diff --git a/docs/Doxyfile.in b/docs/Doxyfile.in
index 207157c415..139300ea80 100644
--- a/docs/Doxyfile.in
+++ b/docs/Doxyfile.in
@@ -491,7 +491,7 @@ EXTRACT_PACKAGE        = NO
 # included in the documentation.
 # The default value is: NO.
 
-EXTRACT_STATIC         = NO
+EXTRACT_STATIC         = YES
 
 # If the EXTRACT_LOCAL_CLASSES tag is set to YES, classes (and structs) defined
 # locally in source files will be included in the documentation. If set to NO,
@@ -1526,7 +1526,7 @@ ECLIPSE_DOC_ID         = org.doxygen.Project
 # The default value is: NO.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
-DISABLE_INDEX          = NO
+DISABLE_INDEX          = YES
 
 # The GENERATE_TREEVIEW tag is used to specify whether a tree-like index
 # structure should be generated to display hierarchical information. If the tag
@@ -1543,7 +1543,7 @@ DISABLE_INDEX          = NO
 # The default value is: NO.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
-GENERATE_TREEVIEW      = NO
+GENERATE_TREEVIEW      = YES
 
 # The ENUM_VALUES_PER_LINE tag can be used to set the number of enum values that
 # doxygen will group on one line in the generated HTML documentation.
@@ -2416,7 +2416,7 @@ INCLUDED_BY_GRAPH      = YES
 # The default value is: NO.
 # This tag requires that the tag HAVE_DOT is set to YES.
 
-CALL_GRAPH             = NO
+CALL_GRAPH             = YES
 
 # If the CALLER_GRAPH tag is set to YES then doxygen will generate a caller
 # dependency graph for every global function or class method.
@@ -2428,7 +2428,7 @@ CALL_GRAPH             = NO
 # The default value is: NO.
 # This tag requires that the tag HAVE_DOT is set to YES.
 
-CALLER_GRAPH           = NO
+CALLER_GRAPH           = YES
 
 # If the GRAPHICAL_HIERARCHY tag is set to YES then doxygen will graphical
 # hierarchy of all classes instead of a textual one.
diff --git a/include/dnode/vnode/meta/meta.h b/include/dnode/vnode/meta/meta.h
index b94ffc7a5d..421f96ef5f 100644
--- a/include/dnode/vnode/meta/meta.h
+++ b/include/dnode/vnode/meta/meta.h
@@ -28,24 +28,24 @@ typedef struct SMetaOptions SMetaOptions;
 typedef struct STbOptions   STbOptions;
 
 // SMeta operations
-SMeta *metaOpen(const char *path, const SMetaOptions *);
-void   metaClose(SMeta *);
+SMeta *metaOpen(const char *path, const SMetaOptions *pOptions);
+void   metaClose(SMeta *pMeta);
 void   metaRemove(const char *path);
-int    metaCreateTable(SMeta *pMeta, const STbOptions *);
+int    metaCreateTable(SMeta *pMeta, const STbOptions *pTbOptions);
 int    metaDropTable(SMeta *pMeta, tb_uid_t uid);
-int    metaCommit(SMeta *);
+int    metaCommit(SMeta *pMeta);
 
 // Options
-void metaOptionsInit(SMetaOptions *);
-void metaOptionsClear(SMetaOptions *);
+void metaOptionsInit(SMetaOptions *pOptions);
+void metaOptionsClear(SMetaOptions *pOptions);
 
 // STableOpts
 #define META_TABLE_OPTS_DECLARE(name) STableOpts name = {0}
-void metaNormalTableOptsInit(STbOptions *, const char *name, const STSchema *pSchema);
-void metaSuperTableOptsInit(STbOptions *, const char *name, tb_uid_t uid, const STSchema *pSchema,
+void metaNormalTableOptsInit(STbOptions *pTbOptions, const char *name, const STSchema *pSchema);
+void metaSuperTableOptsInit(STbOptions *pTbOptions, const char *name, tb_uid_t uid, const STSchema *pSchema,
                             const STSchema *pTagSchema);
-void metaChildTableOptsInit(STbOptions *, const char *name, tb_uid_t suid, const SKVRow tags);
-void metaTableOptsClear(STbOptions *);
+void metaChildTableOptsInit(STbOptions *pTbOptions, const char *name, tb_uid_t suid, const SKVRow tags);
+void metaTableOptsClear(STbOptions *pTbOptions);
 
 #ifdef __cplusplus
 }
diff --git a/include/dnode/vnode/tsdb/tsdb.h b/include/dnode/vnode/tsdb/tsdb.h
index 949ac679ae..e92205378a 100644
--- a/include/dnode/vnode/tsdb/tsdb.h
+++ b/include/dnode/vnode/tsdb/tsdb.h
@@ -16,15 +16,14 @@
 #ifndef _TD_TSDB_H_
 #define _TD_TSDB_H_
 
