diff --git a/cpp/CHANGELOG.md b/cpp/CHANGELOG.md
index a41bc23484..68cd3568b8 100644
--- a/cpp/CHANGELOG.md
+++ b/cpp/CHANGELOG.md
@@ -34,6 +34,7 @@ Please mark all change in change log and use the ticket from JIRA.
 - MS-586 - Remove BUILD_FAISS_WITH_MKL option
 - MS-590 - Refine cmake code to support cpplint
 - MS-600 - Reconstruct unittest code
+- MS-602 - Remove zilliz namespace
 
 # Milvus 0.4.0 (2019-09-12)
 
diff --git a/cpp/src/cache/Cache.h b/cpp/src/cache/Cache.h
index 7818a2e6b7..62a7f13ca8 100644
--- a/cpp/src/cache/Cache.h
+++ b/cpp/src/cache/Cache.h
@@ -25,7 +25,6 @@
 #include <set>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace cache {
 
@@ -88,6 +87,5 @@ class Cache {
 
 }  // namespace cache
 }  // namespace milvus
-}  // namespace zilliz
 
 #include "cache/Cache.inl"
diff --git a/cpp/src/cache/Cache.inl b/cpp/src/cache/Cache.inl
index ebd8f3c25d..2ab6b3ffa6 100644
--- a/cpp/src/cache/Cache.inl
+++ b/cpp/src/cache/Cache.inl
@@ -17,7 +17,7 @@
 
 
 
-namespace zilliz {
+
 namespace milvus {
 namespace cache {
 
@@ -190,5 +190,5 @@ Cache<ItemObj>::print() {
 
 } // namespace cache
 } // namespace milvus
-} // namespace zilliz
+
 
diff --git a/cpp/src/cache/CacheMgr.h b/cpp/src/cache/CacheMgr.h
index 11cd742a6a..f5e04f6509 100644
--- a/cpp/src/cache/CacheMgr.h
+++ b/cpp/src/cache/CacheMgr.h
@@ -24,7 +24,6 @@
 #include <memory>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace cache {
 
@@ -70,6 +69,5 @@ class CacheMgr {
 
 }  // namespace cache
 }  // namespace milvus
-}  // namespace zilliz
 
 #include "cache/CacheMgr.inl"
diff --git a/cpp/src/cache/CacheMgr.inl b/cpp/src/cache/CacheMgr.inl
index b0c47b3dc3..23b2f0df74 100644
--- a/cpp/src/cache/CacheMgr.inl
+++ b/cpp/src/cache/CacheMgr.inl
@@ -16,7 +16,7 @@
 // under the License.
 
 
-namespace zilliz {
+
 namespace milvus {
 namespace cache {
 
@@ -142,4 +142,4 @@ CacheMgr<ItemObj>::SetCapacity(int64_t capacity) {
 
 } // namespace cache
 } // namespace milvus
-} // namespace zilliz
+
diff --git a/cpp/src/cache/CpuCacheMgr.cpp b/cpp/src/cache/CpuCacheMgr.cpp
index 99a284f074..7cfe59e72e 100644
--- a/cpp/src/cache/CpuCacheMgr.cpp
+++ b/cpp/src/cache/CpuCacheMgr.cpp
@@ -21,7 +21,6 @@
 
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace cache {
 
@@ -72,4 +71,3 @@ CpuCacheMgr::GetIndex(const std::string& key) {
 
 }  // namespace cache
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/cache/CpuCacheMgr.h b/cpp/src/cache/CpuCacheMgr.h
index ad6087de7c..2f8c50991a 100644
--- a/cpp/src/cache/CpuCacheMgr.h
+++ b/cpp/src/cache/CpuCacheMgr.h
@@ -23,7 +23,6 @@
 #include <memory>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace cache {
 
@@ -42,4 +41,3 @@ class CpuCacheMgr : public CacheMgr<DataObjPtr> {
 
 }  // namespace cache
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/cache/DataObj.h b/cpp/src/cache/DataObj.h
index 80cc560e7c..eb58b70825 100644
--- a/cpp/src/cache/DataObj.h
+++ b/cpp/src/cache/DataObj.h
@@ -21,7 +21,6 @@
 
 #include <memory>
 
-namespace zilliz {
 namespace milvus {
 namespace cache {
 
@@ -65,4 +64,3 @@ using DataObjPtr = std::shared_ptr<DataObj>;
 
 }  // namespace cache
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/cache/GpuCacheMgr.cpp b/cpp/src/cache/GpuCacheMgr.cpp
index 9c9e94eda9..a9eff6d3c3 100644
--- a/cpp/src/cache/GpuCacheMgr.cpp
+++ b/cpp/src/cache/GpuCacheMgr.cpp
@@ -22,7 +22,6 @@
 #include <sstream>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace cache {
 
@@ -84,4 +83,3 @@ GpuCacheMgr::GetIndex(const std::string& key) {
 
 }  // namespace cache
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/cache/GpuCacheMgr.h b/cpp/src/cache/GpuCacheMgr.h
index 15cdcae28f..8c0d4b9502 100644
--- a/cpp/src/cache/GpuCacheMgr.h
+++ b/cpp/src/cache/GpuCacheMgr.h
@@ -22,7 +22,6 @@
 #include <string>
 #include <unordered_map>
 
-namespace zilliz {
 namespace milvus {
 namespace cache {
 
@@ -46,4 +45,3 @@ class GpuCacheMgr : public CacheMgr<DataObjPtr> {
 
 }  // namespace cache
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/cache/LRU.h b/cpp/src/cache/LRU.h
index d6a5b9ace7..9b0eac0608 100644
--- a/cpp/src/cache/LRU.h
+++ b/cpp/src/cache/LRU.h
@@ -23,7 +23,6 @@
 #include <unordered_map>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace cache {
 
@@ -121,4 +120,3 @@ class LRU {
 
 }  // namespace cache
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/config/ConfigMgr.cpp b/cpp/src/config/ConfigMgr.cpp
index e006217fd2..5889f52fac 100644
--- a/cpp/src/config/ConfigMgr.cpp
+++ b/cpp/src/config/ConfigMgr.cpp
@@ -18,7 +18,6 @@
 #include "config/ConfigMgr.h"
 #include "YamlConfigMgr.h"
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -30,4 +29,3 @@ ConfigMgr::GetInstance() {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/config/ConfigMgr.h b/cpp/src/config/ConfigMgr.h
index e5336ee34d..40753beaa9 100644
--- a/cpp/src/config/ConfigMgr.h
+++ b/cpp/src/config/ConfigMgr.h
@@ -22,7 +22,6 @@
 
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -60,4 +59,3 @@ class ConfigMgr {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/config/ConfigNode.cpp b/cpp/src/config/ConfigNode.cpp
index ff27a0af75..cf148e4d29 100644
--- a/cpp/src/config/ConfigNode.cpp
+++ b/cpp/src/config/ConfigNode.cpp
@@ -23,7 +23,6 @@
 #include <sstream>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -234,4 +233,3 @@ ConfigNode::DumpString(const std::string& prefix) const {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/config/ConfigNode.h b/cpp/src/config/ConfigNode.h
index 937066dbf5..b7bf2c3af1 100644
--- a/cpp/src/config/ConfigNode.h
+++ b/cpp/src/config/ConfigNode.h
@@ -21,7 +21,6 @@
 #include <string>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -94,4 +93,3 @@ class ConfigNode {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/config/YamlConfigMgr.cpp b/cpp/src/config/YamlConfigMgr.cpp
index 02653d6fad..7153549544 100644
--- a/cpp/src/config/YamlConfigMgr.cpp
+++ b/cpp/src/config/YamlConfigMgr.cpp
@@ -20,7 +20,6 @@
 
 #include <sys/stat.h>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -116,4 +115,3 @@ YamlConfigMgr::LoadConfigNode(const YAML::Node& node, ConfigNode& config) {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/config/YamlConfigMgr.h b/cpp/src/config/YamlConfigMgr.h
index 743276b504..1c68bc883f 100644
--- a/cpp/src/config/YamlConfigMgr.h
+++ b/cpp/src/config/YamlConfigMgr.h
@@ -24,7 +24,6 @@
 #include <yaml-cpp/yaml.h>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -62,4 +61,3 @@ class YamlConfigMgr : public ConfigMgr {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/core/build.sh b/cpp/src/core/build.sh
old mode 100755
new mode 100644
diff --git a/cpp/src/core/knowhere/knowhere/adapter/ArrowAdapter.cpp b/cpp/src/core/knowhere/knowhere/adapter/ArrowAdapter.cpp
index bc1dfbf13d..38227f43ab 100644
--- a/cpp/src/core/knowhere/knowhere/adapter/ArrowAdapter.cpp
+++ b/cpp/src/core/knowhere/knowhere/adapter/ArrowAdapter.cpp
@@ -17,7 +17,6 @@
 
 #include "knowhere/adapter/ArrowAdapter.h"
 
-namespace zilliz {
 namespace knowhere {
 
 ArrayPtr
@@ -52,4 +51,3 @@ CopySchema(const SchemaPtr& origin) {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/adapter/ArrowAdapter.h b/cpp/src/core/knowhere/knowhere/adapter/ArrowAdapter.h
index f4d0b348cf..75580cd163 100644
--- a/cpp/src/core/knowhere/knowhere/adapter/ArrowAdapter.h
+++ b/cpp/src/core/knowhere/knowhere/adapter/ArrowAdapter.h
@@ -23,7 +23,6 @@
 
 #include "knowhere/common/Array.h"
 
-namespace zilliz {
 namespace knowhere {
 
 ArrayPtr
@@ -33,4 +32,3 @@ SchemaPtr
 CopySchema(const SchemaPtr& origin);
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/adapter/SptagAdapter.cpp b/cpp/src/core/knowhere/knowhere/adapter/SptagAdapter.cpp
index 8a0ad69591..f4b1a7953f 100644
--- a/cpp/src/core/knowhere/knowhere/adapter/SptagAdapter.cpp
+++ b/cpp/src/core/knowhere/knowhere/adapter/SptagAdapter.cpp
@@ -19,7 +19,6 @@
 #include "knowhere/adapter/Structure.h"
 #include "knowhere/index/vector_index/helpers/Definitions.h"
 
-namespace zilliz {
 namespace knowhere {
 
 std::shared_ptr<SPTAG::MetadataSet>
@@ -121,4 +120,3 @@ ConvertToDataset(std::vector<SPTAG::QueryResult> query_results) {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/adapter/SptagAdapter.h b/cpp/src/core/knowhere/knowhere/adapter/SptagAdapter.h
index 0889657cf9..9f92497562 100644
--- a/cpp/src/core/knowhere/knowhere/adapter/SptagAdapter.h
+++ b/cpp/src/core/knowhere/knowhere/adapter/SptagAdapter.h
@@ -23,7 +23,6 @@
 
 #include "knowhere/common/Dataset.h"
 
-namespace zilliz {
 namespace knowhere {
 
 std::shared_ptr<SPTAG::VectorSet>
@@ -39,4 +38,3 @@ DatasetPtr
 ConvertToDataset(std::vector<SPTAG::QueryResult> query_results);
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/adapter/Structure.cpp b/cpp/src/core/knowhere/knowhere/adapter/Structure.cpp
index 2cd69f3d10..44b068c792 100644
--- a/cpp/src/core/knowhere/knowhere/adapter/Structure.cpp
+++ b/cpp/src/core/knowhere/knowhere/adapter/Structure.cpp
@@ -20,7 +20,6 @@
 #include <string>
 #include <vector>
 
-namespace zilliz {
 namespace knowhere {
 
 ArrayPtr
@@ -86,4 +85,3 @@ ConstructFloatField(const std::string& name) {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/adapter/Structure.h b/cpp/src/core/knowhere/knowhere/adapter/Structure.h
index 526dc91b73..6bde9ddfe6 100644
--- a/cpp/src/core/knowhere/knowhere/adapter/Structure.h
+++ b/cpp/src/core/knowhere/knowhere/adapter/Structure.h
@@ -23,7 +23,6 @@
 
 #include "knowhere/common/Dataset.h"
 
-namespace zilliz {
 namespace knowhere {
 
 extern ArrayPtr
@@ -51,4 +50,3 @@ extern FieldPtr
 ConstructFloatField(const std::string& name);
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/adapter/VectorAdapter.h b/cpp/src/core/knowhere/knowhere/adapter/VectorAdapter.h
index ae4ef998cd..2b16227bb3 100644
--- a/cpp/src/core/knowhere/knowhere/adapter/VectorAdapter.h
+++ b/cpp/src/core/knowhere/knowhere/adapter/VectorAdapter.h
@@ -17,7 +17,6 @@
 
 #pragma once
 
-namespace zilliz {
 namespace knowhere {
 
 #define GETTENSOR(dataset)              \
@@ -27,4 +26,3 @@ namespace knowhere {
     auto rows = tensor->shape()[0];
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/common/Array.h b/cpp/src/core/knowhere/knowhere/common/Array.h
index 89bbf6ccd7..71ad78b79b 100644
--- a/cpp/src/core/knowhere/knowhere/common/Array.h
+++ b/cpp/src/core/knowhere/knowhere/common/Array.h
@@ -22,7 +22,6 @@
 
 #include "Schema.h"
 
-namespace zilliz {
 namespace knowhere {
 
 using ArrayData = arrow::ArrayData;
@@ -49,4 +48,3 @@ using Decimal128Array = arrow::Decimal128Array;
 using Decimal128ArrayPtr = std::shared_ptr<arrow::Decimal128Array>;
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/common/BinarySet.h b/cpp/src/core/knowhere/knowhere/common/BinarySet.h
index 6d8580e071..6e6d53000e 100644
--- a/cpp/src/core/knowhere/knowhere/common/BinarySet.h
+++ b/cpp/src/core/knowhere/knowhere/common/BinarySet.h
@@ -25,7 +25,6 @@
 
 #include "Id.h"
 
-namespace zilliz {
 namespace knowhere {
 
 struct Binary {
@@ -74,4 +73,3 @@ class BinarySet {
 };
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/common/Buffer.h b/cpp/src/core/knowhere/knowhere/common/Buffer.h
index 42af87a09b..d95da18602 100644
--- a/cpp/src/core/knowhere/knowhere/common/Buffer.h
+++ b/cpp/src/core/knowhere/knowhere/common/Buffer.h
@@ -21,7 +21,6 @@
 
 #include <arrow/buffer.h>
 
-namespace zilliz {
 namespace knowhere {
 
 using Buffer = arrow::Buffer;
@@ -60,4 +59,3 @@ MakeMutableBuffer(uint8_t* data, const int64_t size) {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/common/Config.h b/cpp/src/core/knowhere/knowhere/common/Config.h
index afb621d5e1..6191ecb771 100644
--- a/cpp/src/core/knowhere/knowhere/common/Config.h
+++ b/cpp/src/core/knowhere/knowhere/common/Config.h
@@ -19,7 +19,6 @@
 
 #include <memory>
 
-namespace zilliz {
 namespace knowhere {
 
 enum class METRICTYPE {
@@ -55,4 +54,3 @@ struct Cfg {
 using Config = std::shared_ptr<Cfg>;
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/common/Dataset.h b/cpp/src/core/knowhere/knowhere/common/Dataset.h
index 4a4f4bdd80..1331239dd6 100644
--- a/cpp/src/core/knowhere/knowhere/common/Dataset.h
+++ b/cpp/src/core/knowhere/knowhere/common/Dataset.h
@@ -28,7 +28,6 @@
 #include "Tensor.h"
 #include "knowhere/adapter/ArrowAdapter.h"
 
-namespace zilliz {
 namespace knowhere {
 
 class Dataset;
@@ -148,4 +147,3 @@ class Dataset {
 using DatasetPtr = std::shared_ptr<Dataset>;
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/common/Exception.cpp b/cpp/src/core/knowhere/knowhere/common/Exception.cpp
index 75d9ce39bb..4fef9529ac 100644
--- a/cpp/src/core/knowhere/knowhere/common/Exception.cpp
+++ b/cpp/src/core/knowhere/knowhere/common/Exception.cpp
@@ -20,7 +20,6 @@
 #include "Log.h"
 #include "knowhere/common/Exception.h"
 
-namespace zilliz {
 namespace knowhere {
 
 KnowhereException::KnowhereException(const std::string& msg) : msg(msg) {
@@ -48,4 +47,3 @@ KnowhereException::what() const noexcept {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/common/Exception.h b/cpp/src/core/knowhere/knowhere/common/Exception.h
index ec89c4d616..9ffc7838cf 100644
--- a/cpp/src/core/knowhere/knowhere/common/Exception.h
+++ b/cpp/src/core/knowhere/knowhere/common/Exception.h
@@ -20,7 +20,6 @@
 #include <exception>
 #include <string>
 
-namespace zilliz {
 namespace knowhere {
 
 class KnowhereException : public std::exception {
@@ -52,4 +51,3 @@ class KnowhereException : public std::exception {
     } while (false)
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/common/Id.h b/cpp/src/core/knowhere/knowhere/common/Id.h
index 9686075874..1c82161684 100644
--- a/cpp/src/core/knowhere/knowhere/common/Id.h
+++ b/cpp/src/core/knowhere/knowhere/common/Id.h
@@ -17,13 +17,9 @@
 
 #pragma once
 
-//#include "zcommon/id/id.h"
-// using ID = zilliz::common::ID;
-
 #include <stdint.h>
 #include <string>
 
-namespace zilliz {
 namespace knowhere {
 
 class ID {
@@ -58,4 +54,3 @@ class ID {
 };
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/common/Log.h b/cpp/src/core/knowhere/knowhere/common/Log.h
index 1ca78b155a..222d03d73e 100644
--- a/cpp/src/core/knowhere/knowhere/common/Log.h
+++ b/cpp/src/core/knowhere/knowhere/common/Log.h
@@ -19,7 +19,6 @@
 
 #include "utils/easylogging++.h"
 
-namespace zilliz {
 namespace knowhere {
 
 #define KNOWHERE_DOMAIN_NAME "[KNOWHERE] "
@@ -33,4 +32,3 @@ namespace knowhere {
 #define KNOWHERE_LOG_FATAL LOG(FATAL) << KNOWHERE_DOMAIN_NAME
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/common/Schema.h b/cpp/src/core/knowhere/knowhere/common/Schema.h
index 6dc4784e53..c90bac7572 100644
--- a/cpp/src/core/knowhere/knowhere/common/Schema.h
+++ b/cpp/src/core/knowhere/knowhere/common/Schema.h
@@ -21,7 +21,6 @@
 
 #include <arrow/type.h>
 
-namespace zilliz {
 namespace knowhere {
 
 using DataType = arrow::DataType;
@@ -32,4 +31,3 @@ using SchemaPtr = std::shared_ptr<Schema>;
 using SchemaConstPtr = std::shared_ptr<const Schema>;
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/common/Tensor.h b/cpp/src/core/knowhere/knowhere/common/Tensor.h
index cd23933e96..ff957319e5 100644
--- a/cpp/src/core/knowhere/knowhere/common/Tensor.h
+++ b/cpp/src/core/knowhere/knowhere/common/Tensor.h
@@ -21,11 +21,9 @@
 
 #include <arrow/tensor.h>
 
-namespace zilliz {
 namespace knowhere {
 
 using Tensor = arrow::Tensor;
 using TensorPtr = std::shared_ptr<Tensor>;
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/common/Timer.cpp b/cpp/src/core/knowhere/knowhere/common/Timer.cpp
index f4db63203c..fefe1e1705 100644
--- a/cpp/src/core/knowhere/knowhere/common/Timer.cpp
+++ b/cpp/src/core/knowhere/knowhere/common/Timer.cpp
@@ -19,7 +19,6 @@
 
