question Re: Impala connection fails when connection from BI tools in Support Questions

Impala connection fails when connection from BI tools

hadoopranger — Wed, 07 Aug 2024 14:26:25 GMT

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

Re: Impala connection fails when connection from BI tools

AyazHussain — Thu, 08 Aug 2024 05:36:52 GMT

Hi @hadoopranger

Please check if you are using loadbalancer URL or connecting with a Impala daemon.

Sometimes loadbalancer URL causes this intermittent issue.

Re: Impala connection fails when connection from BI tools

vaishaakb — Thu, 08 Aug 2024 07:26:08 GMT

Hello @hadoopranger Thank you for bringing this to our community.

As you highlight, this looks to be intermittent connectivity issue with the Impala and the Client(BI Tool).
Q. May we know what is the name and version of BI tool you are using?

Also, You may want to review some of the related parameters/configuration from the tool.
Max Wait Time
Max Connection Lifetime

Let us know how it goes.

Cheers
V

Re: Impala connection fails when connection from BI tools

hadoopranger — Thu, 08 Aug 2024 07:38:07 GMT

Hi @vaishaakb thanks for the reply

It is IBM cognos server

I doubt we have these properties available in cognos

Re: Impala connection fails when connection from BI tools

vaishaakb — Thu, 08 Aug 2024 10:03:09 GMT

Hey @hadoopranger Upon further research, I see the reqs for IBM-Cloudera Impala JDBC Driver here[0a] Lets make sure this is followed.
[0a] https://www.ibm.com/docs/en/cognos-analytics/11.1.0?topic=troubleshooting-cloudera-impala-jdbc-drivers

Since this is intermittent, see if there are any timeouts/retries presents on the BI Application layer or LB layer.

We still want to know how the BI tool is connecting to Impala.
Is it via LB or Impala daemons directly?

If the Impala CLI is working as expected, You can try the following:
1. Timeout/Retries logic on the LB for client connections.
2. Try recreating your JDBC connections and implement retry logic within your app and restart the client app.
3. Also, Attaching the IBM Cognos User Guide for your reference:
https://www.ibm.com/docs/en/SSEP7J_11.1.0/com.ibm.swg.ba.cognos.ag_manage.doc/ca_manage.pdf

If you still need further help, I encourage you contacting contacting IBM Community for specific configs on the Data Sources.

Let us know how it goes.

Cheers
V

Re: Impala connection fails when connection from BI tools

hadoopranger — Fri, 09 Aug 2024 07:23:08 GMT

It is connecting via impala daemons directly

Re: Impala connection fails when connection from BI tools

vaishaakb — Mon, 19 Aug 2024 14:34:09 GMT

@hadoopranger I am circling back on this.
Did you try the steps shared in my previous reply? If yes, let us know how did it go.

If you find my reply helpful, You may mark it as the accepted solution.

You can also say thanks by clicking on the thumbs up button.