Troubleshooting Temporary DNS Name Resolution Issues While Accessing Azure Redis Cache Inside Azure Container Apps

Question

I am experiencing intermittent connection errors while attempting to connect to an Azure Redis Cache resource within Azure Container Apps. Both resources are located within the same VNet. The specific error message I am seeing is as follows:

"Error -3 connecting to <resource_name>:6379. Temporary failure in name resolution."

What steps can I take to troubleshoot and resolve this issue?

Answer 1

@Revanth GSS Thanks for reaching out.

The error message you are seeing indicates that there is a temporary failure in name resolution when attempting to connect to the Redis Cache resource. This could be caused by a number of issues, including network connectivity problems, DNS resolution issues, or misconfigured firewall rules and I will suggest you verify below steps to resolve the issue.

Check network connectivity: Ensure that the Azure Container Apps and Redis Cache resources are located within the same VNet and that there are no network connectivity issues between them. You can use tools like ping or telnet to test connectivity between the resources.

Check DNS resolution: Verify that the DNS resolution is working correctly for the Redis Cache resource. You can use the nslookup command to check the DNS resolution for the Redis Cache resource.

Check firewall rules: Ensure that the firewall rules for the Redis Cache resource are configured correctly to allow traffic from the Azure Container Apps resource. You can check the firewall rules in the Azure portal or using the Azure CLI.

Check Redis Cache configuration: Verify that the Redis Cache resource is configured correctly and is running without any issues. You can check the Redis Cache logs for any errors or issues.

Check Azure Container Apps configuration: Ensure that the Azure Container Apps resource is configured correctly and is using the correct connection string to connect to the Redis Cache resource.

Retry the connection: If the issue persists, try retrying the connection after some time. The issue could be caused by a temporary network or DNS issue that resolves itself over time.

In case the above doesn't help then this would need one on one support to verify the configuration and test to assist further.