Release Notes

Version 2.0.0

Scaler 2.0.0 focuses on policy-driven scaling, worker manager consolidation, and the YMQ-libuv networking/runtime transition.

Major Changes

  • Scaling policy system reworked: scaling controllers are stateless, REST-driven scaling control is removed, waterfall_v1 is introduced, capability-aware behavior is improved, and the default scheduler scaling policy is now vanilla (with fixed_elastic removed).

  • Worker manager architecture reorganized: worker manager lifecycle and control paths are unified across scheduler, configuration, and entry points, including stricter worker_manager_id handling.

  • New worker managers added:

    • AWS Batch worker manager

    • ORB AWS EC2 worker manager

  • Worker manager implementations simplified: fixed-native behavior is merged into native management paths, reducing overlap and simplifying deployment options.

  • YMQ-libuv becomes the standard network backend: Python wrappers and connector sets are added, object storage and scheduler paths are aligned, and YMQ now uses libuv as the supported I/O backend.

  • Reliability and correctness improvements: targeted fixes across asyncio, connector lifecycle, object storage handling, and YMQ error/overflow paths.

  • Web UI modernization: the Web UI is rewritten and refined with follow-up fixes and usability improvements.

Compatibility Notes

  • Client.map() and Client.starmap() align with Python semantics introduced in recent releases; deprecated tuple-style map usage was removed from tests and examples.

  • Ray compatibility remains available and aligned with current scheduler policy configuration patterns.