# v1.9.1

## Release Notes

## New Features & Enhancements

There are no new features or enhancements in this release. This is a point release in the 1.9 series. Refer to the [v1.9.0 release notes](https://docs.edera.dev/reference/release-notes/v1.9.0/) for more information.

## Bug Fixes

### Observability

- Prevented metrics storms from flooding IDM by adding a host-side metrics cache and raising the minimum metrics collection interval to one second.

### Core

- Destroyed zones are now retained as tombstones so their logs remain available for post-mortem inspection.
- Fixed several IDM deadlocks and throughput bottlenecks under load, including a storm-induced irrecoverable deadlock, bottlenecks that capped packet throughput, and a self-deadlock in stale-stream cleanup, resulting in a 7.5x speedup in IDM throughput.
- Reworked the zone IDM reader to use a per-backend event channel file descriptor with non-blocking polling.
- Fixed Xen event channel issues, including retrying `ioctl`s on `EINTR` and closing a `WakeMap` unbind/subscribe race.
- Raised `protect-daemon` file descriptor limit to 8192.

## Upgrade Notes

There are no known breaking changes in this release from the previous release `v1.9.0`.

Last updated on 2026-06-24