diff --git a/deps/oblib/src/lib/CMakeLists.txt b/deps/oblib/src/lib/CMakeLists.txt
index 685d5183b..e87fbe14a 100644
--- a/deps/oblib/src/lib/CMakeLists.txt
+++ b/deps/oblib/src/lib/CMakeLists.txt
@@ -246,6 +246,7 @@ ob_set_subtarget(ob_malloc_object_list common_alloc
   alloc/alloc_struct.cpp
   alloc/block_set.cpp
   alloc/memory_dump.cpp
+  alloc/ob_free_log_printer.cpp
   alloc/ob_malloc_allocator.cpp
   alloc/ob_malloc_callback.cpp
   alloc/ob_malloc_sample_struct.cpp
diff --git a/deps/oblib/src/lib/alloc/alloc_interface.h b/deps/oblib/src/lib/alloc/alloc_interface.h
index 9bb729425..3e32ac2ae 100644
--- a/deps/oblib/src/lib/alloc/alloc_interface.h
+++ b/deps/oblib/src/lib/alloc/alloc_interface.h
@@ -36,6 +36,11 @@ public:
   virtual ABlock *alloc_block(uint64_t size, const ObMemAttr &attr) = 0;
   virtual void free_block(ABlock *block) = 0;
   virtual int64_t sync_wash(int64_t wash_size) = 0;
+  virtual int64_t get_tenant_id() { return tenant_id_; }
+  virtual int64_t get_ctx_id() { return ctx_id_; }
+  void set_tenant_id(const int64_t tenant_id) { tenant_id_ = tenant_id; }
+  void set_ctx_id(const int64_t ctx_id) { ctx_id_ = ctx_id; }
+protected:
   int64_t tenant_id_;
   int64_t ctx_id_;
 }; // end of class IBlockMgr
diff --git a/deps/oblib/src/lib/alloc/memory_dump.cpp b/deps/oblib/src/lib/alloc/memory_dump.cpp
index 0ae567089..a176a6ccc 100644
--- a/deps/oblib/src/lib/alloc/memory_dump.cpp
+++ b/deps/oblib/src/lib/alloc/memory_dump.cpp
@@ -14,6 +14,7 @@
 
 #include "lib/alloc/memory_dump.h"
 #include <setjmp.h>
+#include "lib/alloc/ob_free_log_printer.h"
 #include "lib/signal/ob_signal_struct.h"
 #include "lib/rc/context.h"
 #include "lib/utility/utility.h"
@@ -428,13 +429,7 @@ int malloc_sample_stat(uint64_t tenant_id, uint64_t ctx_id,
     ObMallocSampleKey key;
     key.tenant_id_ = tenant_id;
     key.ctx_id_ = ctx_id;
-    void **backtrace = reinterpret_cast<void**>(&object->data_[offset]);
-    int32_t bt_size = 0;
-    while (bt_size < AOBJECT_BACKTRACE_COUNT && nullptr != backtrace[bt_size]) {
-      key.bt_[bt_size] = backtrace[bt_size];
-      ++bt_size;
-    }
-    key.bt_size_ = bt_size;
+    MEMCPY((char*)key.bt_, &object->data_[offset], AOBJECT_BACKTRACE_SIZE);
     STRNCPY(key.label_, object->label_, sizeof(key.label_));
     key.label_[sizeof(key.label_) - 1] = '\0';
     ObMallocSampleValue *item = malloc_sample_map.get(key);
@@ -581,6 +576,7 @@ void ObMemoryDump::handle(void *task)
       ObLatchWGuard guard(iter_lock_, common::ObLatchIds::MEM_DUMP_ITER_LOCK);
       std::swap(r_stat_, w_stat_);
     }
+    ObFreeLogPrinter::get_instance().disable_free_log();
   } else {
     int fd = -1;
     if (-1 == (fd = ::open(LOG_FILE,
diff --git a/deps/oblib/src/lib/alloc/ob_free_log_printer.cpp b/deps/oblib/src/lib/alloc/ob_free_log_printer.cpp
new file mode 100644
index 000000000..020c3f189
--- /dev/null
+++ b/deps/oblib/src/lib/alloc/ob_free_log_printer.cpp
@@ -0,0 +1,118 @@
+/**
+ * Copyright (c) 2021 OceanBase
+ * OceanBase CE is licensed under Mulan PubL v2.
+ * You can use this software according to the terms and conditions of the Mulan PubL v2.
