diff --git a/src/impl/MilvusClientImpl.cpp b/src/impl/MilvusClientImpl.cpp
index 712a88d..38c8a8f 100644
--- a/src/impl/MilvusClientImpl.cpp
+++ b/src/impl/MilvusClientImpl.cpp
@@ -141,7 +141,7 @@ MilvusClientImpl::LoadCollection(const std::string& collection_name, int replica
     };
 
     auto wait_for_status = [this, &collection_name, &progress_monitor](const proto::common::Status&) {
-        return waitForStatus(
+        return WaitForStatus(
             [&collection_name, this](Progress& progress) -> Status {
                 CollectionsInfo collections_info;
                 auto collection_names = std::vector<std::string>{collection_name};
@@ -259,7 +259,7 @@ MilvusClientImpl::ShowCollections(const std::vector<std::string>& collection_nam
     };
 
     auto post = [&collections_info](const proto::milvus::ShowCollectionsResponse& response) {
-        for (size_t i = 0; i < response.collection_ids_size(); i++) {
+        for (int i = 0; i < response.collection_ids_size(); i++) {
             auto inmemory_percentage = 0;
             if (response.inmemory_percentages_size() > i) {
                 inmemory_percentage = response.inmemory_percentages(i);
@@ -331,7 +331,7 @@ MilvusClientImpl::LoadPartitions(const std::string& collection_name, const std::
     };
 
     auto wait_for_status = [this, &collection_name, &partition_names, &progress_monitor](const proto::common::Status&) {
-        return waitForStatus(
+        return WaitForStatus(
             [&collection_name, &partition_names, this](Progress& progress) -> Status {
                 PartitionsInfo partitions_info;
                 auto status = ShowPartitions(collection_name, partition_names, partitions_info);
@@ -422,7 +422,7 @@ MilvusClientImpl::ShowPartitions(const std::string& collection_name, const std::
         if (count > 0) {
             partitions_info.reserve(count);
         }
-        for (size_t i = 0; i < count; ++i) {
+        for (int i = 0; i < count; ++i) {
             partitions_info.emplace_back(response.partition_names(i), response.partitionids(i),
                                          response.created_timestamps(i), response.inmemory_percentages(i));
         }
@@ -499,7 +499,7 @@ MilvusClientImpl::CreateIndex(const std::string& collection_name, const IndexDes
     };
 
     auto wait_for_status = [&collection_name, &index_desc, &progress_monitor, this](const proto::common::Status&) {
-        return waitForStatus(
+        return WaitForStatus(
             [&collection_name, &index_desc, this](Progress& progress) -> Status {
                 IndexState index_state;
                 auto status = GetIndexState(collection_name, index_desc.FieldName(), index_state);
@@ -539,13 +539,13 @@ MilvusClientImpl::DescribeIndex(const std::string& collection_name, const std::s
 
     auto post = [&index_desc](const proto::milvus::DescribeIndexResponse& response) {
         auto count = response.index_descriptions_size();
-        for (size_t i = 0; i < count; ++i) {
+        for (int i = 0; i < count; ++i) {
             auto& field_name = response.index_descriptions(i).field_name();
             auto& index_name = response.index_descriptions(i).index_name();
             index_desc.SetFieldName(field_name);
             index_desc.SetIndexName(index_name);
             auto index_params_size = response.index_descriptions(i).params_size();
-            for (size_t j = 0; j < index_params_size; ++j) {
+            for (int j = 0; j < index_params_size; ++j) {
                 const auto& key = response.index_descriptions(i).params(j).key();
                 const auto& value = response.index_descriptions(i).params(j).value();
                 if (key == milvus::KeyIndexType()) {
@@ -759,19 +759,20 @@ MilvusClientImpl::Search(const SearchArguments& arguments, SearchResults& result
         const auto& scores = result_data.scores();
         const auto& fields_data = result_data.fields_data();
         auto num_of_queries = result_data.num_queries();
-        std::vector<int64_t> topks(num_of_queries, result_data.top_k());
+        std::vector<int> topks{};
+        topks.reserve(result_data.topks_size());
         for (int i = 0; i < result_data.topks_size(); ++i) {
-            topks[i] = result_data.topks(i);
+            topks.emplace_back(result_data.topks(i));
         }
         std::vector<SingleResult> single_results;
         single_results.reserve(num_of_queries);
-        size_t offset{0};
-        for (int64_t i = 0; i < num_of_queries; ++i) {
+        int offset{0};
+        for (int i = 0; i < num_of_queries; ++i) {
             std::vector<float> item_scores;
             std::vector<FieldDataPtr> item_field_data;
             auto item_topk = topks[i];
             item_scores.reserve(item_topk);
-            for (int64_t j = 0; j < item_topk; ++j) {
+            for (int j = 0; j < item_topk; ++j) {
                 item_scores.emplace_back(scores.at(offset + j));
             }
             item_field_data.reserve(fields_data.size());
@@ -842,7 +843,7 @@ MilvusClientImpl::CalcDistance(const CalcDistanceArguments& arguments, DistanceA
                     }
 
                     // suppose vectors is not empty, already checked by Validate()
-                    data_array->set_dim(vectors[0].size());
+                    data_array->set_dim(static_cast<int>(vectors[0].size()));
                 } else {
                     auto data_ptr = std::static_pointer_cast<BinaryVecFieldData>(arg_vectors);
                     auto& str = *data_array->mutable_binary_vector();
@@ -853,7 +854,7 @@ MilvusClientImpl::CalcDistance(const CalcDistanceArguments& arguments, DistanceA
                     for (auto& vector : vectors) {
                         str.append(vector);
                     }
-                    data_array->set_dim(dimensions);
+                    data_array->set_dim(static_cast<int>(dimensions));
                 }
 
             } else if (arg_vectors->Type() == DataType::INT64) {
@@ -960,7 +961,7 @@ MilvusClientImpl::Flush(const std::vector<std::string>& collection_names, const
             return Status::OK();
         }
 
-        return waitForStatus(
+        return WaitForStatus(
             [&segment_count, &flush_segments, &finished_count, this](Progress& p) -> Status {
                 p.total_ = segment_count;
 
@@ -1117,7 +1118,7 @@ MilvusClientImpl::ManualCompaction(const std::string& collection_name, uint64_t
         return status;
     }
 
