diff --git a/ddl/column.go b/ddl/column.go
index 933cd9eff5..4808121db6 100644
--- a/ddl/column.go
+++ b/ddl/column.go
@@ -336,7 +336,7 @@ func (d *ddl) backfillColumn(t table.Table, columnInfo *model.ColumnInfo, reorgI
 
 func (d *ddl) backfillColumnData(t table.Table, columnInfo *model.ColumnInfo, handles []int64, reorgInfo *reorgInfo) error {
 	for _, handle := range handles {
-		log.Info("backfill column...", handle)
+		log.Info("[ddl] backfill column...", handle)
 
 		err := kv.RunInNewTxn(d.store, true, func(txn kv.Transaction) error {
 			if err := d.isReorgRunnable(txn); err != nil {
diff --git a/ddl/ddl.go b/ddl/ddl.go
index a2dcacfb8f..e97733ead7 100644
--- a/ddl/ddl.go
+++ b/ddl/ddl.go
@@ -193,7 +193,7 @@ func (d *ddl) SetLease(lease time.Duration) {
 		return
 	}
 
-	log.Warnf("change schema lease %s -> %s", d.lease, lease)
+	log.Warnf("[ddl] change schema lease %s -> %s", d.lease, lease)
 
 	if d.isClosed() {
 		// if already closed, just set lease and return
diff --git a/ddl/ddl_test.go b/ddl/ddl_test.go
index f2885b4d39..85b785731a 100644
--- a/ddl/ddl_test.go
+++ b/ddl/ddl_test.go
@@ -336,7 +336,7 @@ func (ts *testSuite) TestAlterTableColumn(c *C) {
 }
 
 func statement(ctx context.Context, sql string) stmt.Statement {
-	log.Debug("Compile", sql)
+	log.Debug("[ddl] Compile", sql)
 	lexer := parser.NewLexer(sql)
 	parser.YYParse(lexer)
 	compiler := &executor.Compiler{}
diff --git a/ddl/index.go b/ddl/index.go
index 98d3b608e3..446ee00156 100644
--- a/ddl/index.go
+++ b/ddl/index.go
@@ -426,7 +426,7 @@ func (d *ddl) backfillTableIndex(t table.Table, indexInfo *model.IndexInfo, hand
 	kvX := kv.NewKVIndex(t.IndexPrefix(), indexInfo.Name.L, indexInfo.ID, indexInfo.Unique)
 
 	for _, handle := range handles {
-		log.Debug("building index...", handle)
+		log.Debug("[ddl] building index...", handle)
 
 		err := kv.RunInNewTxn(d.store, true, func(txn kv.Transaction) error {
 			if err := d.isReorgRunnable(txn); err != nil {
diff --git a/ddl/worker.go b/ddl/worker.go
index c53101123d..d914f68a88 100644
--- a/ddl/worker.go
+++ b/ddl/worker.go
@@ -51,7 +51,7 @@ func (d *ddl) startJob(ctx context.Context, job *model.Job) error {
 	// notice worker that we push a new job and wait the job done.
 	asyncNotify(d.jobCh)
 
-	log.Warnf("start DDL job %v", job)
+	log.Warnf("[ddl] start DDL job %v", job)
 
 	jobID := job.ID
 
@@ -69,10 +69,10 @@ func (d *ddl) startJob(ctx context.Context, job *model.Job) error {
 
 		historyJob, err = d.getHistoryJob(jobID)
 		if err != nil {
-			log.Errorf("get history job err %v, check again", err)
+			log.Errorf("[ddl] get history job err %v, check again", err)
 			continue
 		} else if historyJob == nil {
-			log.Warnf("job %d is not in history, maybe not run", jobID)
+			log.Warnf("[ddl] job %d is not in history, maybe not run", jobID)
 			continue
 		}
 
@@ -129,11 +129,11 @@ func (d *ddl) checkOwner(t *meta.Meta) (*model.Owner, error) {
 		if err = t.SetDDLOwner(owner); err != nil {
 			return nil, errors.Trace(err)
 		}
-		log.Debugf("become owner %s", owner.OwnerID)
+		log.Debugf("[ddl] become owner %s", owner.OwnerID)
 	}
 
 	if owner.OwnerID != d.uuid {
-		log.Debugf("not owner, owner is %s", owner.OwnerID)
+		log.Debugf("[ddl] not owner, owner is %s", owner.OwnerID)
 		return nil, errors.Trace(ErrNotOwner)
 	}
 
