diff --git a/CHANGELOGS.md b/CHANGELOGS.md
index c8ee3b39fd..a0c7ed62c5 100644
--- a/CHANGELOGS.md
+++ b/CHANGELOGS.md
@@ -19,3 +19,4 @@ Please mark all change in change log and use the ticket from JIRA.
 - MS-202 - Add Milvus Jenkins project email notification
 - MS-215 - Add Milvus cluster CI/CD groovy file 
 - MS-277 - Update CUDA Version to V10.1
+- MS-336 - Scheduler interface
diff --git a/cpp/src/scheduler/CacheMgr.h b/cpp/src/scheduler/CacheMgr.h
new file mode 100644
index 0000000000..321cbbb8a4
--- /dev/null
+++ b/cpp/src/scheduler/CacheMgr.h
@@ -0,0 +1,24 @@
+/*******************************************************************************
+ * 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 <memory>
+
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+// dummy cache_mgr
+class CacheMgr {
+
+};
+
+using CacheMgrPtr = std::shared_ptr<CacheMgr>;
+
+}
+}
+}
diff --git a/cpp/src/scheduler/Cost.h b/cpp/src/scheduler/Cost.h
new file mode 100644
index 0000000000..dc52eacaa3
--- /dev/null
+++ b/cpp/src/scheduler/Cost.h
@@ -0,0 +1,46 @@
+/*******************************************************************************
+ * 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 <vector>
+#include "Task.h"
+#include "CacheMgr.h"
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+// TODO: Policy interface
+// TODO: collect statistics
+
+/*
+ * select tasks to move;
+ * call from scheduler;
+ */
+std::vector<TaskPtr>
+PickToMove(const TaskTable &task_table, const CacheMgr &cache_mgr, double limit) {}
+
+
+/*
+ * select task to load
+ * call from resource;
+ * I DONT SURE NEED THIS;
+ */
+std::vector<TaskPtr>
+PickToLoad(TaskTable task_table, uint64_t limit) {}
+
+/*
+ * select task to execute;
+ * call from resource;
+ * I DONT SURE NEED THIS;
+ */
+std::vector<TaskPtr>
+PickToExecute(TaskTable task_table, uint64_t limit) {}
+
+
+}
+}
+}
diff --git a/cpp/src/scheduler/ResourceFactory.h b/cpp/src/scheduler/ResourceFactory.h
new file mode 100644
index 0000000000..f327522975
--- /dev/null
+++ b/cpp/src/scheduler/ResourceFactory.h
@@ -0,0 +1,41 @@
+/*******************************************************************************
+ * 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 <string>
+#include <memory>
+
+#include "resource/Resource.h"
+#include "resource/CpuResource.h"
+#include "resource/GpuResource.h"
+#include "resource/DiskResource.h"
+
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+class ResourceFactory {
+public:
+    static std::shared_ptr<Resource>
+    Create(const std::string &name, const std::string &alias = "") {
+        if (name == "disk") {
+            return std::make_shared<CpuResource>(alias);
+        } else if (name == "cpu") {
+            return std::make_shared<CpuResource>(alias);
+        } else if (name == "gpu") {
+            return std::make_shared<CpuResource>(alias);
+        } else {
+            return nullptr;
+        }
+    }
+};
+
+
+}
+}
+}
+
diff --git a/cpp/src/scheduler/ResourceMgr.h b/cpp/src/scheduler/ResourceMgr.h
new file mode 100644
index 0000000000..e1cc9110bf
--- /dev/null
+++ b/cpp/src/scheduler/ResourceMgr.h
@@ -0,0 +1,141 @@
+
+/*******************************************************************************
+ * 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 <string>
+#include <vector>
+#include <memory>
+
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+class ResourceMgr {
+public:
+    ResourceMgr() : running_(false) {}
+
+    /******** Management Interface ********/
+
+    /*
+     * Add resource into Resource Management;
+     * Generate functions on events;
+     * Functions only modify bool variable, like event trigger;
+     */
+    ResourceWPtr
+    Add(ResourcePtr &&resource) {
+        ResourceWPtr ret(resource);
+        resources_.emplace_back(resource);
+
+//        resource->RegisterOnStartUp([] {
+//            start_up_event_[index] = true;
+//        });
+//        resource.RegisterOnFinishTask([] {