-#include "impl/tsdbImpl.h"
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
 // TYPES EXPOSED
-typedef struct STsdb        STsdb;
-typedef struct STsdbOptions STsdbOptions;
+typedef struct STsdb             STsdb;
+typedef struct STsdbOptions      STsdbOptions;
+typedef struct STsdbMemAllocator STsdbMemAllocator;
 
 // STsdb
 STsdb *tsdbOpen(const char *path, const STsdbOptions *);
@@ -35,6 +34,12 @@ void   tsdbRemove(const char *path);
 int  tsdbOptionsInit(STsdbOptions *);
 void tsdbOptionsClear(STsdbOptions *);
 
+/* ------------------------ STRUCT DEFINITIONS ------------------------ */
+struct STsdbOptions {
+  uint64_t lruCacheSize;
+  /* TODO */
+};
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/dnode/vnode/vnode.h b/include/dnode/vnode/vnode.h
index 29e14a673a..52470d60a9 100644
--- a/include/dnode/vnode/vnode.h
+++ b/include/dnode/vnode/vnode.h
@@ -17,9 +17,10 @@
 #define _TD_VNODE_H_
 
 #include "os.h"
-#include "trequest.h"
+#include "trpc.h"
 
 #include "meta.h"
+#include "tarray.h"
 #include "tq.h"
 #include "tsdb.h"
 
@@ -32,17 +33,72 @@ typedef struct SVnode        SVnode;
 typedef struct SVnodeOptions SVnodeOptions;
 
 /* ------------------------ SVnode ------------------------ */
+/**
+ * @brief Open a VNODE.
+ *
+ * @param path path of the vnode
+ * @param pVnodeOptions options of the vnode
+ * @return SVnode* The vnode object
+ */
 SVnode *vnodeOpen(const char *path, const SVnodeOptions *pVnodeOptions);
-void    vnodeClose(SVnode *pVnode);
-void    vnodeDestroy(const char *path);
-int     vnodeProcessWriteReqs(SVnode *pVnode, SReqBatch *pReqBatch);
-int     vnodeApplyWriteRequest(SVnode *pVnode, const SRequest *pRequest);
-int     vnodeProcessReadReq(SVnode *pVnode, SRequest *pReq);
-int     vnodeProcessSyncReq(SVnode *pVnode, SRequest *pReq);
+
+/**
+ * @brief Close a VNODE
+ *
+ * @param pVnode The vnode object to close
+ */
+void vnodeClose(SVnode *pVnode);
+
+/**
+ * @brief Destroy a VNODE.
+ *
+ * @param path Path of the VNODE.
+ */
+void vnodeDestroy(const char *path);
+
+/**
+ * @brief Process an array of write messages.
+ *
+ * @param pVnode The vnode object.
+ * @param pMsgs The array of SRpcMsg
+ * @return int 0 for success, -1 for failure
+ */
+int vnodeProcessWMsgs(SVnode *pVnode, SArray *pMsgs);
+
+/**
+ * @brief Apply a write request message.
+ *
+ * @param pVnode The vnode object.
+ * @param pMsg The request message
+ * @param pRsp The response message
+ * @return int 0 for success, -1 for failure
+ */
+int vnodeApplyWMsg(SVnode *pVnode, SRpcMsg *pMsg, SRpcMsg **pRsp);
+
+/**
+ * @brief Process the sync request
+ *
+ * @param pVnode
+ * @param pMsg
+ * @param pRsp
+ * @return int
+ */
+int vnodeProcessSyncReq(SVnode *pVnode, SRpcMsg *pMsg, SRpcMsg **pRsp);
 
 /* ------------------------ SVnodeOptions ------------------------ */
-void vnodeOptionsInit(SVnodeOptions *);
-void vnodeOptionsClear(SVnodeOptions *);
+/**
+ * @brief Initialize VNODE options.
+ *
+ * @param pOptions The options object to be initialized. It should not be NULL.
+ */
+void vnodeOptionsInit(SVnodeOptions *pOptions);
+
+/**
+ * @brief Clear VNODE options.
+ *
+ * @param pOptions Options to clear.
+ */
+void vnodeOptionsClear(SVnodeOptions *pOptions);
 
 /* ------------------------ STRUCT DEFINITIONS ------------------------ */
 struct SVnodeOptions {
diff --git a/include/libs/lru/lru.h b/include/libs/cache/cache.h
similarity index 91%
rename from include/libs/lru/lru.h
rename to include/libs/cache/cache.h
index c82e8ed746..6a2587ee96 100644
--- a/include/libs/lru/lru.h
+++ b/include/libs/cache/cache.h
@@ -13,8 +13,8 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef _TD_LRU_H_
-#define _TD_LRU_H_
+#ifndef _TD_CACHE_H_
+#define _TD_CACHE_H_
 
