Delete all documents from the my-index-000001 data stream or index:

Delete documents from multiple data streams or indices:

Limit the delete by query operation to shards that a particular routing value:

By default _delete_by_query uses scroll batches of 1000. You can change the batch size with the scroll_size URL parameter:

Delete a document using a unique attribute:

Slice a delete by query manually by providing a slice id and total number of slices:

Which you can verify works with:

Which results in a sensible total like this one:

You can also let delete-by-query automatically parallelize using sliced scroll to slice on _id. Use slices to specify the number of slices to use:

Which you also can verify works with:

Which results in a sensible total like this one:

Setting slices to auto will let Elasticsearch choose the number of slices to use. This setting will use one slice per shard, up to a certain limit. If there are multiple source data streams or indices, it will choose the number of slices based on the index or backing index with the smallest number of shards.

Adding slices to _delete_by_query just automates the manual process used in the section above, creating sub-requests which means it has some quirks:

The value of requests_per_second can be changed on a running delete by query using the _rethrottle API. Rethrottling that speeds up the query takes effect immediately but rethrotting that slows down the query takes effect after completing the current batch to prevent scroll timeouts.

Use the tasks API to get the task ID. Set requests_per_second to any positive decimal value or -1 to disable throttling.

Use the tasks API to get the status of a delete by query operation:

The response looks like:

This object contains the actual status. It is just like the response JSON with the important addition of the total field. total is the total number of operations that the reindex expects to perform. You can estimate the progress by adding the updated, created, and deleted fields. The request will finish when their sum is equal to the total field.

With the task id you can look up the task directly:

The advantage of this API is that it integrates with wait_for_completion=false to transparently return the status of completed tasks. If the task is completed and wait_for_completion=false was set on it then it’ll come back with results or an error field. The cost of this feature is the document that wait_for_completion=false creates at .tasks/task/${taskId}. It is up to you to delete that document.

Any delete by query can be canceled using the task cancel API:

The task ID can be found using the tasks API.

Cancellation should happen quickly but might take a few seconds. The task status API above will continue to list the delete by query task until this task checks that it has been cancelled and terminates itself.