diff --git a/src/share/scheduler/ob_dag_scheduler.cpp b/src/share/scheduler/ob_dag_scheduler.cpp
index f07e740a28..cfaf74daca 100755
--- a/src/share/scheduler/ob_dag_scheduler.cpp
+++ b/src/share/scheduler/ob_dag_scheduler.cpp
@@ -876,18 +876,18 @@ int ObIDagNet::add_dag_into_dag_net(ObIDag &dag)
 {
   int ret = OB_SUCCESS;
   void *buf = nullptr;
-  WEAK_BARRIER();
-
   ObDagRecord *dag_record = nullptr;
   int hash_ret = OB_SUCCESS;
   ObMutexGuard guard(lock_);
+  WEAK_BARRIER();
+  const bool is_stop = is_stopped_;
 
   if (OB_NOT_NULL(dag.get_dag_net())) {
     ret = OB_INVALID_ARGUMENT;
     COMMON_LOG(WARN, "dag already belongs to a dag_net", K(ret), K(dag));
-  } else if (is_stopped_) {
+  } else if (is_stop) {
     ret = OB_INNER_STAT_ERROR;
-    LOG_WARN("dag_net is in stop state, not allowed to add dag", K(ret), K(is_stopped_));
+    LOG_WARN("dag_net is in stop state, not allowed to add dag", K(ret), K(is_stop));
   } else if (is_cancel_) {
     ret = OB_CANCELED;
     LOG_WARN("dag net is cancel, do not allow to add new dag", K(ret), K(is_cancel_));
@@ -1000,7 +1000,6 @@ void ObIDagNet::remove_dag_record_(ObDagRecord &dag_record)
 int ObIDagNet::erase_dag_from_dag_net(ObIDag &dag)
 {
   int ret = OB_SUCCESS;
-  bool found = false;
   ObDagRecord *dag_record = nullptr;
   ObMutexGuard guard(lock_);
   WEAK_BARRIER();
@@ -1012,14 +1011,13 @@ int ObIDagNet::erase_dag_from_dag_net(ObIDag &dag)
   } else if (OB_ISNULL(dag_record)) {
     ret = OB_ERR_UNEXPECTED;
     COMMON_LOG(WARN, "dag record should not be NULL", K(ret), KP(this), KP(&dag));
-  } else if (dag_record->dag_ptr_ != &dag) {
+  } else if (OB_UNLIKELY(dag_record->dag_ptr_ != &dag)) {
     ret = OB_ERR_UNEXPECTED;
     COMMON_LOG(WARN, "dag record has unexpected dag value", K(ret), KP(this), KP(&dag), KPC(dag_record));
   } else if (OB_UNLIKELY(ObIDag::is_finish_status(dag_record->dag_status_))) {
     ret = OB_ERR_UNEXPECTED;
     LOG_ERROR("dag status is invalid when erase", K(ret), KPC(dag_record));
   } else {
-    found = true;
     COMMON_LOG(DEBUG, "success to update status", K(ret), KPC(dag_record));
     remove_dag_record_(*dag_record);
     dag.clear_dag_net();
diff --git a/src/storage/compaction/ob_medium_compaction_mgr.cpp b/src/storage/compaction/ob_medium_compaction_mgr.cpp
index dfa7d009b2..c197cf0f94 100644
--- a/src/storage/compaction/ob_medium_compaction_mgr.cpp
+++ b/src/storage/compaction/ob_medium_compaction_mgr.cpp
@@ -230,7 +230,6 @@ int ObTabletMediumCompactionInfoRecorder::inner_replay_clog(
   int ret = OB_SUCCESS;
   ObArenaAllocator tmp_allocator;
   ObMediumCompactionInfo replay_medium_info;
-  ObTabletHandle tmp_tablet_handle;
   if (OB_FAIL(replay_medium_info.deserialize(tmp_allocator, buf, size, pos))) {
     LOG_WARN("failed to deserialize medium compaction info", K(ret));
   } else if (!replay_medium_info.cluster_id_equal()
@@ -252,7 +251,6 @@ int ObTabletMediumCompactionInfoRecorder::inner_replay_clog(
     }
   }
 
