title: Connection timeout expired while connecting to impala with impala JDBC Driver
body: <p>I am using impala2.12.0-cdh5.16.1 and connecting to impala with impala_jdbc_2.6.4.1005. Normally it runs very well, but when I run distcp (which cost the Cluster Network IO and HDFS IO), the java program may throw errors.</p>
  
  <pre><code>2019/02/28 12:54:26 531873 ERROR run.QihooStatusTask(run:88)  - [Cloudera][ImpalaJDBCDriver](700100) Connection timeout expired. Details: java.net.ConnectException: Connection timed out.
  java.sql.SQLException: [Cloudera][ImpalaJDBCDriver](700100) Connection timeout expired. Details: java.net.ConnectException: Connection timed out.
      at com.cloudera.impala.hivecommon.core.HiveJDBCCommonConnection.handleException(Unknown Source)
      at com.cloudera.impala.jdbc.core.LoginTimeoutConnection.connect(Unknown Source)
      at com.cloudera.impala.jdbc.common.BaseConnectionFactory.doConnect(Unknown Source)
      at com.cloudera.impala.jdbc.common.AbstractDriver.connect(Unknown Source)
      at java.sql.DriverManager.getConnection(DriverManager.java:664)
      at java.sql.DriverManager.getConnection(DriverManager.java:270)
  </code></pre>
  
  <p>The full error Message is in the picture:</p>
  
  <p><a href="https://i.stack.imgur.com/lp2eC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/lp2eC.png" alt="enter image description here"></a></p>
  
  <p>I tried to add DriverManager.setLoginTimeout(120) to the program,but the error still exists.
  I think it may be happen because the Cluster Network IO is very high and there may be a parameter which can add the value of timeout so the error will disappear.</p>
  
  <p>So, any suggestion about this? Thx.</p>