Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198. Existing Python UDFs will continue to function until June 30, 2026. For more information, see the [ blog post ](https://aws.amazon.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/). 

# Connection fails
<a name="queries-troubleshooting-connection-fails"></a>

Your query connection can fail because for the following reasons. We suggest the following troubleshooting approaches.

**Client cannot connect to server**  
If you are using SSL or server certificates, first remove this complexity while you troubleshoot the connection issue. Then add SSL or server certificates back when you have found a solution. For more information, go to [Configure Security Options for Connections](https://docs.aws.amazon.com/redshift/latest/mgmt/connecting-ssl-support.html) in the *Amazon Redshift Management Guide.*

**Connection is refused**  
Generally, when you receive an error message indicating that there is a failure to establish a connection, it means that there is an issue with the permission to access the cluster. For more information, go to [The connection is refused or fails](https://docs.aws.amazon.com/redshift/latest/mgmt/connecting-refusal-failure-issues.html) in the *Amazon Redshift Management Guide.*