<!-- Add the related story/sub-task/bug number, like Resolves#123, or
remove if NA -->
**Related issue:** Resolves#43875
`POST /api/mdm/microsoft/management` is the hot endpoint for any
Windows-MDM-enrolled
fleet. Every enrolled host hits it twice per check-in interval. At 40k
hosts that's a
four-figure sustained queries-per-second rate on the database reader
pool, dominated
by one expensive query plus a handful of redundant
`MDMWindowsGetEnrolledDeviceWithDeviceID`
lookups on the same row.
This PR cuts that load by:
1. Short-circuiting the pending-commands query when the device's queue
is empty (the
overwhelming common case). Replaces a 3-table join plus anti-join with a
cheap
primary-key probe.
2. Loading the enrolled device exactly once in `isTrustedRequest` and
threading it
through to every downstream consumer instead of re-fetching it three
times.
No behavior change to the protocol, no schema change. Also filed a
related issue: https://github.com/fleetdm/fleet/issues/43897
# Checklist for submitter
If some of the following don't apply, delete the relevant line.
- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
## Testing
- [x] Added/updated automated tests
- [x] QA'd all new/changed functionality manually
For unreleased bug fixes in a release candidate, one of:
- [x] Alerted the release DRI if additional load testing is needed
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Bug Fixes**
* Improved Windows MDM server performance at scale by reducing database
queries during device check-ins.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Victor Lyuboslavsky
1f6e556818