 #ifdef __cplusplus
 extern "C" {
@@ -24,4 +24,4 @@ extern "C" {
 }
 #endif
 
-#endif /*_TD_LRU_H_*/
\ No newline at end of file
+#endif /*_TD_CACHE_H_*/
\ No newline at end of file
diff --git a/include/util/mallocator.h b/include/util/mallocator.h
index a4705bdd2c..fd66811f38 100644
--- a/include/util/mallocator.h
+++ b/include/util/mallocator.h
@@ -24,37 +24,21 @@ extern "C" {
 
 typedef struct SMemAllocator SMemAllocator;
 
-#define MALLOCATOR_APIS                                        \
-  void *(*malloc)(SMemAllocator *, size_t size);               \
-  void *(*calloc)(SMemAllocator *, size_t nmemb, size_t size); \
-  void *(*realloc)(SMemAllocator *, void *ptr, size_t size);   \
-  void (*free)(SMemAllocator *, void *ptr);                    \
-  size_t (*usage)(SMemAllocator *);
-
-// Interfaces to implement
-typedef struct {
-  MALLOCATOR_APIS
-} SMemAllocatorIf;
-
 struct SMemAllocator {
-  void * impl;
-  size_t usize;
-  MALLOCATOR_APIS
+  char  name[16];
+  void *impl;
+  void *(*malloc)(SMemAllocator *, uint64_t size);
+  void *(*calloc)(SMemAllocator *, uint64_t nmemb, uint64_t size);
+  void *(*realloc)(SMemAllocator *, void *ptr, uint64_t size);
+  void (*free)(SMemAllocator *, void *ptr);
+  uint64_t (*usage)(SMemAllocator *);
 };
 
-// heap allocator
-SMemAllocator *tdCreateHeapAllocator();
-void           tdDestroyHeapAllocator(SMemAllocator *pMemAllocator);
-
-// arena allocator
-SMemAllocator *tdCreateArenaAllocator(size_t size);
-void           tdDestroyArenaAllocator(SMemAllocator *);
-
-#define mMalloc(pMemAllocator, size) (*(pMemAllocator->malloc))(pMemAllocator, size)
-#define mCalloc(pMemAllocator, nmemb, size) (*(pMemAllocator->calloc))(pMemAllocator, nmemb, size)
-#define mRealloc(pMemAllocator, ptr, size) (*(pMemAllocator->realloc))(pMemAllocator, ptr, size)
-#define mFree(pMemAllocator, ptr) (*(pMemAllocator->free))(pMemAllocator, ptr)
-#define mUsage(pMemAllocator) (*(pMemAllocator->usage))(pMemAllocator)
+typedef struct {
+  void *impl;
+  SMemAllocator *(*create)();
+  void (*destroy)(SMemAllocator *);
+} SMemAllocatorFactory;
 
 #ifdef __cplusplus
 }
diff --git a/include/util/tlist.h b/include/util/tlist.h
index 8246205e9b..e803e96605 100644
--- a/include/util/tlist.h
+++ b/include/util/tlist.h
@@ -46,9 +46,10 @@ typedef struct {
 #define isListEmpty(l) ((l)->numOfEles == 0)
 #define listNodeFree(n) free(n)
 
+void       tdListInit(SList *list, int eleSize);
+void       tdListEmpty(SList *list);
 SList *    tdListNew(int eleSize);
 void *     tdListFree(SList *list);
-void       tdListEmpty(SList *list);
 void       tdListPrependNode(SList *list, SListNode *node);
 void       tdListAppendNode(SList *list, SListNode *node);
 int        tdListPrepend(SList *list, void *data);
diff --git a/source/dnode/vnode/impl/inc/vnodeAllocatorPool.h b/source/dnode/vnode/impl/inc/vnodeBufferPool.h
similarity index 68%
rename from source/dnode/vnode/impl/inc/vnodeAllocatorPool.h
rename to source/dnode/vnode/impl/inc/vnodeBufferPool.h
index f02329fa87..3033862779 100644
--- a/source/dnode/vnode/impl/inc/vnodeAllocatorPool.h
+++ b/source/dnode/vnode/impl/inc/vnodeBufferPool.h
@@ -13,27 +13,23 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef _TD_VNODE_ALLOCATOR_POOL_H_
-#define _TD_VNODE_ALLOCATOR_POOL_H_
+#ifndef _TD_VNODE_BUFFER_POOL_H_
+#define _TD_VNODE_BUFFER_POOL_H_
 