@@ -152,7 +152,7 @@ func (d *ddl) updateJob(t *meta.Meta, job *model.Job) error {
 }
 
 func (d *ddl) finishJob(t *meta.Meta, job *model.Job) error {
-	log.Warnf("finish DDL job %v", job)
+	log.Warnf("[ddl] finish DDL job %v", job)
 	// done, notice and run next job.
 	_, err := t.DeQueueDDLJob()
 	if err != nil {
@@ -203,13 +203,13 @@ func (d *ddl) handleJobQueue() error {
 				// wait again.
 				elapsed := time.Duration(time.Now().UnixNano() - job.LastUpdateTS)
 				if elapsed > 0 && elapsed < waitTime {
-					log.Warnf("the elapsed time from last update is %s < %s, wait again", elapsed, waitTime)
+					log.Warnf("[ddl] the elapsed time from last update is %s < %s, wait again", elapsed, waitTime)
 					waitTime -= elapsed
 					return nil
 				}
 			}
 
-			log.Warnf("run DDL job %v", job)
+			log.Warnf("[ddl] run DDL job %v", job)
 
 			d.hook.OnJobRunBefore(job)
 
@@ -281,7 +281,7 @@ func (d *ddl) onWorker() {
 	for {
 		select {
 		case <-ticker.C:
-			log.Debugf("wait %s to check DDL status again", checkTime)
+			log.Debugf("[ddl] wait %s to check DDL status again", checkTime)
 		case <-d.jobCh:
 		case <-d.quitCh:
 			return
@@ -289,7 +289,7 @@ func (d *ddl) onWorker() {
 
 		err := d.handleJobQueue()
 		if err != nil {
-			log.Errorf("handle job err %v", errors.ErrorStack(err))
+			log.Errorf("[ddl] handle job err %v", errors.ErrorStack(err))
 		}
 	}
 }
diff --git a/domain/domain.go b/domain/domain.go
index 773969b4d1..1ac14b6fac 100644
--- a/domain/domain.go
+++ b/domain/domain.go
@@ -55,7 +55,7 @@ func (do *Domain) loadInfoSchema(txn kv.Transaction) (err error) {
 	if info != nil && schemaMetaVersion <= info.SchemaMetaVersion() {
 		// info may be changed by other txn, so here its version may be bigger than schema version,
 		// so we don't need to reload.
-		log.Debugf("schema version is still %d, no need reload", schemaMetaVersion)
+		log.Debugf("[ddl] schema version is still %d, no need reload", schemaMetaVersion)
 		return nil
 	}
 
@@ -85,7 +85,7 @@ func (do *Domain) loadInfoSchema(txn kv.Transaction) (err error) {
 		}
 	}
 
-	log.Infof("loadInfoSchema %d", schemaMetaVersion)
+	log.Infof("[ddl] loadInfoSchema %d", schemaMetaVersion)
 	err = do.infoHandle.Set(schemas, schemaMetaVersion)
 	return errors.Trace(err)
 }
@@ -167,7 +167,7 @@ func (do *Domain) reload() error {
 			}
 
 			if err != nil {
-				log.Errorf("load schema err %v, retry again", errors.ErrorStack(err))
+				log.Errorf("[ddl] load schema err %v, retry again", errors.ErrorStack(err))
 				// TODO: use a backoff algorithm.
 				time.Sleep(500 * time.Millisecond)
 				continue
@@ -192,7 +192,7 @@ func (do *Domain) mustReload() {
 	// if reload error, we will terminate whole program to guarantee data safe.
 	err := do.reload()
 	if err != nil {
-		log.Fatalf("reload schema err %v", errors.ErrorStack(err))
+		log.Fatalf("[ddl] reload schema err %v", errors.ErrorStack(err))
 	}
 }
 
@@ -216,7 +216,7 @@ func (do *Domain) loadSchemaInLoop(lease time.Duration) {
 			if terror.ErrorEqual(err, localstore.ErrDBClosed) {
 				return
 			} else if err != nil {
-				log.Fatalf("reload schema err %v", errors.ErrorStack(err))
+				log.Fatalf("[ddl] reload schema err %v", errors.ErrorStack(err))
 			}
 		case newLease := <-do.leaseCh:
 			if newLease <= 0 {
@@ -245,7 +245,7 @@ func (c *ddlCallback) OnChanged(err error) error {
 	if err != nil {
 		return err
 	}
-	log.Warnf("on DDL change")
+	log.Warnf("[ddl] on DDL change")
 
 	c.do.mustReload()
 	return nil
diff --git a/kv/txn.go b/kv/txn.go
index aa582ae337..2bf483970d 100644
--- a/kv/txn.go
+++ b/kv/txn.go
@@ -48,13 +48,13 @@ func RunInNewTxn(store Storage, retryable bool, f func(txn Transaction) error) e
 	for i := 0; i < maxRetryCnt; i++ {
 		txn, err := store.Begin()
 		if err != nil {
-			log.Errorf("RunInNewTxn error - %v", err)
+			log.Errorf("[kv] RunInNewTxn error - %v", err)
 			return errors.Trace(err)
 		}
 
