diff --git a/cpp/conf/server_config.template b/cpp/conf/server_config.template
index c2ed775601f875ed8c35bda5ff30ba9c4002756a..0383e00b53daf4c773c3534d3f7aca89d2990559 100644
--- a/cpp/conf/server_config.template
+++ b/cpp/conf/server_config.template
@@ -30,4 +30,7 @@ license_config:         # license configure
   license_path: "@MILVUS_DB_PATH@/system.license" # license file path
 
 cache_config:           # cache configure
-  cpu_cache_capacity: 16   # how many memory are used as cache, unit: GB, range: 0 ~ less than total memory
\ No newline at end of file
+  cpu_cache_capacity: 16   # how many memory are used as cache, unit: GB, range: 0 ~ less than total memory
+
+engine_config:
+  nprobe: 10
\ No newline at end of file
diff --git a/cpp/src/db/EngineFactory.cpp b/cpp/src/db/EngineFactory.cpp
index 26ef639c886c9d617d575041d703c718eab11306..bacce70ce4a08779f05cff1582f59d9d627b19b3 100644
--- a/cpp/src/db/EngineFactory.cpp
+++ b/cpp/src/db/EngineFactory.cpp
@@ -7,23 +7,39 @@
 #include "FaissExecutionEngine.h"
 #include "Log.h"
 
+
 namespace zilliz {
 namespace milvus {
 namespace engine {
 
 ExecutionEnginePtr
 EngineFactory::Build(uint16_t dimension,
-        const std::string& location,
-        EngineType type) {
-    switch(type) {
-        case EngineType::FAISS_IDMAP:
-            return ExecutionEnginePtr(new FaissExecutionEngine(dimension, location, "IDMap", "IDMap,Flat"));
-        case EngineType::FAISS_IVFFLAT:
-            return ExecutionEnginePtr(new FaissExecutionEngine(dimension, location, "IVF", "IDMap,Flat"));
-        default:
-            ENGINE_LOG_ERROR << "Unsupportted engine type";
+                     const std::string &location,
+                     EngineType type) {
+
+    ExecutionEnginePtr execution_engine_ptr;
+
+    switch (type) {
+        case EngineType::FAISS_IDMAP: {
+            execution_engine_ptr =
+                ExecutionEnginePtr(new FaissExecutionEngine(dimension, location, "IDMap", "IDMap,Flat"));
+            break;
+        }
+
+        case EngineType::FAISS_IVFFLAT: {
+            execution_engine_ptr =
+                ExecutionEnginePtr(new FaissExecutionEngine(dimension, location, "IVF", "IDMap,Flat"));
+            break;
+        }
+
+        default: {
+            ENGINE_LOG_ERROR << "Unsupported engine type";
             return nullptr;
+        }
     }
+
+    execution_engine_ptr->Init();
+    return execution_engine_ptr;
 }
 
 }
diff --git a/cpp/src/db/ExecutionEngine.h b/cpp/src/db/ExecutionEngine.h
index d2b4d01e670b70e5340d74cc7534bc8c4aea6f95..f8c05f6f9d03bf21a95624cb8e4252b61ad1817e 100644
--- a/cpp/src/db/ExecutionEngine.h
+++ b/cpp/src/db/ExecutionEngine.h
@@ -50,6 +50,8 @@ public:
     virtual std::shared_ptr<ExecutionEngine> BuildIndex(const std::string&) = 0;
 
     virtual Status Cache() = 0;
+
+    virtual Status Init() = 0;
 };
 
 using ExecutionEnginePtr = std::shared_ptr<ExecutionEngine>;
diff --git a/cpp/src/db/FaissExecutionEngine.cpp b/cpp/src/db/FaissExecutionEngine.cpp
index 9dfdd978c35d9d2919acb17e07f0e772be2e095e..20bd530e78c9dc230e36e1d830abe1832d13b900 100644
--- a/cpp/src/db/FaissExecutionEngine.cpp
+++ b/cpp/src/db/FaissExecutionEngine.cpp
@@ -13,6 +13,7 @@
 #include <wrapper/Index.h>
 #include <wrapper/IndexBuilder.h>
 #include <cache/CpuCacheMgr.h>
+#include "faiss/IndexIVF.h"
 #include "metrics/Metrics.h"
 