-    auto pre = [&collection_name, &travel_timestamp, &collection_desc]() {
+    auto pre = [&travel_timestamp, &collection_desc]() {
         proto::milvus::ManualCompactionRequest rpc_request;
         rpc_request.set_collectionid(collection_desc.ID());
         rpc_request.set_timetravel(travel_timestamp);
@@ -1223,7 +1224,7 @@ MilvusClientImpl::ListCredUsers(std::vector<std::string>& users) {
 }
 
 Status
-MilvusClientImpl::waitForStatus(std::function<Status(Progress&)> query_function,
+MilvusClientImpl::WaitForStatus(const std::function<Status(Progress&)>& query_function,
                                 const ProgressMonitor& progress_monitor) {
     // no need to check
     if (progress_monitor.CheckTimeout() == 0) {
diff --git a/src/impl/MilvusClientImpl.h b/src/impl/MilvusClientImpl.h
index 0edacab..c71be7c 100644
--- a/src/impl/MilvusClientImpl.h
+++ b/src/impl/MilvusClientImpl.h
@@ -186,8 +186,8 @@ class MilvusClientImpl : public MilvusClient {
      * @param [in] progress_monitor timeout setting for waiting progress
      * @return Status, the final status
      */
-    Status
-    waitForStatus(std::function<Status(Progress&)> query_function, const ProgressMonitor& progress_monitor);
+    static Status
+    WaitForStatus(const std::function<Status(Progress&)>& query_function, const ProgressMonitor& progress_monitor);
 
     /**
      * @brief template for public api call
@@ -195,7 +195,7 @@ class MilvusClientImpl : public MilvusClient {
      */
     template <typename Request, typename Response>
     Status
-    apiHandler(std::function<Status(void)> validate, std::function<Request(void)> pre,
+    apiHandler(const std::function<Status(void)>& validate, std::function<Request(void)> pre,
                Status (MilvusConnection::*rpc)(const Request&, Response&, const GrpcOpts&),
                std::function<Status(const Response&)> wait_for_status, std::function<void(const Response&)> post,
                const GrpcOpts& options = GrpcOpts{}) {
@@ -215,7 +215,7 @@ class MilvusClientImpl : public MilvusClient {
         auto status = std::bind(rpc, connection_.get(), std::placeholders::_1, std::placeholders::_2,
                                 std::placeholders::_3)(rpc_request, rpc_response, options);
         if (!status.IsOk()) {
-            // resp's status already checked in connection class
+            // response's status already checked in connection class
             return status;
         }
 
diff --git a/src/impl/MilvusConnection.cpp b/src/impl/MilvusConnection.cpp
index 2b2c907..7b66b04 100644
--- a/src/impl/MilvusConnection.cpp
+++ b/src/impl/MilvusConnection.cpp
@@ -20,7 +20,6 @@
 #include <memory>
 
 #include "grpcpp/security/credentials.h"
-#include "milvus/types/ConnectParam.h"
 
 using grpc::Channel;
 using grpc::ClientContext;
@@ -63,8 +62,8 @@ MilvusConnection::~MilvusConnection() {
 Status
 MilvusConnection::Connect(const ConnectParam& param) {
     authorization_value_ = param.Authorizations();
-    std::shared_ptr<grpc::ChannelCredentials> creds{nullptr};
-    auto& uri = param.Uri();
+    std::shared_ptr<grpc::ChannelCredentials> credentials{nullptr};
+    auto uri = param.Uri();
 
     ::grpc::ChannelArguments args;
     args.SetMaxSendMessageSize(-1);     // max send message size: 2GB
@@ -74,12 +73,12 @@ MilvusConnection::Connect(const ConnectParam& param) {
         if (!param.ServerName().empty()) {
             args.SetSslTargetNameOverride(param.ServerName());
         }
-        creds = createTlsCredentials(param.Cert(), param.Key(), param.CaCert());
+        credentials = createTlsCredentials(param.Cert(), param.Key(), param.CaCert());
     } else {
-        creds = ::grpc::InsecureChannelCredentials();
+        credentials = ::grpc::InsecureChannelCredentials();
     }
 
-    channel_ = ::grpc::CreateCustomChannel(uri, creds, args);
+    channel_ = ::grpc::CreateCustomChannel(uri, credentials, args);
     auto connected = channel_->WaitForConnected(std::chrono::system_clock::now() +
                                                 std::chrono::milliseconds{param.ConnectTimeout()});
     if (connected) {
@@ -175,7 +174,7 @@ MilvusConnection::DropPartition(const proto::milvus::DropPartitionRequest& reque
 Status
 MilvusConnection::HasPartition(const proto::milvus::HasPartitionRequest& request, proto::milvus::BoolResponse& response,
                                const GrpcContextOptions& options) {
-    return grpcCall("HasParition", &Stub::HasPartition, request, response, options);
+    return grpcCall("HasPartition", &Stub::HasPartition, request, response, options);
 }
 
 Status
diff --git a/src/impl/MilvusConnection.h b/src/impl/MilvusConnection.h
index aa53948..5f275df 100644
--- a/src/impl/MilvusConnection.h
+++ b/src/impl/MilvusConnection.h
@@ -238,23 +238,23 @@ class MilvusConnection {
     std::shared_ptr<grpc::Channel> channel_;
     std::string authorization_value_{};
 
-    Status
-    statusByProtoResponse(const proto::common::Status& status) {
-        if (status.error_code() != proto::common::ErrorCode::Success) {
+    static Status
+    StatusByProtoResponse(const proto::common::Status& status) {
+        if (status.code() != proto::common::ErrorCode::Success) {
             return Status{StatusCode::SERVER_FAILED, status.reason()};
         }
         return Status::OK();
     }
 
     template <typename Response>
-    Status
-    statusByProtoResponse(const Response& response) {
+    static Status
+    StatusByProtoResponse(const Response& response) {
         const auto& status = response.status();
-        return statusByProtoResponse(status);
+        return StatusByProtoResponse(status);
     }
 
-    StatusCode
-    statusCodeFromGrpcStatus(const ::grpc::Status& grpc_status) {
+    static StatusCode
+    StatusCodeFromGrpcStatus(const ::grpc::Status& grpc_status) {
         if (grpc_status.error_code() == ::grpc::StatusCode::DEADLINE_EXCEEDED) {
             return StatusCode::TIMEOUT;
         }
@@ -284,10 +284,10 @@ class MilvusConnection {
         ::grpc::Status grpc_status = (stub_.get()->*func)(&context, request, &response);
 
         if (!grpc_status.ok()) {
-            return {statusCodeFromGrpcStatus(grpc_status), grpc_status.error_message()};
+            return {StatusCodeFromGrpcStatus(grpc_status), grpc_status.error_message()};
         }
 
