diff --git a/cpp/src/scheduler/ResourceMgr.h b/cpp/src/scheduler/ResourceMgr.h
index 714924c9b906adda40b8d9750b84545255a6dfbd..fc7744cd2bdb14d9ef5fa5d0de270da0393524a3 100644
--- a/cpp/src/scheduler/ResourceMgr.h
+++ b/cpp/src/scheduler/ResourceMgr.h
@@ -88,6 +88,7 @@ private:
 
 };
 
+using ResourceMgrPtr = std::shared_ptr<ResourceMgr>;
 using ResourceMgrWPtr = std::weak_ptr<ResourceMgr>;
 
 }
diff --git a/cpp/src/scheduler/Scheduler.h b/cpp/src/scheduler/Scheduler.h
index 66088dd5b6e350bf1d030248c1f27e5b1a2a6398..5e50826238c985bf5b66b684ea55feb5588f8cc6 100644
--- a/cpp/src/scheduler/Scheduler.h
+++ b/cpp/src/scheduler/Scheduler.h
@@ -5,6 +5,7 @@
  ******************************************************************************/
 #pragma once
 
+#include <memory>
 #include <string>
 #include <mutex>
 #include <thread>
@@ -114,6 +115,8 @@ private:
     std::thread worker_thread_;
 };
 
+using SchedulerPtr = std::shared_ptr<Scheduler>;
+
 }
 }
 }
diff --git a/cpp/src/scheduler/TaskTable.cpp b/cpp/src/scheduler/TaskTable.cpp
index bac4d245da21fc2e262c168fdf7cbd3138f97bc7..807d35be4ac907baa852956fb0b4446b440dc2ba 100644
--- a/cpp/src/scheduler/TaskTable.cpp
+++ b/cpp/src/scheduler/TaskTable.cpp
@@ -5,6 +5,7 @@
  ******************************************************************************/
 
 #include "TaskTable.h"
+#include "event/TaskTableUpdatedEvent.h"
 #include <vector>
 
 
@@ -19,6 +20,9 @@ TaskTable::Put(TaskPtr task) {
     item->task = std::move(task);
     item->state = TaskTableItemState::LOADED;
     table_.push_back(item);
+    if (subscriber_) {
+        subscriber_();
+    }
 }
 
 void
@@ -29,6 +33,9 @@ TaskTable::Put(std::vector<TaskPtr> &tasks) {
         item->state = TaskTableItemState::LOADED;
         table_.push_back(item);
     }
+    if (subscriber_) {
+        subscriber_();
+    }
 }
 
 
diff --git a/cpp/src/scheduler/TaskTable.h b/cpp/src/scheduler/TaskTable.h
index 528c2f3d5cf7577ea8682897aa6de057d1315338..70a2899331239c14d7baaf055186a3823ae668a4 100644
--- a/cpp/src/scheduler/TaskTable.h
+++ b/cpp/src/scheduler/TaskTable.h
@@ -10,6 +10,7 @@
 #include <mutex>
 
 #include "task/SearchTask.h"
+#include "event/Event.h"
 
 
 namespace zilliz {
@@ -48,6 +49,11 @@ class TaskTable {
 public:
     TaskTable() = default;
 
+    inline void
+    RegisterSubscriber(std::function<void(void)> subscriber) {
+        subscriber_ = std::move(subscriber);
+    }
+
     /*
      * Put one task;
      */
@@ -162,6 +168,7 @@ public:
 private:
     // TODO: map better ?
     std::deque<TaskTableItemPtr> table_;
+    std::function<void(void)> subscriber_ = nullptr;
 };
 
 
diff --git a/cpp/src/scheduler/resource/Resource.cpp b/cpp/src/scheduler/resource/Resource.cpp
index cf9ff9d882b6bb2e7b062aeda882a75d81b11339..ea6f71a3591632f82c04c6cb499f6f22a2d89979 100644
--- a/cpp/src/scheduler/resource/Resource.cpp
+++ b/cpp/src/scheduler/resource/Resource.cpp
@@ -16,6 +16,12 @@ Resource::Resource(std::string name, ResourceType type)
       running_(false),
       load_flag_(false),
       exec_flag_(false) {
+    task_table_.RegisterSubscriber([&] {
+        if (subscriber_) {
+            auto event = std::make_shared<TaskTableUpdatedEvent>(shared_from_this());
+            subscriber_(std::static_pointer_cast<Event>(event));
+        }
+    });
 }
 