 
@@ -135,7 +136,16 @@ Status FaissExecutionEngine::Search(long n,
                                     float *distances,
                                     long *labels) const {
     auto start_time = METRICS_NOW_TIME;
-    pIndex_->search(n, data, k, distances, labels);
+
+    std::shared_ptr<faiss::IndexIVF> ivf_index = std::dynamic_pointer_cast<faiss::IndexIVF>(pIndex_);
+    if(ivf_index) {
+        ENGINE_LOG_DEBUG << "Index type: IVFFLAT nProbe: " << nprobe_;
+        ivf_index->nprobe = nprobe_;
+        ivf_index->search(n, data, k, distances, labels);
+    } else {
+        pIndex_->search(n, data, k, distances, labels);
+    }
+
     auto end_time = METRICS_NOW_TIME;
     auto total_time = METRICS_MICROSECONDS(start_time,end_time);
     server::Metrics::GetInstance().QueryIndexTypePerSecondSet(build_index_type_, double(n)/double(total_time));
@@ -149,6 +159,24 @@ Status FaissExecutionEngine::Cache() {
     return Status::OK();
 }
 
+Status FaissExecutionEngine::Init() {
+
+    if(build_index_type_ == "IVF") {
+
+        using namespace zilliz::milvus::server;
+        ServerConfig &config = ServerConfig::GetInstance();
+        ConfigNode engine_config = config.GetConfig(CONFIG_ENGINE);
+        nprobe_ = engine_config.GetInt32Value(CONFIG_NPROBE, 1000);
+
+    } else if(build_index_type_ == "IDMap") {
+        ;
+    } else {
+        return Status::Error("Wrong index type: ", build_index_type_);
+    }
+
+    return Status::OK();
+}
+
 
 } // namespace engine
 } // namespace milvus
diff --git a/cpp/src/db/FaissExecutionEngine.h b/cpp/src/db/FaissExecutionEngine.h
index 5667df34eab5426e756d21ae3b48cfe66e9dd912..f9f37ad978e0a5c5ddb8affe3057f25bd081ad97 100644
--- a/cpp/src/db/FaissExecutionEngine.h
+++ b/cpp/src/db/FaissExecutionEngine.h
@@ -6,14 +6,11 @@
 #pragma once
 
 #include "ExecutionEngine.h"
+#include "faiss/Index.h"
 
 #include <memory>
 #include <string>
 
-namespace faiss {
-    class Index;
-}
-
 namespace zilliz {
 namespace milvus {
 namespace engine {
@@ -58,12 +55,16 @@ public:
 
     Status Cache() override;
 
+    Status Init() override;
+
 protected:
     std::shared_ptr<faiss::Index> pIndex_;
     std::string location_;
 
     std::string build_index_type_;
     std::string raw_index_type_;
+
+    size_t nprobe_ = 0;
 };
 
 
diff --git a/cpp/src/wrapper/Index.cpp b/cpp/src/wrapper/Index.cpp
index 57c462a20197cab24366900d56db9ce2642617a6..18e20d830a1fb6cd6ca2e9dcc05afb2ccfd4f244 100644
--- a/cpp/src/wrapper/Index.cpp
+++ b/cpp/src/wrapper/Index.cpp
@@ -25,32 +25,6 @@ using std::string;
 using std::unordered_map;
 using std::vector;
 
-class Nprobe {
- public:
-    static Nprobe &GetInstance() {
-        static Nprobe instance;
-        return instance;
-    }
-
-    void SelectNprobe() {
-        using namespace zilliz::milvus::server;
-        ServerConfig &config = ServerConfig::GetInstance();
-        ConfigNode engine_config = config.GetConfig(CONFIG_ENGINE);
-        nprobe_ = engine_config.GetInt32Value(CONFIG_NPROBE, 1000);
-    }
-
-    size_t GetNprobe() {
-        return nprobe_;
-    }
-
- private:
-    Nprobe() : nprobe_(1000) { SelectNprobe(); }
-
- private:
-    size_t nprobe_;
-};
-
-
 Index::Index(const std::shared_ptr<faiss::Index> &raw_index) {
     index_ = raw_index;
     dim = index_->d;
@@ -84,9 +58,6 @@ bool Index::add_with_ids(idx_t n, const float *xdata, const long *xids) {
 
 bool Index::search(idx_t n, const float *data, idx_t k, float *distances, long *labels) const {
     try {
-        if(auto ivf_index = std::dynamic_pointer_cast<faiss::IndexIVF>(index_)) {
-            ivf_index->nprobe = Nprobe::GetInstance().GetNprobe();
-        }
         index_->search(n, data, k, distances, labels);
     }
     catch (std::exception &e) {