 #include "knowhere/common/Timer.h"
 
-namespace zilliz {
 namespace knowhere {
 
 TimeRecorder::TimeRecorder(const std::string& header, int64_t log_level) : header_(header), log_level_(log_level) {
@@ -99,4 +98,3 @@ TimeRecorder::ElapseFromBegin(const std::string& msg) {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/common/Timer.h b/cpp/src/core/knowhere/knowhere/common/Timer.h
index b1557e4c20..7e01e88aa9 100644
--- a/cpp/src/core/knowhere/knowhere/common/Timer.h
+++ b/cpp/src/core/knowhere/knowhere/common/Timer.h
@@ -20,7 +20,6 @@
 #include <chrono>
 #include <string>
 
-namespace zilliz {
 namespace knowhere {
 
 class TimeRecorder {
@@ -52,4 +51,3 @@ class TimeRecorder {
 };
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/Index.h b/cpp/src/core/knowhere/knowhere/index/Index.h
index 613a8d049a..ffa685689b 100644
--- a/cpp/src/core/knowhere/knowhere/index/Index.h
+++ b/cpp/src/core/knowhere/knowhere/index/Index.h
@@ -25,7 +25,6 @@
 #include "knowhere/common/Dataset.h"
 #include "knowhere/index/preprocessor/Preprocessor.h"
 
-namespace zilliz {
 namespace knowhere {
 
 class Index {
@@ -66,4 +65,3 @@ class Index {
 using IndexPtr = std::shared_ptr<Index>;
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/IndexModel.h b/cpp/src/core/knowhere/knowhere/index/IndexModel.h
index 64acc5ad22..1229e21f2c 100644
--- a/cpp/src/core/knowhere/knowhere/index/IndexModel.h
+++ b/cpp/src/core/knowhere/knowhere/index/IndexModel.h
@@ -20,7 +20,6 @@
 #include <memory>
 #include "knowhere/common/BinarySet.h"
 
-namespace zilliz {
 namespace knowhere {
 
 class IndexModel {
@@ -35,4 +34,3 @@ class IndexModel {
 using IndexModelPtr = std::shared_ptr<IndexModel>;
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/IndexType.h b/cpp/src/core/knowhere/knowhere/index/IndexType.h
index 64a2188790..e39b57bf44 100644
--- a/cpp/src/core/knowhere/knowhere/index/IndexType.h
+++ b/cpp/src/core/knowhere/knowhere/index/IndexType.h
@@ -17,7 +17,6 @@
 
 #pragma once
 
-namespace zilliz {
 namespace knowhere {
 
 enum class IndexType {
@@ -28,4 +27,3 @@ enum class IndexType {
 };
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/preprocessor/Normalize.cpp b/cpp/src/core/knowhere/knowhere/index/preprocessor/Normalize.cpp
index 2a31a22f16..f21c787abe 100644
--- a/cpp/src/core/knowhere/knowhere/index/preprocessor/Normalize.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/preprocessor/Normalize.cpp
@@ -20,7 +20,7 @@
 #include "knowhere/index/preprocessor/Normalize.h"
 //
 //
-// namespace zilliz {
+//
 // namespace knowhere {
 //
 // DatasetPtr
@@ -54,4 +54,4 @@
 //}
 //
 //} // namespace knowhere
-//} // namespace zilliz
+//
diff --git a/cpp/src/core/knowhere/knowhere/index/preprocessor/Normalize.h b/cpp/src/core/knowhere/knowhere/index/preprocessor/Normalize.h
index 9e918d56b8..572c447b27 100644
--- a/cpp/src/core/knowhere/knowhere/index/preprocessor/Normalize.h
+++ b/cpp/src/core/knowhere/knowhere/index/preprocessor/Normalize.h
@@ -21,7 +21,7 @@
 //#include "preprocessor.h"
 //
 //
-// namespace zilliz {
+//
 // namespace knowhere {
 //
 // class NormalizePreprocessor : public Preprocessor {
@@ -40,4 +40,4 @@
 //
 //
 //} // namespace knowhere
-//} // namespace zilliz
+//
diff --git a/cpp/src/core/knowhere/knowhere/index/preprocessor/Preprocessor.h b/cpp/src/core/knowhere/knowhere/index/preprocessor/Preprocessor.h
index c04dbdf3dc..d1cb1817d6 100644
--- a/cpp/src/core/knowhere/knowhere/index/preprocessor/Preprocessor.h
+++ b/cpp/src/core/knowhere/knowhere/index/preprocessor/Preprocessor.h
@@ -21,7 +21,6 @@
 
 #include "knowhere/common/Dataset.h"
 
-namespace zilliz {
 namespace knowhere {
 
 class Preprocessor {
@@ -33,4 +32,3 @@ class Preprocessor {
 using PreprocessorPtr = std::shared_ptr<Preprocessor>;
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/FaissBaseIndex.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/FaissBaseIndex.cpp
index 5e90da9d56..4fc9a82009 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/FaissBaseIndex.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/FaissBaseIndex.cpp
@@ -23,7 +23,6 @@
 #include "knowhere/index/vector_index/FaissBaseIndex.h"
 #include "knowhere/index/vector_index/helpers/FaissIO.h"
 
-namespace zilliz {
 namespace knowhere {
 
 FaissBaseIndex::FaissBaseIndex(std::shared_ptr<faiss::Index> index) : index_(std::move(index)) {
@@ -79,4 +78,3 @@ FaissBaseIndex::SealImpl() {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/FaissBaseIndex.h b/cpp/src/core/knowhere/knowhere/index/vector_index/FaissBaseIndex.h
index bac4a2bf29..f3fceebb88 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/FaissBaseIndex.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/FaissBaseIndex.h
@@ -23,7 +23,6 @@
 
 #include "knowhere/common/BinarySet.h"
 
-namespace zilliz {
 namespace knowhere {
 
 class FaissBaseIndex {
@@ -44,4 +43,3 @@ class FaissBaseIndex {
 };
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVF.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVF.cpp
index 332d31bce0..dc886b7383 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVF.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVF.cpp
@@ -29,7 +29,6 @@
 #include "knowhere/index/vector_index/helpers/Cloner.h"
 #include "knowhere/index/vector_index/helpers/FaissIO.h"
 
-namespace zilliz {
 namespace knowhere {
 
 IndexModelPtr
@@ -171,7 +170,7 @@ GPUIVF::CopyGpuToCpu(const Config& config) {
 VectorIndexPtr
 GPUIVF::Clone() {
     auto cpu_idx = CopyGpuToCpu(Config());
-    return ::zilliz::knowhere::cloner::CopyCpuToGpu(cpu_idx, gpu_id_, Config());
+    return knowhere::cloner::CopyCpuToGpu(cpu_idx, gpu_id_, Config());
 }
 
 VectorIndexPtr
@@ -201,4 +200,3 @@ GPUIndex::GetGpuDevice() {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVF.h b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVF.h
index 347e255b87..8edd0fe30e 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVF.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVF.h
@@ -23,7 +23,6 @@
 #include "IndexIVF.h"
 #include "knowhere/index/vector_index/helpers/FaissGpuResourceMgr.h"
 
-namespace zilliz {
 namespace knowhere {
 
 class GPUIndex {
@@ -95,4 +94,3 @@ class GPUIVF : public IVF, public GPUIndex {
 };
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFPQ.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFPQ.cpp
index 7aa8f7db2a..077f0817da 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFPQ.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFPQ.cpp
@@ -24,7 +24,6 @@
 #include "knowhere/common/Exception.h"
 #include "knowhere/index/vector_index/IndexGPUIVFPQ.h"
 
-namespace zilliz {
 namespace knowhere {
 
 IndexModelPtr
@@ -68,4 +67,3 @@ GPUIVFPQ::CopyGpuToCpu(const Config& config) {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFPQ.h b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFPQ.h
index 6d298e77e6..13ea1075ca 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFPQ.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFPQ.h
@@ -21,7 +21,6 @@
 
 #include "IndexGPUIVF.h"
 
-namespace zilliz {
 namespace knowhere {
 
 class GPUIVFPQ : public GPUIVF {
@@ -43,4 +42,3 @@ class GPUIVFPQ : public GPUIVF {
 };
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFSQ.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFSQ.cpp
index bf2aa22474..1b4f4e9edb 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFSQ.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFSQ.cpp
@@ -24,7 +24,6 @@
 #include "knowhere/index/vector_index/IndexGPUIVFSQ.h"
 #include "knowhere/index/vector_index/IndexIVFSQ.h"
 
-namespace zilliz {
 namespace knowhere {
 
 IndexModelPtr
@@ -73,4 +72,3 @@ GPUIVFSQ::CopyGpuToCpu(const Config& config) {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFSQ.h b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFSQ.h
index 5c6b4a038b..ed8013d77f 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFSQ.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexGPUIVFSQ.h
@@ -22,7 +22,6 @@
 
 #include "IndexGPUIVF.h"
 
-namespace zilliz {
 namespace knowhere {
 
 class GPUIVFSQ : public GPUIVF {
@@ -42,4 +41,3 @@ class GPUIVFSQ : public GPUIVF {
 };
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIDMAP.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIDMAP.cpp
index 8d4ff16a1f..2371591b5c 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIDMAP.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIDMAP.cpp
@@ -27,7 +27,6 @@
 #include "knowhere/index/vector_index/IndexIDMAP.h"
 #include "knowhere/index/vector_index/helpers/FaissIO.h"
 
-namespace zilliz {
 namespace knowhere {
 
 BinarySet
@@ -269,4 +268,3 @@ GPUIDMAP::search_impl(int64_t n, const float* data, int64_t k, float* distances,
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIDMAP.h b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIDMAP.h
index fd13b87e34..ec1cbb9e77 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIDMAP.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIDMAP.h
@@ -23,7 +23,6 @@
 #include <memory>
 #include <utility>
 
-namespace zilliz {
 namespace knowhere {
 
 class IDMAP : public VectorIndex, public FaissBaseIndex {
@@ -97,4 +96,3 @@ class GPUIDMAP : public IDMAP, public GPUIndex {
 using GPUIDMAPPtr = std::shared_ptr<GPUIDMAP>;
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVF.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVF.cpp
index 13805ce14d..428710d355 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVF.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVF.cpp
@@ -33,7 +33,6 @@
 #include "knowhere/index/vector_index/IndexGPUIVF.h"
 #include "knowhere/index/vector_index/IndexIVF.h"
 
-namespace zilliz {
 namespace knowhere {
 
 IndexModelPtr
@@ -268,4 +267,3 @@ IVFIndexModel::SealImpl() {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVF.h b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVF.h
index 088849c22a..ef9982fa30 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVF.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVF.h
@@ -26,7 +26,6 @@
 #include "VectorIndex.h"
 #include "faiss/IndexIVF.h"
 
-namespace zilliz {
 namespace knowhere {
 
 using Graph = std::vector<std::vector<int64_t>>;
@@ -122,4 +121,3 @@ class IVFIndexModel : public IndexModel, public FaissBaseIndex {
 using IVFIndexModelPtr = std::shared_ptr<IVFIndexModel>;
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFPQ.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFPQ.cpp
index c0eda94310..03acbf31d7 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFPQ.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFPQ.cpp
@@ -24,7 +24,6 @@
 #include "knowhere/common/Exception.h"
 #include "knowhere/index/vector_index/IndexIVFPQ.h"
 
-namespace zilliz {
 namespace knowhere {
 
 IndexModelPtr
@@ -62,4 +61,3 @@ IVFPQ::Clone_impl(const std::shared_ptr<faiss::Index>& index) {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFPQ.h b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFPQ.h
index f071c1e0fa..69aaa5090b 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFPQ.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFPQ.h
@@ -22,7 +22,6 @@
 
 #include "IndexIVF.h"
 
-namespace zilliz {
 namespace knowhere {
 
 class IVFPQ : public IVF {
@@ -44,4 +43,3 @@ class IVFPQ : public IVF {
 };
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFSQ.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFSQ.cpp
index 5406211fa3..11e508549a 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFSQ.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFSQ.cpp
@@ -24,7 +24,6 @@
 #include "knowhere/index/vector_index/IndexIVFSQ.h"
 #include "knowhere/index/vector_index/helpers/FaissGpuResourceMgr.h"
 
-namespace zilliz {
 namespace knowhere {
 
 IndexModelPtr
@@ -70,4 +69,3 @@ IVFSQ::CopyCpuToGpu(const int64_t& device_id, const Config& config) {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFSQ.h b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFSQ.h
index 3a05ca9826..cac95faebf 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFSQ.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexIVFSQ.h
@@ -22,7 +22,6 @@
 
 #include "IndexIVF.h"
 
-namespace zilliz {
 namespace knowhere {
 
 class IVFSQ : public IVF {
@@ -44,4 +43,3 @@ class IVFSQ : public IVF {
 };
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexKDT.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexKDT.cpp
index 6efb839384..c23a6ef61d 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexKDT.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexKDT.cpp
@@ -30,7 +30,6 @@
 #include "knowhere/common/Exception.h"
 #include "knowhere/index/vector_index/helpers/KDTParameterMgr.h"
 
-namespace zilliz {
 namespace knowhere {
 
 BinarySet
@@ -174,4 +173,3 @@ CPUKDTRNGIndexModel::Load(const BinarySet& binary) {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexKDT.h b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexKDT.h
index 86737ac3dd..f6d436995b 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexKDT.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexKDT.h
@@ -23,7 +23,6 @@
 #include "VectorIndex.h"
 #include "knowhere/index/IndexModel.h"
 
-namespace zilliz {
 namespace knowhere {
 
 class CPUKDTRNG : public VectorIndex {
@@ -86,4 +85,3 @@ class CPUKDTRNGIndexModel : public IndexModel {
 using CPUKDTRNGIndexModelPtr = std::shared_ptr<CPUKDTRNGIndexModel>;
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexNSG.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexNSG.cpp
index b731f801b3..f5519b8240 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexNSG.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexNSG.cpp
@@ -25,7 +25,6 @@
 #include "knowhere/index/vector_index/nsg/NSG.h"
 #include "knowhere/index/vector_index/nsg/NSGIO.h"
 
-namespace zilliz {
 namespace knowhere {
 
 BinarySet
@@ -167,4 +166,3 @@ NSG::Seal() {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexNSG.h b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexNSG.h
index 4371ddb65a..04a146d58a 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/IndexNSG.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/IndexNSG.h
@@ -22,7 +22,6 @@
 
 #include "VectorIndex.h"
 
-namespace zilliz {
 namespace knowhere {
 
 namespace algo {
@@ -63,4 +62,3 @@ class NSG : public VectorIndex {
 using NSGIndexPtr = std::shared_ptr<NSG>();
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/VectorIndex.h b/cpp/src/core/knowhere/knowhere/index/vector_index/VectorIndex.h
index e96de885af..810c4d2ea4 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/VectorIndex.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/VectorIndex.h
@@ -25,7 +25,6 @@
 #include "knowhere/index/preprocessor/Preprocessor.h"
 #include "knowhere/index/vector_index/helpers/IndexParameter.h"
 
-namespace zilliz {
 namespace knowhere {
 
 class VectorIndex;
@@ -60,4 +59,3 @@ class VectorIndex : public Index {
 };
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/Cloner.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/Cloner.cpp
index c6f3f81053..16191b8183 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/Cloner.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/Cloner.cpp
@@ -23,7 +23,6 @@
 #include "knowhere/index/vector_index/IndexIVFPQ.h"
 #include "knowhere/index/vector_index/IndexIVFSQ.h"
 
-namespace zilliz {
 namespace knowhere {
 namespace cloner {
 
@@ -57,4 +56,3 @@ CopyCpuToGpu(const VectorIndexPtr& index, const int64_t& device_id, const Config
 
 }  // namespace cloner
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/Cloner.h b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/Cloner.h
index fb5d00d7df..3134238ed8 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/Cloner.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/Cloner.h
@@ -19,7 +19,6 @@
 
 #include "knowhere/index/vector_index/VectorIndex.h"
 
-namespace zilliz {
 namespace knowhere {
 namespace cloner {
 
@@ -32,4 +31,3 @@ CopyGpuToCpu(const VectorIndexPtr& index, const Config& config);
 
 }  // namespace cloner
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/Definitions.h b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/Definitions.h
index d5959f7501..f39a28d20f 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/Definitions.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/Definitions.h
@@ -17,7 +17,6 @@
 
 #pragma once
 
-namespace zilliz {
 namespace knowhere {
 namespace definition {
 
@@ -27,4 +26,3 @@ namespace definition {
 
 }  // namespace definition
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissGpuResourceMgr.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissGpuResourceMgr.cpp
index 70c879d03a..d74c6bc562 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissGpuResourceMgr.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissGpuResourceMgr.cpp
@@ -19,7 +19,6 @@
 
 #include <utility>
 
-namespace zilliz {
 namespace knowhere {
 
 FaissGpuResourceMgr&
@@ -125,4 +124,3 @@ FaissGpuResourceMgr::Dump() {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissGpuResourceMgr.h b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissGpuResourceMgr.h
index 926b8b4e00..bf570ca4eb 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissGpuResourceMgr.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissGpuResourceMgr.h
@@ -26,7 +26,6 @@
 
 #include "src/utils/BlockingQueue.h"
 
-namespace zilliz {
 namespace knowhere {
 
 struct Resource {
@@ -45,7 +44,7 @@ using ResWPtr = std::weak_ptr<Resource>;
 class FaissGpuResourceMgr {
  public:
     friend class ResScope;
-    using ResBQ = zilliz::milvus::server::BlockingQueue<ResPtr>;
+    using ResBQ = milvus::server::BlockingQueue<ResPtr>;
 
  public:
     struct DeviceParams {
@@ -127,4 +126,3 @@ class ResScope {
 };
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissIO.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissIO.cpp
index 30a54b388d..99532137c0 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissIO.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissIO.cpp
@@ -19,7 +19,6 @@
 
 #include "knowhere/index/vector_index/helpers/FaissIO.h"
 
-namespace zilliz {
 namespace knowhere {
 
 // TODO(linxj): Get From Config File
@@ -66,4 +65,3 @@ MemoryIOReader::operator()(void* ptr, size_t size, size_t nitems) {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissIO.h b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissIO.h
index c850e89d9f..7cce5bbbac 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissIO.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/FaissIO.h
@@ -19,7 +19,6 @@
 
 #include <faiss/AuxIndexStructures.h>
 
-namespace zilliz {
 namespace knowhere {
 
 struct MemoryIOWriter : public faiss::IOWriter {
@@ -41,4 +40,3 @@ struct MemoryIOReader : public faiss::IOReader {
 };
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/IndexParameter.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/IndexParameter.cpp
index c4a179bc6a..20f3388174 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/IndexParameter.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/IndexParameter.cpp
@@ -20,7 +20,6 @@
 
 #include <faiss/Index.h>
 
-namespace zilliz {
 namespace knowhere {
 
 faiss::MetricType
@@ -36,4 +35,3 @@ GetMetricType(METRICTYPE& type) {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/IndexParameter.h b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/IndexParameter.h
index d5056d7ee6..b2854abef8 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/IndexParameter.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/IndexParameter.h
@@ -22,7 +22,6 @@
 
 #include "knowhere/common/Config.h"
 
-namespace zilliz {
 namespace knowhere {
 
 extern faiss::MetricType
@@ -132,4 +131,3 @@ struct KDTCfg : public Cfg {
 };
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/KDTParameterMgr.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/KDTParameterMgr.cpp
index 015dc17fc5..19bf070dba 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/KDTParameterMgr.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/KDTParameterMgr.cpp
@@ -19,7 +19,6 @@
 
