@Override
  public ObjectNode execute(final HttpServletRequest request) throws Exception {

    // get cluster object
    Cluster cluster = repository.getCluster();

    // json object to be sent as response
    ObjectNode responseJSON = mapper.createObjectNode();

    // cluster's Members
    responseJSON.set(CLUSTER, getPhysicalServerJson(cluster));
    responseJSON.put(MEMBER_COUNT, cluster.getMemberCount());

    // Send json response
    return responseJSON;
  }
Class ClusterMembersRGraphService

This class contains implementations of getting List of Cluster members and their details

@since GemFire version 7.5
geode-pulse/src/main/java/org/apache/geode/tools/pulse/internal/service/ClusterMembersRGraphService.java