Flume 0.9.1: connection refused when exec refreshAll

[lulynn_2008]

Could you please help to check why this error happened? This error is not 
reproduced stable.
Here is the error log:
Using default report port: 45678
Connecting to Flume master svltest367.svl.ibm.com:35873:45678...
Exception in thread "main" org.apache.thrift.transport.TTransportException: 
java.net.ConnectException: Connection refused
        at org.apache.thrift.transport.TSocket.open(TSocket.java:185)
        at com.cloudera.flume.util.FlumeShell.connectClient(FlumeShell.java:805)
        at com.cloudera.flume.util.FlumeShell.connect(FlumeShell.java:823)
        at com.cloudera.flume.util.FlumeShell.main(FlumeShell.java:895)