 		err = f(txn)
 		if retryable && IsRetryableError(err) {
-			log.Warnf("Retry txn %v", txn)
+			log.Warnf("[kv] Retry txn %v", txn)
 			txn.Rollback()
 			continue
 		}
@@ -64,7 +64,7 @@ func RunInNewTxn(store Storage, retryable bool, f func(txn Transaction) error) e
 
 		err = txn.Commit()
 		if retryable && IsRetryableError(err) {
-			log.Warnf("Retry txn %v", txn)
+			log.Warnf("[kv] Retry txn %v", txn)
 			txn.Rollback()
 			BackOff(i)
 			continue
diff --git a/kv/union_iter.go b/kv/union_iter.go
index f6d119db52..0ef4069b5a 100644
--- a/kv/union_iter.go
+++ b/kv/union_iter.go
@@ -102,7 +102,7 @@ func (iter *UnionIter) updateCur() {
 			} else {
 				// record from dirty comes first
 				if len(iter.dirtyIt.Value()) == 0 {
-					log.Warnf("delete a record not exists? k = %q", iter.dirtyIt.Key())
+					log.Warnf("[kv] delete a record not exists? k = %q", iter.dirtyIt.Key())
 					// jump over this deletion
 					iter.dirtyNext()
 					continue
diff --git a/meta/autoid/autoid.go b/meta/autoid/autoid.go
index 132be1edfc..45aeb3ff86 100644
--- a/meta/autoid/autoid.go
+++ b/meta/autoid/autoid.go
@@ -68,7 +68,7 @@ func (alloc *allocator) Alloc(tableID int64) (int64, error) {
 	}
 
 	alloc.base++
-	log.Infof("Alloc id %d, table ID:%d, from %p, database ID:%d", alloc.base, tableID, alloc, alloc.dbID)
+	log.Debugf("[kv] Alloc id %d, table ID:%d, from %p, database ID:%d", alloc.base, tableID, alloc, alloc.dbID)
 	return alloc.base, nil
 }
 
diff --git a/store/hbase/txn.go b/store/hbase/txn.go
index 69dac89ba3..4910959789 100644
--- a/store/hbase/txn.go
+++ b/store/hbase/txn.go
@@ -65,22 +65,22 @@ func newHbaseTxn(t themis.Txn, storeName string) *hbaseTxn {
 // Implement transaction interface
 
 func (txn *hbaseTxn) Get(k kv.Key) ([]byte, error) {
-	log.Debugf("get key:%q, txn:%d", k, txn.tid)
+	log.Debugf("[kv] get key:%q, txn:%d", k, txn.tid)
 	return txn.UnionStore.Get(k)
 }
 
 func (txn *hbaseTxn) Set(k kv.Key, v []byte) error {
-	log.Debugf("seek %q txn:%d", k, txn.tid)
+	log.Debugf("[kv] seek %q txn:%d", k, txn.tid)
 	return txn.UnionStore.Set(k, v)
 }
 
 func (txn *hbaseTxn) Inc(k kv.Key, step int64) (int64, error) {
-	log.Debugf("Inc %q, step %d txn:%d", k, step, txn.tid)
+	log.Debugf("[kv] Inc %q, step %d txn:%d", k, step, txn.tid)
 	return txn.UnionStore.Inc(k, step)
 }
 
 func (txn *hbaseTxn) GetInt64(k kv.Key) (int64, error) {
-	log.Debugf("GetInt64 %q, txn:%d", k, txn.tid)
+	log.Debugf("[kv] GetInt64 %q, txn:%d", k, txn.tid)
 	return txn.UnionStore.GetInt64(k)
 }
 
@@ -89,7 +89,7 @@ func (txn *hbaseTxn) String() string {
 }
 
 func (txn *hbaseTxn) Seek(k kv.Key) (kv.Iterator, error) {
-	log.Debugf("seek %q txn:%d", k, txn.tid)
+	log.Debugf("[kv] seek %q txn:%d", k, txn.tid)
 	iter, err := txn.UnionStore.Seek(k)
 	if err != nil {
 		return nil, errors.Trace(err)
@@ -98,7 +98,7 @@ func (txn *hbaseTxn) Seek(k kv.Key) (kv.Iterator, error) {
 }
 
 func (txn *hbaseTxn) Delete(k kv.Key) error {
-	log.Debugf("delete %q txn:%d", k, txn.tid)
+	log.Debugf("[kv] delete %q txn:%d", k, txn.tid)
 	err := txn.UnionStore.Delete(k)
 	if err != nil {
 		return errors.Trace(err)
@@ -140,7 +140,7 @@ func (txn *hbaseTxn) doCommit() error {
 	}
 
 	txn.version = kv.NewVersion(txn.txn.GetCommitTS())
-	log.Debugf("commit successfully, txn.version:%d", txn.version.Ver)
+	log.Debugf("[kv] commit successfully, txn.version:%d", txn.version.Ver)
 	return nil
 }
 
