unable to add nodes during cluster setup

The performance runs failed when they tried to add new nodes to set up cluster. The runs were running on build 7.1.0-1488. The UI of 172.23.97.21 is not reachable. I have grabbed the log for the node manually.

http://perf.jenkins.couchbase.com/job/rhea-5node1-10B/104/

http://perf.jenkins.couchbase.com/job/rhea-5node1-10B/106/

http://perf.jenkins.couchbase.com/job/rhea-5node1-10B/107/

2021-10-13T17:55:03 [INFO] Adding new node: 172.23.97.22

2021-10-13T17:56:09 [WARNING] ["Unexpected server error, request logged."]

2021-10-13T17:56:09 [WARNING] Retrying http://172.23.97.21:8091/controller/addNode

2021-10-13T18:02:39 [ERROR] Request http://172.23.97.21:8091/controller/addNode failed after 20 attempts

Build step 'Execute shell' marked build as failure