private ResourceInstance createHostResource() {
    Map<Resource.Type, String> mapIds = new HashMap<>();
    return createResource(Resource.Type.Host, mapIds);
  }
Deletes folders older than (now - recommendationsArtifactsLifetime)
ambari-server/src/main/java/org/apache/ambari/server/api/services/stackadvisor/commands/StackAdvisorCommand.java