Log into the instance on which you want to configure the monitoring console. The instance by default is in standalone mode, unconfigured.
In Splunk Web, select Monitoring Console > Settings > General Setup.
Click Distributed mode.
Confirm the following:
The columns labeled instance and machine are populated correctly and show unique values within each column.
The server roles are correct. For example, a search head that is also a license master must have both server roles listed. If not, click Edit > Edit Server Roles and select the correct server roles for the instance.
If you are using indexer clustering, make sure the cluster master instance is set to the cluster master server role. If not, click Edit > Edit Server Roles and select the correct server role.
If you are hosting the monitoring console on an instance other than the cluster master, you must add the cluster master instance as a search peer and configure the monitoring console instance as a search head in that cluster. See Add Splunk Enterprise instances to the Monitoring Console.
Make sure anything marked as an indexer is actually an indexer.
(Optional) Set custom groups. Custom groups are tags that map directly to distributed search groups. You might find groups useful, for example, if you have multisite indexer clustering in which each group can consist of the indexers in one location, or if you have an indexer cluster plus standalone peers. Custom groups are allowed to overlap. For example, one indexer can belong to multiple groups. See Create distributed search groups in the Distributed Search manual.