private Blueprint parseBlueprint(String blueprintName) throws InvalidTopologyTemplateException  {
    Blueprint blueprint;
    try {
      blueprint = getBlueprintFactory().getBlueprint(blueprintName);
    } catch (NoSuchStackException e) {
      throw new InvalidTopologyTemplateException("Invalid stack specified in the blueprint: " + blueprintName);
    }

    if (blueprint == null) {
      throw new InvalidTopologyTemplateException("The specified blueprint doesn't exist: " + blueprintName);
    }
    return blueprint;
  }
Parse blueprint.

@param blueprintName  blueprint name
@return blueprint instance

@throws InvalidTopologyTemplateException if specified blueprint or stack doesn't exist
ambari-server/src/main/java/org/apache/ambari/server/controller/internal/ScaleClusterRequest.java