+//            finish_task_event_[index] = true;
+//        });
+        return ret;
+    }
+
+    /*
+     * Create connection between A and B;
+     */
+    void
+    Connect(ResourceWPtr &A, ResourceWPtr &B, Connection &connection) {
+        if (auto observe_a = A.lock()) {
+            if (auto observe_b = B.lock()) {
+                observe_a->AddNeighbour(std::static_pointer_cast<Node>(observe_b), connection);
+            }
+        }
+    }
+
+    /*
+     * Synchronous start all resource;
+     * Last, start event process thread;
+     */
+    void
+    StartAll() {
+        for (auto &resource : resources_) {
+            resource->Start();
+        }
+        worker_thread_ = std::thread(&ResourceMgr::EventProcess, this);
+    }
+
+    // TODO: add stats interface(low)
+
+public:
+    /******** Event Register Interface ********/
+
+    /*
+     * Register on start up event;
+     */
+    void
+    RegisterOnStartUp(std::function<void(ResourceWPtr)> &func) {
+        on_start_up_ = func;
+    }
+
+    /*
+     * Register on finish one task event;
+     */
+    void
+    RegisterOnFinishTask(std::function<void(ResourceWPtr)> &func) {
+        on_finish_task_ = func;
+    }
+
+    /*
+     * Register on copy task data completed event;
+     */
+    void
+    RegisterOnCopyCompleted(std::function<void(ResourceWPtr)> &func);
+
+    /*
+     * Register on task table updated event;
+     */
+    void
+    RegisterOnTaskTableUpdated(std::function<void(ResourceWPtr)> &func);
+
+public:
+    /******** Utlitity Functions ********/
+
+    std::string
+    Dump();
+
+private:
+    void
+    EventProcess() {
+        while (running_) {
+            for (uint64_t i = 0; i < resources_.size(); ++i) {
+                if (start_up_event_[i]) {
+                    on_start_up_(resources_[i]);
+                }
+            }
+        }
+
+    }
+
+private:
+    bool running_;
+
+    std::vector<ResourcePtr> resources_;
+    std::thread worker_thread_;
+
+    std::vector<bool> start_up_event_;
+    std::vector<bool> finish_task_event_;
+    std::vector<bool> copy_completed_event_;
+    std::vector<bool> task_table_updated_event_;
+
+    std::function<void(ResourceWPtr)> on_start_up_;
+    std::function<void(ResourceWPtr)> on_finish_task_;
+    std::function<void(ResourceWPtr)> on_copy_completed_;
+    std::function<void(ResourceWPtr)> on_task_table_updated_;
+};
+
+using ResourceMgrWPtr = std::weak_ptr<ResourceMgr>;
+
+}
+}
+}
+
diff --git a/cpp/src/scheduler/Scheduler.h b/cpp/src/scheduler/Scheduler.h
new file mode 100644
index 0000000000..4bb840a68d
--- /dev/null
+++ b/cpp/src/scheduler/Scheduler.h
@@ -0,0 +1,155 @@
+/*******************************************************************************
+ * 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 <string>
+#include <mutex>
+#include <thread>
+#include <queue>
+
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+class Event {
+public:
+    explicit
+    Event(ResourceWPtr &resource)
+        : resource_(resource) {}
+
+public:
+    virtual void
+    Process() = 0;
+
+private:
+    ResourceWPtr resource_;
+};
+
+using EventPtr = std::shared_ptr<Event>;
+
+class StartUpEvent : public Event {
+public:
+    explicit
+    StartUpEvent(ResourceWPtr &resource)
+        : Event(resource) {}
+
+public:
+    void
+    Process() override;
+};
+
+class FinishTaskEvent : public Event {
+public:
+    explicit
+    FinishTaskEvent(ResourceWPtr &resource)
+        : Event(resource) {}
+
+public:
+    void
+    Process() override {
+//        for (nei : res->neighbours) {
+//            tasks = cost(nei->task_table(), nei->connection, limit = 3)
+//            res->task_table()->PutTasks(tasks);
+//        }
+//        res->WakeUpExec();
+    }
+};
+
+class CopyCompletedEvent : public Event {
+public:
+    explicit
+    CopyCompletedEvent(ResourceWPtr &resource)
+        : Event(resource) {}
+
+public:
+    void
+    Process() override;
