private StringBuilder getReadableDecommissionCommandDetail(
      ActionExecutionContext actionExecutionContext, Set<String> includedHosts,
      List<String> listOfExcludedHosts) {
    StringBuilder commandDetail = new StringBuilder();
    commandDetail.append(actionExecutionContext.getActionName());
    if (actionExecutionContext.getParameters().containsKey(IS_ADD_OR_DELETE_SLAVE_REQUEST) &&
      actionExecutionContext.getParameters().get(IS_ADD_OR_DELETE_SLAVE_REQUEST).equalsIgnoreCase("true")) {
      commandDetail.append(", Update Include/Exclude Files");
      return commandDetail;
    }
    if (listOfExcludedHosts.size() > 0) {
      commandDetail.append(", Excluded: ").append(StringUtils.join(listOfExcludedHosts, ','));
    }
    if (includedHosts.size() > 0) {
      commandDetail.append(", Included: ").append(StringUtils.join(includedHosts, ','));
    }
    return commandDetail;
  }
Processes decommission command. Modifies the host components as needed and then
calls into the implementation of a custom command
ambari-server/src/main/java/org/apache/ambari/server/controller/AmbariCustomCommandExecutionHelper.java