 #include "knowhere/index/vector_index/helpers/KDTParameterMgr.h"
 
-namespace zilliz {
 namespace knowhere {
 
 const std::vector<KDTParameter>&
@@ -54,4 +53,3 @@ KDTParameterMgr::KDTParameterMgr() {
 }
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/KDTParameterMgr.h b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/KDTParameterMgr.h
index ec2d73eebb..fe90761e17 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/KDTParameterMgr.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/helpers/KDTParameterMgr.h
@@ -22,7 +22,6 @@
 #include <utility>
 #include <vector>
 
-namespace zilliz {
 namespace knowhere {
 
 using KDTParameter = std::pair<std::string, std::string>;
@@ -51,4 +50,3 @@ class KDTParameterMgr {
 };
 
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSG.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSG.cpp
index 19bc825d81..375664fbf8 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSG.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSG.cpp
@@ -32,7 +32,6 @@
 // TODO: enable macro
 //#include <gperftools/profiler.h>
 
-namespace zilliz {
 namespace knowhere {
 namespace algo {
 
@@ -792,4 +791,3 @@ NsgIndex::SetKnnGraph(Graph& g) {
 
 }  // namespace algo
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSG.h b/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSG.h
index e075260398..160c076e45 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSG.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSG.h
@@ -24,7 +24,6 @@
 #include <boost/dynamic_bitset.hpp>
 #include "Neighbor.h"
 
-namespace zilliz {
 namespace knowhere {
 namespace algo {
 
@@ -143,4 +142,3 @@ class NsgIndex {
 
 }  // namespace algo
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGHelper.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGHelper.cpp
index 1dd306bf77..05e8d18787 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGHelper.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGHelper.cpp
@@ -20,7 +20,6 @@
 
 #include "knowhere/index/vector_index/nsg/NSGHelper.h"
 
-namespace zilliz {
 namespace knowhere {
 namespace algo {
 
@@ -180,4 +179,3 @@ calculate(const float* a, const float* b, unsigned size) {
 
 }  // namespace algo
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGHelper.h b/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGHelper.h
index cb8007f2b1..5007cf019c 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGHelper.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGHelper.h
@@ -25,7 +25,6 @@
 #include "NSG.h"
 #include "knowhere/common/Config.h"
 
-namespace zilliz {
 namespace knowhere {
 namespace algo {
 
@@ -36,4 +35,3 @@ calculate(const float* a, const float* b, unsigned size);
 
 }  // namespace algo
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGIO.cpp b/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGIO.cpp
index db3113da2f..cac3b5864f 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGIO.cpp
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGIO.cpp
@@ -19,7 +19,6 @@
 
 #include "knowhere/index/vector_index/nsg/NSGIO.h"
 
-namespace zilliz {
 namespace knowhere {
 namespace algo {
 
@@ -68,4 +67,3 @@ read_index(MemoryIOReader& reader) {
 
 }  // namespace algo
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGIO.h b/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGIO.h
index fd740a991e..12913b69df 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGIO.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/NSGIO.h
@@ -21,7 +21,6 @@
 #include "knowhere/index/vector_index/IndexIVF.h"
 #include "knowhere/index/vector_index/helpers/FaissIO.h"
 
-namespace zilliz {
 namespace knowhere {
 namespace algo {
 
@@ -32,4 +31,3 @@ read_index(MemoryIOReader& reader);
 
 }  // namespace algo
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/Neighbor.h b/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/Neighbor.h
index ee71a3f66e..c3a314164c 100644
--- a/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/Neighbor.h
+++ b/cpp/src/core/knowhere/knowhere/index/vector_index/nsg/Neighbor.h
@@ -19,7 +19,6 @@
 
 #include <mutex>
 
-namespace zilliz {
 namespace knowhere {
 namespace algo {
 
@@ -61,4 +60,3 @@ typedef std::lock_guard<std::mutex> LockGuard;
 
 }  // namespace algo
 }  // namespace knowhere
-}  // namespace zilliz
diff --git a/cpp/src/core/unittest/kdtree.cpp b/cpp/src/core/unittest/kdtree.cpp
index 351a177d4b..9b1e428a80 100644
--- a/cpp/src/core/unittest/kdtree.cpp
+++ b/cpp/src/core/unittest/kdtree.cpp
@@ -24,7 +24,7 @@
 //
 // namespace {
 //
-// namespace kn = zilliz::knowhere;
+// namespace kn = knowhere;
 //
 //}  // namespace
 //
diff --git a/cpp/src/core/unittest/test_idmap.cpp b/cpp/src/core/unittest/test_idmap.cpp
index 9ee4ea732d..e907d309eb 100644
--- a/cpp/src/core/unittest/test_idmap.cpp
+++ b/cpp/src/core/unittest/test_idmap.cpp
@@ -27,7 +27,7 @@
 
 namespace {
 
-namespace kn = zilliz::knowhere;
+namespace kn = knowhere;
 
 }  // namespace
 
@@ -179,9 +179,9 @@ TEST_F(IDMAPTest, copy_test) {
         auto clone_result = clone_index->Search(query_dataset, conf);
         AssertAnns(clone_result, nq, k);
         ASSERT_THROW({ std::static_pointer_cast<kn::GPUIDMAP>(clone_index)->GetRawVectors(); },
-                     zilliz::knowhere::KnowhereException);
+                     knowhere::KnowhereException);
         ASSERT_THROW({ std::static_pointer_cast<kn::GPUIDMAP>(clone_index)->GetRawIds(); },
-                     zilliz::knowhere::KnowhereException);
+                     knowhere::KnowhereException);
 
         auto binary = clone_index->Serialize();
         clone_index->Load(binary);
diff --git a/cpp/src/core/unittest/test_ivf.cpp b/cpp/src/core/unittest/test_ivf.cpp
index 2aa6937dbe..a0da0eca8e 100644
--- a/cpp/src/core/unittest/test_ivf.cpp
+++ b/cpp/src/core/unittest/test_ivf.cpp
@@ -39,7 +39,7 @@
 
 namespace {
 
-namespace kn = zilliz::knowhere;
+namespace kn = knowhere;
 
 }  // namespace
 
diff --git a/cpp/src/core/unittest/test_json.cpp b/cpp/src/core/unittest/test_json.cpp
index acdddad30a..613e0deff5 100644
--- a/cpp/src/core/unittest/test_json.cpp
+++ b/cpp/src/core/unittest/test_json.cpp
@@ -19,7 +19,7 @@
 
 namespace {
 
-namespace kn = zilliz::knowhere;
+namespace kn = knowhere;
 
 }  // namespace
 
diff --git a/cpp/src/core/unittest/test_kdt.cpp b/cpp/src/core/unittest/test_kdt.cpp
index 85c8650d1b..6fa6ba33f3 100644
--- a/cpp/src/core/unittest/test_kdt.cpp
+++ b/cpp/src/core/unittest/test_kdt.cpp
@@ -30,7 +30,7 @@
 
 namespace {
 
-namespace kn = zilliz::knowhere;
+namespace kn = knowhere;
 
 }  // namespace
 
@@ -132,7 +132,7 @@ TEST_F(KDTTest, kdt_serialize) {
     PrintResult(result, nq, k);
     ASSERT_EQ(new_index->Count(), nb);
     ASSERT_EQ(new_index->Dimension(), dim);
-    ASSERT_THROW({ new_index->Clone(); }, zilliz::knowhere::KnowhereException);
+    ASSERT_THROW({ new_index->Clone(); }, knowhere::KnowhereException);
     ASSERT_NO_THROW({ new_index->Seal(); });
 
     {
diff --git a/cpp/src/core/unittest/test_nsg/test_nsg.cpp b/cpp/src/core/unittest/test_nsg/test_nsg.cpp
index b93a2ddc35..70261a63dc 100644
--- a/cpp/src/core/unittest/test_nsg/test_nsg.cpp
+++ b/cpp/src/core/unittest/test_nsg/test_nsg.cpp
@@ -28,7 +28,7 @@
 
 namespace {
 
-namespace kn = zilliz::knowhere;
+namespace kn = knowhere;
 
 }  // namespace
 
@@ -98,7 +98,7 @@ TEST_F(NSGInterfaceTest, basic_test) {
 
     ASSERT_EQ(index_->Count(), nb);
     ASSERT_EQ(index_->Dimension(), dim);
-    ASSERT_THROW({ index_->Clone(); }, zilliz::knowhere::KnowhereException);
+    ASSERT_THROW({ index_->Clone(); }, knowhere::KnowhereException);
     ASSERT_NO_THROW({
         index_->Add(base_dataset, kn::Config());
         index_->Seal();
diff --git a/cpp/src/core/unittest/utils.cpp b/cpp/src/core/unittest/utils.cpp
index e81ad8ea02..3c342738c1 100644
--- a/cpp/src/core/unittest/utils.cpp
+++ b/cpp/src/core/unittest/utils.cpp
@@ -25,7 +25,7 @@ INITIALIZE_EASYLOGGINGPP
 
 namespace {
 
-namespace kn = zilliz::knowhere;
+namespace kn = knowhere;
 
 }  // namespace
 
@@ -56,7 +56,7 @@ DataGen::Generate(const int& dim, const int& nb, const int& nq) {
     query_dataset = generate_query_dataset(nq, dim, xq.data());
 }
 
-zilliz::knowhere::DatasetPtr
+knowhere::DatasetPtr
 DataGen::GenQuery(const int& nq) {
     xq.resize(nq * dim);
     for (int i = 0; i < nq * dim; ++i) {
diff --git a/cpp/src/core/unittest/utils.h b/cpp/src/core/unittest/utils.h
index 07a104ad4a..acc3e89183 100644
--- a/cpp/src/core/unittest/utils.h
+++ b/cpp/src/core/unittest/utils.h
@@ -34,7 +34,7 @@ class DataGen {
     void
     Generate(const int& dim, const int& nb, const int& nq);
 
-    zilliz::knowhere::DatasetPtr
+    knowhere::DatasetPtr
     GenQuery(const int& nq);
 
  protected:
@@ -45,8 +45,8 @@ class DataGen {
     std::vector<float> xb;
     std::vector<float> xq;
     std::vector<int64_t> ids;
-    zilliz::knowhere::DatasetPtr base_dataset = nullptr;
-    zilliz::knowhere::DatasetPtr query_dataset = nullptr;
+    knowhere::DatasetPtr base_dataset = nullptr;
+    knowhere::DatasetPtr query_dataset = nullptr;
 };
 
 extern void
@@ -62,10 +62,10 @@ GenBase(const int64_t& dim, const int64_t& nb, float* xb, int64_t* ids);
 extern void
 InitLog();
 
-zilliz::knowhere::DatasetPtr
+knowhere::DatasetPtr
 generate_dataset(int64_t nb, int64_t dim, float* xb, int64_t* ids);
 
-zilliz::knowhere::DatasetPtr
+knowhere::DatasetPtr
 generate_query_dataset(int64_t nb, int64_t dim, float* xb);
 
 struct FileIOWriter {
diff --git a/cpp/src/db/Constants.h b/cpp/src/db/Constants.h
index 0feffadaf4..a1e09bc196 100644
--- a/cpp/src/db/Constants.h
+++ b/cpp/src/db/Constants.h
@@ -19,7 +19,6 @@
 
 #include <stdint.h>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -38,4 +37,3 @@ static constexpr uint64_t ONE_GB = ONE_KB * ONE_MB;
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/DB.h b/cpp/src/db/DB.h
index 9a6a2e74a6..a790fadb50 100644
--- a/cpp/src/db/DB.h
+++ b/cpp/src/db/DB.h
@@ -26,7 +26,6 @@
 #include <string>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -96,4 +95,3 @@ using DBPtr = std::shared_ptr<DB>;
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/DBFactory.cpp b/cpp/src/db/DBFactory.cpp
index 89d04b3632..fae3a180c0 100644
--- a/cpp/src/db/DBFactory.cpp
+++ b/cpp/src/db/DBFactory.cpp
@@ -28,7 +28,6 @@
 #include <sstream>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -47,4 +46,3 @@ DBFactory::Build(const DBOptions& options) {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/DBFactory.h b/cpp/src/db/DBFactory.h
index c5c73a0649..e787f7c883 100644
--- a/cpp/src/db/DBFactory.h
+++ b/cpp/src/db/DBFactory.h
@@ -23,7 +23,6 @@
 #include <memory>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -38,4 +37,3 @@ class DBFactory {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/DBImpl.cpp b/cpp/src/db/DBImpl.cpp
index 10cdf60b5a..ece62284f7 100644
--- a/cpp/src/db/DBImpl.cpp
+++ b/cpp/src/db/DBImpl.cpp
@@ -39,7 +39,6 @@
 #include <iostream>
 #include <thread>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -249,7 +248,7 @@ DBImpl::InsertVectors(const std::string& table_id, uint64_t n, const float* vect
     }
 
     Status status;
-    zilliz::milvus::server::CollectInsertMetrics metrics(n, status);
+    milvus::server::CollectInsertMetrics metrics(n, status);
     status = mem_mgr_->InsertVectors(table_id, n, vectors, vector_ids);
     //    std::chrono::microseconds time_span =
     //          std::chrono::duration_cast<std::chrono::microseconds>(end_time - start_time);
@@ -914,4 +913,3 @@ DBImpl::BackgroundBuildIndex() {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/DBImpl.h b/cpp/src/db/DBImpl.h
index 366408d8b0..865b3dfa53 100644
--- a/cpp/src/db/DBImpl.h
+++ b/cpp/src/db/DBImpl.h
@@ -32,7 +32,6 @@
 #include <thread>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -165,4 +164,3 @@ class DBImpl : public DB {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/IDGenerator.cpp b/cpp/src/db/IDGenerator.cpp
index b80e1ce354..6b150a926a 100644
--- a/cpp/src/db/IDGenerator.cpp
+++ b/cpp/src/db/IDGenerator.cpp
@@ -21,7 +21,6 @@
 #include <chrono>
 #include <iostream>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -64,4 +63,3 @@ SimpleIDGenerator::GetNextIDNumbers(size_t n, IDNumbers& ids) {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/IDGenerator.h b/cpp/src/db/IDGenerator.h
index f41f745864..cdd22efc1a 100644
--- a/cpp/src/db/IDGenerator.h
+++ b/cpp/src/db/IDGenerator.h
@@ -22,7 +22,6 @@
 #include <cstddef>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -56,4 +55,3 @@ class SimpleIDGenerator : public IDGenerator {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/Options.cpp b/cpp/src/db/Options.cpp
index edaf69c9e6..9d6a7d0236 100644
--- a/cpp/src/db/Options.cpp
+++ b/cpp/src/db/Options.cpp
@@ -23,7 +23,6 @@
 #include <stdlib.h>
 #include <boost/algorithm/string.hpp>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -91,4 +90,3 @@ ArchiveConf::ParseType(const std::string& type) {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/Options.h b/cpp/src/db/Options.h
index d51a30f2b4..ebecb4de5a 100644
--- a/cpp/src/db/Options.h
+++ b/cpp/src/db/Options.h
@@ -24,7 +24,6 @@
 #include <string>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -81,4 +80,3 @@ struct DBOptions {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/Types.h b/cpp/src/db/Types.h
index c37434a405..94528a9a8a 100644
--- a/cpp/src/db/Types.h
+++ b/cpp/src/db/Types.h
@@ -23,7 +23,6 @@
 #include <utility>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -42,4 +41,3 @@ struct TableIndex {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/Utils.cpp b/cpp/src/db/Utils.cpp
index d9e500f84a..0ddf03568a 100644
--- a/cpp/src/db/Utils.cpp
+++ b/cpp/src/db/Utils.cpp
@@ -25,7 +25,6 @@
 #include <regex>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 namespace utils {
@@ -239,4 +238,3 @@ ParseMetaUri(const std::string& uri, MetaUriInfo& info) {
 }  // namespace utils
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/Utils.h b/cpp/src/db/Utils.h
index c161e32b95..0b157f6dfd 100644
--- a/cpp/src/db/Utils.h
+++ b/cpp/src/db/Utils.h
@@ -24,7 +24,6 @@
 #include <ctime>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 namespace utils {
@@ -69,4 +68,3 @@ ParseMetaUri(const std::string& uri, MetaUriInfo& info);
 }  // namespace utils
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/engine/EngineFactory.cpp b/cpp/src/db/engine/EngineFactory.cpp
index 338b7d72af..c3597d1020 100644
--- a/cpp/src/db/engine/EngineFactory.cpp
+++ b/cpp/src/db/engine/EngineFactory.cpp
@@ -21,7 +21,6 @@
 
 #include <memory>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -43,4 +42,3 @@ EngineFactory::Build(uint16_t dimension, const std::string& location, EngineType
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/engine/EngineFactory.h b/cpp/src/db/engine/EngineFactory.h
index 5d22fbb4d2..d98952ccd9 100644
--- a/cpp/src/db/engine/EngineFactory.h
+++ b/cpp/src/db/engine/EngineFactory.h
@@ -22,7 +22,6 @@
 
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -35,4 +34,3 @@ class EngineFactory {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/engine/ExecutionEngine.h b/cpp/src/db/engine/ExecutionEngine.h
index 4ae3e872b3..1572b967d1 100644
--- a/cpp/src/db/engine/ExecutionEngine.h
+++ b/cpp/src/db/engine/ExecutionEngine.h
@@ -23,7 +23,6 @@
 #include <string>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -105,4 +104,3 @@ using ExecutionEnginePtr = std::shared_ptr<ExecutionEngine>;
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/engine/ExecutionEngineImpl.cpp b/cpp/src/db/engine/ExecutionEngineImpl.cpp
index 2a239ddbea..52365d0915 100644
--- a/cpp/src/db/engine/ExecutionEngineImpl.cpp
+++ b/cpp/src/db/engine/ExecutionEngineImpl.cpp
@@ -34,7 +34,6 @@
 #include <stdexcept>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -324,7 +323,7 @@ ExecutionEngineImpl::Search(int64_t n, const float* data, int64_t k, int64_t npr
 Status
 ExecutionEngineImpl::Cache() {
     cache::DataObjPtr obj = std::make_shared<cache::DataObj>(index_, PhysicalSize());
-    zilliz::milvus::cache::CpuCacheMgr::GetInstance()->InsertItem(location_, obj);
+    milvus::cache::CpuCacheMgr::GetInstance()->InsertItem(location_, obj);
 
     return Status::OK();
 }
@@ -332,7 +331,7 @@ ExecutionEngineImpl::Cache() {
 Status
 ExecutionEngineImpl::GpuCache(uint64_t gpu_id) {
     cache::DataObjPtr obj = std::make_shared<cache::DataObj>(index_, PhysicalSize());
-    zilliz::milvus::cache::GpuCacheMgr::GetInstance(gpu_id)->InsertItem(location_, obj);
+    milvus::cache::GpuCacheMgr::GetInstance(gpu_id)->InsertItem(location_, obj);
 
     return Status::OK();
 }
@@ -351,4 +350,3 @@ ExecutionEngineImpl::Init() {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/engine/ExecutionEngineImpl.h b/cpp/src/db/engine/ExecutionEngineImpl.h
index e8f9521460..62a7b29a63 100644
--- a/cpp/src/db/engine/ExecutionEngineImpl.h
+++ b/cpp/src/db/engine/ExecutionEngineImpl.h
@@ -23,7 +23,6 @@
 #include <memory>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -119,4 +118,3 @@ class ExecutionEngineImpl : public ExecutionEngine {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/insert/MemManager.h b/cpp/src/db/insert/MemManager.h
index 920e6e9692..cc76604165 100644
--- a/cpp/src/db/insert/MemManager.h
+++ b/cpp/src/db/insert/MemManager.h
@@ -24,7 +24,6 @@
 #include <set>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -53,4 +52,3 @@ using MemManagerPtr = std::shared_ptr<MemManager>;
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/insert/MemManagerImpl.cpp b/cpp/src/db/insert/MemManagerImpl.cpp
index 1a59c8b892..69c3397eb9 100644
--- a/cpp/src/db/insert/MemManagerImpl.cpp
+++ b/cpp/src/db/insert/MemManagerImpl.cpp
@@ -22,7 +22,6 @@
 
