Is there a command I can execute? Is there an App I can deploy to see this information?
You can use the dbinspect command to get the count of buckets for each indexer.
Here is an example on how to use dbinspect to get the count of buckets by each Splunk server.
| dbinspect index=_internal | stats count by splunk_server
Here is the documentation to provide additional details and examples of using the dbinspect command.
View solution in original post