diff --git a/source/dnode/vnode/src/tsdb/tsdbCommit2.c b/source/dnode/vnode/src/tsdb/tsdbCommit2.c
index c55e5f92ea..79964c5636 100644
--- a/source/dnode/vnode/src/tsdb/tsdbCommit2.c
+++ b/source/dnode/vnode/src/tsdb/tsdbCommit2.c
@@ -562,6 +562,8 @@ int32_t tsdbCommitBegin(STsdb *tsdb, SCommitInfo *info) {
   } else {
     SCommitter2 committer[1];
 
+    tsdbFSCheckCommit(tsdb->pFS);
+
     code = tsdbOpenCommitter(tsdb, info, committer);
     TSDB_CHECK_CODE(code, lino, _exit);
 
diff --git a/source/dnode/vnode/src/tsdb/tsdbFS2.c b/source/dnode/vnode/src/tsdb/tsdbFS2.c
index 5e5348e9b5..afc9b7db3a 100644
--- a/source/dnode/vnode/src/tsdb/tsdbFS2.c
+++ b/source/dnode/vnode/src/tsdb/tsdbFS2.c
@@ -18,6 +18,8 @@
 #include "vnd.h"
 #include "vndCos.h"
 
+#define BLOCK_COMMIT_FACTOR 3
+
 extern int  vnodeScheduleTask(int (*execute)(void *), void *arg);
 extern int  vnodeScheduleTaskEx(int tpid, int (*execute)(void *), void *arg);
 extern void remove_file(const char *fname);
@@ -65,11 +67,17 @@ static int32_t create_fs(STsdb *pTsdb, STFileSystem **fs) {
   fs[0]->bgTaskQueue->next = fs[0]->bgTaskQueue;
   fs[0]->bgTaskQueue->prev = fs[0]->bgTaskQueue;
 
+  taosThreadMutexInit(&fs[0]->commitMutex, NULL);
+  taosThreadCondInit(&fs[0]->canCommit, NULL);
+  fs[0]->blockCommit = false;
+
   return 0;
 }
 
 static int32_t destroy_fs(STFileSystem **fs) {
   if (fs[0] == NULL) return 0;
+  taosThreadMutexDestroy(&fs[0]->commitMutex);
+  taosThreadCondDestroy(&fs[0]->canCommit);
   taosThreadMutexDestroy(fs[0]->mutex);
 
   ASSERT(fs[0]->bgTaskNum == 0);
@@ -829,6 +837,27 @@ _exit:
   return code;
 }
 
+static int32_t tsdbFSSetBlockCommit(STFileSystem *fs, bool block) {
+  taosThreadMutexLock(&fs->commitMutex);
+  if (block) {
+    fs->blockCommit = true;
+  } else {
+    fs->blockCommit = false;
+    taosThreadCondSignal(&fs->canCommit);
+  }
+  taosThreadMutexUnlock(&fs->commitMutex);
+  return 0;
+}
+
+int32_t tsdbFSCheckCommit(STFileSystem *fs) {
+  taosThreadMutexLock(&fs->commitMutex);
+  while (fs->blockCommit) {
+    taosThreadCondWait(&fs->canCommit, &fs->commitMutex);
+  }
+  taosThreadMutexUnlock(&fs->commitMutex);
+  return 0;
+}
+
 int32_t tsdbFSEditCommit(STFileSystem *fs) {
   int32_t code = 0;
   int32_t lino = 0;
@@ -838,19 +867,36 @@ int32_t tsdbFSEditCommit(STFileSystem *fs) {
   TSDB_CHECK_CODE(code, lino, _exit);
 
   // schedule merge
-  if (fs->tsdb->pVnode->config.sttTrigger != 1) {
+  if (fs->tsdb->pVnode->config.sttTrigger > 1) {
     STFileSet *fset;
+    int32_t    sttTrigger = fs->tsdb->pVnode->config.sttTrigger;
+    bool       schedMerge = false;
+    bool       blockCommit = false;
+
     TARRAY2_FOREACH_REVERSE(fs->fSetArr, fset) {
       if (TARRAY2_SIZE(fset->lvlArr) == 0) continue;
 
