Impala connection fails when connection from BI tools
I am trying to connect to impala using jdbc from one of the BI tools however ,
The connection being successful sometimes disconnects for a while with below error
Caused by: java.sql.SQLException: [Cloudera][ImpalaJDBCDriver](500593) Communication link failure. Failed to connect to server. Reason: java.net.SocketException: Connection or outbound has closed. ExecuteStatment for query "SELECT a,b from test limit 101".
at com.cloudera.impala.hivecommon.api.HS2Client.handleTTransportException(Unknown Source)
at com.cloudera.impala.hivecommon.api.HS2Client.executeStatementInternal(Unknown Source)
at com.cloudera.impala.hivecommon.api.HS2Client.executeStatement(Unknown Source)
at com.cloudera.impala.hivecommon.dataengine.HiveJDBCNativeQueryExecutor.executeNonRowCountQueryHelper(Unknown Source)
at com.cloudera.impala.hivecommon.dataengine.HiveJDBCNativeQueryExecutor.executeQuery(Unknown Source)
at com.cloudera.impala.hivecommon.dataengine.HiveJDBCNativeQueryExecutor.<init>(Unknown Source)
at com.cloudera.impala.hivecommon.dataengine.HiveJDBCDataEngine.prepare(Unknown Source)
at com.cloudera.impala.jdbc.common.SStatement.executeNoParams(Unknown Source)
at com.cloudera.impala.jdbc.common.BaseStatement.execute(Unknown Source)
at com.cloudera.impala.hivecommon.jdbc42.Hive42Statement.execute(Unknown Source)
at com.ibm.cognos.jdbc.adaptor.BaseStatementAdaptor.execute(BaseStatementAdaptor.java:118)
at com.cognos.xqe.data.providers.relational.jdbc.JDBCTabularResult.createJDBCResultSet(JDBCTabularResult.java:424)
at com.cognos.xqe.data.providers.relational.jdbc.JDBCTabularResult.<init>(JDBCTabularResult.java:285)
... 88 more
The port is 21050 firewall is open and no network errors between two servers
Please suggest what might be the cause

