ethdb/leveldb: support more than 7 levels in metrics (#27904)

ethdb/leveldb/leveldb.go

@@ -75,7 +75,7 @@ type Database struct {
  seekCompGauge metrics.Gauge // Gauge for tracking the number of table compaction caused by read opt
  manualMemAllocGauge metrics.Gauge // Gauge to track the amount of memory that has been manually allocated (not a part of runtime/GC)
 
- levelsGauge [7]metrics.Gauge // Gauge for tracking the number of tables in levels
+ levelsGauge []metrics.Gauge // Gauge for tracking the number of tables in levels
 
  quitLock sync.Mutex // Mutex protecting the quit channel access
  quitChan chan chan error // Quit channel to stop the metrics collection before closing the database
@@ -146,13 +146,8 @@ func NewCustom(file string, namespace string, customize func(options *opt.Option
  ldb.seekCompGauge = metrics.NewRegisteredGauge(namespace+"compact/seek", nil)
  ldb.manualMemAllocGauge = metrics.NewRegisteredGauge(namespace+"memory/manualalloc", nil)
 
- // leveldb has only up to 7 levels
- for i := range ldb.levelsGauge {
- ldb.levelsGauge[i] = metrics.NewRegisteredGauge(namespace+fmt.Sprintf("tables/level%v", i), nil)
- }
-
  // Start up the metrics gathering and return
- go ldb.meter(metricsGatheringInterval)
+ go ldb.meter(metricsGatheringInterval, namespace)
  return ldb, nil
 }
 
@@ -271,7 +266,7 @@ func (db *Database) Path() string {
 
 // meter periodically retrieves internal leveldb counters and reports them to
 // the metrics subsystem.
-func (db *Database) meter(refresh time.Duration) {
+func (db *Database) meter(refresh time.Duration, namespace string) {
  // Create the counters to store current and previous compaction values
  compactions := make([][]int64, 2)
  for i := 0; i < 2; i++ {
@@ -360,8 +355,11 @@ func (db *Database) meter(refresh time.Duration) {
  db.nonlevel0CompGauge.Update(int64(stats.NonLevel0Comp))
  db.seekCompGauge.Update(int64(stats.SeekComp))
 
- // update tables amount
  for i, tables := range stats.LevelTablesCounts {
+ // Append metrics for additional layers
+ if i >= len(db.levelsGauge) {
+ db.levelsGauge = append(db.levelsGauge, metrics.NewRegisteredGauge(namespace+fmt.Sprintf("tables/level%v", i), nil))
+ }
  db.levelsGauge[i].Update(int64(tables))
  }