 void Resource::Start() {
diff --git a/cpp/src/scheduler/resource/Resource.h b/cpp/src/scheduler/resource/Resource.h
index a9a1454ed532d2e4af6781b5d2d71a04e1c8cfa6..ab7aab7bacb58b16afad00d46b376329bdcb5ce1 100644
--- a/cpp/src/scheduler/resource/Resource.h
+++ b/cpp/src/scheduler/resource/Resource.h
@@ -16,6 +16,7 @@
 #include "../event/StartUpEvent.h"
 #include "../event/CopyCompletedEvent.h"
 #include "../event/FinishTaskEvent.h"
+#include "../event/TaskTableUpdatedEvent.h"
 #include "../TaskTable.h"
 #include "../task/Task.h"
 #include "../Cost.h"
diff --git a/cpp/src/scheduler/task/TestTask.cpp b/cpp/src/scheduler/task/TestTask.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..a974482e52a6fc65bd59b12980d6b376325817d4
--- /dev/null
+++ b/cpp/src/scheduler/task/TestTask.cpp
@@ -0,0 +1,26 @@
+/*******************************************************************************
+ * Copyright 上海赜睿信息科技有限公司(Zilliz) - All Rights Reserved
+ * Unauthorized copying of this file, via any medium is strictly prohibited.
+ * Proprietary and confidential.
+ ******************************************************************************/
+
+#include "TestTask.h"
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+void
+TestTask::Load(LoadType type, uint8_t device_id) {
+    load_count_++;
+}
+
+void
+TestTask::Execute() {
+    exec_count_++;
+}
+
+}
+}
+}
+
diff --git a/cpp/src/scheduler/task/TestTask.h b/cpp/src/scheduler/task/TestTask.h
new file mode 100644
index 0000000000000000000000000000000000000000..5f49d2e31ebc3399511fdaa463e47c3420f95329
--- /dev/null
+++ b/cpp/src/scheduler/task/TestTask.h
@@ -0,0 +1,34 @@
+/*******************************************************************************
+ * Copyright 上海赜睿信息科技有限公司(Zilliz) - All Rights Reserved
+ * Unauthorized copying of this file, via any medium is strictly prohibited.
+ * Proprietary and confidential.
+ ******************************************************************************/
+#pragma once
+
+#include "Task.h"
+
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+class TestTask : public Task {
+public:
+    TestTask() = default;
+
+public:
+    void
+    Load(LoadType type, uint8_t device_id) override;
+
+    void
+    Execute() override;
+
+public:
+    uint64_t load_count_;
+    uint64_t exec_count_;
+};
+
+
+}
+}
+}
diff --git a/cpp/unittest/scheduler/resource_test.cpp b/cpp/unittest/scheduler/resource_test.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..afb484b376775a1f94ca6f13e7900b67e9187247
--- /dev/null
+++ b/cpp/unittest/scheduler/resource_test.cpp
@@ -0,0 +1,83 @@
+/*******************************************************************************
+ * Copyright 上海赜睿信息科技有限公司(Zilliz) - All Rights Reserved
+ * Unauthorized copying of this file, via any medium is strictly prohibited.
+ * Proprietary and confidential.
+ ******************************************************************************/
+
+#include "scheduler/resource/Resource.h"
+#include "scheduler/resource/DiskResource.h"
+#include "scheduler/resource/CpuResource.h"
+#include "scheduler/resource/GpuResource.h"
+#include "scheduler/task/Task.h"
+#include "scheduler/task/TestTask.h"
+#include "scheduler/ResourceFactory.h"
+#include <gtest/gtest.h>
+
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+class ResourceTest : public testing::Test {
+protected:
+    void
+    SetUp() override {
+        disk_resource_ = ResourceFactory::Create("disk");
+        cpu_resource_ = ResourceFactory::Create("cpu");
+        gpu_resource_ = ResourceFactory::Create("gpu");
+        flag_ = false;
+
+        auto subscriber = [&](EventPtr) {
+            std::unique_lock<std::mutex> lock(mutex_);
+            flag_ = true;
+            cv_.notify_one();
+        };
+
+        disk_resource_->RegisterSubscriber(subscriber);
+        cpu_resource_->RegisterSubscriber(subscriber);
+        gpu_resource_->RegisterSubscriber(subscriber);
+    }
+
+    void
+    Wait() {
+        std::unique_lock<std::mutex> lock(mutex_);
+        cv_.wait(lock, [&] { return flag_; });
+    }
+
+    ResourcePtr disk_resource_;
+    ResourcePtr cpu_resource_;
+    ResourcePtr gpu_resource_;
+    bool flag_;
+    std::mutex mutex_;
+    std::condition_variable cv_;
+};
+
+
+TEST_F(ResourceTest, cpu_resource_test) {
+    auto task = std::make_shared<TestTask>();
+    cpu_resource_->task_table().Put(task);
+    cpu_resource_->WakeupLoader();
+    Wait();
+    ASSERT_EQ(task->load_count_, 1);
+    flag_ = false;
+    cpu_resource_->WakeupExecutor();
+    Wait();
+    ASSERT_EQ(task->exec_count_, 1);
+}
+
+TEST_F(ResourceTest, gpu_resource_test) {
+    auto task = std::make_shared<TestTask>();
+    gpu_resource_->task_table().Put(task);
+    gpu_resource_->WakeupLoader();
+    Wait();
+    ASSERT_EQ(task->load_count_, 1);
+    flag_ = false;
+    gpu_resource_->WakeupExecutor();
+    Wait();
+    ASSERT_EQ(task->exec_count_, 1);
+}
+
+
+}
+}
+}
diff --git a/cpp/unittest/scheduler/scheduler_test.cpp b/cpp/unittest/scheduler/scheduler_test.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..787ae59329c41cf69a99edc01e7c5dc51ea155b3
--- /dev/null
+++ b/cpp/unittest/scheduler/scheduler_test.cpp
@@ -0,0 +1,17 @@
+/*******************************************************************************
+ * Copyright 上海赜睿信息科技有限公司(Zilliz) - All Rights Reserved
+ * Unauthorized copying of this file, via any medium is strictly prohibited.
+ * Proprietary and confidential.
+ ******************************************************************************/
+
+#include <gtest/gtest.h>
+
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+
+}
+}
+}