diff --git a/src/tsdb/inc/tsdbBuffer.h b/src/tsdb/inc/tsdbBuffer.h
index 17919c284e..4b650d3993 100644
--- a/src/tsdb/inc/tsdbBuffer.h
+++ b/src/tsdb/inc/tsdbBuffer.h
@@ -29,6 +29,7 @@ typedef struct {
   int            tBufBlocks;
   int            nBufBlocks;
   int            nRecycleBlocks;
+  int            nElasticBlocks;
   int64_t        index;
   SList*         bufBlockList;  
 } STsdbBufPool;
@@ -41,7 +42,7 @@ int           tsdbOpenBufPool(STsdbRepo* pRepo);
 void          tsdbCloseBufPool(STsdbRepo* pRepo);
 SListNode*    tsdbAllocBufBlockFromPool(STsdbRepo* pRepo);
 int           tsdbExpandPool(STsdbRepo* pRepo, int32_t oldTotalBlocks);
-void          tsdbRecycleBufferBlock(STsdbBufPool* pPool, SListNode *pNode);
+void          tsdbRecycleBufferBlock(STsdbBufPool* pPool, SListNode *pNode, bool bELastic);
 
 // health cite
 STsdbBufBlock *tsdbNewBufBlock(int bufBlockSize);
diff --git a/src/tsdb/src/tsdbBuffer.c b/src/tsdb/src/tsdbBuffer.c
index a8d800208c..06a98323ab 100644
--- a/src/tsdb/src/tsdbBuffer.c
+++ b/src/tsdb/src/tsdbBuffer.c
@@ -67,6 +67,7 @@ int tsdbOpenBufPool(STsdbRepo *pRepo) {
   pPool->bufBlockSize = pCfg->cacheBlockSize * 1024 * 1024; // MB
   pPool->tBufBlocks = pCfg->totalBlocks;
   pPool->nBufBlocks = 0;
+  pPool->nElasticBlocks = 0;
   pPool->index = 0;
   pPool->nRecycleBlocks = 0;
 
@@ -199,10 +200,13 @@ err:
   return err;
 }
 
-void tsdbRecycleBufferBlock(STsdbBufPool* pPool, SListNode *pNode) {
+void tsdbRecycleBufferBlock(STsdbBufPool* pPool, SListNode *pNode, bool bELastic) {
   STsdbBufBlock *pBufBlock = NULL;
   tdListNodeGetData(pPool->bufBlockList, pNode, (void *)(&pBufBlock));
   tsdbFreeBufBlock(pBufBlock);
   free(pNode);
-  pPool->nBufBlocks--;
+  if(bELastic)
+    pPool->nElasticBlocks--;
+  else
+    pPool->nBufBlocks--;
 }
\ No newline at end of file
diff --git a/src/tsdb/src/tsdbHealth.c b/src/tsdb/src/tsdbHealth.c
index e5e95e405f..32f6f4fdb8 100644
--- a/src/tsdb/src/tsdbHealth.c
+++ b/src/tsdb/src/tsdbHealth.c
@@ -32,16 +32,13 @@ int32_t tsdbInsertNewBlock(STsdbRepo * pRepo) {
   if(tsdbIdleMemEnough() && tsdbAllowNewBlock(pRepo)) {
     STsdbBufBlock *pBufBlock = tsdbNewBufBlock(pPool->bufBlockSize);
     if (pBufBlock) {
-      if (tsdbLockRepo(pRepo) >= 0) {
         if (tdListAppend(pPool->bufBlockList, (void *)(&pBufBlock)) < 0) {
           // append error
           tsdbFreeBufBlock(pBufBlock);
         } else {
-          pPool->nRecycleBlocks ++;
+          pPool->nElasticBlocks ++;
           cnt ++ ; 
         }
-        tsdbUnlockRepo(pRepo);  
-      }
     }
  } 
  return cnt;
@@ -91,13 +88,11 @@ bool tsdbIdleMemEnough() {
 
 bool tsdbAllowNewBlock(STsdbRepo* pRepo) {
   //TODO config to taos.cfg
-  int32_t nElasticBlocks = 10;
+  int32_t nMaxElastic = 3;
   STsdbBufPool* pPool = pRepo->pPool;
-  int32_t nOverBlocks = pPool->nBufBlocks - pRepo->config.totalBlocks;
-  if(nOverBlocks > nElasticBlocks) {
-    tsdbWarn("tsdbHealth allowNewBlock forbid. nOverBlocks(%d) > nElasticBlocks(%d)", nOverBlocks, nElasticBlocks);
+  if(pPool->nElasticBlocks >= nMaxElastic) {
+    tsdbWarn("tsdbAllowNewBlock return fasle. nElasticBlock(%d) >= MaxElasticBlocks(%d)", pPool->nElasticBlocks, nMaxElastic);
     return false;
   }
-
   return true;
 }
diff --git a/src/tsdb/src/tsdbMemTable.c b/src/tsdb/src/tsdbMemTable.c
index e766d97a97..02c9946704 100644
--- a/src/tsdb/src/tsdbMemTable.c
+++ b/src/tsdb/src/tsdbMemTable.c
@@ -99,17 +99,22 @@ int tsdbUnRefMemTable(STsdbRepo *pRepo, SMemTable *pMemTable) {
     STsdbBufPool *pBufPool = pRepo->pPool;
 
     SListNode *pNode = NULL;
-    bool recycleBlocks = pBufPool->nRecycleBlocks > 0;
+    bool addNew = false;
     if (tsdbLockRepo(pRepo) < 0) return -1;
     while ((pNode = tdListPopHead(pMemTable->bufBlockList)) != NULL) {
       if (pBufPool->nRecycleBlocks > 0) {
-        tsdbRecycleBufferBlock(pBufPool, pNode);
+        tsdbRecycleBufferBlock(pBufPool, pNode, false);
         pBufPool->nRecycleBlocks -= 1;
       } else {
-        tdListAppendNode(pBufPool->bufBlockList, pNode);
+        if(pBufPool->nElasticBlocks > 0 && listNEles(pBufPool->bufBlockList) > 0) {
+          tsdbRecycleBufferBlock(pBufPool, pNode, true);
+        } else {
+          tdListAppendNode(pBufPool->bufBlockList, pNode);
+          addNew = true;
+        }
       }      
     }
-    if (!recycleBlocks) {
+    if (addNew) {
       int code = pthread_cond_signal(&pBufPool->poolNotEmpty);
       if (code != 0) {
         if (tsdbUnlockRepo(pRepo) < 0) return -1;