       SSttLvl *lvl = TARRAY2_FIRST(fset->lvlArr);
-      if (lvl->level != 0 || TARRAY2_SIZE(lvl->fobjArr) < fs->tsdb->pVnode->config.sttTrigger) continue;
+      if (lvl->level != 0) continue;
 
+      int32_t numFile = TARRAY2_SIZE(lvl->fobjArr);
+      if (numFile >= sttTrigger) {
+        schedMerge = true;
+      }
+
+      if (numFile >= sttTrigger * BLOCK_COMMIT_FACTOR) {
+        blockCommit = true;
+      }
+
+      if (schedMerge && blockCommit) break;
+    }
+
+    if (schedMerge) {
       code = tsdbFSScheduleBgTask(fs, TSDB_BG_TASK_MERGER, tsdbMerge, NULL, fs->tsdb, NULL);
       TSDB_CHECK_CODE(code, lino, _exit);
-
-      break;
     }
+
+    tsdbFSSetBlockCommit(fs, blockCommit);
   }
 
 _exit:
@@ -1104,4 +1150,4 @@ int32_t tsdbFSEnableBgTask(STFileSystem *fs) {
   fs->stop = false;
   taosThreadMutexUnlock(fs->mutex);
   return 0;
-}
+}
\ No newline at end of file
diff --git a/source/dnode/vnode/src/tsdb/tsdbFS2.h b/source/dnode/vnode/src/tsdb/tsdbFS2.h
index e814ab2fff..b0f42a0c48 100644
--- a/source/dnode/vnode/src/tsdb/tsdbFS2.h
+++ b/source/dnode/vnode/src/tsdb/tsdbFS2.h
@@ -67,6 +67,7 @@ int32_t tsdbFSDisableBgTask(STFileSystem *fs);
 int32_t tsdbFSEnableBgTask(STFileSystem *fs);
 // other
 int32_t tsdbFSGetFSet(STFileSystem *fs, int32_t fid, STFileSet **fset);
+int32_t tsdbFSCheckCommit(STFileSystem *fs);
 
 struct STFSBgTask {
   EFSBgTaskT type;
@@ -103,6 +104,11 @@ struct STFileSystem {
   int32_t       bgTaskNum;
   STFSBgTask    bgTaskQueue[1];
   STFSBgTask   *bgTaskRunning;
+
+  // block commit variables
+  TdThreadMutex commitMutex;
+  TdThreadCond  canCommit;
+  bool          blockCommit;
 };
 
 #ifdef __cplusplus
diff --git a/source/dnode/vnode/src/tsdb/tsdbMerge.c b/source/dnode/vnode/src/tsdb/tsdbMerge.c
index a1643acc50..5986e2ed1a 100644
--- a/source/dnode/vnode/src/tsdb/tsdbMerge.c
+++ b/source/dnode/vnode/src/tsdb/tsdbMerge.c
@@ -15,6 +15,8 @@
 
 #include "tsdbMerge.h"
 
+#define TSDB_MAX_LEVEL 6  // means max level is 7
+
 typedef struct {
   STsdb         *tsdb;
   TFileSetArray *fsetArr;
@@ -100,90 +102,142 @@ _exit:
 }
 
