Simpler stz manager by Sayan- · Pull Request #8 · kernel/neko

Sayan- · 2025-10-20T23:51:33Z

Overview

We noticed issues where implementation would have < 0 pending. It seems like the naive assumptions that events would be deduped and delivered exactly once weren't really reliable. Instead swap to a model where we only disable/enable around edges rather than every event

Use global state from the session manager rather than tracking internally
Centralize logic in a simple helper. Call the helper right at start up to be safe
Check errors and only update internal state on success

Testing

Ran locally + against a few unikernels in staging. I would connect and disconnect a bunch of tabs to simulate flaky connections (this was a pretty consistent repro of the original issue)

Example logs from staging:

[neko] 11:19PM INF plugin enabled module=scaletozero
[neko] 11:19PM INF no operation needed; skipping toggle currently_connected_sessions=0 currently_disabled=false module=scaletozero previously_disabled=false
[neko] 11:19PM INF plugin started module=plugins plugin=scaletozero
[neko] 11:29PM INF disabling scale-to-zero connected_sessions=1 module=scaletozero
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=11 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=1 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF enabling scale-to-zero module=scaletozero
[neko] 11:29PM INF disabling scale-to-zero connected_sessions=1 module=scaletozero
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=11 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=1 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF enabling scale-to-zero module=scaletozero
[neko] 11:30PM INF disabling scale-to-zero connected_sessions=1 module=scaletozero
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=11 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=1 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF enabling scale-to-zero module=scaletozero
[neko] 11:30PM INF disabling scale-to-zero connected_sessions=1 module=scaletozero
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=11 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=1 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF enabling scale-to-zero module=scaletozero
[neko] 11:30PM INF disabling scale-to-zero connected_sessions=1 module=scaletozero
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=11 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=1 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF enabling scale-to-zero module=scaletozero
[neko] 11:32PM INF disabling scale-to-zero connected_sessions=2 module=scaletozero
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=11 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=1 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF enabling scale-to-zero module=scaletozero
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=0 currently_disabled=false module=scaletozero previously_disabled=false

mesa-dot-dev · 2025-10-20T23:52:47Z

Mesa Description

Overview

This PR refactors the scaletozero manager to fix a bug where the pending session count could become negative due to unreliable event delivery. The new implementation moves from a naive event-counting model to a more robust state-based approach.

Use Global State: The manager now relies on the session manager's list of active sessions as the single source of truth, rather than tracking connections internally.
Centralized Logic: A new manage() helper method centralizes the logic to enable or disable the scale-to-zero functionality based on whether there are any active sessions. This is also called at startup to ensure a correct initial state.
Stateful Tracking: Replaced the brittle pending counter with a simple disabledScaleToZero boolean flag, which is only updated after a successful state change, preventing state corruption on errors.

Testing

Ran locally + against a few unikernels in staging. I would connect and disconnect a bunch of tabs to simulate flaky connections (this was a pretty consistent repro of the original issue)

Example logs from staging:

[neko] 11:19PM INF plugin enabled module=scaletozero
[neko] 11:19PM INF no operation needed; skipping toggle currently_connected_sessions=0 currently_disabled=false module=scaletozero previously_disabled=false
[neko] 11:19PM INF plugin started module=plugins plugin=scaletozero
[neko] 11:29PM INF disabling scale-to-zero connected_sessions=1 module=scaletozero
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=11 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF no operation needed; skipping toggle currently_connected_sessions=1 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:29PM INF enabling scale-to-zero module=scaletozero
[neko] 11:29PM INF disabling scale-to-zero connected_sessions=1 module=scaletozero
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=11 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=1 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF enabling scale-to-zero module=scaletozero
[neko] 11:30PM INF disabling scale-to-zero connected_sessions=1 module=scaletozero
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=11 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=1 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF enabling scale-to-zero module=scaletozero
[neko] 11:30PM INF disabling scale-to-zero connected_sessions=1 module=scaletozero
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=11 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=1 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF enabling scale-to-zero module=scaletozero
[neko] 11:30PM INF disabling scale-to-zero connected_sessions=1 module=scaletozero
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:30PM INF no operation needed; skipping toggle currently_connected_sessions=11 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF no operation needed; skipping toggle currently_connected_sessions=1 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:31PM INF enabling scale-to-zero module=scaletozero
[neko] 11:32PM INF disabling scale-to-zero connected_sessions=2 module=scaletozero
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:32PM INF no operation needed; skipping toggle currently_connected_sessions=11 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=10 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=9 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=8 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=7 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=6 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=5 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=4 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=3 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=2 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=1 currently_disabled=true module=scaletozero previously_disabled=true
[neko] 11:33PM INF enabling scale-to-zero module=scaletozero
[neko] 11:33PM INF no operation needed; skipping toggle currently_connected_sessions=0 currently_disabled=false module=scaletozero previously_disabled=false

^{Description generated by Mesa. Update settings}

mesa-dot-dev

Performed full review of 46e2fc7...e9293ae

Analysis

Despite the architectural improvements, the PR doesn't address potential race conditions in the new state-based design that could occur during concurrent session state transitions.
The simplified boolean flag disabledScaleToZero may lack granularity compared to the counter approach, potentially making it difficult to handle partial or in-progress scaling operations.
The centralized manage() method creates a potential single point of failure and may become a bottleneck as system complexity grows.
The PR appears to focus on fixing symptoms rather than addressing the root cause of event deduplication failures, which could resurface in other components.

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^{1 files reviewed | 0 comments | Review on Mesa | Edit Reviewer Settings}

rgarcia · 2025-10-21T15:22:38Z

+	connectedSessions := 0
+	for _, s := range m.sessions.List() {
+ if s.State().IsConnected {
+ connectedSessions++


is there a world where a session is disconnected (IsConnected == false) but is trying to reconnect, and by not counting it here we might scale to zero, preventing it from connecting?

Great question! There's a grace period after disconnects for reconnection: https://github.com/onkernel/neko/blob/e9293ae098832ae0c4b63d092a9bd370e3c0ab12/server/internal/session/session.go#L145-L213
Especially wrt to scale to zero that delay + this buffer seems reasonable. For new connections at our proxy layer we'd be "waking up" the VM externally regardless ^^

Pulls in kernel/neko#8 kernel/neko#9  --- > [!NOTE] > Update chromium-headful Dockerfile to use neko base image 3.0.8-v1.3.0. > > - **Docker**: > - Bump base image in `images/chromium-headful/Dockerfile` from `ghcr.io/onkernel/neko/base:3.0.8-v1.1.0` to `3.0.8-v1.3.0`. > > <sup>Written by [Cursor Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit e6afb32. This will update automatically on new commits. Configure [here](https://cursor.com/dashboard?tab=bugbot).</sup>

simpler stz manager
e9293ae

Sayan- requested review from hiroTamada and rgarcia October 20, 2025 23:51

mesa-dot-devBot reviewed Oct 20, 2025
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rgarcia approved these changes Oct 21, 2025
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Sayan- added 2 commits October 21, 2025 13:33

test plugin
dc7d345

udpate wf
2dc4e1c

Sayan- merged commit 560fac5 into masterOct 21, 2025
3 checks passed

Sayan- deleted the sayan/simplify-stz branch October 21, 2025 20:40

Sayan- mentioned this pull request Oct 22, 2025
Sync upstream - v24/v28 (2026-02-04) kernel/kernel-images#83
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Simpler stz manager - #8

Simpler stz manager#8
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Sayan- commented Oct 20, 2025

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