-  tmp_tablet_handle.reset();
   return ret;
 }
 
diff --git a/src/storage/compaction/ob_tablet_merge_task.cpp b/src/storage/compaction/ob_tablet_merge_task.cpp
index dd090ce397..91d809aeab 100755
--- a/src/storage/compaction/ob_tablet_merge_task.cpp
+++ b/src/storage/compaction/ob_tablet_merge_task.cpp
@@ -1236,7 +1236,6 @@ int ObTabletMergeFinishTask::get_merged_sstable(ObTabletMergeCtx &ctx)
 int ObTabletMergeFinishTask::add_sstable_for_merge(ObTabletMergeCtx &ctx)
 {
   int ret = OB_SUCCESS;
-  ObTablet *old_tablet = ctx.tablet_handle_.get_obj();
   const ObMergeType merge_type = ctx.param_.merge_type_;
 
   if (OB_UNLIKELY(!ctx.is_valid())) {
@@ -1256,7 +1255,6 @@ int ObTabletMergeFinishTask::add_sstable_for_merge(ObTabletMergeCtx &ctx)
                                   is_minor_merge(ctx.param_.merge_type_)/*need_check_sstable*/,
                                   false/*allow_duplicate_sstable*/,
                                   ctx.param_.get_merge_type());
-    ObTablet *old_tablet = ctx.tablet_handle_.get_obj();
     ObTabletHandle new_tablet_handle;
     if (ctx.param_.tablet_id_.is_special_merge_tablet()) {
       param.multi_version_start_ = 1;
diff --git a/src/storage/ls/ob_ls_storage_clog_handler.cpp b/src/storage/ls/ob_ls_storage_clog_handler.cpp
index 3d3549c4f8..703238505a 100644
--- a/src/storage/ls/ob_ls_storage_clog_handler.cpp
+++ b/src/storage/ls/ob_ls_storage_clog_handler.cpp
@@ -122,6 +122,10 @@ int ObMediumCompactionClogHandler::inner_replay(
   } else if (OB_FAIL(handle.get_obj()->replay_medium_compaction_clog(scn, buffer, buffer_size, new_pos))) {
     LOG_WARN("failed to replay medium compaction clog", K(ret), K(tablet_id), K(buffer_size), K(new_pos));
   }
+  if (OB_TIMEOUT == ret) {
+    LOG_INFO("replace timeout errno", KR(ret), K(scn), K(tablet_id));
+    ret = OB_EAGAIN;
+  }
   return ret;
 }
 
diff --git a/src/storage/ls/ob_ls_tablet_service.cpp b/src/storage/ls/ob_ls_tablet_service.cpp
index 9260e3a7df..93e44a80cc 100755
--- a/src/storage/ls/ob_ls_tablet_service.cpp
+++ b/src/storage/ls/ob_ls_tablet_service.cpp
@@ -215,6 +215,9 @@ int ObLSTabletService::replay(
     if (OB_TABLET_NOT_EXIST == ret) {
       ret = OB_SUCCESS; // TODO (bowen.gbw): unify multi data replay logic
       LOG_INFO("tablet does not exist, skip", K(ret), K(replayer_executor));
+    } else if (OB_TIMEOUT == ret) {
+      LOG_INFO("replace timeout errno", KR(ret), K(replayer_executor));
+      ret = OB_EAGAIN;
     } else {
       LOG_WARN("failed to replay", K(ret), K(replayer_executor));
     }
@@ -585,64 +588,6 @@ int ObLSTabletService::get_tablet_addr(const ObTabletMapKey &key, ObMetaDiskAddr
   return ret;
 }
 