+ * You may obtain a copy of Mulan PubL v2 at:
+ *          http://license.coscl.org.cn/MulanPubL-2.0
+ * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+ * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+ * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+ * See the Mulan PubL v2 for more details.
+ */
+
+#include "lib/alloc/ob_free_log_printer.h"
+#include "lib/alloc/alloc_struct.h"
+#include "lib/alloc/ob_malloc_sample_struct.h"
+#include "lib/time/ob_time_utility.h"
+#include "lib/utility/utility.h"
+using namespace oceanbase::lib;
+using namespace oceanbase::common;
+
+ObFreeLogPrinter::ObFreeLogPrinter() : level_(DEFAULT), lock_()
+{}
+
+ObFreeLogPrinter& ObFreeLogPrinter::get_instance()
+{
+  static ObFreeLogPrinter free_log_print;
+  return free_log_print;
+}
+
+int ObFreeLogPrinter::get_level()
+{
+  int ret = DEFAULT;
+  int reason = g_alloc_failed_ctx().reason_;
+  switch (reason) {
+  case CTX_HOLD_REACH_LIMIT : {
+      ret = CTX;
+      break;
+    }
+  case TENANT_HOLD_REACH_LIMIT: {
+      ret = TENANT;
+      break;
+    }
+  case SERVER_HOLD_REACH_LIMIT: {
+      ret = SERVER;
+      break;
+    }
+  case PHYSICAL_MEMORY_EXHAUST: {
+      ret = SERVER;
+      break;
+    }
+  }
+  return ret;
+}
+
+void ObFreeLogPrinter::enable_free_log(int64_t tenant_id, int64_t ctx_id, int level)
+{
+  bool has_lock = false;
+  if (DEFAULT == level_ && OB_SUCCESS == lock_.trylock()) {
+    DEFER(lock_.unlock());
+    last_enable_time_ = ObTimeUtility::current_time();
+    tenant_id_ = tenant_id;
+    ctx_id_ = ctx_id;
+    level_ = level;
+    has_lock = true;
+  }
+  if (has_lock) {
+    _OB_LOG(INFO, "start to print free log");
+  }
+}
+
+void ObFreeLogPrinter::disable_free_log()
+{
+  bool has_lock = false;
+  if (DEFAULT != level_ && OB_SUCCESS == lock_.trylock()) {
+    DEFER(lock_.unlock());
+    level_ = DEFAULT;
+    has_lock = true;
+  }
+  if (has_lock) {
+    _OB_LOG(INFO, "finish to print free log");
+  }
+}
+
+void ObFreeLogPrinter::print_free_log(int64_t tenant_id, int64_t ctx_id, AObject *obj)
+{
+  if (DEFAULT != level_ && obj->on_malloc_sample_) {
+    if (ObTimeUtility::current_time() - last_enable_time_ > MAX_FREE_LOG_TIME) {
+      disable_free_log();
+    } else {
+      bool allowed = false;
+      switch (level_) {
+        case CTX: {
+          allowed = tenant_id == tenant_id_ && ctx_id == ctx_id_;
+          break;
+        }
+        case TENANT: {
+          allowed = tenant_id == tenant_id_;
+          break;
+        }
+        case SERVER: {
+          allowed = true;
+          break;
+        }
+      }
+      if (allowed) {
+        char buf[MAX_BACKTRACE_LENGTH];
+        int64_t addrs[AOBJECT_BACKTRACE_COUNT];
+        int64_t offset = obj->alloc_bytes_ - AOBJECT_BACKTRACE_SIZE;
+        MEMCPY((char*)addrs, &obj->data_[offset], sizeof(addrs));
+        IGNORE_RETURN parray(buf, sizeof(buf), addrs, ARRAYSIZEOF(addrs));
+        allow_next_syslog();
+        _OB_LOG(INFO, "[MEMORY][FREE_LOG] tenant_id=%ld, ctx_name=%s, mod=%s, alloc_bytes=%u, malloc_bt=%s\n",
+                tenant_id, get_global_ctx_info().get_ctx_name(ctx_id),
+                obj->label_, obj->alloc_bytes_, buf);
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/deps/oblib/src/lib/alloc/ob_free_log_printer.h b/deps/oblib/src/lib/alloc/ob_free_log_printer.h
new file mode 100644
index 000000000..8c963c794
--- /dev/null
+++ b/deps/oblib/src/lib/alloc/ob_free_log_printer.h
@@ -0,0 +1,48 @@
+/**
+ * Copyright (c) 2021 OceanBase
+ * OceanBase CE is licensed under Mulan PubL v2.