-        return statusByProtoResponse(response);
+        return StatusByProtoResponse(response);
     }
 };
 
diff --git a/src/impl/Status.cpp b/src/impl/Status.cpp
index 7ad613c..f34677d 100644
--- a/src/impl/Status.cpp
+++ b/src/impl/Status.cpp
@@ -16,8 +16,6 @@
 
 #include "milvus/Status.h"
 
-#include <cstring>
-
 namespace milvus {
 
 Status::Status(StatusCode code, std::string msg) : code_(code), msg_(std::move(msg)) {
diff --git a/src/impl/TypeUtils.cpp b/src/impl/TypeUtils.cpp
index 0447d7a..ae213d0 100644
--- a/src/impl/TypeUtils.cpp
+++ b/src/impl/TypeUtils.cpp
@@ -406,7 +406,7 @@ CreateProtoFieldData(const BinaryVecFieldData& field) {
     for (const auto& item : data) {
         std::copy(item.begin(), item.end(), std::back_inserter(vectors_data));
     }
-    ret->set_dim(dim);
+    ret->set_dim(static_cast<int>(dim));
     return ret;
 }
 
@@ -416,11 +416,11 @@ CreateProtoFieldData(const FloatVecFieldData& field) {
     auto& data = field.Data();
     auto dim = data.front().size();
     auto& vectors_data = *(ret->mutable_float_vector()->mutable_data());
-    vectors_data.Reserve(data.size() * dim);
+    vectors_data.Reserve(static_cast<int>(data.size() * dim));
     for (const auto& item : data) {
         vectors_data.Add(item.begin(), item.end());
     }
-    ret->set_dim(dim);
+    ret->set_dim(static_cast<int>(dim));
     return ret;
 }
 
diff --git a/src/impl/types/CalcDistanceArguments.cpp b/src/impl/types/CalcDistanceArguments.cpp
index 2302743..202aa50 100644
--- a/src/impl/types/CalcDistanceArguments.cpp
+++ b/src/impl/types/CalcDistanceArguments.cpp
@@ -16,8 +16,6 @@
 
 #include "milvus/types/CalcDistanceArguments.h"
 
-#include <algorithm>
-#include <functional>
 #include <set>
 #include <unordered_map>
 
diff --git a/src/impl/types/CollectionStat.cpp b/src/impl/types/CollectionStat.cpp
index 3d05456..c060f90 100644
--- a/src/impl/types/CollectionStat.cpp
+++ b/src/impl/types/CollectionStat.cpp
@@ -29,7 +29,7 @@ CollectionStat::RowCount() const {
         // TODO: throw exception or log
         return 0;
     }
-    return std::atoll(iter->second.c_str());
+    return std::strtoll(iter->second.c_str(), nullptr, 10);
 }
 
 void
diff --git a/src/impl/types/CompactionState.cpp b/src/impl/types/CompactionState.cpp
index 4c8ded4..4e05cd6 100644
--- a/src/impl/types/CompactionState.cpp
+++ b/src/impl/types/CompactionState.cpp
@@ -16,8 +16,6 @@
 
 #include "milvus/types/CompactionState.h"
 
-#include <string>
-
 namespace milvus {
 
 CompactionState::CompactionState() = default;
diff --git a/src/impl/types/ConnectParam.cpp b/src/impl/types/ConnectParam.cpp
index 3464c1f..7ac68d7 100644
--- a/src/impl/types/ConnectParam.cpp
+++ b/src/impl/types/ConnectParam.cpp
@@ -40,7 +40,7 @@ ConnectParam::Port() const {
     return port_;
 }
 
-const std::string
+std::string
 ConnectParam::Uri() const {
     return host_ + ":" + std::to_string(port_);
 }
diff --git a/src/impl/types/FieldSchema.cpp b/src/impl/types/FieldSchema.cpp
index 010a4d3..cd4c0c7 100644
--- a/src/impl/types/FieldSchema.cpp
+++ b/src/impl/types/FieldSchema.cpp
@@ -100,7 +100,7 @@ uint32_t
 FieldSchema::Dimension() const {
     auto iter = type_params_.find(FieldDim());
     if (iter != type_params_.end()) {
-        return std::atol(iter->second.c_str());
+        return std::strtol(iter->second.c_str(), nullptr, 10);
     }
     return 0;
 }
@@ -124,7 +124,7 @@ uint32_t
 FieldSchema::MaxLength() const {
     auto iter = type_params_.find(FieldMaxLength());
     if (iter != type_params_.end()) {
-        return std::atol(iter->second.c_str());
+        return std::strtol(iter->second.c_str(), nullptr, 10);
     }
     return 0;
 }
diff --git a/src/impl/types/HybirdTimestamp.cpp b/src/impl/types/HybridTimestamp.cpp
similarity index 57%
rename from src/impl/types/HybirdTimestamp.cpp
rename to src/impl/types/HybridTimestamp.cpp
index c650d79..bcd27b5 100644
--- a/src/impl/types/HybirdTimestamp.cpp
+++ b/src/impl/types/HybridTimestamp.cpp
@@ -14,47 +14,47 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include "milvus/types/HybirdTimestamp.h"
+#include "milvus/types/HybridTimestamp.h"
 
 namespace milvus {
 
-HybirdTimestamp::HybirdTimestamp() = default;
+HybridTimestamp::HybridTimestamp() = default;
 
-HybirdTimestamp::HybirdTimestamp(uint64_t ts) : ts_(ts) {
+HybridTimestamp::HybridTimestamp(uint64_t ts) : ts_(ts) {
 }
 
-HybirdTimestamp::HybirdTimestamp(uint64_t physical, uint64_t logical)
-    : ts_((physical << milvus::HybirdtsLogicalBits()) + logical) {
+HybridTimestamp::HybridTimestamp(uint64_t physical, uint64_t logical)
+    : ts_((physical << milvus::HybridTsLogicalBits()) + logical) {
 }
 
 uint64_t
-HybirdTimestamp::Timestamp() const {
+HybridTimestamp::Timestamp() const {
     return ts_;
 }
 
 uint64_t
-HybirdTimestamp::Logical() const {
-    return ts_ & milvus::HybirdtsLogicalBitsMask();
+HybridTimestamp::Logical() const {
+    return ts_ & milvus::HybridTsLogicalBitsMask();
 }
 
 uint64_t
-HybirdTimestamp::Physical() const {
-    return ts_ >> milvus::HybirdtsLogicalBits();
+HybridTimestamp::Physical() const {
+    return ts_ >> milvus::HybridTsLogicalBits();
 }
 
