Fix MasterNotDiscoveredException

✅ Solution

MasterNotDiscoveredException in Elasticsearch often indicates that the node cannot find or communicate with the elected master node. This can stem from network connectivity issues, incorrect cluster configuration (e.g., discovery settings like `discovery.seed_hosts`), or insufficient resources on the master eligible nodes causing them to become unresponsive. To resolve, ensure all nodes can communicate on the configured ports, verify that `discovery.seed_hosts` lists enough master-eligible nodes, and monitor the health of master-eligible nodes for resource exhaustion, increasing their allocated resources if necessary.