+#include "tlist.h"
 #include "vnode.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-typedef struct {
-  int            nexta;
-  int            enda;
-  SMemAllocator *free[3];
-  SMemAllocator *used[3];
-} SVAllocatorPool;
+typedef struct SVBufPool SVBufPool;
 
-int  vnodeOpenAllocatorPool(SVnode *pVnode);
-void vnodeCloseAllocatorPool(SVnode *pVnode);
+int  vnodeOpenBufPool(SVnode *pVnode);
+void vnodeCloseBufPool(SVnode *pVnode);
 
 #ifdef __cplusplus
 }
 #endif
 
-#endif /*_TD_VNODE_ALLOCATOR_POOL_H_*/
\ No newline at end of file
+#endif /*_TD_VNODE_BUFFER_POOL_H_*/
\ No newline at end of file
diff --git a/source/dnode/vnode/impl/inc/vnodeDef.h b/source/dnode/vnode/impl/inc/vnodeDef.h
index 3ad7de722e..9cf9210cf3 100644
--- a/source/dnode/vnode/impl/inc/vnodeDef.h
+++ b/source/dnode/vnode/impl/inc/vnodeDef.h
@@ -19,9 +19,10 @@
 #include "mallocator.h"
 #include "sync.h"
 #include "tlockfree.h"
+#include "wal.h"
 
 #include "vnode.h"
-#include "vnodeAllocatorPool.h"
+#include "vnodeBufferPool.h"
 #include "vnodeCommit.h"
 #include "vnodeFileSystem.h"
 #include "vnodeOptions.h"
@@ -33,16 +34,16 @@ extern "C" {
 #endif
 
 struct SVnode {
-  char*            path;
-  SVnodeOptions    options;
-  SVState          state;
-  SVAllocatorPool* pool;
-  SMemAllocator*   inuse;
-  SMeta*           pMeta;
-  STsdb*           pTsdb;
-  STQ*             pTq;
-  SVnodeSync*      pSync;
-  SVnodeFS*        pFs;
+  char*         path;
+  SVnodeOptions options;
+  SVState       state;
+  SVBufPool*    pBufPool;
+  SMeta*        pMeta;
+  STsdb*        pTsdb;
+  STQ*          pTq;
+  SWal*         pWal;
+  SVnodeSync*   pSync;
+  SVnodeFS*     pFs;
 };
 
 #ifdef __cplusplus
diff --git a/source/dnode/vnode/impl/inc/vnodeMemAllocator.h b/source/dnode/vnode/impl/inc/vnodeMemAllocator.h
index 7e9bd21fe3..9184eb416b 100644
--- a/source/dnode/vnode/impl/inc/vnodeMemAllocator.h
+++ b/source/dnode/vnode/impl/inc/vnodeMemAllocator.h
@@ -16,10 +16,16 @@
 #ifndef _TD_VNODE_MEM_ALLOCATOR_H_
 #define _TD_VNODE_MEM_ALLOCATOR_H_
 
+#include "mallocator.h"
+#include "vnode.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+SMemAllocator *vnodeCreateMemAllocator(SVnode *pVnode);
+void           vnodeDestroyMemAllocator(SMemAllocator *pma);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/dnode/vnode/impl/inc/vnodeRequest.h b/source/dnode/vnode/impl/inc/vnodeRequest.h
index af909fb636..788918f105 100644
--- a/source/dnode/vnode/impl/inc/vnodeRequest.h
+++ b/source/dnode/vnode/impl/inc/vnodeRequest.h
@@ -20,6 +20,20 @@
 extern "C" {
 #endif
 