-HybirdTimestamp&
-HybirdTimestamp::operator+=(uint64_t milliseconds) {
-    ts_ += (milliseconds << milvus::HybirdtsLogicalBits());
+HybridTimestamp&
+HybridTimestamp::operator+=(uint64_t milliseconds) {
+    ts_ += (milliseconds << milvus::HybridTsLogicalBits());
     return *this;
 }
 
-HybirdTimestamp
-HybirdTimestamp::operator+(uint64_t milliseconds) {
+HybridTimestamp
+HybridTimestamp::operator+(uint64_t milliseconds) const {
     return {Physical() + milliseconds, Logical()};
 }
 
-HybirdTimestamp
-HybirdTimestamp::CreateFromUnixtime(uint64_t epoch_in_milliseconds) {
+HybridTimestamp
+HybridTimestamp::CreateFromUnixTime(uint64_t epoch_in_milliseconds) {
     return {epoch_in_milliseconds, 0};
 }
 }  // namespace milvus
diff --git a/src/impl/types/PartitionStat.cpp b/src/impl/types/PartitionStat.cpp
index ebd47b4..425fa61 100644
--- a/src/impl/types/PartitionStat.cpp
+++ b/src/impl/types/PartitionStat.cpp
@@ -24,7 +24,7 @@ PartitionStat::RowCount() const {
         // TODO: throw exception or log
         return 0;
     }
-    return std::atoll(iter->second.c_str());
+    return std::strtoll(iter->second.c_str(), nullptr, 10);
 }
 
 void
diff --git a/src/impl/types/SearchResults.cpp b/src/impl/types/SearchResults.cpp
index 1a7168e..a2c5b95 100644
--- a/src/impl/types/SearchResults.cpp
+++ b/src/impl/types/SearchResults.cpp
@@ -37,7 +37,7 @@ SingleResult::OutputFields() const {
     return output_fields_;
 }
 
-const FieldDataPtr
+FieldDataPtr
 SingleResult::OutputField(const std::string& name) const {
     for (const auto& output_field : output_fields_) {
         if (output_field->Name() == name) {
diff --git a/src/include/milvus/MilvusClient.h b/src/include/milvus/MilvusClient.h
index e87b23b..f515ce6 100644
--- a/src/include/milvus/MilvusClient.h
+++ b/src/include/milvus/MilvusClient.h
@@ -30,7 +30,7 @@
 #include "types/DistanceArray.h"
 #include "types/DmlResults.h"
 #include "types/FieldData.h"
-#include "types/HybirdTimestamp.h"
+#include "types/HybridTimestamp.h"
 #include "types/IndexDesc.h"
 #include "types/IndexState.h"
 #include "types/PartitionInfo.h"
@@ -174,11 +174,11 @@ class MilvusClient {
                             const ProgressMonitor& progress_monitor = ProgressMonitor::Forever()) = 0;
 
     /**
-     * If the collection_names is empty, list all collections brief informations. \n
+     * If the collection_names is empty, list all collections brief information's. \n
      * If the collection_names is specified, return the specified collection's loading process state.
      *
      * @param [in] collection_names name array of collections
-     * @param [out] collections_info brief informations of the collections
+     * @param [out] collections_info brief information's of the collections
      * @return Status operation successfully or not
      */
     virtual Status
@@ -258,12 +258,12 @@ class MilvusClient {
                            const ProgressMonitor& progress_monitor = ProgressMonitor::Forever()) = 0;
 
     /**
-     * If the partition_names is empty, list all partitions brief informations. \n
+     * If the partition_names is empty, list all partitions brief information's. \n
      * If the partition_names is specified, return the specified partition's loading process state.
      *
      * @param [in] collection_name name of the collection
      * @param [in] partition_names name array of the partitions
-     * @param [out] partitions_info brief informations of the partitions
+     * @param [out] partitions_info brief information's of the partitions
      * @return Status operation successfully or not
      */
     virtual Status
@@ -385,7 +385,7 @@ class MilvusClient {
            DmlResults& results) = 0;
 
     /**
-     * Searche a collection based on the given parameters and return results.
+     * Search a collection based on the given parameters and return results.
      *
      * @param [in] arguments search arguments
      * @param [out] results search results
@@ -424,7 +424,7 @@ class MilvusClient {
 
     /**
      * Flush insert buffer into storage.  \n
-     * To makesure the buffer persisted successfully, it calls GetFlushState() to check related segments state.
+     * To make sure the buffer persisted successfully, it calls GetFlushState() to check related segments state.
      *
      * @param [in] collection_names specify target collection names, if this array is empty, will flush all collections
      * @param [in] progress_monitor timeout setting for waiting progress. Set ProgressMonitor::NoWait() to return
@@ -477,7 +477,7 @@ class MilvusClient {
     GetMetrics(const std::string& request, std::string& response, std::string& component_name) = 0;
 
     /**
-     * Rebalance sealed segments from one query node to others.
+     * Rebalanced sealed segments from one query node to others.
      *
      * @param [in] src_node the source query node id
      * @param [in] dst_nodes the destiny query nodes id array
diff --git a/src/include/milvus/types/ConnectParam.h b/src/include/milvus/types/ConnectParam.h
index 3a221c0..730a9da 100644
--- a/src/include/milvus/types/ConnectParam.h
+++ b/src/include/milvus/types/ConnectParam.h
@@ -50,7 +50,7 @@ class ConnectParam {
     /**
      * @brief Uri for connecting to the milvus.
      */
-    const std::string
+    std::string
     Uri() const;
 
     /**
diff --git a/src/include/milvus/types/Constants.h b/src/include/milvus/types/Constants.h
index 03583c9..216a165 100644
--- a/src/include/milvus/types/Constants.h
+++ b/src/include/milvus/types/Constants.h
@@ -22,7 +22,7 @@ namespace milvus {
 /**
  * @brief Global definition for row count label
  */
-inline const std::string
+inline std::string
 KeyRowCount() {
     return "row_count";
 }
@@ -30,7 +30,7 @@ KeyRowCount() {
 /**
  * @brief Global definition for index type label
  */
-inline const std::string
+inline std::string
 KeyIndexType() {
     return "index_type";
 }
@@ -38,7 +38,7 @@ KeyIndexType() {
 /**
  * @brief Global definition for metric type label
  */
-inline const std::string
+inline std::string
 KeyMetricType() {
     return "metric_type";
 }
@@ -46,7 +46,7 @@ KeyMetricType() {
 /**
  * @brief Global definition for metric type label
  */
-inline const std::string
+inline std::string
 KeyParams() {
     return "params";
 }
@@ -54,7 +54,7 @@ KeyParams() {
 /**
  * @brief Global definition for vector dimension label
  */
-inline const std::string
+inline std::string
 FieldDim() {
     return "dim";
 }
@@ -62,7 +62,7 @@ FieldDim() {
 /**
  * @brief Max length field name for varchar field
  */
-inline const std::string
+inline std::string
 FieldMaxLength() {
     return "max_length";
 }
@@ -84,17 +84,17 @@ GuaranteeEventuallyTs() {
 }
 
