# Only 10 ray data actor is working with ray train and the rest is just idle **URL:** \ **Category:** Ray Train\ **Created:** [June 12, 2026, 9:52am UTC](https://discuss.ray.io/t/only-10-ray-data-actor-is-working-with-ray-train-and-the-rest-is-just-idle/23568 "2026-06-12T09:52:24Z")\ **Posts on this page:** 1\ **Showing post:** 6
**Author:** ![RunLLM](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.ray.io/runllm/32/8249_2.png) [@RunLLM](https://discuss.ray.io/u/RunLLM)\ **Post date:** [June 12, 2026, 1:27pm UTC](https://discuss.ray.io/t/only-10-ray-data-actor-is-working-with-ray-train-and-the-rest-is-just-idle/23568/6 "2026-06-12T13:27:20Z")
Setting `override_num_blocks=int(len(file_paths) / 100)` with 200,000 items should indeed create ~2,000 blocks, which is much more than the number of actors. If you still see only a small number of actors working, the issue is likely not with block count, but with Ray Data’s scheduling, backpressure, or downstream consumption rate ([source](https://discuss.ray.io/t/data-map-batches-is-not-respecting-concurrency-from-the-beginning/16074), [source](https://github.com/ray-project/ray/issues/41504)). Check if downstream operators (e.g., training or further data processing) are consuming data fast enough, as Ray Data may scale down active actors if there is backpressure or idle time. Would you like more detail on how to monitor and address backpressure or actor scaling in Ray Data? Sources: - [https://discuss.ray.io/t/data-map-batches-is-not-respecting-concurrency-from-the-beginning/16074](https://discuss.ray.io/t/data-map-batches-is-not-respecting-concurrency-from-the-beginning/16074) - [https://github.com/ray-project/ray/issues/41504](https://github.com/ray-project/ray/issues/41504) Hint: Mention @RunLLM in the post for followups. --- _[View the full topic](https://discuss.ray.io/t/only-10-ray-data-actor-is-working-with-ray-train-and-the-rest-is-just-idle/23568)._