 #include <thread>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -140,4 +139,3 @@ MemManagerImpl::GetCurrentMem() {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/insert/MemManagerImpl.h b/cpp/src/db/insert/MemManagerImpl.h
index 4de5626459..862b068d0f 100644
--- a/cpp/src/db/insert/MemManagerImpl.h
+++ b/cpp/src/db/insert/MemManagerImpl.h
@@ -30,7 +30,6 @@
 #include <string>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -80,4 +79,3 @@ class MemManagerImpl : public MemManager {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/insert/MemMenagerFactory.cpp b/cpp/src/db/insert/MemMenagerFactory.cpp
index 8f0d6704d7..033992501b 100644
--- a/cpp/src/db/insert/MemMenagerFactory.cpp
+++ b/cpp/src/db/insert/MemMenagerFactory.cpp
@@ -28,7 +28,6 @@
 #include <sstream>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -39,4 +38,3 @@ MemManagerFactory::Build(const std::shared_ptr<meta::Meta>& meta, const DBOption
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/insert/MemMenagerFactory.h b/cpp/src/db/insert/MemMenagerFactory.h
index d7996abe99..a489a3952b 100644
--- a/cpp/src/db/insert/MemMenagerFactory.h
+++ b/cpp/src/db/insert/MemMenagerFactory.h
@@ -22,7 +22,6 @@
 
 #include <memory>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -34,4 +33,3 @@ class MemManagerFactory {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/insert/MemTable.cpp b/cpp/src/db/insert/MemTable.cpp
index e189dbf15b..871eab8d7d 100644
--- a/cpp/src/db/insert/MemTable.cpp
+++ b/cpp/src/db/insert/MemTable.cpp
@@ -21,7 +21,6 @@
 #include <memory>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -104,4 +103,3 @@ MemTable::GetCurrentMem() {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/insert/MemTable.h b/cpp/src/db/insert/MemTable.h
index b2b16cf472..cb22b6ed34 100644
--- a/cpp/src/db/insert/MemTable.h
+++ b/cpp/src/db/insert/MemTable.h
@@ -26,7 +26,6 @@
 #include <string>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -73,4 +72,3 @@ using MemTablePtr = std::shared_ptr<MemTable>;
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/insert/MemTableFile.cpp b/cpp/src/db/insert/MemTableFile.cpp
index 8395b0b62a..5827513297 100644
--- a/cpp/src/db/insert/MemTableFile.cpp
+++ b/cpp/src/db/insert/MemTableFile.cpp
@@ -24,7 +24,6 @@
 #include <cmath>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -126,4 +125,3 @@ MemTableFile::Serialize() {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/insert/MemTableFile.h b/cpp/src/db/insert/MemTableFile.h
index 72ae09c861..e11274b7de 100644
--- a/cpp/src/db/insert/MemTableFile.h
+++ b/cpp/src/db/insert/MemTableFile.h
@@ -25,7 +25,6 @@
 #include <memory>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -66,4 +65,3 @@ using MemTableFilePtr = std::shared_ptr<MemTableFile>;
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/insert/VectorSource.cpp b/cpp/src/db/insert/VectorSource.cpp
index 7a9fdf5d0f..dbedf58029 100644
--- a/cpp/src/db/insert/VectorSource.cpp
+++ b/cpp/src/db/insert/VectorSource.cpp
@@ -21,7 +21,6 @@
 #include "metrics/Metrics.h"
 #include "utils/Log.h"
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -77,4 +76,3 @@ VectorSource::GetVectorIds() {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/insert/VectorSource.h b/cpp/src/db/insert/VectorSource.h
index 4b8e9d21b9..1d936268f4 100644
--- a/cpp/src/db/insert/VectorSource.h
+++ b/cpp/src/db/insert/VectorSource.h
@@ -24,7 +24,6 @@
 
 #include <memory>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -59,4 +58,3 @@ using VectorSourcePtr = std::shared_ptr<VectorSource>;
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/meta/Meta.h b/cpp/src/db/meta/Meta.h
index 3e3128366c..8167834568 100644
--- a/cpp/src/db/meta/Meta.h
+++ b/cpp/src/db/meta/Meta.h
@@ -27,7 +27,6 @@
 #include <string>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 namespace meta {
@@ -124,4 +123,3 @@ using MetaPtr = std::shared_ptr<Meta>;
 }  // namespace meta
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/meta/MetaConsts.h b/cpp/src/db/meta/MetaConsts.h
index 64cfeab78a..e963a63f43 100644
--- a/cpp/src/db/meta/MetaConsts.h
+++ b/cpp/src/db/meta/MetaConsts.h
@@ -17,7 +17,6 @@
 
 #pragma once
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 namespace meta {
@@ -41,4 +40,3 @@ const size_t W_SEC = 7 * D_SEC;
 }  // namespace meta
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/meta/MetaFactory.cpp b/cpp/src/db/meta/MetaFactory.cpp
index d8beecbd4e..8031038e37 100644
--- a/cpp/src/db/meta/MetaFactory.cpp
+++ b/cpp/src/db/meta/MetaFactory.cpp
@@ -30,7 +30,6 @@
 #include <sstream>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -75,4 +74,3 @@ MetaFactory::Build(const DBMetaOptions& metaOptions, const int& mode) {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/meta/MetaFactory.h b/cpp/src/db/meta/MetaFactory.h
index 0792515ac1..f16584426e 100644
--- a/cpp/src/db/meta/MetaFactory.h
+++ b/cpp/src/db/meta/MetaFactory.h
@@ -22,7 +22,6 @@
 
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -37,4 +36,3 @@ class MetaFactory {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/meta/MetaTypes.h b/cpp/src/db/meta/MetaTypes.h
index aad8b61c87..c973f3fdea 100644
--- a/cpp/src/db/meta/MetaTypes.h
+++ b/cpp/src/db/meta/MetaTypes.h
@@ -25,7 +25,6 @@
 #include <string>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 namespace meta {
@@ -96,4 +95,3 @@ using DatePartionedTableFilesSchema = std::map<DateT, TableFilesSchema>;
 }  // namespace meta
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/meta/MySQLConnectionPool.cpp b/cpp/src/db/meta/MySQLConnectionPool.cpp
index 6c93120107..ef013dce95 100644
--- a/cpp/src/db/meta/MySQLConnectionPool.cpp
+++ b/cpp/src/db/meta/MySQLConnectionPool.cpp
@@ -17,7 +17,6 @@
 
 #include "db/meta/MySQLConnectionPool.h"
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 namespace meta {
@@ -95,4 +94,3 @@ MySQLConnectionPool::max_idle_time() {
 }  // namespace meta
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/meta/MySQLConnectionPool.h b/cpp/src/db/meta/MySQLConnectionPool.h
index 9c6b751d1e..60e353c3c4 100644
--- a/cpp/src/db/meta/MySQLConnectionPool.h
+++ b/cpp/src/db/meta/MySQLConnectionPool.h
@@ -23,7 +23,6 @@
 
 #include "utils/Log.h"
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 namespace meta {
@@ -90,4 +89,3 @@ class MySQLConnectionPool : public mysqlpp::ConnectionPool {
 }  // namespace meta
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/meta/MySQLMetaImpl.cpp b/cpp/src/db/meta/MySQLMetaImpl.cpp
index db93ce9ec6..872c1ced2e 100644
--- a/cpp/src/db/meta/MySQLMetaImpl.cpp
+++ b/cpp/src/db/meta/MySQLMetaImpl.cpp
@@ -38,7 +38,6 @@
 #include <string>
 #include <thread>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 namespace meta {
@@ -1994,4 +1993,3 @@ MySQLMetaImpl::DropAll() {
 }  // namespace meta
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/meta/MySQLMetaImpl.h b/cpp/src/db/meta/MySQLMetaImpl.h
index 48bdf5b9ab..7ca66bc992 100644
--- a/cpp/src/db/meta/MySQLMetaImpl.h
+++ b/cpp/src/db/meta/MySQLMetaImpl.h
@@ -27,7 +27,6 @@
 #include <string>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 namespace meta {
@@ -143,4 +142,3 @@ class MySQLMetaImpl : public Meta {
 }  // namespace meta
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/db/meta/SqliteMetaImpl.cpp b/cpp/src/db/meta/SqliteMetaImpl.cpp
index accad0be70..dd9bb6fd30 100644
--- a/cpp/src/db/meta/SqliteMetaImpl.cpp
+++ b/cpp/src/db/meta/SqliteMetaImpl.cpp
@@ -34,7 +34,7 @@
 #include <set>
 #include <sqlite_orm.h>
 
-namespace zilliz {
+
 namespace milvus {
 namespace engine {
 namespace meta {
@@ -1298,4 +1298,4 @@ SqliteMetaImpl::DropAll() {
 } // namespace meta
 } // namespace engine
 } // namespace milvus
-} // namespace zilliz
+
diff --git a/cpp/src/db/meta/SqliteMetaImpl.h b/cpp/src/db/meta/SqliteMetaImpl.h
index 70f22db281..dc132c41ec 100644
--- a/cpp/src/db/meta/SqliteMetaImpl.h
+++ b/cpp/src/db/meta/SqliteMetaImpl.h
@@ -24,7 +24,6 @@
 #include <string>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 namespace meta {
@@ -138,4 +137,3 @@ class SqliteMetaImpl : public Meta {
 }  // namespace meta
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/grpc/cpp_gen.sh b/cpp/src/grpc/cpp_gen.sh
old mode 100755
new mode 100644
diff --git a/cpp/src/main.cpp b/cpp/src/main.cpp
index 5d808a7e4c..b50eedeaba 100644
--- a/cpp/src/main.cpp
+++ b/cpp/src/main.cpp
@@ -99,14 +99,14 @@ main(int argc, char* argv[]) {
     }
 
     /* Handle Signal */
-    signal(SIGHUP, zilliz::milvus::server::SignalUtil::HandleSignal);
-    signal(SIGINT, zilliz::milvus::server::SignalUtil::HandleSignal);
-    signal(SIGUSR1, zilliz::milvus::server::SignalUtil::HandleSignal);
-    signal(SIGSEGV, zilliz::milvus::server::SignalUtil::HandleSignal);
-    signal(SIGUSR2, zilliz::milvus::server::SignalUtil::HandleSignal);
-    signal(SIGTERM, zilliz::milvus::server::SignalUtil::HandleSignal);
+    signal(SIGHUP, milvus::server::SignalUtil::HandleSignal);
+    signal(SIGINT, milvus::server::SignalUtil::HandleSignal);
+    signal(SIGUSR1, milvus::server::SignalUtil::HandleSignal);
+    signal(SIGSEGV, milvus::server::SignalUtil::HandleSignal);
+    signal(SIGUSR2, milvus::server::SignalUtil::HandleSignal);
+    signal(SIGTERM, milvus::server::SignalUtil::HandleSignal);
 
-    zilliz::milvus::server::Server& server = zilliz::milvus::server::Server::GetInstance();
+    milvus::server::Server& server = milvus::server::Server::GetInstance();
     server.Init(start_daemonized, pid_filename, config_filename, log_config_file);
     server.Start();
 
diff --git a/cpp/src/metrics/MetricBase.h b/cpp/src/metrics/MetricBase.h
index 5442b9b714..eeca45e789 100644
--- a/cpp/src/metrics/MetricBase.h
+++ b/cpp/src/metrics/MetricBase.h
@@ -22,7 +22,6 @@
 
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 class MetricsBase {
@@ -208,4 +207,3 @@ class MetricsBase {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/metrics/Metrics.cpp b/cpp/src/metrics/Metrics.cpp
index 9a182ce571..51db5555b8 100644
--- a/cpp/src/metrics/Metrics.cpp
+++ b/cpp/src/metrics/Metrics.cpp
@@ -21,7 +21,6 @@
 
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -47,4 +46,3 @@ Metrics::CreateMetricsCollector() {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/metrics/Metrics.h b/cpp/src/metrics/Metrics.h
index f644004f14..c207a50d9e 100644
--- a/cpp/src/metrics/Metrics.h
+++ b/cpp/src/metrics/Metrics.h
@@ -20,7 +20,6 @@
 #include "MetricBase.h"
 #include "db/meta/MetaTypes.h"
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -255,4 +254,3 @@ class MetricCollector : CollectMetricsBase {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/metrics/PrometheusMetrics.cpp b/cpp/src/metrics/PrometheusMetrics.cpp
index 72b26eb63d..bc1860389f 100644
--- a/cpp/src/metrics/PrometheusMetrics.cpp
+++ b/cpp/src/metrics/PrometheusMetrics.cpp
@@ -24,7 +24,6 @@
 #include <string>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -242,4 +241,3 @@ PrometheusMetrics::GpuCacheUsageGaugeSet() {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/metrics/PrometheusMetrics.h b/cpp/src/metrics/PrometheusMetrics.h
index 9e009186d2..ef60f9a231 100644
--- a/cpp/src/metrics/PrometheusMetrics.h
+++ b/cpp/src/metrics/PrometheusMetrics.h
@@ -31,7 +31,6 @@
 //#define server::Metrics::GetInstance() server::GetInstance()
 #define METRICS_MICROSECONDS(a, b) (std::chrono::duration_cast<std::chrono::microseconds>(b - a)).count();
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -654,4 +653,3 @@ class PrometheusMetrics : public MetricsBase {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/metrics/SystemInfo.cpp b/cpp/src/metrics/SystemInfo.cpp
index 98822945ca..1414d94eae 100644
--- a/cpp/src/metrics/SystemInfo.cpp
+++ b/cpp/src/metrics/SystemInfo.cpp
@@ -25,7 +25,6 @@
 #include <string>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -306,4 +305,3 @@ SystemInfo::Octets() {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/metrics/SystemInfo.h b/cpp/src/metrics/SystemInfo.h
index 7fda0730e6..0176475232 100644
--- a/cpp/src/metrics/SystemInfo.h
+++ b/cpp/src/metrics/SystemInfo.h
@@ -29,7 +29,6 @@
 #include <utility>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -132,4 +131,3 @@ class SystemInfo {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/Algorithm.cpp b/cpp/src/scheduler/Algorithm.cpp
index 48fee94d9c..44f83742c2 100644
--- a/cpp/src/scheduler/Algorithm.cpp
+++ b/cpp/src/scheduler/Algorithm.cpp
@@ -21,7 +21,6 @@
 #include <unordered_map>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -106,4 +105,3 @@ ShortestPath(const ResourcePtr& src, const ResourcePtr& dest, const ResourceMgrP
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/Algorithm.h b/cpp/src/scheduler/Algorithm.h
index ed0f17d762..69ff8f3a70 100644
--- a/cpp/src/scheduler/Algorithm.h
+++ b/cpp/src/scheduler/Algorithm.h
@@ -21,7 +21,6 @@
 #include <string>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -31,4 +30,3 @@ ShortestPath(const ResourcePtr& src, const ResourcePtr& dest, const ResourceMgrP
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/Definition.h b/cpp/src/scheduler/Definition.h
index c886aafdac..162988e90a 100644
--- a/cpp/src/scheduler/Definition.h
+++ b/cpp/src/scheduler/Definition.h
@@ -30,7 +30,6 @@
 #include "db/engine/ExecutionEngine.h"
 #include "db/meta/MetaTypes.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -44,4 +43,3 @@ using MetricType = engine::MetricType;
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/JobMgr.cpp b/cpp/src/scheduler/JobMgr.cpp
index 92cf1189fd..25a4932f03 100644
--- a/cpp/src/scheduler/JobMgr.cpp
+++ b/cpp/src/scheduler/JobMgr.cpp
@@ -21,7 +21,6 @@
 
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -85,4 +84,3 @@ JobMgr::build_task(const JobPtr& job) {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/JobMgr.h b/cpp/src/scheduler/JobMgr.h
index 66adff18d2..4340c9e616 100644
--- a/cpp/src/scheduler/JobMgr.h
+++ b/cpp/src/scheduler/JobMgr.h
@@ -31,7 +31,6 @@
 #include "job/Job.h"
 #include "task/Task.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -72,4 +71,3 @@ using JobMgrPtr = std::shared_ptr<JobMgr>;
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/ResourceFactory.cpp b/cpp/src/scheduler/ResourceFactory.cpp
index f89e8207e4..fad8571b61 100644
--- a/cpp/src/scheduler/ResourceFactory.cpp
+++ b/cpp/src/scheduler/ResourceFactory.cpp
@@ -17,7 +17,6 @@
 
 #include "scheduler/ResourceFactory.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -37,4 +36,3 @@ ResourceFactory::Create(const std::string& name, const std::string& type, uint64
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/ResourceFactory.h b/cpp/src/scheduler/ResourceFactory.h
index bf663a7db8..3290cb023c 100644
--- a/cpp/src/scheduler/ResourceFactory.h
+++ b/cpp/src/scheduler/ResourceFactory.h
@@ -25,7 +25,6 @@
 #include "resource/GpuResource.h"
 #include "resource/Resource.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -38,4 +37,3 @@ class ResourceFactory {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/ResourceMgr.cpp b/cpp/src/scheduler/ResourceMgr.cpp
index ce9fcc9fb9..9906c71bbe 100644
--- a/cpp/src/scheduler/ResourceMgr.cpp
+++ b/cpp/src/scheduler/ResourceMgr.cpp
@@ -19,7 +19,6 @@
 #include "scheduler/ResourceMgr.h"
 #include "utils/Log.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -201,4 +200,3 @@ ResourceMgr::event_process() {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/ResourceMgr.h b/cpp/src/scheduler/ResourceMgr.h
index 531491066f..a81e6c239f 100644
--- a/cpp/src/scheduler/ResourceMgr.h
+++ b/cpp/src/scheduler/ResourceMgr.h
@@ -28,7 +28,6 @@
 #include "resource/Resource.h"
 #include "utils/Log.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -127,4 +126,3 @@ using ResourceMgrWPtr = std::weak_ptr<ResourceMgr>;
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/SchedInst.cpp b/cpp/src/scheduler/SchedInst.cpp
index cdeb834f57..f17aceb596 100644
--- a/cpp/src/scheduler/SchedInst.cpp
+++ b/cpp/src/scheduler/SchedInst.cpp
@@ -26,7 +26,6 @@
 #include <utility>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -171,4 +170,3 @@ StopSchedulerService() {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/SchedInst.h b/cpp/src/scheduler/SchedInst.h
index 9947e9f62b..dc8e4ed478 100644
--- a/cpp/src/scheduler/SchedInst.h
+++ b/cpp/src/scheduler/SchedInst.h
@@ -24,7 +24,6 @@
 #include <memory>
 #include <mutex>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -90,4 +89,3 @@ StopSchedulerService();
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/Scheduler.cpp b/cpp/src/scheduler/Scheduler.cpp
index 8272bf6219..6963ed3c5f 100644
--- a/cpp/src/scheduler/Scheduler.cpp
+++ b/cpp/src/scheduler/Scheduler.cpp
@@ -23,7 +23,6 @@
 
