Index Cluster Error after upgrading from 7.2 to 8.0

[spodda01da]

Hi All,

I am getting following error after upgrading my Indexer from 7.2 to 8.0.

Failed to register with cluster master reason: failed method=POST path=/services/cluster/master/peers/?output_mode=json master=fqdn:8089 rv=0 gotConnectionError=0 gotUnexpectedStatusCode=1 actual_response_code=400 expected_response_code=2xx status_line="Bad Request" socket_error="No error" remote_error=Argument "indexes" is not supported by this handler. [ event=addPeer status=retrying AddPeerRequest: { _id= _indexVec=''active_bundle_id=394AF89AB7DEFE33215AA7DA9985B422 add_type=Initial-Add base_generation_id=0 batch_serialno=1 batch_size=8 forwarderdata_rcv_port=9997 forwarderdata_use_ssl=0 last_complete_generation_id=0 latest_bundle_id=394AF89AB7DEFE33215AA7DA9985B422 mgmt_port=8089 name=C62C0E35-454C-476A-B2E4-D319A733B0CC register_forwarder_address= register_replication_address= register_search_address= replication_port=9887 replication_use_ssl=0 replications= server_name=chi-vmsplunk02 site=default splunk_version=8.0.2.1 splunkd_build_number=f002026bad55 status=Up } ].
3/24/2020, 2:32:59 AM

Don't think it's a network issue as it was working before upgrade. Not sure about compatiblity as current peer is on 8..0.2 and Cluster Master is on 7.2

Can anyone please suggest what could be the issue.

[hakon_nor · Accepted solution]

Always upgrade the Cluster master first, then the peers. See documentation https://docs.splunk.com/Documentation/Splunk/8.0.2/Indexer/Upgradeacluster

[spodda01da]

That really did the trick, thanks.