-int ObLSTabletService::replay_medium_compaction_clog(
-    const share::SCN &scn,
-    const char *buf,
-    const int64_t buf_size,
-    const int64_t pos)
-{
-  int ret = OB_SUCCESS;
-  ObTabletID tablet_id;
-  ObTabletHandle handle;
-  int64_t new_pos = pos;
-
-  if (IS_NOT_INIT) {
-    ret = OB_NOT_INIT;
-    LOG_WARN("not inited", K(ret));
-  } else if (OB_UNLIKELY(buf_size <= pos || pos < 0 || buf_size <= 0)) {
-    ret = OB_INVALID_ARGUMENT;
-    LOG_WARN("invalid argument", K(ret), K(buf_size), K(pos));
-  } else if (OB_FAIL(tablet_id.deserialize(buf, buf_size, new_pos))) {
-    LOG_WARN("fail to deserialize tablet id", K(ret), K(buf_size), K(pos), K(tablet_id));
-  } else if (OB_FAIL(direct_get_tablet(tablet_id, handle))) {
-    if (OB_TABLET_NOT_EXIST == ret) {
-      LOG_INFO("tablet not exist", K(ret), K(tablet_id));
-      ret = OB_SUCCESS;
-    } else {
-      LOG_WARN("failed to get tablet", K(ret), K(tablet_id));
-    }
-  } else if (handle.get_obj()->is_empty_shell()) {
-    LOG_INFO("old tablet is empty shell tablet, should skip this operation", K(ret), "old_tablet", handle.get_obj());
-  } else if (OB_FAIL(handle.get_obj()->replay_medium_compaction_clog(scn, buf, buf_size, new_pos))) {
-    LOG_WARN("update tablet storage schema fail", K(ret), K(tablet_id), K(buf_size), K(new_pos));
-  }
-  return ret;
-}
-
-int ObLSTabletService::replay_update_reserved_snapshot(
-    const share::SCN &scn,
-    const char *buf,
-    const int64_t buf_size,
-    const int64_t pos)
-{
-  int ret = OB_SUCCESS;
-  int64_t new_pos = pos;
-
-  if (IS_NOT_INIT) {
-    ret = OB_NOT_INIT;
-    LOG_WARN("not inited", K(ret));
-  } else if (OB_UNLIKELY(buf_size <= pos || pos < 0 || buf_size <= 0)) {
-    ret = OB_INVALID_ARGUMENT;
-    LOG_WARN("invalid argument", K(ret), K(buf_size), K(pos));
-  } else if (OB_ISNULL(ls_)) {
-    ret = OB_ERR_UNEXPECTED;
-    LOG_WARN("ls is null", K(ret), KPC(ls_));
-  } else if (OB_FAIL(ls_->replay_reserved_snapshot_log(scn, buf, buf_size, new_pos))) {
-    LOG_WARN("replay reserved snapshot log fail", K(ret), KPC(ls_), K(buf_size), K(new_pos));
-  }
-  return ret;
-}
-
 void ObLSTabletService::report_tablet_to_rs(const common::ObTabletID &tablet_id)
 {
   int ret = OB_SUCCESS;
diff --git a/src/storage/ls/ob_ls_tablet_service.h b/src/storage/ls/ob_ls_tablet_service.h
index 68415a6e5a..974da177ec 100755
--- a/src/storage/ls/ob_ls_tablet_service.h
+++ b/src/storage/ls/ob_ls_tablet_service.h
@@ -221,17 +221,6 @@ public:
   int get_bf_optimal_prefix(int64_t &prefix);
   int64_t get_tablet_count() const;
 
-  int replay_medium_compaction_clog(
-      const share::SCN &scn,
-      const char *buf,
-      const int64_t buf_size,
-      const int64_t pos);
-  int replay_update_reserved_snapshot(
-      const share::SCN &scn,
-      const char *buf,
-      const int64_t buf_size,
-      const int64_t pos);
-
   // update tablet
   int update_tablet_checkpoint(
     const ObTabletMapKey &key,