 /**
- * @brief The logical bits in hybird timestamp
+ * @brief The logical bits in hybrid timestamp
  */
-constexpr size_t inline HybirdtsLogicalBits() {
+constexpr size_t inline HybridTsLogicalBits() {
     return 18;
 }
 
 /**
- * @brief The logical bits mask for hybird timestamp
+ * @brief The logical bits mask for hybrid timestamp
  */
-constexpr uint64_t inline HybirdtsLogicalBitsMask() {
-    return (1 << HybirdtsLogicalBits()) - 1;
+constexpr uint64_t inline HybridTsLogicalBitsMask() {
+    return (1 << HybridTsLogicalBits()) - 1;
 }
 
 }  // namespace milvus
diff --git a/src/include/milvus/types/DistanceArray.h b/src/include/milvus/types/DistanceArray.h
index dee9458..8466b0a 100644
--- a/src/include/milvus/types/DistanceArray.h
+++ b/src/include/milvus/types/DistanceArray.h
@@ -83,7 +83,7 @@ class DistanceArray {
     SetIntDistance(std::vector<std::vector<int32_t>>&& distance_array);
 
     /**
-     * @brief Float distance 2-d arraywe called.
+     * @brief Float distance 2-d array we called.
      *        Assume the vectors_left: L_1, L_2, L_3 \n
      *        Assume the vectors_right: R_a, R_b \n
      *        Distance between L_n and R_m we called "D_n_m" \n
diff --git a/src/include/milvus/types/FieldData.h b/src/include/milvus/types/FieldData.h
index 4400405..bf827a3 100644
--- a/src/include/milvus/types/FieldData.h
+++ b/src/include/milvus/types/FieldData.h
@@ -31,7 +31,7 @@ class Field {
     const std::string&
     Name() const;
     /**
-     * @brief Get field data tpye
+     * @brief Get field data type
      */
     DataType
     Type() const;
@@ -53,7 +53,7 @@ class Field {
 using FieldDataPtr = std::shared_ptr<Field>;
 
 /**
- * @brief Template class represents column-based data of a field. Avaiable inheritance classes: \n
+ * @brief Template class represents column-based data of a field. Available inheritance classes: \n
  *  BoolFieldData for boolean scalar field \n
  *  Int8FieldData for 8-bits integer scalar field \n
  *  Int16FieldData for 16-bits integer scalar field \n
@@ -96,13 +96,13 @@ class FieldData : public Field {
     /**
      * @brief Add element to field data
      */
-    StatusCode
+    virtual StatusCode
     Add(const T& element);
 
     /**
      * @brief Add element to field data
      */
-    StatusCode
+    virtual StatusCode
     Add(T&& element);
 
     /**
@@ -114,13 +114,13 @@ class FieldData : public Field {
     /**
      * @brief Field elements array
      */
-    const std::vector<T>&
+    virtual const std::vector<T>&
     Data() const;
 
     /**
      * @brief Field elements array
      */
-    std::vector<T>&
+    virtual std::vector<T>&
     Data();
 
  private:
@@ -159,13 +159,13 @@ class BinaryVecFieldData : public FieldData<std::string, DataType::BINARY_VECTOR
      * @brief Field elements array
      */
     const std::vector<std::string>&
-    Data() const;
+    Data() const override;
 
     /**
      * @brief Field elements array
      */
     std::vector<std::string>&
-    Data();
+    Data() override;
 
     /**
      * @brief Data export as uint8_t's vector
@@ -177,14 +177,14 @@ class BinaryVecFieldData : public FieldData<std::string, DataType::BINARY_VECTOR
      * @brief Add element to field data
      */
     StatusCode
-    Add(const std::string& element);
+    Add(const std::string& element) override;
 
     /**
      * @brief Add element to field data
      */
 
     StatusCode
-    Add(std::string&& element);
+    Add(std::string&& element) override;
 
     /**
      * @brief Add element to field data
diff --git a/src/include/milvus/types/FieldSchema.h b/src/include/milvus/types/FieldSchema.h
index 13e765f..91edec1 100644
--- a/src/include/milvus/types/FieldSchema.h
+++ b/src/include/milvus/types/FieldSchema.h
@@ -165,7 +165,7 @@ class FieldSchema {
  private:
     std::string name_;
     std::string description_;
-    DataType data_type_;
+    DataType data_type_{DataType::FLOAT};
     bool is_primary_key_ = false;
     bool auto_id_ = false;
     std::map<std::string, std::string> type_params_;
diff --git a/src/include/milvus/types/HybirdTimestamp.h b/src/include/milvus/types/HybridTimestamp.h
similarity index 70%
rename from src/include/milvus/types/HybirdTimestamp.h
rename to src/include/milvus/types/HybridTimestamp.h
index 30767f8..26be4c8 100644
--- a/src/include/milvus/types/HybirdTimestamp.h
+++ b/src/include/milvus/types/HybridTimestamp.h
@@ -22,25 +22,25 @@
 namespace milvus {
 
 template <typename Duration>
-struct _is_std_duration;
+struct is_std_duration;
 
-template <typename _Rep, typename _Period>
-struct _is_std_duration<std::chrono::duration<_Rep, _Period>> {
+template <typename Rep, typename Period>
+struct is_std_duration<std::chrono::duration<Rep, Period>> {
     static const bool value = true;
 };
 
 /**
- * @brief Hybird Timestamp
+ * @brief Hybrid Timestamp
  */
-class HybirdTimestamp {
+class HybridTimestamp {
     uint64_t ts_{0};
 
  public:
-    HybirdTimestamp();
+    HybridTimestamp();
 
-    explicit HybirdTimestamp(uint64_t ts);
+    explicit HybridTimestamp(uint64_t ts);
 