+typedef struct SVnodeReq SVnodeReq;
+typedef struct SVnodeRsp SVnodeRsp;
+
+typedef enum {
+} EVReqT;
+
+struct SVnodeReq {
+  /* TODO */
+};
+
+struct SVnodeRsp {
+  /* TODO */
+};
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/source/dnode/vnode/impl/src/vnodeBufferPool.c b/source/dnode/vnode/impl/src/vnodeBufferPool.c
new file mode 100644
index 0000000000..eba71b5ba3
--- /dev/null
+++ b/source/dnode/vnode/impl/src/vnodeBufferPool.c
@@ -0,0 +1,188 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "vnodeDef.h"
+
+/* ------------------------ STRUCTURES ------------------------ */
+#define VNODE_BUF_POOL_SHARDS 3
+
+struct SVBufPool {
+  SList      free;
+  SList      incycle;
+  SListNode *inuse;
+};
+
+typedef enum {
+  // Heap allocator
+  E_V_HEAP_ALLOCATOR = 0,
+  // Arena allocator
+  E_V_ARENA_ALLOCATOR
+} EVMemAllocatorT;
+
+typedef struct {
+  /* TODO */
+} SVHeapAllocator;
+
+typedef struct SVArenaNode {
+  struct SVArenaNode *prev;
+  uint64_t            size;
+  void *              ptr;
+  char                data[];
+} SVArenaNode;
+
+typedef struct {
+  uint64_t     ssize;  // step size
+  uint64_t     lsize;  // limit size
+  SVArenaNode *inuse;
+  SVArenaNode  node;
+} SVArenaAllocator;
+
+typedef struct {
+  T_REF_DECLARE()
+  uint64_t        capacity;
+  EVMemAllocatorT type;
+  union {
+    SVHeapAllocator  vha;
+    SVArenaAllocator vaa;
+  };
+} SVMemAllocator;
+
+static SListNode *vBufPoolNewNode(uint64_t capacity, EVMemAllocatorT type);
+static void       vBufPoolFreeNode(SListNode *pNode);
+
+int vnodeOpenBufPool(SVnode *pVnode) {
+  uint64_t        capacity;
+  EVMemAllocatorT type = E_V_ARENA_ALLOCATOR;
+
+  if ((pVnode->pBufPool = (SVBufPool *)calloc(1, sizeof(SVBufPool))) == NULL) {
+    /* TODO */
+    return -1;
+  }
+
+  tdListInit(&(pVnode->pBufPool->free), 0);
+  tdListInit(&(pVnode->pBufPool->incycle), 0);
+
+  capacity = pVnode->options.wsize / VNODE_BUF_POOL_SHARDS;
+  if (pVnode->options.isHeapAllocator) {
+    type = E_V_HEAP_ALLOCATOR;
+  }
+
+  for (int i = 0; i < VNODE_BUF_POOL_SHARDS; i++) {
+    SListNode *pNode = vBufPoolNewNode(capacity, type);
+    if (pNode == NULL) {
+      vnodeCloseBufPool(pVnode);
+      return -1;
+    }
+
+    tdListAppendNode(&(pVnode->pBufPool->free), pNode);
+  }
+
+  return 0;
+}
+
+void vnodeCloseBufPool(SVnode *pVnode) {
+  SListNode *pNode;
+  if (pVnode->pBufPool) {
+    // Clear free list
+    while ((pNode = tdListPopHead(&(pVnode->pBufPool->free))) != NULL) {
+      vBufPoolFreeNode(pNode);
+    }
+
+    // Clear incycle list
+    while ((pNode = tdListPopHead(&(pVnode->pBufPool->incycle))) != NULL) {
+      vBufPoolFreeNode(pNode);
+    }
+
+    // Free inuse node
+    if (pVnode->pBufPool->inuse) {
+      vBufPoolFreeNode(pVnode->pBufPool->inuse);
+    }
+
+    free(pVnode->pBufPool);
+    pVnode->pBufPool = NULL;
+  }
+}
+
+/* ------------------------ STATIC METHODS ------------------------ */
+static void vArenaAllocatorInit(SVArenaAllocator *pvaa, uint64_t capacity, uint64_t ssize, uint64_t lsize) { /* TODO */
+  pvaa->ssize = ssize;
+  pvaa->lsize = lsize;
+  pvaa->inuse = &pvaa->node;
+
+  pvaa->node.prev = NULL;
+  pvaa->node.size = capacity;
+  pvaa->node.ptr = pvaa->node.data;
+}
+
+static void vArenaAllocatorClear(SVArenaAllocator *pvaa) { /* TODO */
+  while (pvaa->inuse != &(pvaa->node)) {
+    SVArenaNode *pANode = pvaa->inuse;
+    pvaa->inuse = pANode->prev;
+    free(pANode);
+  }
+}
+
+static SListNode *vBufPoolNewNode(uint64_t capacity, EVMemAllocatorT type) {
+  SListNode *     pNode;
+  SVMemAllocator *pvma;
+  uint64_t        msize;
+  uint64_t        ssize = 0;  // TODO
+  uint64_t        lsize = 0;  // TODO
+
+  msize = sizeof(SListNode) + sizeof(SVMemAllocator);
+  if (type == E_V_ARENA_ALLOCATOR) {
+    msize += capacity;
+  }
+
+  pNode = (SListNode *)calloc(1, msize);
+  if (pNode == NULL) {
+    // TODO: handle error
+    return NULL;
+  }
+
+  pvma = (SVMemAllocator *)(pNode->data);
+  pvma->capacity = capacity;
+  pvma->type = type;
+
+  switch (type) {
+    case E_V_ARENA_ALLOCATOR:
+      vArenaAllocatorInit(&(pvma->vaa), capacity, ssize, lsize);
+      break;
+    case E_V_HEAP_ALLOCATOR:
+      // vHeapAllocatorInit(&(pvma->vha));
+      break;
+    default:
+      ASSERT(0);
+  }
+
+  return pNode;
+}
+
+static void vBufPoolFreeNode(SListNode *pNode) {
+  SVMemAllocator *pvma = (SVMemAllocator *)(pNode->data);
+
+  switch (pvma->type) {
+    case E_V_ARENA_ALLOCATOR:
+      vArenaAllocatorClear(&(pvma->vaa));
+      break;
+    case E_V_HEAP_ALLOCATOR:
+      // vHeapAllocatorClear(&(pvma->vha));
+      break;
+    default:
+      break;
+  }
+
+  free(pNode);
+}
\ No newline at end of file
diff --git a/source/dnode/vnode/impl/src/vnodeMain.c b/source/dnode/vnode/impl/src/vnodeMain.c
index f9efb88bd9..7381fb28af 100644
--- a/source/dnode/vnode/impl/src/vnodeMain.c
+++ b/source/dnode/vnode/impl/src/vnodeMain.c
@@ -87,8 +87,7 @@ static void vnodeFree(SVnode *pVnode) {
 static int vnodeOpenImpl(SVnode *pVnode) {
   char dir[TSDB_FILENAME_LEN];
 
