Method plan

tsdb/compact.go:279–328

(dms []dirMeta)

}

func (c *LeveledCompactor) plan(dms []dirMeta) ([]string, error) {
	if len(dms) == 0 {
		return nil, nil
	}

	slices.SortFunc(dms, func(a, b dirMeta) int {
		switch {
		case a.meta.MinTime < b.meta.MinTime:
			return -1
		case a.meta.MinTime > b.meta.MinTime:
			return 1
		default:
			return 0
		}
	})

	res := c.selectOverlappingDirs(dms)
	if len(res) > 0 {
		return res, nil
	}
	// No overlapping blocks, do compaction the usual way.
	// We do not include a recently created block with max(minTime), so the block which was just created from WAL.
	// This gives users a window of a full block size to piece-wise backup new data without having to care about data overlap.
	dms = dms[:len(dms)-1]

	for _, dm := range c.selectDirs(dms) {
		res = append(res, dm.dir)
	}
	if len(res) > 0 {
		return res, nil
	}

	// Compact any blocks with big enough time range that have >5% tombstones.
	for i := len(dms) - 1; i >= 0; i-- {
		meta := dms[i].meta
		if meta.MaxTime-meta.MinTime < c.ranges[len(c.ranges)/2] {
			// If the block is entirely deleted, then we don't care about the block being big enough.
			// TODO: This is assuming a single tombstone is for a distinct series, which might not be true.
			if meta.Stats.NumTombstones > 0 && meta.Stats.NumTombstones >= meta.Stats.NumSeries {
				return []string{dms[i].dir}, nil
			}
			break
		}
		if float64(meta.Stats.NumTombstones)/float64(meta.Stats.NumSeries+1) > 0.05 {
			return []string{dms[i].dir}, nil
		}
	}

	return nil, nil
}

// selectDirs returns the dir metas that should be compacted into a single new block.
// If only a single block range is configured, the result is always nil.