@Override
  public void clusterChanged(ClusterChangedEvent event) {
    if (!VALID_CLUSTER_STATES.contains(event.state().status())) {
      // Only process fully applied cluster states
      return;
    }

    if (eventBus != null) {
      final List<String> indicesDeleted = event.indicesDeleted();
      if (!indicesDeleted.isEmpty()) {
        eventBus.post(IndicesDeletedEvent.create(indicesDeleted));
      }
    }
  }
  private void applyDeletedIndices(final ClusterChangedEvent event) {
    final ClusterState previousState = event.previousState();
    final String localNodeId = event.state().nodes().localNodeId();
    assert localNodeId != null;

    for (IndexService indexService : indicesService) {
      IndexMetaData indexMetaData = event.state().metaData().index(indexService.index().name());
      if (indexMetaData != null) {
        if (!indexMetaData.isSameUUID(indexService.indexUUID())) {
          logger.debug(
              "[{}] mismatch on index UUIDs between cluster state and local state, cleaning the index so it will be recreated",
              indexMetaData.index());
          deleteIndex(
              indexMetaData.index(),
              "mismatch on index UUIDs between cluster state and local state, cleaning the index so it will be recreated");
        }
      }
    }

    for (String index : event.indicesDeleted()) {
      if (logger.isDebugEnabled()) {
        logger.debug("[{}] cleaning index, no longer part of the metadata", index);
      }
      final Settings indexSettings;
      final IndexService idxService = indicesService.indexService(index);
      if (idxService != null) {
        indexSettings = idxService.getIndexSettings();
        deleteIndex(index, "index no longer part of the metadata");
      } else {
        final IndexMetaData metaData = previousState.metaData().index(index);
        assert metaData != null;
        indexSettings = metaData.settings();
        indicesService.deleteClosedIndex(
            "closed index no longer part of the metadata", metaData, event.state());
      }
      try {
        nodeIndexDeletedAction.nodeIndexDeleted(event.state(), index, indexSettings, localNodeId);
      } catch (Throwable e) {
        logger.debug("failed to send to master index {} deleted event", e, index);
      }
    }
  }