-  // Open allocator pool
-  if (vnodeOpenAllocatorPool(pVnode) < 0) {
+  if (vnodeOpenBufPool(pVnode) < 0) {
     // TODO: handle error
     return -1;
   }
@@ -132,8 +131,6 @@ static int vnodeOpenImpl(SVnode *pVnode) {
 static void vnodeCloseImpl(SVnode *pVnode) {
   if (pVnode) {
     vnodeCloseBufPool(pVnode);
-    walClose(pVnode->pWal);
-    tqClose(pVnode->pTq);
     tsdbClose(pVnode->pTsdb);
     metaClose(pVnode->pMeta);
   }
diff --git a/source/dnode/vnode/impl/src/vnodeMemAllocator.c b/source/dnode/vnode/impl/src/vnodeMemAllocator.c
index 3771a14113..902014eb47 100644
--- a/source/dnode/vnode/impl/src/vnodeMemAllocator.c
+++ b/source/dnode/vnode/impl/src/vnodeMemAllocator.c
@@ -15,6 +15,17 @@
 
 #include "vnodeDef.h"
 
+SMemAllocator *vnodeCreateMemAllocator(SVnode *pVnode) {
+  SMemAllocator *pma = NULL;
+  /* TODO */
+  return pma;
+}
+
+void vnodeDestroyMemAllocator(SMemAllocator *pma) {
+  // TODO
+}
+
+#if 0
 #define VNODE_HEAP_ALLOCATOR 0
 #define VNODE_ARENA_ALLOCATOR 1
 
@@ -97,4 +108,6 @@ void vnodeUnrefMemAllocator(SMemAllocator *pma) {
 
 /* ------------------------ Heap Allocator IMPL ------------------------ */
 
-/* ------------------------ Arena Allocator IMPL ------------------------ */
\ No newline at end of file
+/* ------------------------ Arena Allocator IMPL ------------------------ */
+
+#endif
\ No newline at end of file
diff --git a/source/dnode/vnode/impl/src/vnodeWrite.c b/source/dnode/vnode/impl/src/vnodeWrite.c
index f3204cfd37..810ac570bc 100644
--- a/source/dnode/vnode/impl/src/vnodeWrite.c
+++ b/source/dnode/vnode/impl/src/vnodeWrite.c
@@ -15,24 +15,25 @@
 
 #include "vnodeDef.h"
 
-int vnodeProcessWriteReqs(SVnode *pVnode, SReqBatch *pReqBatch) {
+int vnodeProcessWMsgs(SVnode *pVnode, SArray *pMsgs) {
   /* TODO */
   return 0;
 }
 
-int vnodeApplyWriteRequest(SVnode *pVnode, const SRequest *pRequest) {
+int vnodeApplyWMsg(SVnode *pVnode, SRpcMsg *pMsg, SRpcMsg **pRsp) {
+#if 0
   int      reqType;        /* TODO */
   size_t   reqSize;        /* TODO */
   uint64_t reqVersion = 0; /* TODO */
   int      code = 0;
 
   // Copy the request to vnode buffer
-  SRequest *pReq = mMalloc(pVnode->inuse, reqSize);
+  void *pReq = mMalloc(pVnode->inuse, reqSize);
   if (pReq == NULL) {
     // TODO: handle error
   }
 
-  memcpy(pReq, pRequest, reqSize);
+  memcpy(pReq, pMsg, reqSize);
 
