When adding an existing cluster to OpsCenter 5.0.0 the request often times out.
"Error creating cluster: Timeout while adding cluster. Please check the log for details on the problem."
This is due to Network Latency.
There is a timeout when adding a cluster to OpsCenter, There is a way of bypassing this timeout by creating the <cluster_name>.conf file on the OpsCenter host manually.
Depending on if you have Authentication configured on your cluster, or not. You can create the cluster *.conf file in the following directory /etc/opscenter/clusters/<cluster_name>.conf with the following information.
Note: if the file name has spaces you'll need to replace the spaces with the underscore character "_" for example:
"My new cluster" will be My_new_cluster.conf
username = <jmx_username>
If you do not have Authentication setup then you only need the following two lines in the <cluster_name>.conf:
seed_hosts = (IP of seed node)
After you have created this file, restart opscenterd and your cluster will be included in the dashboard.
This issue is fixed in OpsCenter Release 5.0.1 and greater