diff --git a/pkg/config/config.go b/pkg/config/config.go
index 8a20e2e64..d2b140af6 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -69,12 +69,12 @@ type cluster struct {
 }
 
 type shard struct {
+	// control gorutine number for read
+	GorutineNum int `env:"ZINC_SHARD_GORUTINE_NUM,default=3"`
 	// DefaultNum is the default number of shards.
 	Num int64 `env:"ZINC_SHARD_NUM,default=3"`
 	// MaxSize is the maximum size limit for one shard, or will create a new shard.
 	MaxSize uint64 `env:"ZINC_SHARD_MAX_SIZE,default=1073741824"`
-	// control gorutine number for read
-	GorutineNum int `env:"ZINC_SHARD_GORUTINE_NUM,default=10"`
 }
 
 type etcd struct {
diff --git a/pkg/core/index.go b/pkg/core/index.go
index e873f3581..cf54d00fa 100644
--- a/pkg/core/index.go
+++ b/pkg/core/index.go
@@ -90,6 +90,12 @@ func (index *Index) GetStats() meta.IndexStat {
 	return s
 }
 
+func (index *Index) UpdateWALSize(size uint64) {
+	index.lock.Lock()
+	index.ref.Stats.WALSize = size
+	index.lock.Unlock()
+}
+
 func (index *Index) GetAnalyzers() map[string]*analysis.Analyzer {
 	index.lock.RLock()
 	a := index.analyzers
diff --git a/pkg/core/index_shards_wal.go b/pkg/core/index_shards_wal.go
index e2c83632a..ea650190d 100644
--- a/pkg/core/index_shards_wal.go
+++ b/pkg/core/index_shards_wal.go
@@ -159,7 +159,7 @@ func (s *IndexShard) ConsumeWAL() bool {
 	if minID == maxID {
 		return false // no new entries
 	}
-	// log.Debug().Str("index", s.GetIndexName()).Int64("shard", s.GetID()).Uint64("minID", minID).Uint64("maxID", maxID).Msg("consume wal begin")
+	log.Debug().Str("index", s.GetIndexName()).Str("shard", s.GetID()).Uint64("minID", minID).Uint64("maxID", maxID).Msg("consume wal begin")
 
 	// limit max batch size
 	if maxID-minID > MaxBatchSize {
@@ -218,7 +218,7 @@ func (s *IndexShard) ConsumeWAL() bool {
 			return false
 		}
 	}
-	// log.Debug().Str("index", s.GetIndexName()).Int64("shard", s.GetID()).Uint64("minID", minID).Uint64("maxID", maxID).Msg("consume wal end")
+	log.Debug().Str("index", s.GetIndexName()).Str("shard", s.GetID()).Uint64("minID", minID).Uint64("maxID", maxID).Msg("consume wal end")
 
 	// Truncate log
 	if err = s.wal.TruncateFront(minID); err != nil {
diff --git a/pkg/core/index_shards_wallist.go b/pkg/core/index_shards_wallist.go
index 426ccf135..ded43ea1c 100644
--- a/pkg/core/index_shards_wallist.go
+++ b/pkg/core/index_shards_wallist.go
@@ -116,8 +116,9 @@ func (t *IndexShardWALList) ConsumeWAL() {
 			if size == uint64(index.GetShardNum()) {
 				size = 0
 			}
+			index.UpdateWALSize(size)
+
 			stats := index.GetStats()
-			atomic.StoreUint64(&stats.WALSize, size)
 			SetMetricStatsByIndex(name, "doc_num", float64(atomic.LoadUint64(&stats.DocNum)))
 			SetMetricStatsByIndex(name, "storage_size", float64(atomic.LoadUint64(&stats.StorageSize)/1024/1024)) // convert to MB