Opensearch 2.5 to 2.11 rolling upgrade

[pablo]

Could you confirm if this case is a duplicate of

Internal:coordination/fault_detection/follower_check from 2.5 to 2.11(also 9) node

Versions (relevant - OpenSearch/Dashboard/Server OS/Browser): 2.5 to 2.9 rolling upgrade Describe the issue: Do I miss any additional permissions while upgrading from 2.5 to 2.11 ? Stopping any master node is OK while all nodes are on 2.5, but opensearch service stop fails, for hours with below logs, during rolling upgrade on cluster manager node which is still on 2.5. Seams 2.5 cluster manager is having problems to check followers which are upgraded to 2.11. Cluster is green, and upgraded …