Delete 100000 records from datastore using java

Question

Program to delete 100000 records in bulk from datastore using java.Currently i am doing.

 public void deleteExistingResults() throws InterruptedException {
      log.info("inside deleteExistingResults");
    ArrayList<Key> keys = new ArrayList<Key>();
    List<Entity> results = getResults();
    for (Entity entity : results) {
      keys.add(entity.getKey());
      }
    log.info("deleteExistingResults:outside loop");
    service.delete(keys);
  }

where getResults return all the keys from datastore.I am getting this error. com.insightsapp.cron.controller.CronTask runTask: Encountered an exception too much contention on these datastore entities. please try again.

Answer 1

I'd recommend using something like the MapReduce library or at least using the Task Queue for deleting in batches of hundreds or so.