Troubleshoot: Failure to connect to a cluster in Azure Data Explorer

If you can't connect to a cluster in Azure Data Explorer, try the following steps.

1. Make sure the connection string is correct. It should be in the form: https://<ClusterName>.<Region>.kusto.windows.net. For example, https://docscluster.westus.kusto.windows.net.

2. Make sure you have the right permissions. If you don't, you get an unauthorized response.

   For more information about permissions, see Manage database permissions. If necessary, work with your cluster administrator so they can add you to the appropriate role.

3. If you're connecting from an external tenant, make sure the cluster has the correct permissions.

   For more information about cross tenant scenarios, see Allow cross-tenant queries and commands.

4. Make sure your cluster is active. Clusters can automatically stop due to auto-stop settings.

   1. From the Azure portal, go to Azure Data Explorer Clusters and view your cluster.

   2. If the value in the State column is Stopped, select your cluster to open the overview page.

   3. From the Command bar, select Start. Then try reconnecting.

5. Check your subscription activity log to verify that the cluster wasn't deleted.

6. Check the Azure service health dashboard. Look for the status of Azure Data Explorer in the region where you're trying to connect to a cluster.

   If the status isn't Good (green check mark), try connecting to the cluster after the status improves.

7. If you still need assistance solving your problem, open a support request in the Azure portal.