topic Issues Connecting Qlik Sense On-Premise to Databricks – ThriftExtension and ODBC Errors in Connectivity & Data Prep

Issues Connecting Qlik Sense On-Premise to Databricks – ThriftExtension and ODBC Errors

vkal12 — Thu, 07 Aug 2025 09:05:11 GMT

Hi everyone,

we are currently trying to establish a connection from our Qlik Sense On-Premise environment to Databricks. All connection details (host, port, authentication, etc.) have been double-checked and are correct.

From the Qlik Sense server, we can reach Databricks via the web and authenticate successfully (tested via browser). However, when we try to set up the connection in Qlik Sense, we encounter the following errors:

ERROR [HY000] [Qlik][ThriftExtension] (14) Unexpected response from server during a HTTP connection: connect() failed: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond..
ERROR [01004] [Microsoft][ODBC Driver Manager] Data truncated
ERROR [HY000] [Qlik][ThriftExtension] (14) Unexpected response from server during a HTTP connection: connect() failed: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond..

Additional information:

Qlik Sense is running On-Premise (not SaaS).
The Databricks cluster is up and running.
Network connectivity from the Qlik Sense server to Databricks is confirmed (no firewall or proxy issues).
Authentication via browser from the Qlik Sense server to Databricks works as expected.

Questions:

Has anyone experienced similar issues when connecting Qlik Sense On-Premise to Databricks?
Are there any known limitations or special configurations required for this setup?
What could be the cause of the "ThriftExtension" and "Data truncated" errors in this context?
Are there any recommended troubleshooting steps or logs I should check on either the Qlik or Databricks side?

Any advice or shared experiences would be greatly appreciated!

Thank you in advance for your support.

Best regards,
Vanessa

Re: Issues Connecting Qlik Sense On-Premise to Databricks – ThriftExtension and ODBC Errors

dballing — Thu, 02 Oct 2025 23:50:45 GMT

Did you try updating the ODBC connector to a later version?

Are you able to preview the data when inspecting the schema in the load script/data connection settings?

To fix truncating behaviour, recent Qlik ODBC connectors seem to have a 255 character max string lenght per default. Try, under the Advanced section of the data connection configurator, to add this param under Name and Value:

useBulkReader = false

Additionally you can update Max String Length atrribute to be 4096.

Re: Issues Connecting Qlik Sense On-Premise to Databricks – ThriftExtension and ODBC Errors

vkal12 — Mon, 06 Oct 2025 07:11:14 GMT

Hello,

thank you for your response. We solved the aboved mentioned error messages doing the following:

1. Update to the newest version of ODBC connector
2. Set a new encryption key for ODBC connector package

With this we have been able to create a connection through the driver directly on the server. This means we can now use the data from DataBricks. Unfortunately the creating of a connnection through the hub and the DataBricks connector still does not work. So now, we are investigating the new problem that the authentification via OAuth fails. See: New data connection with OAuth - Error message "Co... - Qlik Community - 2532305