diff --git a/cpp/CHANGELOG.md b/cpp/CHANGELOG.md
index 812b090724530b48fc6f83d82964356aa1434cba..671d865a028b5851662e2798131cb2289b70088e 100644
--- a/cpp/CHANGELOG.md
+++ b/cpp/CHANGELOG.md
@@ -5,6 +5,8 @@ Please mark all change in change log and use the ticket from JIRA.
 # Milvus 0.4.0 (2019-07-28)
 
 ## Bug
+- MS-411 - Fix metric unittest linking error
+- MS-412 - Fix gpu cache logical error
 
 ## Improvement
 - MS-327 - Clean code for milvus
@@ -80,7 +82,6 @@ Please mark all change in change log and use the ticket from JIRA.
 - MS-330 - Stability test failed caused by server core dumped
 - MS-347 - Build index hangs again
 - MS-382 - fix MySQLMetaImpl::CleanUpFilesWithTTL unknown column bug
-- MS-411 - Fix metric unittest linking error
 
 ## Improvement
 - MS-156 - Add unittest for merge result functions
diff --git a/cpp/conf/server_config.template b/cpp/conf/server_config.template
index d895dbbfb64c76673411ff3503de0c32aa2b4729..0a363eff8cf3a6010fb00d9084cb69352230f507 100644
--- a/cpp/conf/server_config.template
+++ b/cpp/conf/server_config.template
@@ -65,21 +65,21 @@ resource_config:
       memory: 64
       device_id: 0
       enable_loader: true
-      enable_executor: true
+      enable_executor: false
 
     gtx1060:
       type: GPU
       memory: 6
       device_id: 0
-      enable_loader: false
-      enable_executor: false
+      enable_loader: true
+      enable_executor: true
 
     gtx1660:
       type: GPU
       memory: 6
       device_id: 1
-      enable_loader: false
-      enable_executor: false
+      enable_loader: true
+      enable_executor: true
 
   # connection list, length: 0~N
   # format: -${resource_name}===${resource_name}
diff --git a/cpp/src/db/engine/ExecutionEngineImpl.cpp b/cpp/src/db/engine/ExecutionEngineImpl.cpp
index 5ef2fc0c72c2bacbd77724883ed0fc1a059785d7..7489e7849e3b407669948ae382fba465380cb1e8 100644
--- a/cpp/src/db/engine/ExecutionEngineImpl.cpp
+++ b/cpp/src/db/engine/ExecutionEngineImpl.cpp
@@ -139,9 +139,11 @@ Status ExecutionEngineImpl::Load(bool to_cache) {
 }
 
 Status ExecutionEngineImpl::CopyToGpu(uint64_t device_id) {
-    index_ = zilliz::milvus::cache::GpuCacheMgr::GetInstance(device_id)->GetIndex(location_);
-    bool already_in_cache = (index_ != nullptr);
-    if (!index_) {
+    auto index = zilliz::milvus::cache::GpuCacheMgr::GetInstance(device_id)->GetIndex(location_);
+    bool already_in_cache = (index != nullptr);
+    if (already_in_cache) {
+        index_ = index;
+    } else {
         try {
             index_ = index_->CopyToGpu(device_id);
             ENGINE_LOG_DEBUG << "CPU to GPU" << device_id;
@@ -161,9 +163,11 @@ Status ExecutionEngineImpl::CopyToGpu(uint64_t device_id) {
 }
 
 Status ExecutionEngineImpl::CopyToCpu() {
-    index_ = zilliz::milvus::cache::CpuCacheMgr::GetInstance()->GetIndex(location_);
-    bool already_in_cache = (index_ != nullptr);
-    if (!index_) {
+    auto index = zilliz::milvus::cache::CpuCacheMgr::GetInstance()->GetIndex(location_);
+    bool already_in_cache = (index != nullptr);
+    if (already_in_cache) {
+        index_ = index;
+    } else {
         try {
             index_ = index_->CopyToCpu();
             ENGINE_LOG_DEBUG << "GPU to CPU";
@@ -175,7 +179,7 @@ Status ExecutionEngineImpl::CopyToCpu() {
         }
     }
 
-    if(!already_in_cache) {
+    if (!already_in_cache) {
         Cache();
     }
     return Status::OK();
@@ -276,7 +280,7 @@ Status ExecutionEngineImpl::Init() {
     using namespace zilliz::milvus::server;
     ServerConfig &config = ServerConfig::GetInstance();
     ConfigNode server_config = config.GetConfig(CONFIG_SERVER);
-        gpu_num_ = server_config.GetInt32Value("gpu_index", 0);
+    gpu_num_ = server_config.GetInt32Value("gpu_index", 0);
 
     return Status::OK();
 }
diff --git a/cpp/src/scheduler/action/PushTaskToNeighbour.cpp b/cpp/src/scheduler/action/PushTaskToNeighbour.cpp
index 7c5855c11181a6b481e026608f6baaae9f17b75f..9afeac688a5ff1ce9126c1e619d99d5427467110 100644
--- a/cpp/src/scheduler/action/PushTaskToNeighbour.cpp
+++ b/cpp/src/scheduler/action/PushTaskToNeighbour.cpp
@@ -5,6 +5,7 @@
  ******************************************************************************/
 
 #include <list>
+#include <random>
 #include "Action.h"
 
 
@@ -38,6 +39,22 @@ push_task_round_robin(TaskTable &self_task_table, std::list<ResourcePtr> &neighb
     }
 }
 
+void
+push_task_randomly(TaskTable &self_task_table, std::vector<ResourcePtr> &neighbours) {
+    std::random_device rd;
+    std::mt19937 mt(rd());
+    std::uniform_int_distribution<uint64_t> dist(0, neighbours.size() - 1);
+    CacheMgr cache;
+
+    auto indexes = PickToMove(self_task_table, cache, self_task_table.Size());
+    for (auto index : indexes) {
+        if (self_task_table.Move(index)) {
+            auto task = self_task_table.Get(index)->task;
+            neighbours[dist(mt)]->task_table().Put(task);
+        }
+    }
+}
+
 void
 Action::PushTaskToNeighbour(const ResourceWPtr &res) {
     auto self = res.lock();
@@ -60,18 +77,21 @@ Action::PushTaskToNeighbourHasExecutor(const ResourceWPtr &res) {
     auto self = res.lock();
     if (not self) return;
 
-    std::list<ResourcePtr> neighbours;
+    std::list<ResourcePtr> l_neighbours;
+    std::vector<ResourcePtr> v_neighbours;
     for (auto &neighbour_node : self->GetNeighbours()) {
         auto node = neighbour_node.neighbour_node.lock();
         if (not node) continue;
 
         auto resource = std::static_pointer_cast<Resource>(node);
         if (resource->HasExecutor()) {
-            neighbours.emplace_back(resource);
+            l_neighbours.push_back(resource);
+            v_neighbours.push_back(resource);
         }
     }
 
-    push_task_round_robin(self->task_table(), neighbours);
+//    push_task_round_robin(self->task_table(), l_neighbours);
+    push_task_randomly(self->task_table(), v_neighbours);
 }