   // Push the request to TQ so consumers can consume
   tqPushMsg(pVnode->pTq, pReq, 0);
@@ -45,7 +46,9 @@ int vnodeApplyWriteRequest(SVnode *pVnode, const SRequest *pRequest) {
     case TSDB_MSG_TYPE_DROP_TABLE:
       code = metaDropTable(pVnode->pMeta, 0 /* TODO */);
       break;
+    case TSDB_MSG_TYPE_SUBMIT:
       /* TODO */
+      break;
     default:
       break;
   }
@@ -57,6 +60,8 @@ int vnodeApplyWriteRequest(SVnode *pVnode, const SRequest *pRequest) {
   }
 
   return code;
+#endif
+  return 0;
 }
 
 /* ------------------------ STATIC METHODS ------------------------ */
\ No newline at end of file
diff --git a/source/dnode/vnode/meta/inc/metaDef.h b/source/dnode/vnode/meta/inc/metaDef.h
index 562476a439..b0d31de1b4 100644
--- a/source/dnode/vnode/meta/inc/metaDef.h
+++ b/source/dnode/vnode/meta/inc/metaDef.h
@@ -16,6 +16,8 @@
 #ifndef _TD_META_DEF_H_
 #define _TD_META_DEF_H_
 
+#include "mallocator.h"
+
 #include "meta.h"
 #include "metaCache.h"
 #include "metaDB.h"
@@ -30,12 +32,13 @@ extern "C" {
 #endif
 
 struct SMeta {
-  char*           path;     // path of current meta
-  SMetaOptions    options;  // meta option
-  meta_db_t*      pDB;      // raw data db
-  meta_index_t*   pIdx;     // tag index
-  meta_cache_t*   pCache;   // LRU cache
-  STbUidGenerator uidGnrt;  // meta table UID generator
+  char*                 path;
+  SMetaOptions          options;
+  meta_db_t*            pDB;
+  meta_index_t*         pIdx;
+  meta_cache_t*         pCache;
+  STbUidGenerator       uidGnrt;
+  SMemAllocatorFactory* pmaf;
 };
 
 #ifdef __cplusplus
diff --git a/source/dnode/vnode/tsdb/inc/tsdbDef.h b/source/dnode/vnode/tsdb/inc/tsdbDef.h
index ebe0d6b4b0..ca3d0319c1 100644
--- a/source/dnode/vnode/tsdb/inc/tsdbDef.h
+++ b/source/dnode/vnode/tsdb/inc/tsdbDef.h
@@ -16,7 +16,10 @@
 #ifndef _TD_TSDB_DEF_H_
 #define _TD_TSDB_DEF_H_
 
+#include "mallocator.h"
+
 #include "tsdb.h"
+#include "tsdbMemTable.h"
 #include "tsdbOptions.h"
 
 #ifdef __cplusplus
@@ -24,8 +27,9 @@ extern "C" {
 #endif
 
 struct STsdb {
-  char *       path;
-  STsdbOptions options;
+  char *                path;
+  STsdbOptions          options;
+  SMemAllocatorFactory *pmaf;
 };
 
 #ifdef __cplusplus
diff --git a/include/dnode/vnode/tsdb/impl/tsdbImpl.h b/source/dnode/vnode/tsdb/inc/tsdbMemTable.h
similarity index 80%
rename from include/dnode/vnode/tsdb/impl/tsdbImpl.h
rename to source/dnode/vnode/tsdb/inc/tsdbMemTable.h
index 04d2ec43c9..6be90ef53c 100644
--- a/include/dnode/vnode/tsdb/impl/tsdbImpl.h
+++ b/source/dnode/vnode/tsdb/inc/tsdbMemTable.h
@@ -13,22 +13,22 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef _TD_TSDB_IMPL_H_
-#define _TD_TSDB_IMPL_H_
+#ifndef _TD_TSDB_MEM_TABLE_H_
+#define _TD_TSDB_MEM_TABLE_H_
 
-#include "os.h"
+#include "tsdb.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-struct STsdbOptions {
-  size_t lruCacheSize;
+typedef struct SMemTable {
   /* TODO */
-};
+  SMemAllocator *pma;
+} SMemTable;
 