-    HybirdTimestamp(uint64_t physical, uint64_t logical);
+    HybridTimestamp(uint64_t physical, uint64_t logical);
 
     /**
      * @brief Hybird timestamp value
@@ -64,8 +64,8 @@ class HybirdTimestamp {
      * @brief Increase duration in physical part
      *
      */
-    template <typename Duration, std::enable_if_t<_is_std_duration<Duration>::value, bool> = true>
-    HybirdTimestamp&
+    template <typename Duration, std::enable_if_t<is_std_duration<Duration>::value, bool> = true>
+    HybridTimestamp&
     operator+=(Duration duration) {
         auto milliseconds = std::chrono::duration_cast<std::chrono::milliseconds>(duration).count();
         return *this += milliseconds;
@@ -75,19 +75,19 @@ class HybirdTimestamp {
      * @brief Increase milliseconds in physical part
      *
      * @param milliseconds
-     * @return HybirdTimestamp
+     * @return HybridTimestamp
      */
-    HybirdTimestamp&
+    HybridTimestamp&
     operator+=(uint64_t milliseconds);
 
     /**
      * @brief Add duration in physical part
      *
      * @param duration Duration
-     * @return HybirdTimestamp
+     * @return HybridTimestamp
      */
-    template <typename Duration, std::enable_if_t<_is_std_duration<Duration>::value, bool> = true>
-    HybirdTimestamp
+    template <typename Duration, std::enable_if_t<is_std_duration<Duration>::value, bool> = true>
+    HybridTimestamp
     operator+(Duration duration) {
         auto milliseconds = std::chrono::duration_cast<std::chrono::milliseconds>(duration).count();
         return *this + milliseconds;
@@ -97,15 +97,15 @@ class HybirdTimestamp {
      * @brief Add milliseconds in physical part
      *
      * @param milliseconds
-     * @return HybirdTimestamp
+     * @return HybridTimestamp
      */
-    HybirdTimestamp
-    operator+(uint64_t milliseconds);
+    HybridTimestamp
+    operator+(uint64_t milliseconds) const;
 
     /**
-     * @brief Create hybird timestamp from unix time
+     * @brief Create hybrid timestamp from unix time
      */
-    static HybirdTimestamp
-    CreateFromUnixtime(uint64_t epoch_in_milliseconds);
+    static HybridTimestamp
+    CreateFromUnixTime(uint64_t epoch_in_milliseconds);
 };
 }  // namespace milvus
diff --git a/src/include/milvus/types/ProgressMonitor.h b/src/include/milvus/types/ProgressMonitor.h
index 434eb4e..1009cda 100644
--- a/src/include/milvus/types/ProgressMonitor.h
+++ b/src/include/milvus/types/ProgressMonitor.h
@@ -40,7 +40,7 @@ struct Progress {
     Done() const;
 
     /**
-     * @brief How much work is finised
+     * @brief How much work is finished
      */
     uint32_t finished_ = 0;
 
@@ -108,7 +108,7 @@ class ProgressMonitor {
     /**
      * @brief Set call back function to receive progress notification.
      *
-     * @param [in] func call back function to recieve progress notification.
+     * @param [in] func call back function to receive progress notification.
      */
     void
     SetCallbackFunc(CallbackFunc func);
diff --git a/src/include/milvus/types/SearchResults.h b/src/include/milvus/types/SearchResults.h
index 0a3e521..5cc1a36 100644
--- a/src/include/milvus/types/SearchResults.h
+++ b/src/include/milvus/types/SearchResults.h
@@ -40,7 +40,7 @@ struct SingleResult {
     Scores() const;
 
     /**
-     * @brief Topk id array of one target vecotor
+     * @brief Topk id array of one target vector
      */
     const IDArray&
     Ids() const;
@@ -54,7 +54,7 @@ struct SingleResult {
     /**
      * @brief Get an output field by name
      */
-    const FieldDataPtr
+    FieldDataPtr
     OutputField(const std::string& name) const;
 
  private:
diff --git a/test/it/TestCalcDistance.cpp b/test/it/TestCalcDistance.cpp
index 9725712..fed2172 100644
--- a/test/it/TestCalcDistance.cpp
+++ b/test/it/TestCalcDistance.cpp
@@ -52,9 +52,9 @@ TEST_F(MilvusMockedTest, CalcDistanceFloat) {
         .WillOnce([&](::grpc::ServerContext*, const CalcDistanceRequest* request, CalcDistanceResults* response) {
             // validate params
             auto& params = request->params();
-            for (int i = 0; i < params.size(); ++i) {
-                if (params[i].key() == "metric") {
-                    EXPECT_EQ(params[i].value(), "IP");
+            for (const auto& param : params) {
+                if (param.key() == "metric") {
+                    EXPECT_EQ(param.value(), "IP");
                 }
             }
 
@@ -140,9 +140,9 @@ TEST_F(MilvusMockedTest, CalcDistanceBinary) {
         .WillOnce([&](::grpc::ServerContext*, const CalcDistanceRequest* request, CalcDistanceResults* response) {
             // validate metric
             auto& params = request->params();
-            for (int i = 0; i < params.size(); ++i) {
-                if (params[i].key() == "metric") {
-                    EXPECT_EQ(params[i].value(), "HAMMING");
+            for (const auto& param : params) {
+                if (param.key() == "metric") {
+                    EXPECT_EQ(param.value(), "HAMMING");
                 }
             }
 
@@ -164,7 +164,7 @@ TEST_F(MilvusMockedTest, CalcDistanceBinary) {
                 auto& binary_array = data_arr.binary_vector();
                 EXPECT_GE(binary_array.length(), offset + element.size());
                 for (auto i = 0; i < element.size(); ++i) {
-                    EXPECT_EQ(binary_array.data()[offset + i], element[i]);
+                    EXPECT_EQ(binary_array[offset + i], element[i]);
                 }
             };
 
@@ -224,9 +224,9 @@ TEST_F(MilvusMockedTest, CalcDistanceIDArray) {
         .WillOnce([&](::grpc::ServerContext*, const CalcDistanceRequest* request, CalcDistanceResults* response) {
             // validate metric
             auto& params = request->params();
-            for (int i = 0; i < params.size(); ++i) {
-                if (params[i].key() == "metric") {
-                    EXPECT_EQ(params[i].value(), "L2");
+            for (const auto& param : params) {
+                if (param.key() == "metric") {
+                    EXPECT_EQ(param.value(), "L2");
                 }
             }
 
diff --git a/test/it/TestCompact.cpp b/test/it/TestCompact.cpp
index c767b1b..2d0c40f 100644
--- a/test/it/TestCompact.cpp
+++ b/test/it/TestCompact.cpp
@@ -41,8 +41,7 @@ TEST_F(MilvusMockedTest, GetCompactionStateFoo) {
     const int64_t completed_id = 102;
 
