Cluster Manager Not Reachable

[SplunkNinja]

From Splunk Monitoring Console (MC), I am seeing the Cluster Manager Not Reachable.  I believe this was previously working.  My servers are running Splunk Enterprise 10.0.9.

[SplunkNinja]

Here are some more info:

Verify the CM is still running -> yes CM is running
Verify the CM is a search peer of the MC -> yes CM is search peer of the MC
Confirm there are no pending changes waiting to be applied in the MC -> I do not see any pending changes
Confirm the MC is still allowed to connect to the CM (new firewall rule, perhaps) -> I confirmed a curl from MC to CM is successful on tcp/8089
Check the MC's logs to see if reports any messages when trying to contact the CM.  From the CM I am seeing these messages:  

8-10-2026 20:33:25.292 +0000 ERROR HttpClientRequest [7217 LMTrackerExecutorWorker-0] - HTTP client error=Connection refused while accessing server=https://<LM>:8089 for request=https://<LM>:8089/services/masterlm/usage.
08-10-2026 20:33:25.292 +0000 WARN HttpClientRequest [7217 LMTrackerExecutorWorker-0] - Returning error HTTP/1.1 502 Connection refused
08-10-2026 20:33:25.292 +0000 ERROR LMTracker [7217 LMTrackerExecutorWorker-0] - failed to send rows, reason='Unable to connect to license manager=https://<LM>:8089 Connection refused

Restart the Splunk instance running the CM -> I restarted and even deleted the CM on the LM and re-added
Restart the Splunk instance running the MC -> I restarted the MC

[PickleRick]

Obviously you have some connectivity problems with your LM or simply your LM is down. I haven't had this kind of problems lately but I suppose if you restarted your CM _and_ it wasn't able to contact LM to confirm that your installation is actually licensed for cluster operations it _might_ refuse to work. 

[SplunkNinja]

My LM and MC are on the same server.  The MC shows all instances have Status Up including the CM server.  But from the MC Indexer Clustering Status, the Cluster Manager Not Reachable message is seen.

We have Splunk Enteprise licensing that allows for Clustering.

[PickleRick]

Yes, but if CM cannot contact LM, it might not be aware of the fact that your license supports clustering.

[richgalloway]

Here are some things to try.

1. Verify the CM is still running.
2. Verify the CM is a search peer of the MC.
3. Confirm there are no pending changes waiting to be applied in the MC.
4. Confirm the MC is still allowed to connect to the CM (new firewall rule, perhaps).
5. Check the MC's logs to see if reports any messages when trying to contact the CM.
6. Restart the Splunk instance running the CM.
7. Restart the Splunk instance running the MC.

If you still can't figure it out, post a reply with more detail.