th