@Siddharth Krishna​ :

When you kill a cluster in Databricks, the connection details for accessing the cluster will change, as the cluster will no longer exist. You will need to create a new cluster and update your connection details to reflect the new cluster.

To avoid impacting end-users when you need to update your clusters, you can set up a load balancer or proxy server in front of your Databricks clusters. This allows you to direct traffic to different clusters without exposing the underlying cluster details to end-users. This way, you can update your clusters or switch to new clusters without impacting the end-users.

Regarding calling a Delta table from an API using JDBC - The SQL endpoint is more performant because it allows you to execute SQL queries directly on the cluster.

In terms of major differences between the two, the JDBC API requires more setup and configuration, while the SQL endpoint is easier to use.