protected void clearMongoDB(MongoDBRepositoryDescriptor descriptor) throws UnknownHostException {
   MongoClient mongoClient = MongoDBRepository.newMongoClient(descriptor);
   try {
     DBCollection coll = MongoDBRepository.getCollection(descriptor, mongoClient);
     coll.dropIndexes();
     coll.remove(new BasicDBObject());
     coll = MongoDBRepository.getCountersCollection(descriptor, mongoClient);
     coll.dropIndexes();
     coll.remove(new BasicDBObject());
   } finally {
     mongoClient.close();
   }
 }