     EXPECT_CALL(service_, GetCompactionState(_, Property(&GetCompactionStateRequest::compactionid, compaction_id), _))
-        .WillOnce([executing_id, timeout_id, completed_id](::grpc::ServerContext*, const GetCompactionStateRequest*,
-                                                           GetCompactionStateResponse* response) {
+        .WillOnce([&](::grpc::ServerContext*, const GetCompactionStateRequest*, GetCompactionStateResponse* response) {
             response->set_executingplanno(executing_id);
             response->set_timeoutplanno(timeout_id);
             response->set_completedplanno(completed_id);
@@ -112,8 +111,7 @@ TEST_F(MilvusMockedTest, ManualCompactionFoo) {
 
     EXPECT_CALL(service_,
                 DescribeCollection(_, Property(&DescribeCollectionRequest::collection_name, collection_name), _))
-        .WillOnce([collection_id](::grpc::ServerContext*, const DescribeCollectionRequest*,
-                                  DescribeCollectionResponse* response) {
+        .WillOnce([&](::grpc::ServerContext*, const DescribeCollectionRequest*, DescribeCollectionResponse* response) {
             response->set_collectionid(collection_id);
             return ::grpc::Status{};
         });
@@ -122,8 +120,7 @@ TEST_F(MilvusMockedTest, ManualCompactionFoo) {
                                            AllOf(Property(&ManualCompactionRequest::collectionid, collection_id),
                                                  Property(&ManualCompactionRequest::timetravel, travel_ts)),
                                            _))
-        .WillOnce([compaction_id](::grpc::ServerContext*, const ManualCompactionRequest*,
-                                  ManualCompactionResponse* response) {
+        .WillOnce([&](::grpc::ServerContext*, const ManualCompactionRequest*, ManualCompactionResponse* response) {
             response->set_compactionid(compaction_id);
             return ::grpc::Status{};
         });
@@ -178,8 +175,7 @@ TEST_F(MilvusMockedTest, GetCompactionPlansFoo) {
 
     EXPECT_CALL(service_,
                 GetCompactionStateWithPlans(_, Property(&GetCompactionPlansRequest::compactionid, compaction_id), _))
-        .WillOnce([&sources, &target](::grpc::ServerContext*, const GetCompactionPlansRequest*,
-                                      GetCompactionPlansResponse* response) {
+        .WillOnce([&](::grpc::ServerContext*, const GetCompactionPlansRequest*, GetCompactionPlansResponse* response) {
             auto info = response->add_mergeinfos();
             for (auto i : sources) {
                 info->add_sources(i);
diff --git a/test/it/TestCreateCollection.cpp b/test/it/TestCreateCollection.cpp
index fb49fed..3f17218 100644
--- a/test/it/TestCreateCollection.cpp
+++ b/test/it/TestCreateCollection.cpp
@@ -70,7 +70,7 @@ TEST_F(MilvusMockedTest, CreateCollectionFooFailed) {
     EXPECT_CALL(service_, CreateCollection(_, Property(&CreateCollectionRequest::collection_name, "Foo"), _))
         .WillOnce([error_code](::grpc::ServerContext*, const CreateCollectionRequest* request,
                                ::milvus::proto::common::Status* status) {
-            status->set_error_code(error_code);
+            status->set_code(error_code);
             return ::grpc::Status{::grpc::StatusCode::UNKNOWN, ""};
         });
     auto status = client_->CreateCollection(collection_schema);
diff --git a/test/it/TestCreateIndex.cpp b/test/it/TestCreateIndex.cpp
index 895bfc9..5b90059 100644
--- a/test/it/TestCreateIndex.cpp
+++ b/test/it/TestCreateIndex.cpp
@@ -76,7 +76,7 @@ TEST_F(MilvusMockedTest, TestCreateIndexFlushFailedInstantly) {
 
     EXPECT_CALL(service_, Flush(_, AllOf(Property(&FlushRequest::collection_names, ElementsAre(collection_name))), _))
         .WillOnce([&](::grpc::ServerContext*, const FlushRequest*, FlushResponse* resp) {
-            resp->mutable_status()->set_error_code(::milvus::proto::common::ErrorCode::UnexpectedError);
+            resp->mutable_status()->set_code(::milvus::proto::common::ErrorCode::UnexpectedError);
             return ::grpc::Status{};
         });
 
@@ -117,7 +117,7 @@ TEST_F(MilvusMockedTest, TestCreateIndexWithProgress) {
             EXPECT_EQ(params[milvus::KeyMetricType()], std::to_string(metric_type));
             EXPECT_EQ(params[milvus::KeyParams()], "{\"nlist\":1024}");
 
-            status->set_error_code(milvus::proto::common::ErrorCode::Success);
+            status->set_code(milvus::proto::common::ErrorCode::Success);
             return ::grpc::Status{};
         });
 
@@ -164,7 +164,7 @@ TEST_F(MilvusMockedTest, TestCreateIndexFailed) {
                                             Property(&CreateIndexRequest::field_name, field_name)),
                                       _))
         .WillRepeatedly([](::grpc::ServerContext*, const CreateIndexRequest*, ::milvus::proto::common::Status* status) {
-            status->set_error_code(milvus::proto::common::ErrorCode::Success);
+            status->set_code(milvus::proto::common::ErrorCode::Success);
             return ::grpc::Status{};
         });
 