+ * You can use this software according to the terms and conditions of the Mulan PubL v2.
+ * You may obtain a copy of Mulan PubL v2 at:
+ *          http://license.coscl.org.cn/MulanPubL-2.0
+ * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+ * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+ * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+ * See the Mulan PubL v2 for more details.
+ */
+
+#ifndef _OB_FREE_LOG_PRINTER_H_
+#define _OB_FREE_LOG_PRINTER_H_
+#include "lib/lock/ob_mutex.h"
+namespace oceanbase
+{
+namespace lib
+{
+class AObject;
+class ObFreeLogPrinter
+{
+public:
+  const int64_t MAX_FREE_LOG_TIME = 30 * 1000 * 1000; //30s
+  enum Level
+  {
+    DEFAULT = 0,
+    CTX = 1,
+    TENANT = 2,
+    SERVER = 3,
+  };
+  ObFreeLogPrinter();
+  static ObFreeLogPrinter& get_instance();
+  static int get_level();
+  void enable_free_log(int64_t tenant_id , int64_t ctx_id, int level);
+  void disable_free_log();
+  void print_free_log(int64_t tenant_id, int64_t ctx_id, AObject *obj);
+private:
+  int64_t last_enable_time_;
+  int64_t tenant_id_;
+  int64_t ctx_id_;
+  int level_;
+  ObMutex lock_;
+};
+}
+}
+
+#endif
\ No newline at end of file
diff --git a/deps/oblib/src/lib/alloc/ob_malloc_sample_struct.h b/deps/oblib/src/lib/alloc/ob_malloc_sample_struct.h
index ecfe26779..448bbc67c 100644
--- a/deps/oblib/src/lib/alloc/ob_malloc_sample_struct.h
+++ b/deps/oblib/src/lib/alloc/ob_malloc_sample_struct.h
@@ -22,6 +22,7 @@ namespace lib
 {
 static const int32_t AOBJECT_BACKTRACE_COUNT = 16;
 static const int32_t AOBJECT_BACKTRACE_SIZE = sizeof(void*) * AOBJECT_BACKTRACE_COUNT;
+static const int32_t MAX_BACKTRACE_LENGTH = 512;
 static const int32_t MAX_MALLOC_SAMPLER_NUM = (1<<15) - 1;
 
 class ObMallocSampleLimiter
@@ -51,7 +52,6 @@ struct ObMallocSampleKey
   bool operator==(const ObMallocSampleKey &other) const;
   int64_t tenant_id_;
   int64_t ctx_id_;
-  int32_t bt_size_;
   char label_[lib::AOBJECT_LABEL_SIZE + 1];
   void *bt_[AOBJECT_BACKTRACE_COUNT];
 };
@@ -140,7 +140,7 @@ inline int64_t ObMallocSampleKey::hash() const
   hash_val = murmurhash(&tenant_id_, sizeof(tenant_id_), hash_val);
   hash_val = murmurhash(&ctx_id_, sizeof(ctx_id_), hash_val);
   hash_val = murmurhash(label_, sizeof(label_), hash_val);
-  hash_val = murmurhash(bt_, bt_size_ * sizeof(void*), hash_val);
+  hash_val = murmurhash(bt_, sizeof(bt_), hash_val);
   return hash_val;
 }
 
@@ -148,28 +148,17 @@ inline bool ObMallocSampleKey::operator==(const ObMallocSampleKey &other) const
 {
   bool ret = true;
   if (tenant_id_ != other.tenant_id_ || ctx_id_ != other.ctx_id_
-        || 0 != STRNCMP(label_, other.label_, sizeof(label_))) {
+      || 0 != STRNCMP(label_, other.label_, sizeof(label_))
+      || 0 != MEMCMP((char*)bt_, (char*)other.bt_, sizeof(bt_))) {
     ret = false;
   }
-  if (ret) {
-    if (other.bt_size_ != bt_size_) {
-      ret = false;
-    } else {
-      for (int i = 0; i < bt_size_; ++i) {
-        if ((int64_t)bt_[i] != (int64_t)other.bt_[i]) {
-          ret = false;
-          break;
-        }
-      }
-    }
-  }
   return ret;
 }
 
 #define ob_malloc_sample_backtrace(obj, size)                                                       \
   {                                                                                                 \
     if (OB_UNLIKELY(obj->on_malloc_sample_)) {                                                      \