+};
+
+class TaskTableUpdatedEvent : public Event {
+public:
+    explicit
+    TaskTableUpdatedEvent(ResourceWPtr &resource)
+        : Event(resource) {}
+
+public:
+    void
+    Process() override;
+};
+
+class Scheduler {
+public:
+    explicit
+    Scheduler(ResourceMgrWPtr res_mgr)
+        : running_(false),
+          res_mgr_(std::move(res_mgr)) {
+//        res_mgr.Register();
+//        res_mgr.Register();
+//        res_mgr.Register();
+//        res_mgr.Register();
+    }
+
+    void
+    Start() {}
+
+    /******** Events ********/
+
+    /*
+     * Process start up events;
+     */
+    void
+    OnStartUp(ResourceWPtr &resource) {
+        // call from res_mgr, non-blocking, if queue size over limit, exception!
+        auto event = std::make_shared<StartUpEvent>(resource);
+        event_queue_.push(event);
+    }
+
+    /*
+     * Process finish task events;
+     */
+    void
+    OnFinishTask(ResourceWPtr);
+
+    /*
+     * Process copy completed events;
+     */
+    void
+    OnCopyCompleted(ResourceWPtr);
+
+    /*
+     * Process task table updated events;
+     */
+    void
+    OnTaskTableUpdated(ResourceWPtr);
+
+
+public:
+    std::string
+    Dump();
+
+
+private:
+    void
+    worker_function() {
+        while (running_) {
+            auto event = event_queue_.front();
+            event->Process();
+        }
+    }
+
+private:
+    bool running_;
+
+    ResourceMgrWPtr res_mgr_;
+    std::queue<EventPtr> event_queue_;
+    std::thread worker_thread_;
+};
+
+}
+}
+}
+
diff --git a/cpp/src/scheduler/Task.h b/cpp/src/scheduler/Task.h
new file mode 100644
index 0000000000..e7f33049e5
--- /dev/null
+++ b/cpp/src/scheduler/Task.h
@@ -0,0 +1,29 @@
+/*******************************************************************************
+ * 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 <string>
+#include <memory>
+
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+// dummy task
+class Task {
+public:
+    Task(const std::string &name) {}
+
+    void
+    Execute() {}
+};
+
+using TaskPtr = std::shared_ptr<Task>;
+
+}
+}
+}
diff --git a/cpp/src/scheduler/TaskTable.h b/cpp/src/scheduler/TaskTable.h
new file mode 100644
index 0000000000..567aa6214d
--- /dev/null
+++ b/cpp/src/scheduler/TaskTable.h
@@ -0,0 +1,164 @@
+/*******************************************************************************
+ * 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 <vector>
+#include <deque>
+#include <mutex>
+
+#include "Task.h"
+
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+enum class TaskTableItemState {
+    INVALID,
+    START, // idle
+    LOADING, // loading data from other resource
+    LOADED, // ready to exec or move
+    EXECUTING, // executing, locking util executed or failed
+    EXECUTED, // executed, termination state
+    MOVING, // moving to another resource, locking util executed or failed
+    MOVED, // moved, termination state
+};
+
+struct TaskTableItem {
+    TaskTableItem() : id(0), state(TaskTableItemState::INVALID), mutex(), priority(0) {}
+
+    TaskTableItem(const TaskTableItem &src)
+    : id(src.id), state(src.state), mutex(), priority(src.priority) {}
+
+    uint64_t id; // auto increment from 0;
+    // TODO: add tag into task
+    TaskPtr task; // the task;
+    TaskTableItemState state; // the state;
+    std::mutex mutex;
+
+    uint8_t priority; // just a number, meaningless;
+};
+
+class TaskTable {
+public:
+    TaskTable() = default;
+
+    explicit
+    TaskTable(std::vector<TaskPtr> &&tasks) {}
+
+    /*
+     * Put one task;
+     */
+    void
+    Put(TaskPtr task) {}
+
+    /*
+     * Put tasks back of task table;
+     * Called by DBImpl;
+     */
+    void
+    Put(std::vector<TaskPtr> &tasks) {}
+
+    /*
+     * Return task table item reference;
+     */
+    TaskTableItem &
+    Get(uint64_t index) {}
+
+    /*
+     * TODO
+     * Remove sequence task which is DONE or MOVED from front;
+     * Called by ?
