Troubleshooting cluster registration errors

While trying to resume the registration process, you can identify the problem behind the error and fix it.

Issues during registration in CDP Management Console

Error or issue details	Resolution
Alert: Registration is pending for a cluster with the same details.	Check if you are not trying to add a cluster that has already been registered. Navigate to the Classic Clusters page and search for your cluster in the list.
Alert: Cluster name given in Step 1 is not the same as the name discovered from Cloudera Manager. Clicking on Proceed will delete the cluster from Classic Clusters and take you to Step 1.	The cluster names entered are case-sensitive. Make sure the cluster name matches exactly with the name discovered from Cloudera Manager.

Cluster side issues

Error or issue details	Resolution
When installing the AutoSSH rpm on a cluster node, fetching the autossh package failed. Multiple mirrors were tried but a lot of them resulted in 404/ timed out errors.	Install autossh independently and then try installing the script.
Change in port number.	Delete your registration attempt from pending registrations tab and add the cluster again with right port number. Note that you must run the command systemctl stop ccm-tunnel@CM.service before you run ./install.sh again.
Connection refused even though the systemctl status ccm-tunnel@CM.service shows that the autossh client is running.	Make sure you copied the right ssh setup files for the cluster or check if the port number CCM_TUNNEL_SERVICE_PORT in cm_reverse_tunnel.conf is your Cloudera Manager's port number.
When running install script on cluster node, the ssh tunnel could not be established (as indicated in the logs generated using journalctl -xe).	Check if outbound connection to CDP control plane (host/port = CCM_HOST/CCM_SSH_PORT) is allowed. Make sure to check the firewall rules.