* master: add conditional grow by average fill ratio to VolumeGrow gRPC
Callers that pre-grow volumes on fill level currently have to list all
volumes of a collection and sum sizes themselves, which is expensive on
clusters with millions of volumes. The master already tracks each
writable volume's effective size in memory, so it can answer the
question directly.
Add grow_avg_fill_threshold to VolumeGrowRequest: when set (e.g. 0.6),
growth only happens once the layout's writable volumes have reached
that average fill ratio. A layout with no writable volumes skips the
check, since that is the case growth exists to fix. VolumeGrowResponse
now reports the observed avg_fill and writable_count whether or not
growth was triggered.
* master: unit tests for WritableAvgFill and FindVolumeLayout
Covers the average-fill computation (mixed fills, no writables, a
writable volume without a size-tracking entry yet) and that
FindVolumeLayout resolves existing layouts without creating missing
collections.
* address review: report avg_fill and writable_count for every VolumeGrow
The stats were only read when grow_avg_fill_threshold was set, so a
request without a threshold got AvgFill=0 and WritableCount=0 even when
writable volumes existed. Read the layout stats unconditionally and use
the threshold only to decide whether growth happens.
* master: scope the grow fill check to the requested target
A VolumeGrow aimed at a data center, rack or node must not skip growth
because fill elsewhere keeps the layout average below the threshold.
Measure only writables serving the target; a target with none still
grows.
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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
---------
Co-authored-by: Chris Lu <chrislusf@users.noreply.github.com>
Co-authored-by: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>