-      void *addrs[100] = {nullptr};                                                                 \
+      void *addrs[100];                                                                 \
       int bt_len = backtrace(addrs, ARRAYSIZEOF(addrs));                                            \
       MEMCPY(&obj->data_[size], (char*)addrs, AOBJECT_BACKTRACE_SIZE);                              \
       if (AOBJECT_BACKTRACE_COUNT > bt_len) {                                                       \
@@ -177,7 +166,6 @@ inline bool ObMallocSampleKey::operator==(const ObMallocSampleKey &other) const
       }                                                                                             \
     }                                                                                               \
   }
-
 } // end of namespace lib
 } // end of namespace oceanbase
 
diff --git a/deps/oblib/src/lib/alloc/ob_tenant_ctx_allocator.cpp b/deps/oblib/src/lib/alloc/ob_tenant_ctx_allocator.cpp
index 7a3fc41b9..95a731403 100644
--- a/deps/oblib/src/lib/alloc/ob_tenant_ctx_allocator.cpp
+++ b/deps/oblib/src/lib/alloc/ob_tenant_ctx_allocator.cpp
@@ -14,6 +14,7 @@
 
 #include "lib/alloc/ob_tenant_ctx_allocator.h"
 #include "lib/alloc/ob_malloc_sample_struct.h"
+#include "lib/alloc/ob_free_log_printer.h"
 #include "lib/allocator/ob_mem_leak_checker.h"
 #include "lib/allocator/ob_tc_malloc.h"
 #include "lib/utility/ob_print_utils.h"
@@ -418,6 +419,9 @@ void* ObTenantCtxAllocator::common_alloc(const int64_t size, const ObMemAttr &at
                                      alloc_size - size + sizeof(AOBJECT_TAIL_MAGIC_CODE));
   }
   if (OB_UNLIKELY(nullptr == obj) && REACH_TIME_INTERVAL(1 * 1000 * 1000)) {
+    int level = ObFreeLogPrinter::get_level();
+    ObFreeLogPrinter::get_instance().enable_free_log(attr.tenant_id_,
+                                                     attr.ctx_id_, level);
     const char *msg = alloc_failed_msg();
     LOG_DBA_WARN(OB_ALLOCATE_MEMORY_FAILED, "[OOPS]", "alloc failed reason", KCSTRING(msg));
     _OB_LOG_RET(WARN, OB_ALLOCATE_MEMORY_FAILED, "oops, alloc failed, tenant_id=%ld, ctx_id=%ld, ctx_name=%s, ctx_hold=%ld, "
@@ -425,6 +429,7 @@ void* ObTenantCtxAllocator::common_alloc(const int64_t size, const ObMemAttr &at
                 attr.tenant_id_, attr.ctx_id_,
                 get_global_ctx_info().get_ctx_name(attr.ctx_id_),
                 ta.get_hold(), ta.get_limit(), ta.get_tenant_hold(), ta.get_tenant_limit());
+    ObMallocAllocator::get_instance()->print_tenant_memory_usage(attr.tenant_id_);
     // 49 is the user defined signal to dump memory
     raise(49);
   }
@@ -465,6 +470,9 @@ void* ObTenantCtxAllocator::common_realloc(const void *ptr, const int64_t size,
     SANITY_POISON((void*)upper_align((int64_t)obj->data_ + size, 8),
                                      alloc_size - size + sizeof(AOBJECT_TAIL_MAGIC_CODE));
   } else if (REACH_TIME_INTERVAL(1 * 1000 * 1000)) {
+    int level = ObFreeLogPrinter::get_level();
+    ObFreeLogPrinter::get_instance().enable_free_log(attr.tenant_id_,
+                                                     attr.ctx_id_, level);
     const char *msg = alloc_failed_msg();
     LOG_DBA_WARN(OB_ALLOCATE_MEMORY_FAILED, "[OOPS]", "alloc failed reason", KCSTRING(msg));
