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# AI 3.8-15.1.9 Release Notes

## Summary

### New Features

* **Bulk unmount support** adds REST- and CLI-based unmount of multiple mount points, including wildcard and dry-run workflows.

### Major Enhancements

* **Job Service load operations are the main focus of this release.** Performance is significantly improved by moving load operations onto a unified streaming path, decoupling file listing from task dispatch through background prefetching, improving scheduler behavior on small clusters, and reducing large-file memory pressure so the system can sustain higher throughput across both many-file and large-file workloads.
* **Job Service load operations stability** is also strengthened. Retries are better aligned with worker-loss behavior, offline-worker tasks can be reassigned more safely, and executor behavior is hardened so saturated workers are less likely to leave load operations stuck indefinitely.
* **S3 List API performance and compatibility** are another major focus. Non-delimited `ListObjectsV2` over large prefixes is faster, paging behavior is more robust, empty `start-after` handling is safer for S3-compatible stores such as BOS, and S3 Express directory-bucket listing behavior is improved.
* **Stale-cache cleanup is significantly safer and more usable.** This release fixes an important issue where stale-cache cleanup could remove valid segments of segmented files, and it adds a safer scan-oriented mode so operators can inspect stale cache before taking cleanup actions. See [Removing Data from the Cache](/ee-ai-en/ai-3.8-15.1.x/cache/removing-data-from-the-cache.md).
* **Worker-side S3 read behavior** is improved for bursty reads and slow or stalled UFS connections, helping reduce silent stalls in affected read paths.
* **Control-plane resilience improvements** strengthen etcd recovery, membership handling, dynamic-config behavior, and repeated mount/update scenarios.

### Bug Fixes

* **S3 request-path correctness fixes** address event-loop blocking, HTTP state-machine corruption, `aws-chunked` decode failures, list paging overruns, and idle-close issues on in-flight requests.
* **Local page-store correctness fixes** ensure page-write failures surface properly and prevent stale maintenance logic from deleting valid cache data.
* **Stale-cache cleanup correctness fixes** prevent valid cache segments from being removed during cleanup workflows.
* **Job Service load operations recovery fixes** prevent operations from stalling or losing files when workers go offline during a load.
* **Embedded JVM UFS loading and metadata fallback behavior** are more reliable in affected environments.

## Breaking Changes

No breaking changes in this release.

## Upgrade Notes

No migration steps are required for this release.