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -139,4 +138,3 @@ Scheduler::OnTaskTableUpdated(const EventPtr& event) {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/Scheduler.h b/cpp/src/scheduler/Scheduler.h
index 58cb4cbce8..1d8af9f4d4 100644
--- a/cpp/src/scheduler/Scheduler.h
+++ b/cpp/src/scheduler/Scheduler.h
@@ -28,7 +28,6 @@
 #include "resource/Resource.h"
 #include "utils/Log.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -133,4 +132,3 @@ using SchedulerPtr = std::shared_ptr<Scheduler>;
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/TaskCreator.cpp b/cpp/src/scheduler/TaskCreator.cpp
index cfcb0eb448..a82328a9bf 100644
--- a/cpp/src/scheduler/TaskCreator.cpp
+++ b/cpp/src/scheduler/TaskCreator.cpp
@@ -19,7 +19,6 @@
 #include "scheduler/tasklabel/BroadcastLabel.h"
 #include "tasklabel/DefaultLabel.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -65,4 +64,3 @@ TaskCreator::Create(const DeleteJobPtr& job) {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/TaskCreator.h b/cpp/src/scheduler/TaskCreator.h
index 5ae6a0763a..1c1e98a615 100644
--- a/cpp/src/scheduler/TaskCreator.h
+++ b/cpp/src/scheduler/TaskCreator.h
@@ -34,7 +34,6 @@
 #include "task/SearchTask.h"
 #include "task/Task.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -53,4 +52,3 @@ class TaskCreator {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/TaskTable.cpp b/cpp/src/scheduler/TaskTable.cpp
index db06abd966..0d6742c649 100644
--- a/cpp/src/scheduler/TaskTable.cpp
+++ b/cpp/src/scheduler/TaskTable.cpp
@@ -23,7 +23,6 @@
 #include <sstream>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -244,4 +243,3 @@ TaskTable::Dump() {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/TaskTable.h b/cpp/src/scheduler/TaskTable.h
index 80c8438eb1..35becbe5f8 100644
--- a/cpp/src/scheduler/TaskTable.h
+++ b/cpp/src/scheduler/TaskTable.h
@@ -28,7 +28,6 @@
 #include "event/Event.h"
 #include "task/SearchTask.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -257,4 +256,3 @@ class TaskTable {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/Utils.cpp b/cpp/src/scheduler/Utils.cpp
index b50fe4adb9..071f152227 100644
--- a/cpp/src/scheduler/Utils.cpp
+++ b/cpp/src/scheduler/Utils.cpp
@@ -20,7 +20,6 @@
 #include <cuda_runtime.h>
 #include <chrono>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -41,4 +40,3 @@ get_num_gpu() {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/Utils.h b/cpp/src/scheduler/Utils.h
index eec5f8ba68..e999e0fda3 100644
--- a/cpp/src/scheduler/Utils.h
+++ b/cpp/src/scheduler/Utils.h
@@ -17,7 +17,6 @@
 
 #include <cstdint>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -29,4 +28,3 @@ get_num_gpu();
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/action/Action.h b/cpp/src/scheduler/action/Action.h
index b75dc4515f..51c788f82f 100644
--- a/cpp/src/scheduler/action/Action.h
+++ b/cpp/src/scheduler/action/Action.h
@@ -22,7 +22,6 @@
 
 #include <memory>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -47,4 +46,3 @@ class Action {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/action/PushTaskToNeighbour.cpp b/cpp/src/scheduler/action/PushTaskToNeighbour.cpp
index 6fb861c8f3..22b82864b6 100644
--- a/cpp/src/scheduler/action/PushTaskToNeighbour.cpp
+++ b/cpp/src/scheduler/action/PushTaskToNeighbour.cpp
@@ -21,7 +21,6 @@
 #include "Action.h"
 #include "src/cache/GpuCacheMgr.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -113,7 +112,7 @@ Action::DefaultLabelTaskScheduler(ResourceMgrWPtr res_mgr, ResourcePtr resource,
             auto location = index_engine->GetLocation();
 
             for (auto i = 0; i < res_mgr.lock()->GetNumGpuResource(); ++i) {
-                auto index = zilliz::milvus::cache::GpuCacheMgr::GetInstance(i)->GetIndex(location);
+                auto index = milvus::cache::GpuCacheMgr::GetInstance(i)->GetIndex(location);
                 if (index != nullptr) {
                     moved = true;
                     auto dest_resource = res_mgr.lock()->GetResource(ResourceType::GPU, i);
@@ -178,4 +177,3 @@ Action::SpecifiedResourceLabelTaskScheduler(ResourceMgrWPtr res_mgr, ResourcePtr
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/event/Event.h b/cpp/src/scheduler/event/Event.h
index 6d55820248..5b1f37fb99 100644
--- a/cpp/src/scheduler/event/Event.h
+++ b/cpp/src/scheduler/event/Event.h
@@ -21,7 +21,6 @@
 #include <string>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -54,4 +53,3 @@ using EventPtr = std::shared_ptr<Event>;
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/event/EventDump.cpp b/cpp/src/scheduler/event/EventDump.cpp
index 6cc40ea28c..91e2da369a 100644
--- a/cpp/src/scheduler/event/EventDump.cpp
+++ b/cpp/src/scheduler/event/EventDump.cpp
@@ -21,7 +21,6 @@
 #include "StartUpEvent.h"
 #include "TaskTableUpdatedEvent.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -57,4 +56,3 @@ operator<<(std::ostream& out, const TaskTableUpdatedEvent& event) {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/event/FinishTaskEvent.h b/cpp/src/scheduler/event/FinishTaskEvent.h
index b593abfe31..1b2d8f9818 100644
--- a/cpp/src/scheduler/event/FinishTaskEvent.h
+++ b/cpp/src/scheduler/event/FinishTaskEvent.h
@@ -24,7 +24,6 @@
 #include <string>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -48,4 +47,3 @@ class FinishTaskEvent : public Event {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/event/LoadCompletedEvent.h b/cpp/src/scheduler/event/LoadCompletedEvent.h
index fa1f34b8c1..5a701e0dfc 100644
--- a/cpp/src/scheduler/event/LoadCompletedEvent.h
+++ b/cpp/src/scheduler/event/LoadCompletedEvent.h
@@ -24,7 +24,6 @@
 #include <string>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -48,4 +47,3 @@ class LoadCompletedEvent : public Event {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/event/StartUpEvent.h b/cpp/src/scheduler/event/StartUpEvent.h
index 037bf0f4d0..c4abb4e27c 100644
--- a/cpp/src/scheduler/event/StartUpEvent.h
+++ b/cpp/src/scheduler/event/StartUpEvent.h
@@ -23,7 +23,6 @@
 #include <string>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -43,4 +42,3 @@ class StartUpEvent : public Event {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/event/TaskTableUpdatedEvent.h b/cpp/src/scheduler/event/TaskTableUpdatedEvent.h
index 814b25f056..ed64a42d89 100644
--- a/cpp/src/scheduler/event/TaskTableUpdatedEvent.h
+++ b/cpp/src/scheduler/event/TaskTableUpdatedEvent.h
@@ -23,7 +23,6 @@
 #include <string>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -44,4 +43,3 @@ class TaskTableUpdatedEvent : public Event {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/job/DeleteJob.cpp b/cpp/src/scheduler/job/DeleteJob.cpp
index 5fcbb40513..96a6bb1817 100644
--- a/cpp/src/scheduler/job/DeleteJob.cpp
+++ b/cpp/src/scheduler/job/DeleteJob.cpp
@@ -19,7 +19,6 @@
 
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -48,4 +47,3 @@ DeleteJob::ResourceDone() {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/job/DeleteJob.h b/cpp/src/scheduler/job/DeleteJob.h
index 6c2f1e40c7..4ac48f6913 100644
--- a/cpp/src/scheduler/job/DeleteJob.h
+++ b/cpp/src/scheduler/job/DeleteJob.h
@@ -30,7 +30,6 @@
 #include "Job.h"
 #include "db/meta/Meta.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -70,4 +69,3 @@ using DeleteJobPtr = std::shared_ptr<DeleteJob>;
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/job/Job.h b/cpp/src/scheduler/job/Job.h
index ccfa3518f9..5fe645363f 100644
--- a/cpp/src/scheduler/job/Job.h
+++ b/cpp/src/scheduler/job/Job.h
@@ -27,7 +27,6 @@
 #include <unordered_map>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -66,4 +65,3 @@ using JobWPtr = std::weak_ptr<Job>;
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/job/SearchJob.cpp b/cpp/src/scheduler/job/SearchJob.cpp
index b4d3ef84c2..518e3111c0 100644
--- a/cpp/src/scheduler/job/SearchJob.cpp
+++ b/cpp/src/scheduler/job/SearchJob.cpp
@@ -18,12 +18,10 @@
 #include "scheduler/job/SearchJob.h"
 #include "utils/Log.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
-SearchJob::SearchJob(zilliz::milvus::scheduler::JobId id, uint64_t topk, uint64_t nq, uint64_t nprobe,
-                     const float* vectors)
+SearchJob::SearchJob(milvus::scheduler::JobId id, uint64_t topk, uint64_t nq, uint64_t nprobe, const float* vectors)
     : Job(id, JobType::SEARCH), topk_(topk), nq_(nq), nprobe_(nprobe), vectors_(vectors) {
 }
 
@@ -67,4 +65,3 @@ SearchJob::GetStatus() {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/job/SearchJob.h b/cpp/src/scheduler/job/SearchJob.h
index 7ffb0cd201..aed40cd942 100644
--- a/cpp/src/scheduler/job/SearchJob.h
+++ b/cpp/src/scheduler/job/SearchJob.h
@@ -31,7 +31,6 @@
 #include "Job.h"
 #include "db/meta/MetaTypes.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -107,4 +106,3 @@ using SearchJobPtr = std::shared_ptr<SearchJob>;
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/resource/Connection.h b/cpp/src/scheduler/resource/Connection.h
index ac2ac81bf5..421d32f768 100644
--- a/cpp/src/scheduler/resource/Connection.h
+++ b/cpp/src/scheduler/resource/Connection.h
@@ -21,7 +21,6 @@
 #include <string>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -61,4 +60,3 @@ class Connection {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/resource/CpuResource.cpp b/cpp/src/scheduler/resource/CpuResource.cpp
index d1b0e2b8c3..500737a829 100644
--- a/cpp/src/scheduler/resource/CpuResource.cpp
+++ b/cpp/src/scheduler/resource/CpuResource.cpp
@@ -19,7 +19,6 @@
 
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -45,4 +44,3 @@ CpuResource::Process(TaskPtr task) {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/resource/CpuResource.h b/cpp/src/scheduler/resource/CpuResource.h
index 562a306373..e3e4fc383f 100644
--- a/cpp/src/scheduler/resource/CpuResource.h
+++ b/cpp/src/scheduler/resource/CpuResource.h
@@ -21,7 +21,6 @@
 
 #include "Resource.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -47,4 +46,3 @@ class CpuResource : public Resource {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/resource/DiskResource.cpp b/cpp/src/scheduler/resource/DiskResource.cpp
index 08c03d2ef2..fe1fc9c8d9 100644
--- a/cpp/src/scheduler/resource/DiskResource.cpp
+++ b/cpp/src/scheduler/resource/DiskResource.cpp
@@ -20,7 +20,6 @@
 #include <string>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -44,4 +43,3 @@ DiskResource::Process(TaskPtr task) {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/resource/DiskResource.h b/cpp/src/scheduler/resource/DiskResource.h
index d86de49934..2346cd115a 100644
--- a/cpp/src/scheduler/resource/DiskResource.h
+++ b/cpp/src/scheduler/resource/DiskResource.h
@@ -21,7 +21,6 @@
 
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -47,4 +46,3 @@ class DiskResource : public Resource {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/resource/GpuResource.cpp b/cpp/src/scheduler/resource/GpuResource.cpp
index a28b00bbe5..20ed73e38c 100644
--- a/cpp/src/scheduler/resource/GpuResource.cpp
+++ b/cpp/src/scheduler/resource/GpuResource.cpp
@@ -17,7 +17,6 @@
 
 #include "scheduler/resource/GpuResource.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -43,4 +42,3 @@ GpuResource::Process(TaskPtr task) {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/resource/GpuResource.h b/cpp/src/scheduler/resource/GpuResource.h
index 33a197aed0..e0df03d5a7 100644
--- a/cpp/src/scheduler/resource/GpuResource.h
+++ b/cpp/src/scheduler/resource/GpuResource.h
@@ -22,7 +22,6 @@
 #include <string>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -48,4 +47,3 @@ class GpuResource : public Resource {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/resource/Node.cpp b/cpp/src/scheduler/resource/Node.cpp
index 39333cc072..5401c36441 100644
--- a/cpp/src/scheduler/resource/Node.cpp
+++ b/cpp/src/scheduler/resource/Node.cpp
@@ -20,7 +20,6 @@
 #include <atomic>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -61,4 +60,3 @@ Node::AddNeighbour(const NeighbourNodePtr& neighbour_node, Connection& connectio
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/resource/Node.h b/cpp/src/scheduler/resource/Node.h
index 588eef5f2e..071ee9bab8 100644
--- a/cpp/src/scheduler/resource/Node.h
+++ b/cpp/src/scheduler/resource/Node.h
@@ -25,7 +25,6 @@
 #include "Connection.h"
 #include "scheduler/TaskTable.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -67,4 +66,3 @@ using NodeWPtr = std::weak_ptr<Node>;
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/resource/Resource.cpp b/cpp/src/scheduler/resource/Resource.cpp
index 48208a07a5..8fea475d70 100644
--- a/cpp/src/scheduler/resource/Resource.cpp
+++ b/cpp/src/scheduler/resource/Resource.cpp
@@ -21,7 +21,6 @@
 #include <iostream>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -178,4 +177,3 @@ Resource::executor_function() {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/resource/Resource.h b/cpp/src/scheduler/resource/Resource.h
index 2bffaae5cf..e8b50fe9af 100644
--- a/cpp/src/scheduler/resource/Resource.h
+++ b/cpp/src/scheduler/resource/Resource.h
@@ -35,7 +35,6 @@
 #include "Connection.h"
 #include "Node.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -211,4 +210,3 @@ using ResourceWPtr = std::weak_ptr<Resource>;
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/resource/TestResource.cpp b/cpp/src/scheduler/resource/TestResource.cpp
index dd16117236..c8c2fb7537 100644
--- a/cpp/src/scheduler/resource/TestResource.cpp
+++ b/cpp/src/scheduler/resource/TestResource.cpp
@@ -19,7 +19,6 @@
 
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -45,4 +44,3 @@ TestResource::Process(TaskPtr task) {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/resource/TestResource.h b/cpp/src/scheduler/resource/TestResource.h
index 45dbe67500..9bbc5a54d0 100644
--- a/cpp/src/scheduler/resource/TestResource.h
+++ b/cpp/src/scheduler/resource/TestResource.h
@@ -22,7 +22,6 @@
 #include <string>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -48,4 +47,3 @@ class TestResource : public Resource {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/task/DeleteTask.cpp b/cpp/src/scheduler/task/DeleteTask.cpp
index c6cc33ac88..480fb86056 100644
--- a/cpp/src/scheduler/task/DeleteTask.cpp
+++ b/cpp/src/scheduler/task/DeleteTask.cpp
@@ -17,7 +17,6 @@
 
 #include "scheduler/task/DeleteTask.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -36,4 +35,3 @@ XDeleteTask::Execute() {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/task/DeleteTask.h b/cpp/src/scheduler/task/DeleteTask.h
index 473fee2681..75f0969bff 100644
--- a/cpp/src/scheduler/task/DeleteTask.h
+++ b/cpp/src/scheduler/task/DeleteTask.h
@@ -20,7 +20,6 @@
 #include "Task.h"
 #include "scheduler/job/DeleteJob.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -40,4 +39,3 @@ class XDeleteTask : public Task {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/task/Path.h b/cpp/src/scheduler/task/Path.h
index 2be2a7fc0d..c23db9bb09 100644
--- a/cpp/src/scheduler/task/Path.h
+++ b/cpp/src/scheduler/task/Path.h
@@ -20,7 +20,6 @@
 #include <string>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -82,4 +81,3 @@ class Path {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/task/SearchTask.cpp b/cpp/src/scheduler/task/SearchTask.cpp
index 0255699915..cf247ca421 100644
--- a/cpp/src/scheduler/task/SearchTask.cpp
+++ b/cpp/src/scheduler/task/SearchTask.cpp
@@ -26,7 +26,6 @@
 #include <thread>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -374,4 +373,3 @@ XSearchTask::TopkResult(scheduler::ResultSet& result_src, uint64_t topk, bool as
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/task/SearchTask.h b/cpp/src/scheduler/task/SearchTask.h
index a89df4637b..3143799715 100644
--- a/cpp/src/scheduler/task/SearchTask.h
+++ b/cpp/src/scheduler/task/SearchTask.h
@@ -23,7 +23,6 @@
 
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -63,4 +62,3 @@ class XSearchTask : public Task {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/task/Task.h b/cpp/src/scheduler/task/Task.h
index da5fb3b3af..c4b118e0c8 100644
--- a/cpp/src/scheduler/task/Task.h
+++ b/cpp/src/scheduler/task/Task.h
@@ -25,7 +25,6 @@
 #include <memory>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -93,4 +92,3 @@ class Task {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/task/TestTask.cpp b/cpp/src/scheduler/task/TestTask.cpp
index aba7343467..76e814a628 100644
--- a/cpp/src/scheduler/task/TestTask.cpp
+++ b/cpp/src/scheduler/task/TestTask.cpp
@@ -18,7 +18,6 @@
 #include "scheduler/task/TestTask.h"
 #include "cache/GpuCacheMgr.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -48,4 +47,3 @@ TestTask::Wait() {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/task/TestTask.h b/cpp/src/scheduler/task/TestTask.h
index 5d96b888aa..3ad9cb16e1 100644
--- a/cpp/src/scheduler/task/TestTask.h
+++ b/cpp/src/scheduler/task/TestTask.h
@@ -19,7 +19,6 @@
 
 #include "SearchTask.h"
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -48,4 +47,3 @@ class TestTask : public XSearchTask {
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/tasklabel/BroadcastLabel.h b/cpp/src/scheduler/tasklabel/BroadcastLabel.h
index ed68d3ccc1..f0b48afb23 100644
--- a/cpp/src/scheduler/tasklabel/BroadcastLabel.h
+++ b/cpp/src/scheduler/tasklabel/BroadcastLabel.h
@@ -21,7 +21,6 @@
 
 #include <memory>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -35,4 +34,3 @@ using BroadcastLabelPtr = std::shared_ptr<BroadcastLabel>;
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/tasklabel/DefaultLabel.h b/cpp/src/scheduler/tasklabel/DefaultLabel.h
index fe7019f655..c215743575 100644
--- a/cpp/src/scheduler/tasklabel/DefaultLabel.h
+++ b/cpp/src/scheduler/tasklabel/DefaultLabel.h
@@ -21,7 +21,6 @@
 