+     */
+    void
+    Clear() {
+        // find first task is NOT (done or moved), erase from begin to it;
+//        auto iterator = table_.begin();
+//        while (iterator->state == TaskTableItemState::EXECUTED or
+//            iterator->state == TaskTableItemState::MOVED)
+//            iterator++;
+//        table_.erase(table_.begin(), iterator);
+    }
+
+
+public:
+
+    /******** Action ********/
+    /*
+     * Move a task;
+     * Set state moving;
+     * Called by scheduler;
+     */
+
+    // TODO: bool to Status
+    bool
+    Move(uint64_t index) {
+        auto &task = table_[index];
+
+        std::lock_guard<std::mutex> lock(task.mutex);
+        if (task.state == TaskTableItemState::START) {
+            task.state = TaskTableItemState::LOADING;
+            return true;
+        }
+        return false;
+    }
+
+    /*
+     * Move task finished;
+     * Set state moved;
+     * Called by scheduler;
+     */
+    bool
+    Moved(uint64_t index) {}
+
+    /*
+     * Load a task;
+     * Set state loading;
+     * Called by loader;
+     */
+    bool
+    Load(uint64_t index) {}
+
+    /*
+     * Load task finished;
+     * Set state loaded;
+     * Called by loader;
+     */
+    bool
+    Loaded(uint64_t index) {}
+
+    /*
+     * Execute a task;
+     * Set state executing;
+     * Called by executor;
+     */
+    bool
+    Execute(uint64_t index) {}
+
+    /*
+     * Execute task finished;
+     * Set state executed;
+     * Called by executor;
+     */
+    bool
+    Executed(uint64_t index) {}
+
+public:
+    /*
+     * Dump;
+     */
+    std::string
+    Dump();
+
+private:
+    // TODO: map better ?
+    std::deque<TaskTableItem> table_;
+};
+
+
+}
+}
+}
diff --git a/cpp/src/scheduler/resource/Connection.h b/cpp/src/scheduler/resource/Connection.h
new file mode 100644
index 0000000000..0f1088e7fe
--- /dev/null
+++ b/cpp/src/scheduler/resource/Connection.h
@@ -0,0 +1,47 @@
+/*******************************************************************************
+ * 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 <string>
+#include <sstream>
+
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+class Connection {
+public:
+    Connection(std::string name, double speed)
+        : name_(std::move(name)), speed_(speed) {}
+
+    const std::string &
+    get_name() const {
+        return name_;
+    }
+
+    const double
+    get_speed() const {
+        return speed_;
+    }
+
+public:
+    std::string
+    Dump() const {
+        std::stringstream ss;
+        ss << "<name: " << name_ << ", speed: " << speed_ << ">";
+        return ss.str();
+    }
+
+private:
+    std::string name_;
+    double speed_;
+};
+
+
+}
+}
+}
diff --git a/cpp/src/scheduler/resource/CpuResource.h b/cpp/src/scheduler/resource/CpuResource.h
new file mode 100644
index 0000000000..995615d1ab
--- /dev/null
+++ b/cpp/src/scheduler/resource/CpuResource.h
@@ -0,0 +1,47 @@
+/*******************************************************************************
+ * 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 <string>
+
+#include "Resource.h"
+
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+class CpuResource : public Resource {
+public:
+    explicit
+    CpuResource(std::string name)
+        : Resource(std::move(name), ResourceType::CPU) {}
+
+protected:
+    void
+    LoadFile(TaskPtr task) override {
+//        if (src.type == DISK) {
+//            fd = open(filename);
+//            content = fd.read();
+//            close(fd);
+//        } else if (src.type == CPU) {
+//            memcpy(src, dest, len);
+//        } else if (src.type == GPU) {
+//            cudaMemcpyD2H(src, dest);
+//        } else {
+//            // unknown type, exception
+//        }
+    }
+
+    void
+    Process(TaskPtr task) override {
+        task->Execute();
+    }
+};
+
+}
+}
+}
diff --git a/cpp/src/scheduler/resource/DiskResource.h b/cpp/src/scheduler/resource/DiskResource.h
new file mode 100644
index 0000000000..b4ff32e75e
