// Helper method to create mock ClusterHealthResponse
    private ClusterHealthResponse createMockHealthResponse(String clusterName, ClusterHealthStatus status) {
        return new ClusterHealthResponse() {
            @Override
            public String getClusterName() {
                return clusterName;
            }

            @Override
            public ClusterHealthStatus getStatus() {

            final ClusterHealthResponse response =
                    esClient.admin().cluster().prepareHealth().execute().actionGet(fessConfig.getIndexHealthTimeout());
            engineObj.clusterName = response.getClusterName();
            engineObj.numberOfNodes = response.getNumberOfNodes();
            engineObj.numberOfDataNodes = response.getNumberOfDataNodes();

        return serverAddress;
    }
    
    // Query for cluster witness service via DNS
    try {
        String clusterName = getClusterName(serverAddress);
        if (clusterName != null) {
            return InetAddress.getByName(clusterName + "-witness");
        }
    } catch (Exception e) {
        log.debug("Failed to discover cluster witness via DNS", e);
    }