 static int32_t tsdbMergeFileSetBeginOpenReader(SMerger *merger) {
-  int32_t code = 0;
-  int32_t lino = 0;
-
-  merger->ctx->toData = true;
-  merger->ctx->level = 0;
-
-  // find the highest level that can be merged to
-  for (int32_t i = 0, numCarry = 0;;) {
-    int32_t numFile = numCarry;
-    if (i < TARRAY2_SIZE(merger->ctx->fset->lvlArr) &&
-        merger->ctx->level == TARRAY2_GET(merger->ctx->fset->lvlArr, i)->level) {
-      numFile += TARRAY2_SIZE(TARRAY2_GET(merger->ctx->fset->lvlArr, i)->fobjArr);
-      i++;
-    }
-
-    numCarry = numFile / merger->sttTrigger;
-    if (numCarry == 0) {
-      break;
-    } else {
-      merger->ctx->level++;
-    }
-  }
-
-  ASSERT(merger->ctx->level > 0);
-
+  int32_t  code = 0;
+  int32_t  lino = 0;
   SSttLvl *lvl;
+
+  bool hasLevelLargerThanMax = false;
   TARRAY2_FOREACH_REVERSE(merger->ctx->fset->lvlArr, lvl) {
-    if (TARRAY2_SIZE(lvl->fobjArr) == 0) {
-      continue;
-    }
-
-    if (lvl->level <= merger->ctx->level) {
-      merger->ctx->toData = false;
-    }
-    break;
-  }
-
-  // get number of level-0 files to merge
-  int32_t numFile = pow(merger->sttTrigger, merger->ctx->level);
-  TARRAY2_FOREACH(merger->ctx->fset->lvlArr, lvl) {
-    if (lvl->level == 0) continue;
-    if (lvl->level >= merger->ctx->level) break;
-
-    numFile = numFile - TARRAY2_SIZE(lvl->fobjArr) * pow(merger->sttTrigger, lvl->level);
-  }
-
-  ASSERT(numFile >= 0);
-
-  // get file system operations
-  TARRAY2_FOREACH(merger->ctx->fset->lvlArr, lvl) {
-    if (lvl->level >= merger->ctx->level) {
+    if (lvl->level <= TSDB_MAX_LEVEL) {
+      break;
+    } else if (TARRAY2_SIZE(lvl->fobjArr) > 0) {
+      hasLevelLargerThanMax = true;
       break;
     }
+  }
 
-    int32_t numMergeFile;
-    if (lvl->level == 0) {
-      numMergeFile = numFile;
-    } else {
-      numMergeFile = TARRAY2_SIZE(lvl->fobjArr);
+  if (hasLevelLargerThanMax) {
+    // merge all stt files
+    merger->ctx->toData = true;
+    merger->ctx->level = TSDB_MAX_LEVEL;
+
+    TARRAY2_FOREACH(merger->ctx->fset->lvlArr, lvl) {
+      int32_t numMergeFile = TARRAY2_SIZE(lvl->fobjArr);
+
+      for (int32_t i = 0; i < numMergeFile; ++i) {
+        STFileObj *fobj = TARRAY2_GET(lvl->fobjArr, i);
+
+        STFileOp op = {
+            .optype = TSDB_FOP_REMOVE,
+            .fid = merger->ctx->fset->fid,
+            .of = fobj->f[0],
+        };
+        code = TARRAY2_APPEND(merger->fopArr, op);
+        TSDB_CHECK_CODE(code, lino, _exit);
+
+        SSttFileReader      *reader;
+        SSttFileReaderConfig config = {
+            .tsdb = merger->tsdb,
+            .szPage = merger->szPage,
+            .file[0] = fobj->f[0],
+        };
+
+        code = tsdbSttFileReaderOpen(fobj->fname, &config, &reader);
+        TSDB_CHECK_CODE(code, lino, _exit);
+
+        code = TARRAY2_APPEND(merger->sttReaderArr, reader);
+        TSDB_CHECK_CODE(code, lino, _exit);
+      }
+    }
+  } else {
+    // do regular merge
+    merger->ctx->toData = true;
+    merger->ctx->level = 0;
+
+    // find the highest level that can be merged to
+    for (int32_t i = 0, numCarry = 0;;) {
+      int32_t numFile = numCarry;
+      if (i < TARRAY2_SIZE(merger->ctx->fset->lvlArr) &&
+          merger->ctx->level == TARRAY2_GET(merger->ctx->fset->lvlArr, i)->level) {
+        numFile += TARRAY2_SIZE(TARRAY2_GET(merger->ctx->fset->lvlArr, i)->fobjArr);
+        i++;
+      }
+
+      numCarry = numFile / merger->sttTrigger;
+      if (numCarry == 0) {
+        break;
+      } else {
+        merger->ctx->level++;
+      }
     }
 
