A DeleteByQueryRequest can be used to delete documents from an index. It requires an existing index (or a set of indices) on which deletion is to be performed.

The simplest form of a DeleteByQueryRequest looks like:

DeleteByQueryRequest request = new DeleteByQueryRequest("source1", "source2"); 

By default version conflicts abort the DeleteByQueryRequest process but you can just count them by settings it to proceed in the request body

request.setConflicts("proceed"); 

You can limit the documents by adding a query.

request.setQuery(new TermQueryBuilder("user", "kimchy")); 

It’s also possible to limit the number of processed documents by setting size.

request.setSize(10); 

By default DeleteByQueryRequest uses batches of 1000. You can change the batch size with setBatchSize.

request.setBatchSize(100); 

DeleteByQueryRequest also helps in automatically parallelizing using sliced-scroll to slice on _uid. Use setSlices to specify the number of slices to use.

request.setSlices(2); 

DeleteByQueryRequest uses the scroll parameter to control how long it keeps the "search context" alive.

request.setScroll(TimeValue.timeValueMinutes(10)); 

If you provide routing then the routing is copied to the scroll query, limiting the process to the shards that match that routing value.

request.setRouting("=cat"); 

In addition to the options above the following arguments can optionally be also provided:

request.setTimeout(TimeValue.timeValueMinutes(2)); 

request.setRefresh(true); 

request.setIndicesOptions(IndicesOptions.LENIENT_EXPAND_OPEN); 

The asynchronous execution of an delete by query request requires both the DeleteByQueryRequest instance and an ActionListener instance to be passed to the asynchronous method:

client.deleteByQueryAsync(request, RequestOptions.DEFAULT, listener); 

The asynchronous method does not block and returns immediately. Once it is completed the ActionListener is called back using the onResponse method if the execution successfully completed or using the onFailure method if it failed.

A typical listener for BulkByScrollResponse looks like:

ActionListener<BulkByScrollResponse> listener = new ActionListener<BulkByScrollResponse>() {
    @Override
    public void onResponse(BulkByScrollResponse bulkResponse) {
        
    }

    @Override
    public void onFailure(Exception e) {
        
    }
};

The returned BulkByScrollResponse contains information about the executed operations and allows to iterate over each result as follows:

TimeValue timeTaken = bulkResponse.getTook(); 
boolean timedOut = bulkResponse.isTimedOut(); 
long totalDocs = bulkResponse.getTotal(); 
long deletedDocs = bulkResponse.getDeleted(); 
long batches = bulkResponse.getBatches(); 
long noops = bulkResponse.getNoops(); 
long versionConflicts = bulkResponse.getVersionConflicts(); 
long bulkRetries = bulkResponse.getBulkRetries(); 
long searchRetries = bulkResponse.getSearchRetries(); 
TimeValue throttledMillis = bulkResponse.getStatus().getThrottled(); 
TimeValue throttledUntilMillis = bulkResponse.getStatus().getThrottledUntil(); 
List<ScrollableHitSource.SearchFailure> searchFailures = bulkResponse.getSearchFailures(); 
List<BulkItemResponse.Failure> bulkFailures = bulkResponse.getBulkFailures();