diff --git a/deps/oblib/src/lib/tc/ob_tc_stat.cpp b/deps/oblib/src/lib/tc/ob_tc_stat.cpp
index 4ab2e7647..a245d9f3f 100644
--- a/deps/oblib/src/lib/tc/ob_tc_stat.cpp
+++ b/deps/oblib/src/lib/tc/ob_tc_stat.cpp
@@ -18,7 +18,7 @@ public:
   }
   ~QSchedStat() {}
   void try_report(int n_chan, int64_t cur_us, bool leaf_only) {
-    char buf[4096];
+    char buf[7168];
     int idx[128];
     StrFormat f(buf, sizeof(buf));
     int active_cnt = 0;
diff --git a/src/share/io/io_schedule/ob_io_schedule_v2.cpp b/src/share/io/io_schedule/ob_io_schedule_v2.cpp
index 25b3a2c03..30718fe42 100644
--- a/src/share/io/io_schedule/ob_io_schedule_v2.cpp
+++ b/src/share/io/io_schedule/ob_io_schedule_v2.cpp
@@ -289,6 +289,9 @@ int64_t ObTenantIOSchedulerV2::get_qindex(ObIORequest& req)
   } else if (OB_FAIL(req.tenant_io_mgr_.get_ptr()->get_group_index(grp_key, (uint64_t&)index))) {
     if (ret == OB_HASH_NOT_EXIST || ret == OB_STATE_NOT_MATCH) {
       ret = OB_SUCCESS;
+      if (REACH_TIME_INTERVAL(1 * 1000L * 1000L)) {
+        LOG_INFO("get group index failed, but maybe it is ok", K(ret), K(grp_key), K(index)); // group is not build
+      }
     } else {
       LOG_WARN("get group index failed", K(ret), K(grp_key), K(index));
     }
@@ -298,19 +301,20 @@ int64_t ObTenantIOSchedulerV2::get_qindex(ObIORequest& req)
   }
   return index;
 }
-
-int ObTenantIOSchedulerV2::get_qid(int64_t index)
+int ObTenantIOSchedulerV2::get_qid(int64_t index, ObIORequest& req, bool& is_default_q)
 {
   int qid = -1;
   if (index >= 0 && index < qid_.count()) {
     qid = qid_.at(index);
   }
-  if (qid < 0 && index >= 0) {
-    qid = default_qid_[index % N_SUB_ROOT];
+  if (qid < 0) {
+    is_default_q = true;
+    ObIOGroupKey grp_key = req.get_group_key();
+    int default_index = static_cast<int>(grp_key.mode_);
+    qid = default_qid_[default_index % N_SUB_ROOT];
   }
   return qid;
 }
-
 static uint32_t g_io_chan_id = 0;
 static uint32_t assign_chan_id()
 {
@@ -320,17 +324,23 @@ static uint32_t assign_chan_id()
 int ObTenantIOSchedulerV2::schedule_request(ObIORequest &req)
 {
   int ret = OB_SUCCESS;
+  bool is_default_q = false;
   int root = OB_IO_MANAGER_V2.get_root_qid();
   int64_t index = get_qindex(req);
-  int qid = get_qid(index);
+  int qid = get_qid(index, req, is_default_q);
   fill_qsched_req(req, qid);
   req.inc_ref("phyqueue_inc"); //ref for phy_queue
   if (OB_ISNULL(req.io_result_)) {
     ret = OB_INVALID_ARGUMENT;
     LOG_WARN("io result is null", K(ret), K(req));
+  } else if (FALSE_IT(req.io_result_->time_log_.enqueue_ts_ = ObTimeUtility::fast_current_time())) {
+  } else if (OB_UNLIKELY(is_default_q)) {
+    if (0 != qsched_submit(root, &req.qsched_req_, assign_chan_id())) {
+      ret = OB_ERR_UNEXPECTED;
+      LOG_WARN("qsched_submit fail", K(ret), K(req));
+    }
   } else if (OB_FAIL(OB_IO_MANAGER.get_tc().register_bucket(req, qid))) {
     LOG_WARN("register bucket fail", K(ret), K(req));
-  } else if (FALSE_IT(req.io_result_->time_log_.enqueue_ts_ = ObTimeUtility::fast_current_time())) {
   } else if (0 != qsched_submit(root, &req.qsched_req_, assign_chan_id())) {
     ret = OB_ERR_UNEXPECTED;
     LOG_WARN("qsched_submit fail", K(ret), K(req));
diff --git a/src/share/io/io_schedule/ob_io_schedule_v2.h b/src/share/io/io_schedule/ob_io_schedule_v2.h
index faadb4544..db1f481d4 100644
--- a/src/share/io/io_schedule/ob_io_schedule_v2.h
+++ b/src/share/io/io_schedule/ob_io_schedule_v2.h
@@ -71,7 +71,7 @@ public:
   int schedule_request(ObIORequest &req);
 private:
   static int64_t get_qindex(ObIORequest& req);
-  int get_qid(int64_t index);
+  int get_qid(int64_t index, ObIORequest& req, bool& is_default_q);
 private:
   DRWLock rwlock_;
   uint64_t tenant_id_;
diff --git a/src/share/io/ob_io_define.cpp b/src/share/io/ob_io_define.cpp
index e392ab023..858ec3764 100644
--- a/src/share/io/ob_io_define.cpp
+++ b/src/share/io/ob_io_define.cpp
@@ -774,7 +774,6 @@ ObIOMode ObIOResult::get_mode() const
   return flag_.get_mode();
 }
 
