fix: reduce excessive CPU usage during compaction planning (#26432) (#27169)

Co-authored-by: devanbenz <devandbenz@gmail.com>
Co-authored-by: Geoffrey Wossum <gwossum@influxdata.com>
fix: reduce excessive CPU usage during compaction planning (#26432)

Author: devanbenz

tsdb/engine/tsm1/compact.go

@@ -168,9 +168,8 @@ type DefaultPlanner struct {
 }
 
 type fileStore interface {
-	Stats() []FileStat
+	Stats() []ExtFileStat
 	LastModified() time.Time
-	BlockCount(path string, idx int) int
 	ParseFileName(path string) (int, int, error)
 	NextGeneration() int
 	TSMReader(path string) (*TSMReader, error)
@@ -190,7 +189,7 @@ func NewDefaultPlanner(fs fileStore, writeColdDuration time.Duration) *DefaultPl
 // 000001 each with different sequence numbers.
 type tsmGeneration struct {
 	id            int
-	files         []FileStat
+	files         []ExtFileStat
 	parseFileName ParseFileNameFunc
 }
 
@@ -265,7 +264,10 @@ func (c *DefaultPlanner) generationsFullyCompacted(gens tsmGenerations) (bool, s
 			aggressivePointsPerBlockCount := 0
 			filesUnderMaxTsmSizeCount := 0
 			for _, tsmFile := range gens[0].files {
-				if c.FileStore.BlockCount(tsmFile.Path, 1) >= c.GetAggressiveCompactionPointsPerBlock() {
+				// We check for greater than the default points per block here because the admin may
+				// have increased aggressive points per block in the config and wants to
+				// recompact files at the new higher max.
+				if tsmFile.FirstBlockCount > tsdb.DefaultMaxPointsPerBlock {
 					aggressivePointsPerBlockCount++
 				}
 				if tsmFile.Size < tsdb.MaxTSMFileSize {
@@ -505,7 +507,7 @@ func (c *DefaultPlanner) Plan(lastWrite time.Time) ([]CompactionGroup, int64) {
 			var skip bool
 
 			// Skip the file if it's over the max size and contains a full block and it does not have any tombstones
-			if len(generations) > 2 && group.size() > uint64(tsdb.MaxTSMFileSize) && c.FileStore.BlockCount(group.files[0].Path, 1) >= tsdb.DefaultMaxPointsPerBlock && !group.hasTombstones() {
+			if len(generations) > 2 && group.size() > uint64(tsdb.MaxTSMFileSize) && group.files[0].FirstBlockCount >= tsdb.DefaultMaxPointsPerBlock && !group.hasTombstones() {
 				skip = true
 			}
 
@@ -581,7 +583,7 @@ func (c *DefaultPlanner) Plan(lastWrite time.Time) ([]CompactionGroup, int64) {
 		// Skip the file if it's over the max size and contains a full block or the generation is split
 		// over multiple files.  In the latter case, that would mean the data in the file spilled over
 		// the 2GB limit.
-		if g.size() > uint64(tsdb.MaxTSMFileSize) && c.FileStore.BlockCount(g.files[0].Path, 1) >= tsdb.DefaultMaxPointsPerBlock {
+		if g.size() > uint64(tsdb.MaxTSMFileSize) && g.files[0].FirstBlockCount >= tsdb.DefaultMaxPointsPerBlock {
 			start = i + 1
 		}
 
@@ -625,7 +627,7 @@ func (c *DefaultPlanner) Plan(lastWrite time.Time) ([]CompactionGroup, int64) {
 			}
 
 			// Skip the file if it's over the max size and it contains a full block
-			if gen.size() >= uint64(tsdb.MaxTSMFileSize) && c.FileStore.BlockCount(gen.files[0].Path, 1) >= tsdb.DefaultMaxPointsPerBlock && !gen.hasTombstones() {
+			if gen.size() >= uint64(tsdb.MaxTSMFileSize) && gen.files[0].FirstBlockCount >= tsdb.DefaultMaxPointsPerBlock && !gen.hasTombstones() {
 				startIndex++
 				continue
 			}