 #include <memory>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -35,4 +34,3 @@ using DefaultLabelPtr = std::shared_ptr<DefaultLabel>;
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/tasklabel/SpecResLabel.h b/cpp/src/scheduler/tasklabel/SpecResLabel.h
index b5bea81b39..2e42e6c2e9 100644
--- a/cpp/src/scheduler/tasklabel/SpecResLabel.h
+++ b/cpp/src/scheduler/tasklabel/SpecResLabel.h
@@ -26,7 +26,6 @@ class Resource;
 
 using ResourceWPtr = std::weak_ptr<Resource>;
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -55,4 +54,3 @@ using SpecResLabelPtr = std::shared_ptr<SpecResLabel>();
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/scheduler/tasklabel/TaskLabel.h b/cpp/src/scheduler/tasklabel/TaskLabel.h
index 57f486ea89..d35ce409ff 100644
--- a/cpp/src/scheduler/tasklabel/TaskLabel.h
+++ b/cpp/src/scheduler/tasklabel/TaskLabel.h
@@ -19,7 +19,6 @@
 
 #include <memory>
 
-namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
@@ -48,4 +47,3 @@ using TaskLabelPtr = std::shared_ptr<TaskLabel>;
 
 }  // namespace scheduler
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/server/Config.cpp b/cpp/src/server/Config.cpp
index 76ac246c24..5d6a237c1d 100644
--- a/cpp/src/server/Config.cpp
+++ b/cpp/src/server/Config.cpp
@@ -30,7 +30,6 @@
 #include "utils/CommonUtil.h"
 #include "utils/ValidationUtil.h"
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -1363,4 +1362,3 @@ Config::SetResourceConfigMode(const std::string& value) {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/server/Config.h b/cpp/src/server/Config.h
index 4e3d563901..9f6932d267 100644
--- a/cpp/src/server/Config.h
+++ b/cpp/src/server/Config.h
@@ -26,7 +26,6 @@
 #include "config/ConfigNode.h"
 #include "utils/Status.h"
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -359,4 +358,3 @@ class Config {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/server/DBWrapper.cpp b/cpp/src/server/DBWrapper.cpp
index 713714cadc..401c494575 100644
--- a/cpp/src/server/DBWrapper.cpp
+++ b/cpp/src/server/DBWrapper.cpp
@@ -26,7 +26,6 @@
 #include <omp.h>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -170,4 +169,3 @@ DBWrapper::StopService() {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/server/DBWrapper.h b/cpp/src/server/DBWrapper.h
index 6adc68dcb3..08e07c09f6 100644
--- a/cpp/src/server/DBWrapper.h
+++ b/cpp/src/server/DBWrapper.h
@@ -22,7 +22,6 @@
 
 #include <memory>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -59,4 +58,3 @@ class DBWrapper {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/server/Server.cpp b/cpp/src/server/Server.cpp
index 2e06cccf8a..d9aabfc179 100644
--- a/cpp/src/server/Server.cpp
+++ b/cpp/src/server/Server.cpp
@@ -37,7 +37,6 @@
 #include "utils/TimeRecorder.h"
 #include "wrapper/KnowhereResource.h"
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -264,4 +263,3 @@ Server::StopService() {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/server/Server.h b/cpp/src/server/Server.h
index b86945cef9..658dbf7c30 100644
--- a/cpp/src/server/Server.h
+++ b/cpp/src/server/Server.h
@@ -22,7 +22,6 @@
 #include <cstdint>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -65,4 +64,3 @@ class Server {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/server/grpc_impl/GrpcRequestHandler.cpp b/cpp/src/server/grpc_impl/GrpcRequestHandler.cpp
index 6089df6f8e..a9ee3d77d0 100644
--- a/cpp/src/server/grpc_impl/GrpcRequestHandler.cpp
+++ b/cpp/src/server/grpc_impl/GrpcRequestHandler.cpp
@@ -21,7 +21,6 @@
 
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 namespace grpc {
@@ -197,4 +196,3 @@ GrpcRequestHandler::DropIndex(::grpc::ServerContext* context, const ::milvus::gr
 }  // namespace grpc
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/server/grpc_impl/GrpcRequestHandler.h b/cpp/src/server/grpc_impl/GrpcRequestHandler.h
index 66ec126371..0decf61500 100644
--- a/cpp/src/server/grpc_impl/GrpcRequestHandler.h
+++ b/cpp/src/server/grpc_impl/GrpcRequestHandler.h
@@ -23,7 +23,6 @@
 #include "grpc/gen-milvus/milvus.grpc.pb.h"
 #include "grpc/gen-status/status.pb.h"
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 namespace grpc {
@@ -324,4 +323,3 @@ class GrpcRequestHandler final : public ::milvus::grpc::MilvusService::Service {
 }  // namespace grpc
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/server/grpc_impl/GrpcRequestScheduler.cpp b/cpp/src/server/grpc_impl/GrpcRequestScheduler.cpp
index 9135cd6f6c..b2aefe4f65 100644
--- a/cpp/src/server/grpc_impl/GrpcRequestScheduler.cpp
+++ b/cpp/src/server/grpc_impl/GrpcRequestScheduler.cpp
@@ -22,7 +22,6 @@
 
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 namespace grpc {
@@ -239,4 +238,3 @@ GrpcRequestScheduler::PutTaskToQueue(const BaseTaskPtr& task_ptr) {
 }  // namespace grpc
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/server/grpc_impl/GrpcRequestScheduler.h b/cpp/src/server/grpc_impl/GrpcRequestScheduler.h
index d38f4c67ac..802d247fb5 100644
--- a/cpp/src/server/grpc_impl/GrpcRequestScheduler.h
+++ b/cpp/src/server/grpc_impl/GrpcRequestScheduler.h
@@ -28,7 +28,6 @@
 #include <thread>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 namespace grpc {
@@ -130,4 +129,3 @@ class GrpcRequestScheduler {
 }  // namespace grpc
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/server/grpc_impl/GrpcRequestTask.cpp b/cpp/src/server/grpc_impl/GrpcRequestTask.cpp
index 241e24e8f6..9f0b8fd95d 100644
--- a/cpp/src/server/grpc_impl/GrpcRequestTask.cpp
+++ b/cpp/src/server/grpc_impl/GrpcRequestTask.cpp
@@ -34,7 +34,6 @@
 #include "utils/TimeRecorder.h"
 #include "utils/ValidationUtil.h"
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 namespace grpc {
@@ -43,8 +42,8 @@ static const char* DQL_TASK_GROUP = "dql";
 static const char* DDL_DML_TASK_GROUP = "ddl_dml";
 static const char* PING_TASK_GROUP = "ping";
 
-using DB_META = zilliz::milvus::engine::meta::Meta;
-using DB_DATE = zilliz::milvus::engine::meta::DateT;
+using DB_META = milvus::engine::meta::Meta;
+using DB_DATE = milvus::engine::meta::DateT;
 
 namespace {
 engine::EngineType
@@ -934,4 +933,3 @@ DropIndexTask::OnExecute() {
 }  // namespace grpc
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/server/grpc_impl/GrpcRequestTask.h b/cpp/src/server/grpc_impl/GrpcRequestTask.h
index af5ed2bc80..ad2828ebf3 100644
--- a/cpp/src/server/grpc_impl/GrpcRequestTask.h
+++ b/cpp/src/server/grpc_impl/GrpcRequestTask.h
@@ -29,7 +29,6 @@
 #include <string>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 namespace grpc {
@@ -271,4 +270,3 @@ class DropIndexTask : public GrpcBaseTask {
 }  // namespace grpc
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/server/grpc_impl/GrpcServer.cpp b/cpp/src/server/grpc_impl/GrpcServer.cpp
index dd7895c679..5e0c5f3169 100644
--- a/cpp/src/server/grpc_impl/GrpcServer.cpp
+++ b/cpp/src/server/grpc_impl/GrpcServer.cpp
@@ -36,7 +36,6 @@
 #include <grpcpp/create_channel.h>
 #include <grpcpp/security/credentials.h>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 namespace grpc {
@@ -119,4 +118,3 @@ GrpcServer::StopService() {
 }  // namespace grpc
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/server/grpc_impl/GrpcServer.h b/cpp/src/server/grpc_impl/GrpcServer.h
index 9f3f827936..aeaf9f0dca 100644
--- a/cpp/src/server/grpc_impl/GrpcServer.h
+++ b/cpp/src/server/grpc_impl/GrpcServer.h
@@ -25,7 +25,6 @@
 #include <string>
 #include <thread>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 namespace grpc {
@@ -60,4 +59,3 @@ class GrpcServer {
 }  // namespace grpc
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/BlockingQueue.h b/cpp/src/utils/BlockingQueue.h
index 422f170cd6..dc7968fcb6 100644
--- a/cpp/src/utils/BlockingQueue.h
+++ b/cpp/src/utils/BlockingQueue.h
@@ -23,7 +23,6 @@
 #include <queue>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -69,6 +68,5 @@ class BlockingQueue {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
 
 #include "./BlockingQueue.inl"
diff --git a/cpp/src/utils/BlockingQueue.inl b/cpp/src/utils/BlockingQueue.inl
index ed15aac77a..c4318c5fc6 100644
--- a/cpp/src/utils/BlockingQueue.inl
+++ b/cpp/src/utils/BlockingQueue.inl
@@ -18,7 +18,7 @@
 
 #pragma once
 
-namespace zilliz {
+
 namespace milvus {
 namespace server {
 
@@ -94,5 +94,5 @@ BlockingQueue<T>::SetCapacity(const size_t capacity) {
 
 } // namespace server
 } // namespace milvus
-} // namespace zilliz
+
 
diff --git a/cpp/src/utils/CommonUtil.cpp b/cpp/src/utils/CommonUtil.cpp
index 14ed34481f..fbf3112aeb 100644
--- a/cpp/src/utils/CommonUtil.cpp
+++ b/cpp/src/utils/CommonUtil.cpp
@@ -38,7 +38,6 @@
 #define THREAD_MULTIPLY_CPU 1
 #endif
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -225,4 +224,3 @@ CommonUtil::ConvertTime(tm time_struct, time_t& time_integer) {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/CommonUtil.h b/cpp/src/utils/CommonUtil.h
index 58ac41ecb1..939bdd6d31 100644
--- a/cpp/src/utils/CommonUtil.h
+++ b/cpp/src/utils/CommonUtil.h
@@ -22,7 +22,6 @@
 #include <time.h>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -61,4 +60,3 @@ class CommonUtil {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/Error.h b/cpp/src/utils/Error.h
index 59e9015afb..81403947c8 100644
--- a/cpp/src/utils/Error.h
+++ b/cpp/src/utils/Error.h
@@ -21,7 +21,6 @@
 #include <exception>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 
 using ErrorCode = int32_t;
@@ -123,4 +122,3 @@ class ServerException : public std::exception {
 }  // namespace server
 
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/Exception.h b/cpp/src/utils/Exception.h
index 2ca61c4884..a2d8473fa3 100644
--- a/cpp/src/utils/Exception.h
+++ b/cpp/src/utils/Exception.h
@@ -22,7 +22,6 @@
 #include <exception>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 
 class Exception : public std::exception {
@@ -62,4 +61,3 @@ class InvalidArgumentException : public Exception {
 };
 
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/Log.h b/cpp/src/utils/Log.h
index 64a8622b73..1dd116367a 100644
--- a/cpp/src/utils/Log.h
+++ b/cpp/src/utils/Log.h
@@ -19,7 +19,6 @@
 
 #include "utils/easylogging++.h"
 
-namespace zilliz {
 namespace milvus {
 
 /////////////////////////////////////////////////////////////////////////////////////////////////
@@ -53,4 +52,3 @@ namespace milvus {
 #define WRAPPER_LOG_FATAL LOG(FATAL) << WRAPPER_DOMAIN_NAME
 
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/LogUtil.cpp b/cpp/src/utils/LogUtil.cpp
index 32e942bca3..ed2e1a446b 100644
--- a/cpp/src/utils/LogUtil.cpp
+++ b/cpp/src/utils/LogUtil.cpp
@@ -21,7 +21,6 @@
 #include <libgen.h>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -95,4 +94,3 @@ InitLog(const std::string& log_config_file) {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/LogUtil.h b/cpp/src/utils/LogUtil.h
index eb396f266e..9926939442 100644
--- a/cpp/src/utils/LogUtil.h
+++ b/cpp/src/utils/LogUtil.h
@@ -23,7 +23,6 @@
 #include <sstream>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -35,11 +34,10 @@ RolloutHandler(const char* filename, std::size_t size, el::Level level);
 
 #define SHOW_LOCATION
 #ifdef SHOW_LOCATION
-#define LOCATION_INFO "[" << zilliz::sql::server::GetFileName(__FILE__) << ":" << __LINE__ << "] "
+#define LOCATION_INFO "[" << sql::server::GetFileName(__FILE__) << ":" << __LINE__ << "] "
 #else
 #define LOCATION_INFO ""
 #endif
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/SignalUtil.cpp b/cpp/src/utils/SignalUtil.cpp
index a01e7573c7..5531aaed27 100644
--- a/cpp/src/utils/SignalUtil.cpp
+++ b/cpp/src/utils/SignalUtil.cpp
@@ -23,7 +23,6 @@
 #include <signal.h>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -68,4 +67,3 @@ SignalUtil::PrintStacktrace() {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/SignalUtil.h b/cpp/src/utils/SignalUtil.h
index 414b320321..2ecfdecfba 100644
--- a/cpp/src/utils/SignalUtil.h
+++ b/cpp/src/utils/SignalUtil.h
@@ -17,7 +17,6 @@
 
 #pragma once
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -31,4 +30,3 @@ class SignalUtil {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/Status.cpp b/cpp/src/utils/Status.cpp
index 95132d3a2a..ad97717cf7 100644
--- a/cpp/src/utils/Status.cpp
+++ b/cpp/src/utils/Status.cpp
@@ -19,7 +19,6 @@
 
 #include <cstring>
 
-namespace zilliz {
 namespace milvus {
 
 constexpr int CODE_WIDTH = sizeof(StatusCode);
@@ -138,4 +137,3 @@ Status::ToString() const {
 }
 
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/Status.h b/cpp/src/utils/Status.h
index cb6c134781..07a12261bb 100644
--- a/cpp/src/utils/Status.h
+++ b/cpp/src/utils/Status.h
@@ -21,7 +21,6 @@
 
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 
 using StatusCode = ErrorCode;
@@ -75,4 +74,3 @@ class Status {
 };  // Status
 
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/StringHelpFunctions.cpp b/cpp/src/utils/StringHelpFunctions.cpp
index 444467845f..230cc1a0ff 100644
--- a/cpp/src/utils/StringHelpFunctions.cpp
+++ b/cpp/src/utils/StringHelpFunctions.cpp
@@ -19,7 +19,6 @@
 
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -125,4 +124,3 @@ StringHelpFunctions::SplitStringByQuote(const std::string& str, const std::strin
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/StringHelpFunctions.h b/cpp/src/utils/StringHelpFunctions.h
index 06615fc740..cb355332f1 100644
--- a/cpp/src/utils/StringHelpFunctions.h
+++ b/cpp/src/utils/StringHelpFunctions.h
@@ -22,7 +22,6 @@
 #include <string>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -61,4 +60,3 @@ class StringHelpFunctions {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/ThreadPool.h b/cpp/src/utils/ThreadPool.h
index db4c9d11ad..d605d70018 100644
--- a/cpp/src/utils/ThreadPool.h
+++ b/cpp/src/utils/ThreadPool.h
@@ -30,7 +30,6 @@
 
 #define MAX_THREADS_NUM 32
 
-namespace zilliz {
 namespace milvus {
 
 class ThreadPool {
@@ -118,4 +117,3 @@ inline ThreadPool::~ThreadPool() {
 }
 
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/TimeRecorder.cpp b/cpp/src/utils/TimeRecorder.cpp
index cffcbc98ef..f3061d9d2b 100644
--- a/cpp/src/utils/TimeRecorder.cpp
+++ b/cpp/src/utils/TimeRecorder.cpp
@@ -18,7 +18,6 @@
 #include "utils/TimeRecorder.h"
 #include "utils/Log.h"
 
-namespace zilliz {
 namespace milvus {
 
 TimeRecorder::TimeRecorder(const std::string& header, int64_t log_level) : header_(header), log_level_(log_level) {
@@ -98,4 +97,3 @@ TimeRecorder::ElapseFromBegin(const std::string& msg) {
 }
 
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/TimeRecorder.h b/cpp/src/utils/TimeRecorder.h
index 8f795f01c3..cc0a86fbe0 100644
--- a/cpp/src/utils/TimeRecorder.h
+++ b/cpp/src/utils/TimeRecorder.h
@@ -20,7 +20,6 @@
 #include <chrono>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 
 class TimeRecorder {
@@ -52,4 +51,3 @@ class TimeRecorder {
 };
 
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/ValidationUtil.cpp b/cpp/src/utils/ValidationUtil.cpp
index a39427ef15..248be51088 100644
--- a/cpp/src/utils/ValidationUtil.cpp
+++ b/cpp/src/utils/ValidationUtil.cpp
@@ -25,7 +25,6 @@
 #include <regex>
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -290,4 +289,3 @@ ValidationUtil::ValidateDbURI(const std::string& uri) {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/utils/ValidationUtil.h b/cpp/src/utils/ValidationUtil.h
index 415347cec5..7b24c93fb5 100644
--- a/cpp/src/utils/ValidationUtil.h
+++ b/cpp/src/utils/ValidationUtil.h
@@ -22,7 +22,6 @@
 
 #include <string>
 
-namespace zilliz {
 namespace milvus {
 namespace server {
 
@@ -79,4 +78,3 @@ class ValidationUtil {
 
 }  // namespace server
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/wrapper/ConfAdapter.cpp b/cpp/src/wrapper/ConfAdapter.cpp
index 09d219b999..2dcf6bab7e 100644
--- a/cpp/src/wrapper/ConfAdapter.cpp
+++ b/cpp/src/wrapper/ConfAdapter.cpp
@@ -24,7 +24,6 @@
 
 // TODO(lxj): add conf checker
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -162,4 +161,3 @@ NSGConfAdapter::MatchSearch(const TempMetaConf& metaconf, const IndexType& type)
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/wrapper/ConfAdapter.h b/cpp/src/wrapper/ConfAdapter.h
index e02d76e441..4c8e528a2d 100644
--- a/cpp/src/wrapper/ConfAdapter.h
+++ b/cpp/src/wrapper/ConfAdapter.h
@@ -22,7 +22,6 @@
 
 #include <memory>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -93,4 +92,3 @@ class NSGConfAdapter : public IVFConfAdapter {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/wrapper/ConfAdapterMgr.cpp b/cpp/src/wrapper/ConfAdapterMgr.cpp
index 4ed80b22b7..05c23c4238 100644
--- a/cpp/src/wrapper/ConfAdapterMgr.cpp
+++ b/cpp/src/wrapper/ConfAdapterMgr.cpp
@@ -18,7 +18,6 @@
 #include "wrapper/ConfAdapterMgr.h"
 #include "utils/Exception.h"
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -59,4 +58,3 @@ AdapterMgr::RegisterAdapter() {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/wrapper/ConfAdapterMgr.h b/cpp/src/wrapper/ConfAdapterMgr.h
index 1ac0647c16..a88e090760 100644
--- a/cpp/src/wrapper/ConfAdapterMgr.h
+++ b/cpp/src/wrapper/ConfAdapterMgr.h
@@ -23,7 +23,6 @@
 #include <map>
 #include <memory>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -55,4 +54,3 @@ class AdapterMgr {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/wrapper/DataTransfer.cpp b/cpp/src/wrapper/DataTransfer.cpp
index ac771c1895..5eb83290d1 100644
--- a/cpp/src/wrapper/DataTransfer.cpp
+++ b/cpp/src/wrapper/DataTransfer.cpp
@@ -21,7 +21,6 @@
 #include <utility>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -57,4 +56,3 @@ GenDataset(const int64_t& nb, const int64_t& dim, const float* xb) {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/wrapper/DataTransfer.h b/cpp/src/wrapper/DataTransfer.h
index ad5361c4f5..e945eaa6db 100644
--- a/cpp/src/wrapper/DataTransfer.h
+++ b/cpp/src/wrapper/DataTransfer.h
@@ -19,16 +19,14 @@
 
