diff --git a/CMakeLists.txt b/CMakeLists.txt
index 538d761e16dfae5855d96a51a3640cbbf0e34773..adeaa2ae0a78ad1400ae050745c117f7dcabae6f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -74,17 +74,28 @@ target_include_directories(api INTERFACE "include/client")
 # src
 add_subdirectory(source)
 
-# docs
+# docs 
+# https://vicrucann.github.io/tutorials/quick-cmake-doxygen/
 if(${BUILD_DOCS})
-    find_program(DOC_GENERATOR doxygen)
-    if(NOT DOC_GENERATOR)
-        message("doxygen is not found, skip doc build")
-    else()
-        execute_process(
-            COMMAND doxygen ${CMAKE_SOURCE_DIR}/docs/Doxyfile
-            WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+    find_package(Doxygen)
+    if (DOXYGEN_FOUND)
+        # Build the doc
+        set(DOXYGEN_IN ${CMAKE_SOURCE_DIR}/docs/Doxyfile.in)
+        set(DOXYGEN_OUT ${CMAKE_BINARY_DIR}/Doxyfile)
+
+        configure_file(${DOXYGEN_IN} ${DOXYGEN_OUT} @ONLY)
+        message("Doxygen build start")
+
+        add_custom_target(
+            tdengine_doxygen ALL
+            COMMAND ${DOXYGEN_EXECUTABLE} ${DOXYGEN_OUT}
+            WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}
+            COMMENT "Generating API doxumentation with Doxygen"
+            VERBATIM
         )
-    endif(NOT DOC_GENERATOR)
+    else(DOXYGEN_FOUND)
+        message("Doxygen need to be installed to generate the doxygen documentation")
+    endif(DOXYGEN_FOUND)
 endif(${BUILD_DOCS})
 
 # tests (TODO)
diff --git a/cmake/cmake.options b/cmake/cmake.options
index 88f2b88fa639e2c39c0a70632a5b47132f15922a..7b5aeb8e652f4537efd65f6ec103124f6ec96126 100644
--- a/cmake/cmake.options
+++ b/cmake/cmake.options
@@ -40,5 +40,5 @@ option(
 option(
     BUILD_DOCS
     "If use doxygen build documents" 
-    OFF
+    ON
 )
\ No newline at end of file
diff --git a/docs/Doxyfile b/docs/Doxyfile.in
similarity index 100%
rename from docs/Doxyfile
rename to docs/Doxyfile.in
diff --git a/source/dnode/vnode/impl/src/vnodeMemAllocator.c b/source/dnode/vnode/impl/src/vnodeMemAllocator.c
index a61b8808da87abc0e2c875f89ad6fe0f4a447e43..3771a14113f1802aace28ecde6c5a3a0c7b1c4bd 100644
--- a/source/dnode/vnode/impl/src/vnodeMemAllocator.c
+++ b/source/dnode/vnode/impl/src/vnodeMemAllocator.c
@@ -15,6 +15,9 @@
 
 #include "vnodeDef.h"
 
+#define VNODE_HEAP_ALLOCATOR 0
+#define VNODE_ARENA_ALLOCATOR 1
+
 typedef struct {
   uint64_t tsize;
   uint64_t used;
@@ -22,9 +25,13 @@ typedef struct {
 
 typedef struct SVArenaNode {
   struct SVArenaNode *prev;
+  void *              nptr;
+  char                data[];
 } SVArenaNode;
 
 typedef struct {
+  SVArenaNode *inuse;
+  SVArenaNode  node;
 } SVArenaAllocator;
 
 typedef struct {
@@ -37,64 +44,57 @@ typedef struct {
   };
 } SVMemAllocator;
 
-SMemAllocator *vnodeCreateMemAllocator(int8_t type, uint64_t size) {
-  /* TODO */
-  return NULL;
-}
-
-void vnodeDestroyMemAllocator(SMemAllocator *pma) {
-  // TODO
-}
-
-void vnodeRefMemAllocator(SMemAllocator *pma) {
-  // TODO
-}
-
-void vnodeUnrefMemAllocator(SMemAllocator *pma) {
-  // TODO
-}
-
-/* ------------------------ Heap Allocator IMPL ------------------------ */
+SMemAllocator *vnodeCreateMemAllocator(int8_t type, uint64_t tsize, uint64_t ssize /* step size only for arena */) {
+  SMemAllocator * pma;
+  uint64_t        msize;
+  SVMemAllocator *pva;
 
-SMemAllocator *vhaCreate(uint64_t size) {
-  SMemAllocator *pma;
+  msize = sizeof(*pma) + sizeof(SVMemAllocator);
+  if (type == VNODE_ARENA_ALLOCATOR) {
+    msize += tsize;
+  }
 
-  pma = (SMemAllocator *)calloc(1, sizeof(*pma) + sizeof(SVHeapAllocator));
+  pma = (SMemAllocator *)calloc(1, msize);
   if (pma == NULL) {
     return NULL;
   }
 
   pma->impl = POINTER_SHIFT(pma, sizeof(*pma));
+  pva = (SVMemAllocator *)(pma->impl);
+  pva->type = type;
+  pva->tsize = tsize;
+
+  if (type == VNODE_HEAP_ALLOCATOR) {
+    pma->malloc = NULL;
+    pma->calloc = NULL;
+    pma->realloc = NULL;
+    pma->free = NULL;
+    pma->usage = NULL;
+  } else if (type == VNODE_ARENA_ALLOCATOR) {
+    pma->malloc = NULL;
+    pma->calloc = NULL;
+    pma->realloc = NULL;
+    pma->free = NULL;
+    pma->usage = NULL;
+  } else {
+    ASSERT(0);
+  }
 
-  /* TODO */
-  return NULL;
-}
-
-void vhaDestroy(SMemAllocator *pma) { /* TODO */
-}
-
-static void *vhaMalloc(SMemAllocator *pma, uint64_t size) {
-  SVHeapAllocator *pvha = (SVHeapAllocator *)(pma->impl);
-  /* TODO */
-  return NULL;
+  return pma;
 }
 
-static void *vhaCalloc(SMemAllocator *pma, size_t nmemb, uint64_t size) {
-  // todo
-  return NULL;
+void vnodeDestroyMemAllocator(SMemAllocator *pma) {
+  // TODO
 }
 
-static void *vhaRealloc(SMemAllocator *pma, void *ptr, uint64_t size) {
-  /* TODO */
-  return NULL;
+void vnodeRefMemAllocator(SMemAllocator *pma) {
+  // TODO
 }
 
-static void vhaFree(SMemAllocator *pma, void *ptr) { /* TODO */
+void vnodeUnrefMemAllocator(SMemAllocator *pma) {
+  // TODO
 }
 
-static uint64_t vhaUsage(SMemAllocator *pma) {
-  /* TODO */
-  return 0;
-}
+/* ------------------------ Heap Allocator IMPL ------------------------ */
 
 /* ------------------------ Arena Allocator IMPL ------------------------ */
\ No newline at end of file