@Override
  protected AdminResponse createResponse(DistributionManager dm) {
    HashSet<PersistentID> persistentIds;
    try {
      persistentIds = finishBackupFactory.createFinishBackup(dm.getCache()).run();
    } catch (IOException e) {
      logger.error(String.format("Error processing request %s.", getClass()), e);
      return AdminFailureResponse.create(getSender(), e);
    }
    return finishBackupFactory.createBackupResponse(getSender(), persistentIds);
  }
A request send from an admin VM to all of the peers to indicate that that should complete the
backup operation.
geode-core/src/main/java/org/apache/geode/internal/cache/backup/FinishBackupRequest.java