 #include "knowhere/adapter/Structure.h"
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
-extern zilliz::knowhere::DatasetPtr
+extern knowhere::DatasetPtr
 GenDatasetWithIds(const int64_t& nb, const int64_t& dim, const float* xb, const int64_t* ids);
 
-extern zilliz::knowhere::DatasetPtr
+extern knowhere::DatasetPtr
 GenDataset(const int64_t& nb, const int64_t& dim, const float* xb);
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/wrapper/KnowhereResource.cpp b/cpp/src/wrapper/KnowhereResource.cpp
index 7194ba2374..d291bb9299 100644
--- a/cpp/src/wrapper/KnowhereResource.cpp
+++ b/cpp/src/wrapper/KnowhereResource.cpp
@@ -25,7 +25,6 @@
 #include <utility>
 #include <vector>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -85,4 +84,3 @@ KnowhereResource::Finalize() {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/wrapper/KnowhereResource.h b/cpp/src/wrapper/KnowhereResource.h
index 144d632c07..dff8b32c0b 100644
--- a/cpp/src/wrapper/KnowhereResource.h
+++ b/cpp/src/wrapper/KnowhereResource.h
@@ -19,7 +19,6 @@
 
 #include "utils/Status.h"
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -34,4 +33,3 @@ class KnowhereResource {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/wrapper/VecImpl.cpp b/cpp/src/wrapper/VecImpl.cpp
index 0e90ab135e..a6023052db 100644
--- a/cpp/src/wrapper/VecImpl.cpp
+++ b/cpp/src/wrapper/VecImpl.cpp
@@ -28,7 +28,6 @@
  * only responible for index combination
  */
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -115,14 +114,14 @@ VecIndexImpl::Search(const int64_t& nq, const float* xq, float* dist, int64_t* i
     return Status::OK();
 }
 
-zilliz::knowhere::BinarySet
+knowhere::BinarySet
 VecIndexImpl::Serialize() {
     type = ConvertToCpuIndexType(type);
     return index_->Serialize();
 }
 
 Status
-VecIndexImpl::Load(const zilliz::knowhere::BinarySet& index_binary) {
+VecIndexImpl::Load(const knowhere::BinarySet& index_binary) {
     index_->Load(index_binary);
     dim = Dimension();
     return Status::OK();
@@ -146,7 +145,7 @@ VecIndexImpl::GetType() {
 VecIndexPtr
 VecIndexImpl::CopyToGpu(const int64_t& device_id, const Config& cfg) {
     // TODO(linxj): exception handle
-    auto gpu_index = zilliz::knowhere::cloner::CopyCpuToGpu(index_, device_id, cfg);
+    auto gpu_index = knowhere::cloner::CopyCpuToGpu(index_, device_id, cfg);
     auto new_index = std::make_shared<VecIndexImpl>(gpu_index, ConvertToGpuIndexType(type));
     new_index->dim = dim;
     return new_index;
@@ -155,7 +154,7 @@ VecIndexImpl::CopyToGpu(const int64_t& device_id, const Config& cfg) {
 VecIndexPtr
 VecIndexImpl::CopyToCpu(const Config& cfg) {
     // TODO(linxj): exception handle
-    auto cpu_index = zilliz::knowhere::cloner::CopyGpuToCpu(index_, cfg);
+    auto cpu_index = knowhere::cloner::CopyGpuToCpu(index_, cfg);
     auto new_index = std::make_shared<VecIndexImpl>(cpu_index, ConvertToCpuIndexType(type));
     new_index->dim = dim;
     return new_index;
@@ -259,7 +258,7 @@ IVFMixIndex::BuildAll(const int64_t& nb, const float* xb, const int64_t* ids, co
 }
 
 Status
-IVFMixIndex::Load(const zilliz::knowhere::BinarySet& index_binary) {
+IVFMixIndex::Load(const knowhere::BinarySet& index_binary) {
     index_->Load(index_binary);
     dim = Dimension();
     return Status::OK();
@@ -267,4 +266,3 @@ IVFMixIndex::Load(const zilliz::knowhere::BinarySet& index_binary) {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/wrapper/VecImpl.h b/cpp/src/wrapper/VecImpl.h
index fe015424f6..2be822084f 100644
--- a/cpp/src/wrapper/VecImpl.h
+++ b/cpp/src/wrapper/VecImpl.h
@@ -23,13 +23,12 @@
 #include <memory>
 #include <utility>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
 class VecIndexImpl : public VecIndex {
  public:
-    explicit VecIndexImpl(std::shared_ptr<zilliz::knowhere::VectorIndex> index, const IndexType& type)
+    explicit VecIndexImpl(std::shared_ptr<knowhere::VectorIndex> index, const IndexType& type)
         : index_(std::move(index)), type(type) {
     }
 
@@ -55,11 +54,11 @@ class VecIndexImpl : public VecIndex {
     Status
     Add(const int64_t& nb, const float* xb, const int64_t* ids, const Config& cfg) override;
 
-    zilliz::knowhere::BinarySet
+    knowhere::BinarySet
     Serialize() override;
 
     Status
-    Load(const zilliz::knowhere::BinarySet& index_binary) override;
+    Load(const knowhere::BinarySet& index_binary) override;
 
     VecIndexPtr
     Clone() override;
@@ -75,12 +74,12 @@ class VecIndexImpl : public VecIndex {
 
     IndexType type = IndexType::INVALID;
 
-    std::shared_ptr<zilliz::knowhere::VectorIndex> index_ = nullptr;
+    std::shared_ptr<knowhere::VectorIndex> index_ = nullptr;
 };
 
 class IVFMixIndex : public VecIndexImpl {
  public:
-    explicit IVFMixIndex(std::shared_ptr<zilliz::knowhere::VectorIndex> index, const IndexType& type)
+    explicit IVFMixIndex(std::shared_ptr<knowhere::VectorIndex> index, const IndexType& type)
         : VecIndexImpl(std::move(index), type) {
     }
 
@@ -89,12 +88,12 @@ class IVFMixIndex : public VecIndexImpl {
              const float* xt) override;
 
     Status
-    Load(const zilliz::knowhere::BinarySet& index_binary) override;
+    Load(const knowhere::BinarySet& index_binary) override;
 };
 
 class BFIndex : public VecIndexImpl {
  public:
-    explicit BFIndex(std::shared_ptr<zilliz::knowhere::VectorIndex> index)
+    explicit BFIndex(std::shared_ptr<knowhere::VectorIndex> index)
         : VecIndexImpl(std::move(index), IndexType::FAISS_IDMAP) {
     }
 
@@ -114,4 +113,3 @@ class BFIndex : public VecIndexImpl {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/wrapper/VecIndex.cpp b/cpp/src/wrapper/VecIndex.cpp
index c5ebd684fa..627f3515e4 100644
--- a/cpp/src/wrapper/VecIndex.cpp
+++ b/cpp/src/wrapper/VecIndex.cpp
@@ -31,7 +31,6 @@
 
 #include <cuda.h>
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
@@ -95,51 +94,51 @@ FileIOWriter::operator()(void* ptr, size_t size) {
 
 VecIndexPtr
 GetVecIndexFactory(const IndexType& type, const Config& cfg) {
-    std::shared_ptr<zilliz::knowhere::VectorIndex> index;
+    std::shared_ptr<knowhere::VectorIndex> index;
     auto gpu_device = -1;  // TODO(linxj): remove hardcode here
     switch (type) {
         case IndexType::FAISS_IDMAP: {
-            index = std::make_shared<zilliz::knowhere::IDMAP>();
+            index = std::make_shared<knowhere::IDMAP>();
             return std::make_shared<BFIndex>(index);
         }
         case IndexType::FAISS_IVFFLAT_CPU: {
-            index = std::make_shared<zilliz::knowhere::IVF>();
+            index = std::make_shared<knowhere::IVF>();
             break;
         }
         case IndexType::FAISS_IVFFLAT_GPU: {
-            index = std::make_shared<zilliz::knowhere::GPUIVF>(gpu_device);
+            index = std::make_shared<knowhere::GPUIVF>(gpu_device);
             break;
         }
         case IndexType::FAISS_IVFFLAT_MIX: {
-            index = std::make_shared<zilliz::knowhere::GPUIVF>(gpu_device);
+            index = std::make_shared<knowhere::GPUIVF>(gpu_device);
             return std::make_shared<IVFMixIndex>(index, IndexType::FAISS_IVFFLAT_MIX);
         }
         case IndexType::FAISS_IVFPQ_CPU: {
-            index = std::make_shared<zilliz::knowhere::IVFPQ>();
+            index = std::make_shared<knowhere::IVFPQ>();
             break;
         }
         case IndexType::FAISS_IVFPQ_GPU: {
-            index = std::make_shared<zilliz::knowhere::GPUIVFPQ>(gpu_device);
+            index = std::make_shared<knowhere::GPUIVFPQ>(gpu_device);
             break;
         }
         case IndexType::SPTAG_KDT_RNT_CPU: {
-            index = std::make_shared<zilliz::knowhere::CPUKDTRNG>();
+            index = std::make_shared<knowhere::CPUKDTRNG>();
             break;
         }
         case IndexType::FAISS_IVFSQ8_MIX: {
-            index = std::make_shared<zilliz::knowhere::GPUIVFSQ>(gpu_device);
+            index = std::make_shared<knowhere::GPUIVFSQ>(gpu_device);
             return std::make_shared<IVFMixIndex>(index, IndexType::FAISS_IVFSQ8_MIX);
         }
         case IndexType::FAISS_IVFSQ8_CPU: {
-            index = std::make_shared<zilliz::knowhere::IVFSQ>();
+            index = std::make_shared<knowhere::IVFSQ>();
             break;
         }
         case IndexType::FAISS_IVFSQ8_GPU: {
-            index = std::make_shared<zilliz::knowhere::GPUIVFSQ>(gpu_device);
+            index = std::make_shared<knowhere::GPUIVFSQ>(gpu_device);
             break;
         }
         case IndexType::NSG_MIX: {
-            index = std::make_shared<zilliz::knowhere::NSG>(gpu_device);
+            index = std::make_shared<knowhere::NSG>(gpu_device);
             break;
         }
         default: { return nullptr; }
@@ -148,7 +147,7 @@ GetVecIndexFactory(const IndexType& type, const Config& cfg) {
 }
 
 VecIndexPtr
-LoadVecIndex(const IndexType& index_type, const zilliz::knowhere::BinarySet& index_binary) {
+LoadVecIndex(const IndexType& index_type, const knowhere::BinarySet& index_binary) {
     auto index = GetVecIndexFactory(index_type);
     index->Load(index_binary);
     return index;
@@ -267,4 +266,3 @@ ConvertToGpuIndexType(const IndexType& type) {
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/src/wrapper/VecIndex.h b/cpp/src/wrapper/VecIndex.h
index 4bc51021ce..d2088b64ef 100644
--- a/cpp/src/wrapper/VecIndex.h
+++ b/cpp/src/wrapper/VecIndex.h
@@ -24,11 +24,10 @@
 #include "knowhere/common/Config.h"
 #include "utils/Status.h"
 
-namespace zilliz {
 namespace milvus {
 namespace engine {
 
-using Config = zilliz::knowhere::Config;
+using Config = knowhere::Config;
 
 enum class IndexType {
     INVALID = 0,
@@ -82,11 +81,11 @@ class VecIndex {
     virtual int64_t
     Count() = 0;
 
-    virtual zilliz::knowhere::BinarySet
+    virtual knowhere::BinarySet
     Serialize() = 0;
 
     virtual Status
-    Load(const zilliz::knowhere::BinarySet& index_binary) = 0;
+    Load(const knowhere::BinarySet& index_binary) = 0;
 };
 
 extern Status
@@ -99,7 +98,7 @@ extern VecIndexPtr
 GetVecIndexFactory(const IndexType& type, const Config& cfg = Config());
 
 extern VecIndexPtr
-LoadVecIndex(const IndexType& index_type, const zilliz::knowhere::BinarySet& index_binary);
+LoadVecIndex(const IndexType& index_type, const knowhere::BinarySet& index_binary);
 
 extern IndexType
 ConvertToCpuIndexType(const IndexType& type);
@@ -109,4 +108,3 @@ ConvertToGpuIndexType(const IndexType& type);
 
 }  // namespace engine
 }  // namespace milvus
-}  // namespace zilliz
diff --git a/cpp/unittest/db/test_db.cpp b/cpp/unittest/db/test_db.cpp
index 0bb74437b0..413e192335 100644
--- a/cpp/unittest/db/test_db.cpp
+++ b/cpp/unittest/db/test_db.cpp
@@ -30,7 +30,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 static const char *TABLE_NAME = "test_group";
 static constexpr int64_t TABLE_DIM = 256;
@@ -81,11 +81,11 @@ ConvertTimeRangeToDBDates(const std::string &start_value,
 
     time_t tt_start, tt_end;
     tm tm_start, tm_end;
-    if (!zilliz::milvus::server::CommonUtil::TimeStrToTime(start_value, tt_start, tm_start)) {
+    if (!milvus::server::CommonUtil::TimeStrToTime(start_value, tt_start, tm_start)) {
         return;
     }
 
-    if (!zilliz::milvus::server::CommonUtil::TimeStrToTime(end_value, tt_end, tm_end)) {
+    if (!milvus::server::CommonUtil::TimeStrToTime(end_value, tt_end, tm_end)) {
         return;
     }
 
@@ -98,7 +98,7 @@ ConvertTimeRangeToDBDates(const std::string &start_value,
     for (int64_t i = 0; i < days; i++) {
         time_t tt_day = tt_start + DAY_SECONDS * i;
         tm tm_day;
-        zilliz::milvus::server::CommonUtil::ConvertTime(tt_day, tm_day);
+        milvus::server::CommonUtil::ConvertTime(tt_day, tm_day);
 
         int64_t date = tm_day.tm_year * 10000 + tm_day.tm_mon * 100 +
             tm_day.tm_mday;//according to db logic
diff --git a/cpp/unittest/db/test_db_mysql.cpp b/cpp/unittest/db/test_db_mysql.cpp
index 2a7456785e..89d92c1e06 100644
--- a/cpp/unittest/db/test_db_mysql.cpp
+++ b/cpp/unittest/db/test_db_mysql.cpp
@@ -28,7 +28,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 static const char *TABLE_NAME = "test_group";
 static constexpr int64_t TABLE_DIM = 256;
diff --git a/cpp/unittest/db/test_engine.cpp b/cpp/unittest/db/test_engine.cpp
index 517b2fd506..40afbb38f9 100644
--- a/cpp/unittest/db/test_engine.cpp
+++ b/cpp/unittest/db/test_engine.cpp
@@ -25,7 +25,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 }
 
diff --git a/cpp/unittest/db/test_mem.cpp b/cpp/unittest/db/test_mem.cpp
index 93500acce7..a99631155e 100644
--- a/cpp/unittest/db/test_mem.cpp
+++ b/cpp/unittest/db/test_mem.cpp
@@ -37,7 +37,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 static constexpr int64_t TABLE_DIM = 256;
 
diff --git a/cpp/unittest/db/test_meta.cpp b/cpp/unittest/db/test_meta.cpp
index 39217ea298..b8eb690462 100644
--- a/cpp/unittest/db/test_meta.cpp
+++ b/cpp/unittest/db/test_meta.cpp
@@ -27,7 +27,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 } // namespace
 
diff --git a/cpp/unittest/db/test_meta_mysql.cpp b/cpp/unittest/db/test_meta_mysql.cpp
index 5605b9eb14..c1d33a17a4 100644
--- a/cpp/unittest/db/test_meta_mysql.cpp
+++ b/cpp/unittest/db/test_meta_mysql.cpp
@@ -29,7 +29,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 }
 
diff --git a/cpp/unittest/db/test_misc.cpp b/cpp/unittest/db/test_misc.cpp
index d6b024930f..18cca45b4b 100644
--- a/cpp/unittest/db/test_misc.cpp
+++ b/cpp/unittest/db/test_misc.cpp
@@ -29,7 +29,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 } // namespace
 
diff --git a/cpp/unittest/db/test_search.cpp b/cpp/unittest/db/test_search.cpp
index d0d55a11c6..12fc8e277a 100644
--- a/cpp/unittest/db/test_search.cpp
+++ b/cpp/unittest/db/test_search.cpp
@@ -24,7 +24,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 static constexpr uint64_t NQ = 15;
 static constexpr uint64_t TOP_K = 64;
diff --git a/cpp/unittest/db/utils.cpp b/cpp/unittest/db/utils.cpp
index 2ad7c4f743..61c75a0933 100644
--- a/cpp/unittest/db/utils.cpp
+++ b/cpp/unittest/db/utils.cpp
@@ -33,7 +33,7 @@ INITIALIZE_EASYLOGGINGPP
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 class DBTestEnvironment : public ::testing::Environment {
  public:
@@ -73,14 +73,14 @@ void
 BaseTest::SetUp() {
     InitLog();
 
-    zilliz::knowhere::FaissGpuResourceMgr::GetInstance().InitDevice(0, 1024 * 1024 * 200, 1024 * 1024 * 300, 2);
+    knowhere::FaissGpuResourceMgr::GetInstance().InitDevice(0, 1024 * 1024 * 200, 1024 * 1024 * 300, 2);
 }
 
 void
 BaseTest::TearDown() {
-    zilliz::milvus::cache::CpuCacheMgr::GetInstance()->ClearCache();
-    zilliz::milvus::cache::GpuCacheMgr::GetInstance(0)->ClearCache();
-    zilliz::knowhere::FaissGpuResourceMgr::GetInstance().Free();
+    milvus::cache::CpuCacheMgr::GetInstance()->ClearCache();
+    milvus::cache::GpuCacheMgr::GetInstance(0)->ClearCache();
+    knowhere::FaissGpuResourceMgr::GetInstance().Free();
 }
 
 ms::engine::DBOptions
diff --git a/cpp/unittest/db/utils.h b/cpp/unittest/db/utils.h
index dee9dcf843..8da160dc92 100644
--- a/cpp/unittest/db/utils.h
+++ b/cpp/unittest/db/utils.h
@@ -48,13 +48,13 @@ class BaseTest : public ::testing::Test {
 
     void SetUp() override;
     void TearDown() override;
-    virtual zilliz::milvus::engine::DBOptions GetOptions();
+    virtual milvus::engine::DBOptions GetOptions();
 };
 
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 class DBTest : public BaseTest {
  protected:
-    zilliz::milvus::engine::DBPtr db_;
+    milvus::engine::DBPtr db_;
 
     void SetUp() override;
     void TearDown() override;
@@ -63,7 +63,7 @@ class DBTest : public BaseTest {
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 class DBTest2 : public DBTest {
  protected:
-    zilliz::milvus::engine::DBOptions GetOptions() override;
+    milvus::engine::DBOptions GetOptions() override;
 };
 
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////
@@ -73,7 +73,7 @@ class EngineTest : public DBTest {
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 class MetaTest : public BaseTest {
  protected:
-    std::shared_ptr<zilliz::milvus::engine::meta::SqliteMetaImpl> impl_;
+    std::shared_ptr<milvus::engine::meta::SqliteMetaImpl> impl_;
 
     void SetUp() override;
     void TearDown() override;
@@ -82,17 +82,17 @@ class MetaTest : public BaseTest {
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 class MySqlDBTest : public DBTest {
  protected:
-    zilliz::milvus::engine::DBOptions GetOptions() override;
+    milvus::engine::DBOptions GetOptions() override;
 };
 