--- /dev/null
+++ b/cpp/src/scheduler/resource/DiskResource.h
@@ -0,0 +1,21 @@
+/*******************************************************************************
+ * 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 "Resource.h"
+
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+class DiskResource : public Resource {
+};
+
+}
+}
+}
diff --git a/cpp/src/scheduler/resource/GpuResource.h b/cpp/src/scheduler/resource/GpuResource.h
new file mode 100644
index 0000000000..be91950b78
--- /dev/null
+++ b/cpp/src/scheduler/resource/GpuResource.h
@@ -0,0 +1,21 @@
+/*******************************************************************************
+ * 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 "Resource.h"
+
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+class GpuResource : public Resource {
+};
+
+}
+}
+}
diff --git a/cpp/src/scheduler/resource/Node.h b/cpp/src/scheduler/resource/Node.h
new file mode 100644
index 0000000000..a32c14ec51
--- /dev/null
+++ b/cpp/src/scheduler/resource/Node.h
@@ -0,0 +1,55 @@
+/*******************************************************************************
+ * 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 <vector>
+#include <memory>
+
+#include "../TaskTable.h"
+#include "Connection.h"
+
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+class Node;
+
+using NeighbourNodePtr = std::weak_ptr<Node>;
+
+struct Neighbour {
+    NeighbourNodePtr neighbour_node;
+    Connection connection;
+};
+
+class Node {
+public:
+    void
+    AddNeighbour(const NeighbourNodePtr &neighbour_node, Connection &connection) {
+        Neighbour neighbour{.neighbour_node = neighbour_node, .connection = connection};
+        neighbours_.push_back(neighbour);
+    }
+
+    void
+    DelNeighbour(NeighbourNodePtr &neighbour_ptr);
+
+    bool
+    IsNeighbour(NeighbourNodePtr &neighbour_ptr);
+
+    std::vector<NeighbourNodePtr>
+    GetNeighbours();
+
+public:
+    std::string
+    Dump();
+
+private:
+    std::vector<Neighbour> neighbours_;
+};
+
+}
+}
+}
diff --git a/cpp/src/scheduler/resource/Resource.h b/cpp/src/scheduler/resource/Resource.h
new file mode 100644
index 0000000000..5b7bb13a80
--- /dev/null
+++ b/cpp/src/scheduler/resource/Resource.h
@@ -0,0 +1,229 @@
+/*******************************************************************************
+ * 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 <string>
+#include <vector>
+#include <memory>
+#include <thread>
+#include <functional>
+#include <condition_variable>
+
+#include "../TaskTable.h"
+#include "../Task.h"
+#include "../Cost.h"
+#include "Node.h"
+#include "Connection.h"
+
+
+namespace zilliz {
+namespace milvus {
+namespace engine {
+
+enum class ResourceType {
+    DISK = 0,
+    CPU = 1,
+    GPU = 2
+};
+
+class Resource : public Node {
+public:
+    void
+    Start() {
+        loader_thread_ = std::thread(&Resource::loader_function, this);
+        executor_thread_ = std::thread(&Resource::executor_function, this);
+    }
+
+    void
+    Stop() {
+        running_ = false;
+        WakeupLoader();
+        WakeupExecutor();
+    }
+
+    TaskTable &
+    task_table() {
+        return task_table_;
+    }
+
+public:
+    /*
+     * wake up executor;
+     */
+    void
+    WakeupExecutor() {
+        exec_cv_.notify_one();
+    }
+
+    /* 
+     * wake up loader;
+     */
+    void
+    WakeupLoader() {
+        load_cv_.notify_one();
+    }
+
+public:
+    /*
+     * Event function MUST be a short function, never blocking;
+     */
+
+    /*
+     * Register on start up event;
+     */
+    void
+    RegisterOnStartUp(std::function<void(void)> func);
+
+    /*
+     * Register on finish one task event;
+     */
+    void
+    RegisterOnFinishTask(std::function<void(void)> func);
+
+    /*
+     * Register on copy task data completed event;
+     */
+    void
+    RegisterOnCopyCompleted(std::function<void(void)> func);
+
+    /*
+     * Register on task table updated event;
+     */
+    void
+    RegisterOnTaskTableUpdated(std::function<void(void)> func);