     _OB_LOG_RET(WARN, OB_ALLOCATE_MEMORY_FAILED, "oops, alloc failed, tenant_id=%ld, ctx_id=%ld, ctx_name=%s, ctx_hold=%ld, "
@@ -472,6 +480,7 @@ void* ObTenantCtxAllocator::common_realloc(const void *ptr, const int64_t size,
                 attr.tenant_id_, attr.ctx_id_,
                 get_global_ctx_info().get_ctx_name(attr.ctx_id_),
                 ta.get_hold(), ta.get_limit(), ta.get_tenant_hold(), ta.get_tenant_limit());
+    ObMallocAllocator::get_instance()->print_tenant_memory_usage(attr.tenant_id_);
     // 49 is the user defined signal to dump memory
     raise(49);
   }
@@ -497,6 +506,10 @@ void ObTenantCtxAllocator::common_free(void *ptr)
     abort_unless(block->obj_set_ != NULL);
 
     ObjectSet *os = block->obj_set_;
+    auto blk_mgr = os->get_block_mgr();
+    int64_t tenant_id = blk_mgr->get_tenant_id();
+    int64_t ctx_id = blk_mgr->get_ctx_id();
+    ObFreeLogPrinter::get_instance().print_free_log(tenant_id, ctx_id, obj);
     os->free_object(obj);
   }
 }
diff --git a/deps/oblib/src/lib/alloc/object_set.cpp b/deps/oblib/src/lib/alloc/object_set.cpp
index 8887910b2..0121cacd9 100644
--- a/deps/oblib/src/lib/alloc/object_set.cpp
+++ b/deps/oblib/src/lib/alloc/object_set.cpp
@@ -56,7 +56,7 @@ AObject *ObjectSet::alloc_object(
   const uint64_t adj_size = MAX(size, MIN_AOBJECT_SIZE);
   const uint64_t all_size = align_up2(adj_size + AOBJECT_META_SIZE, 16);
 
-  const int64_t ctx_id = blk_mgr_->ctx_id_;
+  const int64_t ctx_id = blk_mgr_->get_ctx_id();
   abort_unless(ctx_id == attr.ctx_id_);
   if (OB_UNLIKELY(common::ObCtxIds::LIBEASY == ctx_id)) {
     do_free_dirty_list();
@@ -279,8 +279,8 @@ void ObjectSet::free_normal_object(AObject *obj)
   normal_used_bytes_ -= obj->nobjs_ * AOBJECT_CELL_BYTES;
 
   AObject *newobj = merge_obj(obj);
-  auto ctx_id = blk_mgr_->ctx_id_;
-  auto tenant_id = blk_mgr_->tenant_id_;
+  auto ctx_id = blk_mgr_->get_ctx_id();
+  auto tenant_id = blk_mgr_->get_tenant_id();
   if (newobj->nobjs_ == cells_per_block_) {
     hold_bytes_ -= ablock_size_;
     normal_hold_bytes_ -= ablock_size_;
@@ -376,7 +376,7 @@ void ObjectSet::free_object(AObject *obj)
     memset(obj->data_, 0xAA, obj->alloc_bytes_);
   }
 #endif
-  const int64_t ctx_id = blk_mgr_->ctx_id_;
+  const int64_t ctx_id = blk_mgr_->get_ctx_id();
   ObDisableDiagnoseGuard diagnose_disable_guard;
   if (ctx_id == common::ObCtxIds::LIBEASY) {
     if (locker_->trylock()) {
@@ -560,8 +560,8 @@ bool ObjectSet::build_free_lists()
 {
   abort_unless(NULL == bm_ && NULL == free_lists_);
   ObMemAttr attr;
-  attr.tenant_id_ = blk_mgr_->tenant_id_;
-  attr.ctx_id_ = blk_mgr_->ctx_id_;
+  attr.tenant_id_ = blk_mgr_->get_tenant_id();
+  attr.ctx_id_ = blk_mgr_->get_ctx_id();
   attr.label_ = common::ObModIds::OB_OBJ_FREELISTS;
   ABlock *new_block = alloc_block(sizeof (FreeList) * (cells_per_block_ + 1) +
       sizeof (BitMap) + BitMap::buf_len(cells_per_block_ + 1), attr);
diff --git a/deps/oblib/src/lib/allocator/ob_allocator_v2.h b/deps/oblib/src/lib/allocator/ob_allocator_v2.h
index 7b79bd04a..bd338ae88 100644
--- a/deps/oblib/src/lib/allocator/ob_allocator_v2.h
+++ b/deps/oblib/src/lib/allocator/ob_allocator_v2.h
@@ -147,8 +147,8 @@ inline int ObAllocator::init()
     blk_mgr = pm;
     pm_ = pm;
   } else {
-    blk_mgr_.tenant_id_ = attr_.tenant_id_;
-    blk_mgr_.ctx_id_ = attr_.ctx_id_;
+    blk_mgr_.set_tenant_id(attr_.tenant_id_);