 #ifdef __cplusplus
 }
 #endif
 
-#endif /*_TD_TSDB_IMPL_H_*/
\ No newline at end of file
+#endif /*_TD_TSDB_MEM_TABLE_H_*/
\ No newline at end of file
diff --git a/source/libs/lru/src/lru.c b/source/dnode/vnode/tsdb/src/tsdbMemTable.c
similarity index 100%
rename from source/libs/lru/src/lru.c
rename to source/dnode/vnode/tsdb/src/tsdbMemTable.c
diff --git a/source/libs/CMakeLists.txt b/source/libs/CMakeLists.txt
index eeaac61e21..007bb1e967 100644
--- a/source/libs/CMakeLists.txt
+++ b/source/libs/CMakeLists.txt
@@ -5,7 +5,7 @@ add_subdirectory(index)
 add_subdirectory(wal)
 add_subdirectory(parser)
 add_subdirectory(scheduler)
-add_subdirectory(lru)
+add_subdirectory(cache)
 add_subdirectory(catalog)
 add_subdirectory(executor)
 add_subdirectory(planner)
diff --git a/source/libs/cache/CMakeLists.txt b/source/libs/cache/CMakeLists.txt
new file mode 100644
index 0000000000..5ba59ef160
--- /dev/null
+++ b/source/libs/cache/CMakeLists.txt
@@ -0,0 +1,7 @@
+aux_source_directory(src CACHE_SRC)
+add_library(cache ${CACHE_SRC})
+target_include_directories(
+    cache
+    PUBLIC "${CMAKE_SOURCE_DIR}/include/libs/cache"
+    PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/inc"
+)
\ No newline at end of file
diff --git a/source/libs/lru/inc/lruInt.h b/source/libs/cache/inc/cacheDef.h
similarity index 90%
rename from source/libs/lru/inc/lruInt.h
rename to source/libs/cache/inc/cacheDef.h
index e0da680104..2e0dbfcdb6 100644
--- a/source/libs/lru/inc/lruInt.h
+++ b/source/libs/cache/inc/cacheDef.h
@@ -13,8 +13,8 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef _TD_LRU_INT_H_
-#define _TD_LRU_INT_H_
+#ifndef _TD_CACHE_DEF_H_
+#define _TD_CACHE_DEF_H_
 
 #ifdef __cplusplus
 extern "C" {
@@ -24,4 +24,4 @@ extern "C" {
 }
 #endif
 
-#endif /*_TD_LRU_INT_H_*/
\ No newline at end of file
+#endif /*_TD_CACHE_DEF_H_*/
\ No newline at end of file
diff --git a/source/dnode/vnode/impl/src/vnodeAllocatorPool.c b/source/libs/cache/src/cache.c
similarity index 61%
rename from source/dnode/vnode/impl/src/vnodeAllocatorPool.c
rename to source/libs/cache/src/cache.c
index b5617210a0..6dea4a4e57 100644
--- a/source/dnode/vnode/impl/src/vnodeAllocatorPool.c
+++ b/source/libs/cache/src/cache.c
@@ -11,27 +11,4 @@
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include "vnodeDef.h"
-
-int vnodeOpenAllocatorPool(SVnode *pVnode) {
-  // TODO
-  return 0;
-}
-
-void vnodeCloseAllocatorPool(SVnode *pVnode) {
-  if (pVnode->pool) {
-  }
-}
-
-/* ------------------------ STATIC METHODS ------------------------ */
-static SVAllocatorPool *vapCreate() {
-  SVAllocatorPool *pPool = NULL;
-  /* TODO */
-  return pPool;
-}
-
-static void vapDestroy() {
-  // TODO
-}
\ No newline at end of file
+ */
\ No newline at end of file
diff --git a/source/libs/lru/test/lruTests.cpp b/source/libs/cache/test/cacheTests.cpp
similarity index 100%
rename from source/libs/lru/test/lruTests.cpp
rename to source/libs/cache/test/cacheTests.cpp
diff --git a/source/libs/lru/CMakeLists.txt b/source/libs/lru/CMakeLists.txt
deleted file mode 100644
index b65615dbbf..0000000000
--- a/source/libs/lru/CMakeLists.txt
+++ /dev/null
@@ -1,7 +0,0 @@
-aux_source_directory(src LRU_SRC)
-add_library(lru ${LRU_SRC})
-target_include_directories(
-    lru
-    PUBLIC "${CMAKE_SOURCE_DIR}/include/libs/lru"
-    PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/inc"
-)
\ No newline at end of file
diff --git a/source/util/src/tlist.c b/source/util/src/tlist.c
index c5b4dbad10..6756af226f 100644
--- a/source/util/src/tlist.c
+++ b/source/util/src/tlist.c
@@ -13,16 +13,20 @@
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "os.h"
 #include "tlist.h"
+#include "os.h"
+
+void tdListInit(SList *list, int eleSize) {
+  list->eleSize = eleSize;
+  list->numOfEles = 0;
+  list->head = list->tail = NULL;
+}
 
 SList *tdListNew(int eleSize) {
   SList *list = (SList *)malloc(sizeof(SList));
   if (list == NULL) return NULL;
 
-  list->eleSize = eleSize;
-  list->numOfEles = 0;
-  list->head = list->tail = NULL;
+  tdListInit(list, eleSize);
   return list;
 }