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Connection refused on Impala connection with JDBC, kerberos

We have Cloudera5.12.2 and we’d like to connect to Impala(impala-2.9.0+cdh5.12.2+0) with JDBC. We use kerberos and we checked that we can kinit with the user we intend to use. We just DL the latest denodo express. Java is version8. We have DL ClouderaImpalaJDBC41_2.5.43 and placed those jar in $denodo_home/extensions/lib/extensions/jdbc-drivers/ So driver is as below $denodo_home/extensions/lib/extensions/jdbc-drivers/ClouderaImpalaJDBC41_2.5.43/ImpalaJDBC41.jar We have added $denodo_home/extensions/lib/extensions/jdbc-drivers/ClouderaImpalaJDBC41_2.5.43 to CLASSPATH. Now on Virtual Dataport Administration Tool, we are creating New DataSource with JDBC. Database adapter: Generic Driver class path: $denodo_home/extensions/lib/extensions/jdbc-drivers/ClouderaImpalaJDBC41_2.5.43 Driver class com.cloudera.impala.jdbc41.Driver Database URI: jdbc:impala://server-IP:Port Authentication: Use Kerberos Kerberos login: user-name Use password From Driver properties, [NAME=userKerberos VALUE=true] If Driver class path points to ImpalaJDBC41.jar, we get “insufficient” error, so we’re pointing folder instead. Still we get com.denodo.vdb.admin.model.introspect.VQLSourceIntrospectionService [] - com.denodo.vdb.admin.model.vdbserverproxy.VDBServerProxyException: java.sql.SQLException: [Simba][ImpalaJDBCDriver](500164) Error initialized or created transport for authentication: java.net.ConnectException: Connection refused (Connection refused). Any suggestion on this issue? We’re refering to the page below. https://community.denodo.com/docs/html/browse/7.0/vdp/administration/creating_data_sources_and_base_views/jdbc_sources/jdbc_sources Thank you.
user
26-02-2019 02:17:03 -0500

6 Answers

Hi, For this Scenario, I would recommend you to do the following checks: * Check whether the Cloudera instance is properly launched. * Check the **Database URI** that you have specified in the data source configuration. * Check the vdp.log file located in the directory **<DENODO_HOME>/logs/vdp** to know more about this error. Instead of “Generic” adapter you can also use the “Impala 2.3” adapter in the data source configuration to connect Impala from the Denodo Platform. You can refer to the sections [Supported JDBC Data Sources](https://community.denodo.com/docs/html/browse/7.0/vdp/administration/appendix/supported_jdbc_data_sources/supported_jdbc_data_sources) and [Connecting to a JDBC Source with Kerberos Authentication](https://community.denodo.com/docs/html/browse/7.0/vdp/administration/creating_data_sources_and_base_views/jdbc_sources/jdbc_sources#connecting-to-a-jdbc-source-with-kerberos-authentication) of Virtual DataPort Administration Guide for more information. Hope this helps!
Denodo Team
05-03-2019 06:33:30 -0500
Denodo Team Thanks. However, Denodo Japan just told us via a vendor that Express version they sent us do not support Hadoop connection. No wonder why we couldn't connect. It's shame that it took few days for them to find out. Anyway, we're now closing this issue.
user
 Edited on: 25-05-2019 03:57:25 -0400
Hello! In my experience working with the Denodo Express, I did not find any issue connecting to Impala. I am able to connect and combine data using the Impala 2.3 adapter. You can enable Kerberos but you have to keep in mind that you cannot define new users or roles with Denodo Express. The Denodo Express is a very good option to ease into data virtualization and scale smoothly to experience the full power of the Denodo Platform. If you have a good use case defined, you can ask for an evaluation license by contacting sales@denodo.com or filling this contact form https://www.denodo.com/action/contact-us/. Probably the Denodo Japan team just recommends that you use an evaluation license instead of the Denodo Express, as an evaluation license is a full version of the Denodo Platform limited for a specific period of time. Hope this helps!
Denodo Team
15-03-2019 06:19:54 -0400
Thank you. I sent vdp.log file to Denodo Japan and their answer was "Express version does not support impala connection or s3 connection". That's not correct?
user
 Edited on: 25-05-2019 03:57:25 -0400
Hi, The Denodo Express support connecting to Impala. I use Denodo Express to connect to impala and I can run queries in a similar way than a connection to a relational database. Keep in mind that you need to provide the impala JDBC driver jars to be able to connect. Of course, you can also connect to Amazon S3. For that you could use the Amazon S3 REST API. You have more information about how to set this connection in the KB article "[How to integrate Amazon S3 with the Denodo Platform](https://community.denodo.com/kb/view/document/How%20to%20integrate%20Amazon%20S3%20with%20the%20Denodo%20Platform?category=Data+Sources)". What you cannot do with Denodo Express is to use a Custom Wrapper, that is another way to connect to S3. Hope this helps!
Denodo Team
03-04-2019 05:59:19 -0400
Dear Uchiyama-san, Thank you very much for having a meeting with us last week. I believe we have a better understanding on the topics for now as we had a good discussion. Let’s continue our discussion and if you have any question or concern, please let us know. Best regards, Gije Cho Denodo Japan
Denodo Team
07-04-2019 23:34:39 -0400
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