+
+protected:
+    Resource(std::string name, ResourceType type)
+        : name_(std::move(name)),
+          type_(type),
+          on_start_up_(nullptr),
+          on_finish_task_(nullptr),
+          on_copy_completed_(nullptr),
+          on_task_table_updated_(nullptr),
+          running_(false),
+          load_flag_(false),
+          exec_flag_(false) {
+    }
+
+    // TODO: SearchContextPtr to TaskPtr
+    /*
+     * Implementation by inherit class;
+     * Blocking function;
+     */
+    virtual void
+    LoadFile(TaskPtr task) = 0;
+
+    /*
+     * Implementation by inherit class;
+     * Blocking function;
+     */
+    virtual void
+    Process(TaskPtr task) = 0;
+
+private:
+    /*
+     * These function should move to cost.h ???
+     * COST.H ???
+     */
+
+    /*
+     * Pick one task to load;
+     * Order by start time;
+     */
+    TaskPtr
+    pick_task_load() {
+        auto tasks = PickToLoad(task_table_, 3);
+        for (uint64_t i = 0; i < tasks.size(); ++i) {
+            // try to set one task loading, then return
+            if (task_table_.Load(i))
+                return task_table_.Get(i).task;
+            // else try next
+        }
+        return nullptr;
+    }
+
+    /*
+     * Pick one task to execute;
+     * Pick by start time and priority;
+     */
+    TaskPtr
+    pick_task_execute() {
+        auto tasks = PickToExecute(task_table_, 3);
+        for (uint64_t i = 0; i < tasks.size(); ++i) {
+            // try to set one task executing, then return
+            if (task_table_.Execute(i))
+                return task_table_.Get(i).task;
+            // else try next
+        }
+        return nullptr;
+    }
+
+private:
+    /*
+     * Only called by load thread;
+     */
+    void
+    loader_function() {
+        while (running_) {
+            std::unique_lock<std::mutex> lock(load_mutex_);
+            load_cv_.wait(lock, [&] { return load_flag_; });
+            auto task = pick_task_load();
+            if (task) {
+                LoadFile(task);
+                on_copy_completed_();
+            }
+        }
+
+    }
+
+    /*
+     * Only called by worker thread;
+     */
+    void
+    executor_function() {
+        on_start_up_();
+        while (running_) {
+            std::unique_lock<std::mutex> lock(exec_mutex_);
+            exec_cv_.wait(lock, [&] { return exec_flag_; });
+            auto task = pick_task_execute();
+            if (task) {
+                Process(task);
+                on_finish_task_();
+            }
+        }
+    }
+
+
+private:
+    std::string name_;
+    ResourceType type_;
+
+    TaskTable task_table_;
+
+    std::function<void(void)> on_start_up_;
+    std::function<void(void)> on_finish_task_;
+    std::function<void(void)> on_copy_completed_;
+    std::function<void(void)> on_task_table_updated_;
+
+    bool running_;
+    std::thread loader_thread_;
+    std::thread executor_thread_;
+
+    bool load_flag_;
+    bool exec_flag_;
+    std::mutex load_mutex_;
+    std::mutex exec_mutex_;
+    std::condition_variable load_cv_;
+    std::condition_variable exec_cv_;
+};
+
+using ResourcePtr = std::shared_ptr<Resource>;
+using ResourceWPtr = std::weak_ptr<Resource>;
+
+}
+}
+}
+
diff --git a/cpp/unittest/CMakeLists.txt b/cpp/unittest/CMakeLists.txt
index aa96fa6e25..287fe51128 100644
--- a/cpp/unittest/CMakeLists.txt
+++ b/cpp/unittest/CMakeLists.txt
@@ -42,4 +42,5 @@ add_subdirectory(server)
 add_subdirectory(db)
 add_subdirectory(knowhere)
 add_subdirectory(metrics)
+add_subdirectory(scheduler)
 #add_subdirectory(storage)
\ No newline at end of file
diff --git a/cpp/unittest/scheduler/CMakeLists.txt b/cpp/unittest/scheduler/CMakeLists.txt
new file mode 100644
index 0000000000..d62d80f969
--- /dev/null
+++ b/cpp/unittest/scheduler/CMakeLists.txt
@@ -0,0 +1,36 @@
+#-------------------------------------------------------------------------------
+# 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.