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 class MySqlMetaTest : public BaseTest {
  protected:
-    std::shared_ptr<zilliz::milvus::engine::meta::MySQLMetaImpl> impl_;
+    std::shared_ptr<milvus::engine::meta::MySQLMetaImpl> impl_;
 
     void SetUp() override;
     void TearDown() override;
-    zilliz::milvus::engine::DBOptions GetOptions() override;
+    milvus::engine::DBOptions GetOptions() override;
 };
 
 /////////////////////////////////////////////////////////////////////////////////////////////////////////////////
diff --git a/cpp/unittest/metrics/test_metricbase.cpp b/cpp/unittest/metrics/test_metricbase.cpp
index 7f77312480..4edb3b8151 100644
--- a/cpp/unittest/metrics/test_metricbase.cpp
+++ b/cpp/unittest/metrics/test_metricbase.cpp
@@ -23,7 +23,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 } // namespace
 
diff --git a/cpp/unittest/metrics/test_metrics.cpp b/cpp/unittest/metrics/test_metrics.cpp
index ec950fedcc..ba0b51af00 100644
--- a/cpp/unittest/metrics/test_metrics.cpp
+++ b/cpp/unittest/metrics/test_metrics.cpp
@@ -31,7 +31,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 } // namespace
 
@@ -47,8 +47,8 @@ TEST_F(MetricTest, METRIC_TEST) {
     ms::server::Metrics::GetInstance().Init();
 
 //    server::PrometheusMetrics::GetInstance().exposer_ptr()->RegisterCollectable(server::PrometheusMetrics::GetInstance().registry_ptr());
-    zilliz::milvus::cache::CpuCacheMgr::GetInstance()->SetCapacity(1UL * 1024 * 1024 * 1024);
-    std::cout << zilliz::milvus::cache::CpuCacheMgr::GetInstance()->CacheCapacity() << std::endl;
+    milvus::cache::CpuCacheMgr::GetInstance()->SetCapacity(1UL * 1024 * 1024 * 1024);
+    std::cout << milvus::cache::CpuCacheMgr::GetInstance()->CacheCapacity() << std::endl;
 
     static const char *group_name = "test_group";
     static const int group_dim = 256;
diff --git a/cpp/unittest/metrics/test_prometheus.cpp b/cpp/unittest/metrics/test_prometheus.cpp
index 4847e61627..14982d058d 100644
--- a/cpp/unittest/metrics/test_prometheus.cpp
+++ b/cpp/unittest/metrics/test_prometheus.cpp
@@ -24,7 +24,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 } // namespace
 
diff --git a/cpp/unittest/metrics/utils.cpp b/cpp/unittest/metrics/utils.cpp
index 8275222766..c2a53babc3 100644
--- a/cpp/unittest/metrics/utils.cpp
+++ b/cpp/unittest/metrics/utils.cpp
@@ -28,7 +28,7 @@ INITIALIZE_EASYLOGGINGPP
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 class DBTestEnvironment : public ::testing::Environment {
  public:
diff --git a/cpp/unittest/metrics/utils.h b/cpp/unittest/metrics/utils.h
index 3daeeb8fa6..996dec89f5 100644
--- a/cpp/unittest/metrics/utils.h
+++ b/cpp/unittest/metrics/utils.h
@@ -41,7 +41,7 @@
 #endif
 
 void
-ASSERT_STATS(zilliz::milvus::Status &stat);
+ASSERT_STATS(milvus::Status &stat);
 
 //class TestEnv : public ::testing::Environment {
 //public:
@@ -66,10 +66,10 @@ ASSERT_STATS(zilliz::milvus::Status &stat);
 
 class MetricTest : public ::testing::Test {
  protected:
-    zilliz::milvus::engine::DBPtr db_;
+    milvus::engine::DBPtr db_;
 
     void InitLog();
     void SetUp() override;
     void TearDown() override;
-    virtual zilliz::milvus::engine::DBOptions GetOptions();
+    virtual milvus::engine::DBOptions GetOptions();
 };
diff --git a/cpp/unittest/scheduler/task_test.cpp b/cpp/unittest/scheduler/task_test.cpp
index d4bb0318da..ce91a62a52 100644
--- a/cpp/unittest/scheduler/task_test.cpp
+++ b/cpp/unittest/scheduler/task_test.cpp
@@ -19,7 +19,7 @@
 #include "scheduler/task/SearchTask.h"
 #include <gtest/gtest.h>
 
-namespace zilliz {
+
 namespace milvus {
 namespace scheduler {
 
@@ -30,5 +30,5 @@ TEST(TaskTest, INVALID_INDEX) {
 
 } // namespace scheduler
 } // namespace milvus
-} // namespace zilliz
+
 
diff --git a/cpp/unittest/scheduler/test_algorithm.cpp b/cpp/unittest/scheduler/test_algorithm.cpp
index 56574a7463..bcb9087373 100644
--- a/cpp/unittest/scheduler/test_algorithm.cpp
+++ b/cpp/unittest/scheduler/test_algorithm.cpp
@@ -24,7 +24,7 @@
 #include "scheduler/ResourceFactory.h"
 #include "scheduler/Algorithm.h"
 
-namespace zilliz {
+
 namespace milvus {
 namespace scheduler {
 
@@ -105,4 +105,4 @@ TEST_F(AlgorithmTest, SHORTESTPATH_TEST) {
 
 } // namespace scheduler
 } // namespace milvus
-} // namespace zilliz
+
diff --git a/cpp/unittest/scheduler/test_event.cpp b/cpp/unittest/scheduler/test_event.cpp
index 73fffc8f6e..07d51e8557 100644
--- a/cpp/unittest/scheduler/test_event.cpp
+++ b/cpp/unittest/scheduler/test_event.cpp
@@ -23,7 +23,7 @@
 #include "scheduler/event/StartUpEvent.h"
 
 
-namespace zilliz {
+
 namespace milvus {
 namespace scheduler {
 
@@ -62,5 +62,5 @@ TEST(EventTest, TASKTABLE_UPDATED_EVENT) {
 
 } // namespace scheduler
 } // namespace milvus
-} // namespace zilliz
+
 
diff --git a/cpp/unittest/scheduler/test_node.cpp b/cpp/unittest/scheduler/test_node.cpp
index 3323453f0b..9b34b73191 100644
--- a/cpp/unittest/scheduler/test_node.cpp
+++ b/cpp/unittest/scheduler/test_node.cpp
@@ -21,7 +21,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus::scheduler;
+namespace ms = milvus::scheduler;
 
 } // namespace
 
diff --git a/cpp/unittest/scheduler/test_normal.cpp b/cpp/unittest/scheduler/test_normal.cpp
index e24b43c6f8..fb59b04214 100644
--- a/cpp/unittest/scheduler/test_normal.cpp
+++ b/cpp/unittest/scheduler/test_normal.cpp
@@ -27,7 +27,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus::scheduler;
+namespace ms = milvus::scheduler;
 
 } // namespace
 
diff --git a/cpp/unittest/scheduler/test_resource.cpp b/cpp/unittest/scheduler/test_resource.cpp
index b6c522b8b5..7245761393 100644
--- a/cpp/unittest/scheduler/test_resource.cpp
+++ b/cpp/unittest/scheduler/test_resource.cpp
@@ -26,7 +26,7 @@
 #include "scheduler/ResourceFactory.h"
 #include <gtest/gtest.h>
 
-namespace zilliz {
+
 namespace milvus {
 namespace scheduler {
 
@@ -282,4 +282,4 @@ TEST_F(ResourceAdvanceTest, TEST_RESOURCE_TEST) {
 
 } // namespace scheduler
 } // namespace milvus
-} // namespace zilliz
+
diff --git a/cpp/unittest/scheduler/test_resource_factory.cpp b/cpp/unittest/scheduler/test_resource_factory.cpp
index 679edc6e3f..aaad3aa2c9 100644
--- a/cpp/unittest/scheduler/test_resource_factory.cpp
+++ b/cpp/unittest/scheduler/test_resource_factory.cpp
@@ -21,7 +21,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus::scheduler;
+namespace ms = milvus::scheduler;
 
 } // namespace
 
diff --git a/cpp/unittest/scheduler/test_resource_mgr.cpp b/cpp/unittest/scheduler/test_resource_mgr.cpp
index bf8ade9f64..40633baa54 100644
--- a/cpp/unittest/scheduler/test_resource_mgr.cpp
+++ b/cpp/unittest/scheduler/test_resource_mgr.cpp
@@ -24,7 +24,7 @@
 #include "scheduler/ResourceMgr.h"
 #include <gtest/gtest.h>
 
-namespace zilliz {
+
 namespace milvus {
 namespace scheduler {
 
@@ -191,4 +191,4 @@ TEST_F(ResourceMgrAdvanceTest, REGISTER_SUBSCRIBER) {
 
 } // namespace scheduler
 } // namespace milvus
-} // namespace zilliz
+
diff --git a/cpp/unittest/scheduler/test_schedinst.cpp b/cpp/unittest/scheduler/test_schedinst.cpp
index 4f3364c8fb..e63a9615bc 100644
--- a/cpp/unittest/scheduler/test_schedinst.cpp
+++ b/cpp/unittest/scheduler/test_schedinst.cpp
@@ -21,7 +21,7 @@
 #include "server/Config.h"
 #include "scheduler/SchedInst.h"
 
-namespace zilliz {
+
 namespace milvus {
 namespace scheduler {
 
@@ -83,6 +83,6 @@ TEST_F(SchedInstTest, SIMPLE_GPU) {
 
 } // namespace scheduler
 } // namespace milvus
-} // namespace zilliz
+
 
 
diff --git a/cpp/unittest/scheduler/test_scheduler.cpp b/cpp/unittest/scheduler/test_scheduler.cpp
index 4acfda315a..9666cc9812 100644
--- a/cpp/unittest/scheduler/test_scheduler.cpp
+++ b/cpp/unittest/scheduler/test_scheduler.cpp
@@ -28,7 +28,7 @@
 #include "utils/Error.h"
 #include "wrapper/VecIndex.h"
 
-namespace zilliz {
+
 namespace milvus {
 namespace scheduler {
 
@@ -43,7 +43,7 @@ class MockVecIndex : public engine::VecIndex {
     }
 
     engine::VecIndexPtr Clone() override {
-        return zilliz::milvus::engine::VecIndexPtr();
+        return milvus::engine::VecIndexPtr();
     }
 
     int64_t GetDeviceId() override {
@@ -81,12 +81,12 @@ class MockVecIndex : public engine::VecIndex {
         return ntotal_;
     }
 
-    virtual zilliz::knowhere::BinarySet Serialize() {
-        zilliz::knowhere::BinarySet binset;
+    virtual knowhere::BinarySet Serialize() {
+        knowhere::BinarySet binset;
         return binset;
     }
 
-    virtual Status Load(const zilliz::knowhere::BinarySet &index_binary) {
+    virtual Status Load(const knowhere::BinarySet &index_binary) {
     }
 
  public:
@@ -253,4 +253,4 @@ TEST_F(SchedulerTest2, SPECIFIED_RESOURCE_TEST) {
 
 } // namespace scheduler
 } // namespace milvus
-} // namespace zilliz
+
diff --git a/cpp/unittest/scheduler/test_tasktable.cpp b/cpp/unittest/scheduler/test_tasktable.cpp
index 0cb7018023..3cfbb5a27f 100644
--- a/cpp/unittest/scheduler/test_tasktable.cpp
+++ b/cpp/unittest/scheduler/test_tasktable.cpp
@@ -22,7 +22,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus::scheduler;
+namespace ms = milvus::scheduler;
 
 } // namespace
 
diff --git a/cpp/unittest/server/test_cache.cpp b/cpp/unittest/server/test_cache.cpp
index 8fea11fa62..754f23f51b 100644
--- a/cpp/unittest/server/test_cache.cpp
+++ b/cpp/unittest/server/test_cache.cpp
@@ -23,7 +23,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 class InvalidCacheMgr : public ms::cache::CacheMgr<ms::cache::DataObjPtr> {
  public:
@@ -55,7 +55,7 @@ class MockVecIndex : public ms::engine::VecIndex {
     }
 
     ms::engine::VecIndexPtr Clone() override {
-        return zilliz::milvus::engine::VecIndexPtr();
+        return milvus::engine::VecIndexPtr();
     }
 
     int64_t GetDeviceId() override {
@@ -98,12 +98,12 @@ class MockVecIndex : public ms::engine::VecIndex {
         return ntotal_;
     }
 
-    virtual zilliz::knowhere::BinarySet Serialize() {
-        zilliz::knowhere::BinarySet binset;
+    virtual knowhere::BinarySet Serialize() {
+        knowhere::BinarySet binset;
         return binset;
     }
 
-    virtual ms::Status Load(const zilliz::knowhere::BinarySet &index_binary) {
+    virtual ms::Status Load(const knowhere::BinarySet &index_binary) {
         return ms::Status();
     }
 
@@ -127,7 +127,7 @@ TEST(CacheTest, DUMMY_TEST) {
     mock_index.CopyToGpu(1, cfg);
     mock_index.GetDeviceId();
     mock_index.GetType();
-    zilliz::knowhere::BinarySet index_binary;
+    knowhere::BinarySet index_binary;
     mock_index.Load(index_binary);
     mock_index.Serialize();
 }
diff --git a/cpp/unittest/server/test_config.cpp b/cpp/unittest/server/test_config.cpp
index 0c613d8954..ef708a8382 100644
--- a/cpp/unittest/server/test_config.cpp
+++ b/cpp/unittest/server/test_config.cpp
@@ -25,7 +25,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 static const char *CONFIG_FILE_PATH = "./milvus/conf/server_config.yaml";
 static const char *LOG_FILE_PATH = "./milvus/conf/log_config.conf";
diff --git a/cpp/unittest/server/test_rpc.cpp b/cpp/unittest/server/test_rpc.cpp
index 3a36e3ee50..5baaed3152 100644
--- a/cpp/unittest/server/test_rpc.cpp
+++ b/cpp/unittest/server/test_rpc.cpp
@@ -36,7 +36,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 static const char *TABLE_NAME = "test_grpc";
 static constexpr int64_t TABLE_DIM = 256;
diff --git a/cpp/unittest/server/util_test.cpp b/cpp/unittest/server/util_test.cpp
index 89095193fb..0ee214a7e7 100644
--- a/cpp/unittest/server/util_test.cpp
+++ b/cpp/unittest/server/util_test.cpp
@@ -33,7 +33,7 @@
 
 namespace {
 
-namespace ms = zilliz::milvus;
+namespace ms = milvus;
 
 static const char *LOG_FILE_PATH = "./milvus/conf/log_config.conf";
 
diff --git a/cpp/unittest/wrapper/test_wrapper.cpp b/cpp/unittest/wrapper/test_wrapper.cpp
index b97b96d205..4dd2e33bd5 100644
--- a/cpp/unittest/wrapper/test_wrapper.cpp
+++ b/cpp/unittest/wrapper/test_wrapper.cpp
@@ -27,8 +27,8 @@ INITIALIZE_EASYLOGGINGPP
 
 namespace {
 
-namespace ms = zilliz::milvus::engine;
-namespace kw = zilliz::knowhere;
+namespace ms = milvus::engine;
+namespace kw = knowhere;
 
 } // namespace
 
@@ -50,41 +50,41 @@ class ParamGenerator {
     kw::Config Gen(const ms::IndexType &type) {
         switch (type) {
             case ms::IndexType::FAISS_IDMAP: {
-                auto tempconf = std::make_shared<zilliz::knowhere::Cfg>();
-                tempconf->metric_type = zilliz::knowhere::METRICTYPE::L2;
+                auto tempconf = std::make_shared<knowhere::Cfg>();
+                tempconf->metric_type = knowhere::METRICTYPE::L2;
                 return tempconf;
             }
             case ms::IndexType::FAISS_IVFFLAT_CPU:
             case ms::IndexType::FAISS_IVFFLAT_GPU:
             case ms::IndexType::FAISS_IVFFLAT_MIX: {
-                auto tempconf = std::make_shared<zilliz::knowhere::IVFCfg>();
+                auto tempconf = std::make_shared<knowhere::IVFCfg>();
                 tempconf->nlist = 100;
                 tempconf->nprobe = 16;
-                tempconf->metric_type = zilliz::knowhere::METRICTYPE::L2;
+                tempconf->metric_type = knowhere::METRICTYPE::L2;
                 return tempconf;
             }
             case ms::IndexType::FAISS_IVFSQ8_CPU:
             case ms::IndexType::FAISS_IVFSQ8_GPU:
             case ms::IndexType::FAISS_IVFSQ8_MIX: {
-                auto tempconf = std::make_shared<zilliz::knowhere::IVFSQCfg>();
+                auto tempconf = std::make_shared<knowhere::IVFSQCfg>();
                 tempconf->nlist = 100;
                 tempconf->nprobe = 16;
                 tempconf->nbits = 8;
-                tempconf->metric_type = zilliz::knowhere::METRICTYPE::L2;
+                tempconf->metric_type = knowhere::METRICTYPE::L2;
                 return tempconf;
             }
             case ms::IndexType::FAISS_IVFPQ_CPU:
             case ms::IndexType::FAISS_IVFPQ_GPU: {
-                auto tempconf = std::make_shared<zilliz::knowhere::IVFPQCfg>();
+                auto tempconf = std::make_shared<knowhere::IVFPQCfg>();
                 tempconf->nlist = 100;
                 tempconf->nprobe = 16;
                 tempconf->nbits = 8;
                 tempconf->m = 8;
-                tempconf->metric_type = zilliz::knowhere::METRICTYPE::L2;
+                tempconf->metric_type = knowhere::METRICTYPE::L2;
                 return tempconf;
             }
             case ms::IndexType::NSG_MIX: {
-                auto tempconf = std::make_shared<zilliz::knowhere::NSGCfg>();
+                auto tempconf = std::make_shared<knowhere::NSGCfg>();
                 tempconf->nlist = 100;
                 tempconf->nprobe = 16;
                 tempconf->search_length = 8;
@@ -92,7 +92,7 @@ class ParamGenerator {
                 tempconf->search_length = 40; // TODO(linxj): be 20 when search
                 tempconf->out_degree = 60;
                 tempconf->candidate_pool_size = 200;
-                tempconf->metric_type = zilliz::knowhere::METRICTYPE::L2;
+                tempconf->metric_type = knowhere::METRICTYPE::L2;
                 return tempconf;
             }
         }
@@ -103,7 +103,7 @@ class KnowhereWrapperTest
     : public TestWithParam<::std::tuple<ms::IndexType, std::string, int, int, int, int>> {
  protected:
     void SetUp() override {
-        zilliz::knowhere::FaissGpuResourceMgr::GetInstance().InitDevice(DEVICE_ID,
+        knowhere::FaissGpuResourceMgr::GetInstance().InitDevice(DEVICE_ID,
                                                                         1024 * 1024 * 200,
                                                                         1024 * 1024 * 300,
                                                                         2);
@@ -123,7 +123,7 @@ class KnowhereWrapperTest
     }
 
     void TearDown() override {
-        zilliz::knowhere::FaissGpuResourceMgr::GetInstance().Free();
+        knowhere::FaissGpuResourceMgr::GetInstance().Free();
     }
 
     void AssertResult(const std::vector<int64_t> &ids, const std::vector<float> &dis) {