pkg/ccl/storageccl/engineccl: ensure encryption percentage does not e…

[raggar]

ensure encryption percentage does not exceed 100%

package: pkg/ccl/storageccl/engineccl

Previously, the TotalFiles property from GenEnvStats() returned the
total number of files known to Pebble, however this results in encryption
percentages that are greater than 100%. The fix is to set TotalFiles to
be the maximum of the files known to Pebble and the files known by the
file registry. This applies to the TotalBytes property as well.

Fixes: #97874

Release note: None

[cockroach-teamcity]

This change is 

[RaduBerinde]

pkg/storage/pebble.go line 1877 at r1 (raw file):

	// Ensure that encryption percentage does not exceed 100%.
	frFileLen := uint64(len(fr.Files))
	if stats.TotalFiles < frFileLen {

Don't we want to cap it to ActiveFiles?

[RaduBerinde]

pkg/storage/pebble.go line 1877 at r1 (raw file):

Previously, RaduBerinde wrote…

Don't we want to cap it to ActiveFiles?

Feels like if there are files unaccounted by Pebble, we would show something under 100% in the steady-state

[jbowens]

Reviewed all commit messages.
Reviewable status: complete! 1 of 0 LGTMs obtained (waiting on @itsbilal and @RaduBerinde)

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pkg/storage/pebble.go line 1877 at r1 (raw file):

Previously, RaduBerinde wrote…

Feels like if there are files unaccounted by Pebble, we would show something under 100% in the steady-state

Since there's a bit of subtlety here, maybe we should add a comment:

len(fr.Files) is the total number of files known to the file registry. This includes all files created by Cockroach since encryption-at-rest was first enabled. If encryption-at-rest is subsequently disabled, new files will still be encoded within the registry. If encryption-at-rest has always been enabled, this count is as complete as you can get.

The existing stats.TotalFiles (computed up above from Pebble Metrics), holds an approximation of all the files known to Pebble. This does not include files that are being asynchronously deleted by Pebble, files that are stored in the auxiliary directory (typically sstables being prepared for ingestion by sideloading), or files created by spilling-to-disk.

If we knew encryption-at-rest had always been enabled, len(fr.Files) would be the true number of files. Since we don't know that, we use Pebble's count of files as a lower bound.

[raggar]

bors r+

[craig]

This PR was included in a batch that timed out, it will be automatically retried

[craig]

Build succeeded:

• Bazel Essential CI (Cockroach)