-    for (int32_t i = 0; i < numMergeFile; ++i) {
-      STFileObj *fobj = TARRAY2_GET(lvl->fobjArr, i);
+    ASSERT(merger->ctx->level > 0);
 
-      STFileOp op = {
-          .optype = TSDB_FOP_REMOVE,
-          .fid = merger->ctx->fset->fid,
-          .of = fobj->f[0],
-      };
-      code = TARRAY2_APPEND(merger->fopArr, op);
-      TSDB_CHECK_CODE(code, lino, _exit);
+    if (merger->ctx->level <= TSDB_MAX_LEVEL) {
+      TARRAY2_FOREACH_REVERSE(merger->ctx->fset->lvlArr, lvl) {
+        if (TARRAY2_SIZE(lvl->fobjArr) == 0) {
+          continue;
+        }
 
-      SSttFileReader      *reader;
-      SSttFileReaderConfig config = {
-          .tsdb = merger->tsdb,
-          .szPage = merger->szPage,
-          .file[0] = fobj->f[0],
-      };
+        if (lvl->level >= merger->ctx->level) {
+          merger->ctx->toData = false;
+        }
+        break;
+      }
+    }
 
-      code = tsdbSttFileReaderOpen(fobj->fname, &config, &reader);
-      TSDB_CHECK_CODE(code, lino, _exit);
+    // get number of level-0 files to merge
+    int32_t numFile = pow(merger->sttTrigger, merger->ctx->level);
+    TARRAY2_FOREACH(merger->ctx->fset->lvlArr, lvl) {
+      if (lvl->level == 0) continue;
+      if (lvl->level >= merger->ctx->level) break;
 
-      code = TARRAY2_APPEND(merger->sttReaderArr, reader);
-      TSDB_CHECK_CODE(code, lino, _exit);
+      numFile = numFile - TARRAY2_SIZE(lvl->fobjArr) * pow(merger->sttTrigger, lvl->level);
+    }
+
+    ASSERT(numFile >= 0);
+
+    // get file system operations
+    TARRAY2_FOREACH(merger->ctx->fset->lvlArr, lvl) {
+      if (lvl->level >= merger->ctx->level) {
+        break;
+      }
+
+      int32_t numMergeFile;
+      if (lvl->level == 0) {
+        numMergeFile = numFile;
+      } else {
+        numMergeFile = TARRAY2_SIZE(lvl->fobjArr);
+      }
+
+      for (int32_t i = 0; i < numMergeFile; ++i) {
+        STFileObj *fobj = TARRAY2_GET(lvl->fobjArr, i);
+
+        STFileOp op = {
+            .optype = TSDB_FOP_REMOVE,
+            .fid = merger->ctx->fset->fid,
+            .of = fobj->f[0],
+        };
+        code = TARRAY2_APPEND(merger->fopArr, op);
+        TSDB_CHECK_CODE(code, lino, _exit);
+
+        SSttFileReader      *reader;
+        SSttFileReaderConfig config = {
+            .tsdb = merger->tsdb,
+            .szPage = merger->szPage,
+            .file[0] = fobj->f[0],
+        };
+
+        code = tsdbSttFileReaderOpen(fobj->fname, &config, &reader);
+        TSDB_CHECK_CODE(code, lino, _exit);
+
+        code = TARRAY2_APPEND(merger->sttReaderArr, reader);
+        TSDB_CHECK_CODE(code, lino, _exit);
+      }
+    }
+
+    if (merger->ctx->level > TSDB_MAX_LEVEL) {
+      merger->ctx->level = TSDB_MAX_LEVEL;
     }
   }