@@ -148,7 +148,7 @@ func (txn *hbaseTxn) Commit() error {
 	if !txn.valid {
 		return kv.ErrInvalidTxn
 	}
-	log.Debugf("start to commit txn %d", txn.tid)
+	log.Debugf("[kv] start to commit txn %d", txn.tid)
 	defer func() {
 		txn.close()
 	}()
@@ -174,7 +174,7 @@ func (txn *hbaseTxn) Rollback() error {
 	if !txn.valid {
 		return kv.ErrInvalidTxn
 	}
-	log.Warnf("Rollback txn %d", txn.tid)
+	log.Warnf("[kv] Rollback txn %d", txn.tid)
 	return txn.close()
 }
 
diff --git a/store/localstore/compactor.go b/store/localstore/compactor.go
index a60eb2086e..2a70276261 100644
--- a/store/localstore/compactor.go
+++ b/store/localstore/compactor.go
@@ -100,7 +100,7 @@ func (gc *localstoreCompactor) deleteWorker() {
 			batch.Delete(key)
 			// Batch delete.
 			if cnt == gc.policy.BatchDeleteCnt {
-				log.Debugf("GC delete commit %d keys", batch.Len())
+				log.Debugf("[kv] GC delete commit %d keys", batch.Len())
 				err := gc.db.Commit(batch)
 				if err != nil {
 					log.Error(err)
@@ -117,7 +117,7 @@ func (gc *localstoreCompactor) checkExpiredKeysWorker() {
 	for {
 		select {
 		case <-gc.stopCh:
-			log.Debug("GC stopped")
+			log.Debug("[kv] GC stopped")
 			return
 		case <-gc.ticker.C:
 			gc.mu.Lock()
@@ -169,7 +169,9 @@ func (gc *localstoreCompactor) Compact(k kv.Key) error {
 		return errors.Trace(err)
 	}
 	filteredKeys := gc.filterExpiredKeys(keys)
-	log.Debugf("GC send %d keys to delete worker", len(filteredKeys))
+	if len(filteredKeys) > 0 {
+		log.Debugf("[kv] GC send %d keys to delete worker", len(filteredKeys))
+	}
 	for _, key := range filteredKeys {
 		gc.delCh <- key
 	}
diff --git a/store/localstore/kv.go b/store/localstore/kv.go
index 10749b5c1e..7750192170 100644
--- a/store/localstore/kv.go
+++ b/store/localstore/kv.go
@@ -82,7 +82,7 @@ func (d Driver) Open(schema string) (kv.Storage, error) {
 
 	if store, ok := mc.cache[schema]; ok {
 		// TODO: check the cache store has the same engine with this Driver.
-		log.Info("cache store", schema)
+		log.Info("[kv] cache store", schema)
 		return store, nil
 	}
 
@@ -91,7 +91,7 @@ func (d Driver) Open(schema string) (kv.Storage, error) {
 		return nil, errors.Trace(err)
 	}
 
-	log.Info("New store", schema)
+	log.Info("[kv] New store", schema)
 	s := &dbStore{
 		txns:       make(map[uint64]*dbTxn),
 		keysLocked: make(map[string]uint64),
@@ -164,7 +164,7 @@ func (s *dbStore) Begin() (kv.Transaction, error) {
 		version:      kv.MinVersion,
 		snapshotVals: make(map[string]struct{}),
 	}
-	log.Debugf("Begin txn:%d", txn.tid)
+	log.Debugf("[kv] Begin txn:%d", txn.tid)
 	txn.UnionStore = kv.NewUnionStore(newSnapshot(s, s.db, beginVer))
 	return txn, nil
 }
@@ -247,7 +247,7 @@ func (s *dbStore) tryConditionLockKey(tid uint64, key string) error {
 
