---
metadata:
  - name: generator
    content: Diplodoc Platform v5.50.4
alternate:
  - https://ydb.tech/docs/en/troubleshooting/spilling/can-not-run-operation.md
  - https://ydb.tech/docs/ru/troubleshooting/spilling/can-not-run-operation.md
sourcePath: en/core/troubleshooting/spilling/can-not-run-operation.md
---
> **Documentation Index:** Fetch the complete configuration index at https://ydb.tech/docs/en/llms.txt

# Can not run operation

I/O thread pool operation queue overflow. This occurs when the spilling I/O thread pool queue is full and cannot accept new operations, causing spilling operations to fail.

## Diagnostics

Check the I/O thread pool configuration and usage:

- Check the `queue_size` parameter in `io_thread_pool` configuration
- Review the `workers_count` parameter for the I/O thread pool

## Recommendations

To resolve this issue:

1. **Increase queue size:**
   - Increase `queue_size` in `io_thread_pool` configuration
   - This allows more operations to be queued before overflow occurs

2. **Increase worker threads:**
   - Increase `workers_count` for faster operation processing
   - More worker threads can process operations faster, reducing queue buildup

{% note info %}

The I/O thread pool processes spilling operations asynchronously. If the queue overflows, new spilling operations will fail until space becomes available.

{% endnote %}