batch delete (delete_many) fails with unclear error on timeout. #1030

collection = client.collections.get(collection_name)
end_date = datetime.strptime("2024-04-09T20:16:10Z", "%Y-%m-%dT%H:%M:%SZ")
where_clause =  Filter.by_property("scrape_date").less_or_equal(end_date)
collection.data.delete_many(
 where=where_clause,
)

Traceback (most recent call last):
  File "/usr/local/lib/python3.10/site-packages/weaviate/collections/batch/grpc_batch_delete.py", line 33, in batch_delete
    res, _ = self._connection.grpc_stub.BatchDelete.with_call(
  File "/usr/local/lib/python3.10/site-packages/grpc/_channel.py", line 1193, in with_call
    return _end_unary_response_blocking(state, call, True, None)
  File "/usr/local/lib/python3.10/site-packages/grpc/_channel.py", line 1005, in _end_unary_response_blocking
    raise _InactiveRpcError(state)  # pytype: disable=not-instantiable
grpc._channel._InactiveRpcError: <_InactiveRpcError of RPC that terminated with:
	status = StatusCode.UNAVAILABLE
	details = "unavailable"
	debug_error_string = "UNKNOWN:Error received from peer  {created_time:"2024-04-29T15:18:19.331980027+00:00", grpc_status:14, grpc_message:"unavailable"}"
>

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.10/site-packages/weaviate/collections/data.py", line 162, in delete_many
    return self._batch_delete_grpc.batch_delete(
  File "/usr/local/lib/python3.10/site-packages/weaviate/collections/batch/grpc_batch_delete.py", line 67, in batch_delete
    raise WeaviateDeleteManyError(e.details())  # pyright: ignore
weaviate.exceptions.WeaviateDeleteManyError: Query call with protocol GRPC delete failed with message unavailable.

There is a configurable [maximum limit (QUERY_MAXIMUM_RESULTS)](https://weaviate.io/developers/weaviate/config-refs/env-vars#general) on the number of objects that can be deleted in a single query (default 10,000). To delete more objects than the limit, re-run the query.