+    blk_mgr_.set_ctx_id(attr_.ctx_id_);
     blk_mgr = &blk_mgr_;
   }
   if (OB_SUCC(ret)) {
diff --git a/deps/oblib/src/lib/allocator/ob_page_manager.h b/deps/oblib/src/lib/allocator/ob_page_manager.h
index 3c5f67754..99f69bac2 100644
--- a/deps/oblib/src/lib/allocator/ob_page_manager.h
+++ b/deps/oblib/src/lib/allocator/ob_page_manager.h
@@ -64,14 +64,12 @@ public:
     return tenant_id_ < tenant_id ||
       (tenant_id_ == tenant_id && id_ < id);
   }
-  int set_tenant_ctx(const uint64_t tenant_id, const uint64_t ctx_id);
+  int set_tenant_ctx(const int64_t tenant_id, const int64_t ctx_id);
   void set_max_chunk_cache_cnt(const int cnt)
   { bs_.set_max_chunk_cache_cnt(cnt); }
   void reset();
   int64_t get_hold() const;
   int64_t get_tid() const { return tid_; }
-  int64_t get_tenant_id() const { return tenant_id_; }
-  int64_t get_ctx_id() const { return ctx_id_; }
   // IBlockMgr interface
   virtual ABlock *alloc_block(uint64_t size, const ObMemAttr &attr=default_memattr) override;
   virtual void free_block(ABlock *block) override;
@@ -135,7 +133,7 @@ inline ObPageManager::~ObPageManager()
   }
 }
 
-inline int ObPageManager::set_tenant_ctx(const uint64_t tenant_id, const uint64_t ctx_id)
+inline int ObPageManager::set_tenant_ctx(const int64_t tenant_id, const int64_t ctx_id)
 {
   int ret = OB_SUCCESS;
   auto &pmc = ObPageManagerCenter::get_instance();
diff --git a/src/diagnose/lua/ob_lua_api.cpp b/src/diagnose/lua/ob_lua_api.cpp
index 396aa6626..255a11662 100644
--- a/src/diagnose/lua/ob_lua_api.cpp
+++ b/src/diagnose/lua/ob_lua_api.cpp
@@ -1964,8 +1964,8 @@ int select_malloc_sample_info(lua_State *L)
       gen.next_column(it->first.label_);
       // back_trace
       {
-        char bt[512];
-        parray(bt, sizeof(bt), (int64_t*)*&(it->first.bt_), it->first.bt_size_);
+        char bt[MAX_BACKTRACE_LENGTH];
+        IGNORE_RETURN parray(bt, sizeof(bt), (int64_t*)it->first.bt_, AOBJECT_BACKTRACE_COUNT);
         gen.next_column(bt);
       }
       // ctx_name
diff --git a/src/observer/virtual_table/ob_all_virtual_malloc_sample_info.cpp b/src/observer/virtual_table/ob_all_virtual_malloc_sample_info.cpp
index 3140b68d8..3bba257e4 100644
--- a/src/observer/virtual_table/ob_all_virtual_malloc_sample_info.cpp
+++ b/src/observer/virtual_table/ob_all_virtual_malloc_sample_info.cpp
@@ -118,7 +118,7 @@ int ObMallocSampleInfo::fill_row(ObNewRow *&row)
           break;
         }
       case BACKTRACE: {
-          parray(bt_, sizeof(bt_), (int64_t*)*&(it_->first.bt_), it_->first.bt_size_);
+          IGNORE_RETURN parray(bt_, sizeof(bt_), (int64_t*)it_->first.bt_, AOBJECT_BACKTRACE_COUNT);
           cells[i].set_varchar(bt_);
           cells[i].set_collation_type(
               ObCharset::get_default_collation(ObCharset::get_default_charset()));
diff --git a/src/observer/virtual_table/ob_all_virtual_malloc_sample_info.h b/src/observer/virtual_table/ob_all_virtual_malloc_sample_info.h
index d66cffab5..60f72bca3 100644
--- a/src/observer/virtual_table/ob_all_virtual_malloc_sample_info.h
+++ b/src/observer/virtual_table/ob_all_virtual_malloc_sample_info.h
@@ -45,7 +45,7 @@ private:
     ALLOC_BYTES,
   };
   char ip_buf_[common::OB_IP_STR_BUFF];
-  char bt_[512];
+  char bt_[lib::MAX_BACKTRACE_LENGTH];
   lib::ObMallocSampleMap::const_iterator it_;
   lib::ObMallocSampleMap malloc_sample_map_;
   int64_t col_count_;