+#-------------------------------------------------------------------------------
+aux_source_directory(${MILVUS_ENGINE_SRC}/scheduler/resource scheduler_resource_srcs)
+aux_source_directory(${MILVUS_ENGINE_SRC}/scheduler scheduler_srcs)
+aux_source_directory(./ test_srcs)
+
+include_directories(/usr/local/cuda/include)
+link_directories("/usr/local/cuda/lib64")
+
+include_directories(/usr/include/mysql)
+
+#add_definitions(-DBOOST_ERROR_CODE_HEADER_ONLY)
+
+set(scheduler_test_src
+        ${scheduler_resource_srcs}
+        ${scheduler_srcs}
+        ${test_srcs}
+        )
+
+cuda_add_executable(scheduler_test ${scheduler_test_src})
+
+set(scheduler_libs
+        sqlite
+        boost_system_static
+        boost_filesystem_static
+        lz4
+        mysqlpp
+        )
+
+target_link_libraries(scheduler_test ${scheduler_libs} ${unittest_libs})
+
+install(TARGETS scheduler_test DESTINATION bin)
+
diff --git a/cpp/unittest/scheduler/normal_test.cpp b/cpp/unittest/scheduler/normal_test.cpp
new file mode 100644
index 0000000000..7318efc9df
--- /dev/null
+++ b/cpp/unittest/scheduler/normal_test.cpp
@@ -0,0 +1,39 @@
+#include "scheduler/ResourceFactory.h"
+#include "scheduler/ResourceMgr.h"
+#include "scheduler/Scheduler.h"
+#include <gtest/gtest.h>
+
+
+using namespace zilliz::milvus::engine;
+
+int main() {
+
+    // ResourceMgr only compose resources, provide unified event
+    auto res_mgr = std::make_shared<ResourceMgr>();
+    auto disk = res_mgr->Add(ResourceFactory::Create("disk", "ssd"));
+    auto cpu = res_mgr->Add(ResourceFactory::Create("cpu"));
+    auto gpu1 = res_mgr->Add(ResourceFactory::Create("gpu"));
+    auto gpu2 = res_mgr->Add(ResourceFactory::Create("gpu"));
+
+    auto IO = Connection("IO", 500.0);
+    auto PCIE = Connection("IO", 11000.0);
+    res_mgr->Connect(disk, cpu, IO);
+    res_mgr->Connect(cpu, gpu1, PCIE);
+    res_mgr->Connect(cpu, gpu2, PCIE);
+
+    res_mgr->StartAll();
+
+    auto task1 = std::make_shared<Task>("123456789");
+    auto task2 = std::make_shared<Task>("222222222");
+    if (auto observe = disk.lock()) {
+        observe->task_table().Put(task1);
+        observe->task_table().Put(task2);
+        observe->task_table().Put(task1);
+        observe->task_table().Put(task1);
+    }
+
+    auto scheduler = new Scheduler(res_mgr);
+    scheduler->Start();
+
+    while (true) sleep(1);
+}