 	// If there's newer version of this key, returns error.
 	if ver > tid {
-		log.Warnf("txn:%d, tryLockKey condition not match for key %s, currValue:%q", tid, key, currValue)
+		log.Warnf("[kv] txn:%d, tryLockKey condition not match for key %s, currValue:%q", tid, key, currValue)
 		return errors.Trace(kv.ErrConditionNotMatch)
 	}
 
diff --git a/store/localstore/local_version_provider.go b/store/localstore/local_version_provider.go
index a29bda4437..8450647678 100644
--- a/store/localstore/local_version_provider.go
+++ b/store/localstore/local_version_provider.go
@@ -37,7 +37,7 @@ func (l *LocalVersionProvider) CurrentVersion() (kv.Version, error) {
 		ts = uint64((time.Now().UnixNano() / int64(time.Millisecond)) << timePrecisionOffset)
 
 		if l.lastTimestamp > ts {
-			log.Error("invalid physical time stamp")
+			log.Error("[kv] invalid physical time stamp")
 			continue
 		}
 
diff --git a/store/localstore/txn.go b/store/localstore/txn.go
index c448fe21e1..6644a8f0b0 100644
--- a/store/localstore/txn.go
+++ b/store/localstore/txn.go
@@ -50,7 +50,7 @@ func (txn *dbTxn) markOrigin(k []byte) {
 // Implement transaction interface
 
 func (txn *dbTxn) Get(k kv.Key) ([]byte, error) {
-	log.Debugf("get key:%q, txn:%d", k, txn.tid)
+	log.Debugf("[kv] get key:%q, txn:%d", k, txn.tid)
 	val, err := txn.UnionStore.Get(k)
 	if err != nil {
 		return nil, errors.Trace(err)
@@ -60,7 +60,7 @@ func (txn *dbTxn) Get(k kv.Key) ([]byte, error) {
 }
 
 func (txn *dbTxn) Set(k kv.Key, data []byte) error {
-	log.Debugf("set key:%q, txn:%d", k, txn.tid)
+	log.Debugf("[kv] set key:%q, txn:%d", k, txn.tid)
 	err := txn.UnionStore.Set(k, data)
 	if err != nil {
 		return errors.Trace(err)
@@ -71,7 +71,7 @@ func (txn *dbTxn) Set(k kv.Key, data []byte) error {
 }
 
 func (txn *dbTxn) Inc(k kv.Key, step int64) (int64, error) {
-	log.Debugf("Inc %q, step %d txn:%d", k, step, txn.tid)
+	log.Debugf("[kv] Inc %q, step %d txn:%d", k, step, txn.tid)
 
 	txn.markOrigin(k)
 	val, err := txn.UnionStore.Inc(k, step)
@@ -83,7 +83,7 @@ func (txn *dbTxn) Inc(k kv.Key, step int64) (int64, error) {
 }
 
 func (txn *dbTxn) GetInt64(k kv.Key) (int64, error) {
-	log.Debugf("GetInt64 %q, txn:%d", k, txn.tid)
+	log.Debugf("[kv] GetInt64 %q, txn:%d", k, txn.tid)
 	val, err := txn.UnionStore.GetInt64(k)
 	if err != nil {
 		return 0, errors.Trace(err)
@@ -97,7 +97,7 @@ func (txn *dbTxn) String() string {
 }
 
 func (txn *dbTxn) Seek(k kv.Key) (kv.Iterator, error) {
-	log.Debugf("seek key:%q, txn:%d", k, txn.tid)
+	log.Debugf("[kv] seek key:%q, txn:%d", k, txn.tid)
 	iter, err := txn.UnionStore.Seek(k)
 	if err != nil {
 		return nil, errors.Trace(err)
@@ -110,7 +110,7 @@ func (txn *dbTxn) Seek(k kv.Key) (kv.Iterator, error) {
 }
 
 func (txn *dbTxn) Delete(k kv.Key) error {
-	log.Debugf("delete key:%q, txn:%d", k, txn.tid)
+	log.Debugf("[kv] delete key:%q, txn:%d", k, txn.tid)
 	err := txn.UnionStore.Delete(k)
 	if err != nil {
 		return errors.Trace(err)
@@ -177,7 +177,7 @@ func (txn *dbTxn) Commit() error {
 	if !txn.valid {
 		return errors.Trace(kv.ErrInvalidTxn)
 	}
-	log.Infof("commit txn %d", txn.tid)
+	log.Debugf("[kv] commit txn %d", txn.tid)
 	defer func() {
 		txn.close()
 	}()
@@ -204,7 +204,7 @@ func (txn *dbTxn) Rollback() error {
 	if !txn.valid {
 		return errors.Trace(kv.ErrInvalidTxn)
 	}
-	log.Warnf("Rollback txn %d", txn.tid)
+	log.Warnf("[kv] Rollback txn %d", txn.tid)
 	return txn.close()
 }