Support Questions

Find answers, ask questions, and share your expertise

Impala query error

avatar
New Contributor

Hi,I'm trying to connect the impala on cdp throught JDBC,but it didn't work.It just show:

 

[Cloudera][ImpalaJDBCDriver](500051) ERROR processing query/statement. Error Code: 0, SQL state: Exec() rpc failed: Remote error: Service unavailable: ExecQueryFInstances request on impala.ControlService from 21.97.66.145:38012 dropped due to backpressure. The service queue contains 0 items out of a maximum of 2147483647; memory consumption is 0.
, Query: SELECT 1 as `expr_0`.
java.sql.SQLException: [Cloudera][ImpalaJDBCDriver](500051) ERROR processing query/statement. Error Code: 0, SQL state: Exec() rpc failed: Remote error: Service unavailable: ExecQueryFInstances request on impala.ControlService from 21.97.66.145:38012 dropped due to backpressure. The service queue contains 0 items out of a maximum of 2147483647; memory consumption is 0.
, Query: SELECT 1 as `expr_0`.
at com.cloudera.impala.hivecommon.api.HS2Client.pollForOperationCompletion(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.executeQuery(Unknown Source) ~[?:?]
at com.cloudera.impala.hivecommon.dataengine.HiveJDBCDSIExtQueryExecutor.execute(Unknown Source) ~[?:?]
at com.cloudera.impala.jdbc.common.SStatement.executeNoParams(Unknown Source) ~[?:?]
at com.cloudera.impala.jdbc.common.BaseStatement.executeQuery(Unknown Source) ~[?:?]
at com.cloudera.impala.hivecommon.jdbc41.Hive41Statement.executeQuery(Unknown Source) ~[?:?]

 

Any help with this impala error is much appreciated.

1 REPLY 1

avatar
Expert Contributor

@WuHua 

Can you please try to add this property and re-run query?

 

 Add
--control_service_queue_mem_limit=200M
to
"Impala Daemon Command Line Argument Advanced Configuration Snippet (Safety Valve)"

 

Thanks !