protected ServerName[] getCurrentServers() throws IOException {
    ClusterMetrics clusterStatus = cluster.getClusterMetrics();
    Collection<ServerName> regionServers = clusterStatus.getLiveServerMetrics().keySet();
    int count = regionServers.size();
    if (count <= 0) {
      return new ServerName[] {};
    }
    ServerName master = clusterStatus.getMasterName();
    Set<ServerName> masters = new HashSet<>();
    masters.add(master);
    masters.addAll(clusterStatus.getBackupMasterNames());
    ArrayList<ServerName> tmp = new ArrayList<>(count);
    tmp.addAll(regionServers);
    tmp.removeAll(masters);

    if (skipMetaRS) {
      ServerName metaServer = cluster.getServerHoldingMeta();
      tmp.remove(metaServer);
    }

    return tmp.toArray(new ServerName[0]);
  }
Returns current region servers - active master
hbase-it/src/test/java/org/apache/hadoop/hbase/chaos/actions/Action.java