-
 ObIOGroupKey ObIOResult::get_group_key() const
 {
   return ObIOGroupKey(flag_.get_resource_group_id(), is_object_device_req_ ? get_mode() : ObIOMode::MAX_MODE);
@@ -1271,7 +1270,7 @@ const ObIOFlag &ObIORequest::get_flag() const
 
 ObIOMode ObIORequest::get_mode() const
 {
-  return io_result_->flag_.get_mode();
+  return io_result_->flag_.get_mode(); // 2 mode : read and write
 }
 
 ObIOGroupMode ObIORequest::get_group_mode() const
diff --git a/src/share/io/ob_io_define.h b/src/share/io/ob_io_define.h
index 6641fe5a9..f27dd2077 100644
--- a/src/share/io/ob_io_define.h
+++ b/src/share/io/ob_io_define.h
@@ -532,7 +532,7 @@ public:
   void cancel();
   int wait(int64_t wait_ms);
   void finish(const ObIORetCode &ret_code, ObIORequest *req = nullptr);
-  ObIOMode get_mode() const;
+  ObIOMode get_mode() const; // 2 mode : read and write
   ObIOGroupKey get_group_key() const;
   uint64_t get_sys_module_id() const;
   bool is_sys_module() const;
@@ -609,8 +609,8 @@ public:
   bool is_sys_module() const;
   char *calc_io_buf();  // calc the aligned io_buf of raw_buf_, which interact with the operating system
   const ObIOFlag &get_flag() const;
-  ObIOMode get_mode() const;
-  ObIOGroupMode get_group_mode() const;
+  ObIOMode get_mode() const; // 2 mode
+  ObIOGroupMode get_group_mode() const; // 4 mode
   ObIOCallback *get_callback() const;
   int alloc_io_buf(char *&io_buf);
   int get_buf_size() const;
diff --git a/src/share/io/ob_io_manager.cpp b/src/share/io/ob_io_manager.cpp
index 5e04f873e..435983a3f 100644
--- a/src/share/io/ob_io_manager.cpp
+++ b/src/share/io/ob_io_manager.cpp
@@ -198,7 +198,7 @@ int ObTrafficControl::ObSharedDeviceControlV2::fill_qsched_req_storage_key(ObIOR
 }
 
 int ObTrafficControl::ObSharedDeviceControlV2::add_group(const ObIOSSGrpKey &grp_key, const int qid) {
-  return group_list_.add_group(grp_key, qid, limit_ids_, ResourceType::ResourceTypeCnt);
+  return transform_ret(group_list_.add_group(grp_key, qid, limit_ids_, ResourceType::ResourceTypeCnt));
 }
 
 
@@ -341,6 +341,31 @@ int ObTrafficControl::calc_usage(ObIORequest &req)
   }
   return ret;
 }
+int ObTrafficControl::transform_ret(int ret)
+{
+  switch (ret) {
+    case 0:
+      ret = OB_SUCCESS;
+      break;
+    case ENOENT:
+      ret = OB_EAGAIN;
+      break;
+    case -ENOENT:
+      ret = OB_EAGAIN;
+      break;
+    case ENOMEM:
+      ret = OB_ALLOCATE_MEMORY_FAILED;
+      break;
+    case -ENOMEM:
+      ret = OB_ALLOCATE_MEMORY_FAILED;
+      break;
+    default:
+      LOG_WARN("unknow ret", K(ret));
+      ret = OB_ERR_UNEXPECTED;
+      break;
+  }
+  return ret;
+}
 
 void ObTrafficControl::print_server_status()
 {
diff --git a/src/share/io/ob_io_manager.h b/src/share/io/ob_io_manager.h
index 68dee88c8..3db4c67ed 100644
--- a/src/share/io/ob_io_manager.h
+++ b/src/share/io/ob_io_manager.h
@@ -298,7 +298,7 @@ public:
   int gc_tenant_infos();
 private:
   void inner_calc_();
-
+  static int transform_ret(int ret);
 private:
   // for device limitation
   hash::ObHashMap<ObStorageKey, ObSharedDeviceControl> shared_device_map_;