diff --git a/test/it/TestCreatePartition.cpp b/test/it/TestCreatePartition.cpp
index 1e80296..747e296 100644
--- a/test/it/TestCreatePartition.cpp
+++ b/test/it/TestCreatePartition.cpp
@@ -59,7 +59,7 @@ TEST_F(MilvusMockedTest, CreatePartitionFooFailed) {
                                           _))
         .WillOnce([error_code](::grpc::ServerContext*, const CreatePartitionRequest* request,
                                ::milvus::proto::common::Status* status) {
-            status->set_error_code(error_code);
+            status->set_code(error_code);
             return ::grpc::Status{::grpc::StatusCode::UNKNOWN, ""};
         });
     auto status = client_->CreatePartition(collection, partition);
diff --git a/test/it/TestCredential.cpp b/test/it/TestCredential.cpp
index 8fc002a..02e344c 100644
--- a/test/it/TestCredential.cpp
+++ b/test/it/TestCredential.cpp
@@ -54,7 +54,7 @@ TEST_F(MilvusMockedTest, CreateCredentialError) {
                                            _))
         .WillOnce([](::grpc::ServerContext*, const CreateCredentialRequest* request,
                      ::milvus::proto::common::Status* status) {
-            status->set_error_code(milvus::proto::common::ErrorCode::CreateCredentialFailure);
+            status->set_code(milvus::proto::common::ErrorCode::CreateCredentialFailure);
             return ::grpc::Status{};
         });
     auto status = client_->CreateCredential("username", "password");
diff --git a/test/it/TestDescribeCollection.cpp b/test/it/TestDescribeCollection.cpp
index 59d2ab8..23310ce 100644
--- a/test/it/TestDescribeCollection.cpp
+++ b/test/it/TestDescribeCollection.cpp
@@ -43,8 +43,7 @@ TEST_F(MilvusMockedTest, DescribeCollectionFoo) {
 
     EXPECT_CALL(service_, DescribeCollection(
                               _, Property(&DescribeCollectionRequest::collection_name, collection_schema.Name()), _))
-        .WillOnce([&collection_id, &shards_num, &aliases, &created_ts, &collection_schema](
-                      ::grpc::ServerContext*, const DescribeCollectionRequest*, DescribeCollectionResponse* response) {
+        .WillOnce([&](::grpc::ServerContext*, const DescribeCollectionRequest*, DescribeCollectionResponse* response) {
             response->set_collectionid(collection_id);
             response->set_shards_num(shards_num);
             for (auto& alias : aliases) {
diff --git a/test/it/TestDescribeIndex.cpp b/test/it/TestDescribeIndex.cpp
index 667468f..b500508 100644
--- a/test/it/TestDescribeIndex.cpp
+++ b/test/it/TestDescribeIndex.cpp
@@ -59,7 +59,7 @@ TEST_F(MilvusMockedTest, DescribeIndexFoo) {
 
             kv = index_desc_ptr->add_params();
             kv->set_key(milvus::KeyParams());
-            kv->set_value("{\"nlist\": 1024}");
+            kv->set_value(R"({"nlist": 1024})");
 
             return ::grpc::Status{};
         });
diff --git a/test/it/TestDropCollection.cpp b/test/it/TestDropCollection.cpp
index 6f03f44..da988a2 100644
--- a/test/it/TestDropCollection.cpp
+++ b/test/it/TestDropCollection.cpp
@@ -63,7 +63,7 @@ TEST_F(MilvusMockedTest, DropCollectionFooFailed) {
     EXPECT_CALL(service_, DropCollection(_, Property(&DropCollectionRequest::collection_name, collection_name), _))
         .WillOnce([error_code](::grpc::ServerContext*, const DropCollectionRequest*,
                                ::milvus::proto::common::Status* status) {
-            status->set_error_code(error_code);
+            status->set_code(error_code);
             return ::grpc::Status{::grpc::StatusCode::UNKNOWN, "Collection drop failed. Internal error"};
         });
     auto status = client_->DropCollection(collection_name);
diff --git a/test/it/TestDropIndex.cpp b/test/it/TestDropIndex.cpp
index 93366fd..0dbd34d 100644
--- a/test/it/TestDropIndex.cpp
+++ b/test/it/TestDropIndex.cpp
@@ -56,7 +56,7 @@ TEST_F(MilvusMockedTest, DropIndexFooFailed) {
                                     _))
         .WillOnce([error_code](::grpc::ServerContext*, const DropIndexRequest* request,
                                ::milvus::proto::common::Status* status) {
-            status->set_error_code(error_code);
+            status->set_code(error_code);
             return ::grpc::Status{::grpc::StatusCode::UNKNOWN, ""};
         });
     auto status = client_->DropIndex(collection_name, field_name);
diff --git a/test/it/TestDropPartition.cpp b/test/it/TestDropPartition.cpp
index dbcd5f6..ee765a6 100644
--- a/test/it/TestDropPartition.cpp
+++ b/test/it/TestDropPartition.cpp
@@ -59,7 +59,7 @@ TEST_F(MilvusMockedTest, DropPartitionFooFailed) {
                                         _))
         .WillOnce([error_code](::grpc::ServerContext*, const DropPartitionRequest* request,
                                ::milvus::proto::common::Status* status) {
-            status->set_error_code(error_code);
+            status->set_code(error_code);
             return ::grpc::Status{::grpc::StatusCode::UNKNOWN, ""};
         });
     auto status = client_->DropPartition(collection, partition);
diff --git a/test/it/TestFlush.cpp b/test/it/TestFlush.cpp
index 3f46524..c9b2e80 100644
--- a/test/it/TestFlush.cpp
+++ b/test/it/TestFlush.cpp
@@ -64,7 +64,7 @@ TEST_F(MilvusMockedTest, FlushFailure) {
 
     EXPECT_CALL(service_, Flush(_, AllOf(Property(&FlushRequest::collection_names_size, collections.size())), _))
         .WillOnce([](::grpc::ServerContext*, const FlushRequest*, FlushResponse* response) {
-            response->mutable_status()->set_error_code(::milvus::proto::common::ErrorCode::UnexpectedError);
+            response->mutable_status()->set_code(::milvus::proto::common::ErrorCode::UnexpectedError);
             return ::grpc::Status{};
         });
 
@@ -171,7 +171,7 @@ TEST_F(MilvusMockedTest, FlushGetStateFailure) {
         .Times(1)
         .WillRepeatedly(
             [](::grpc::ServerContext*, const GetFlushStateRequest* request, GetFlushStateResponse* response) {
-                response->mutable_status()->set_error_code(::milvus::proto::common::ErrorCode::UnexpectedError);
+                response->mutable_status()->set_code(::milvus::proto::common::ErrorCode::UnexpectedError);
                 return ::grpc::Status{};
             });
 
diff --git a/test/it/TestGetCollectionsStatistics.cpp b/test/it/TestGetCollectionsStatistics.cpp
index 683e0c2..0fbbad7 100644
--- a/test/it/TestGetCollectionsStatistics.cpp
+++ b/test/it/TestGetCollectionsStatistics.cpp
@@ -87,7 +87,7 @@ TEST_F(MilvusMockedTest, GetCollectionStatisticsWithFlushFailure) {
 
     EXPECT_CALL(service_, Flush(_, AllOf(Property(&FlushRequest::collection_names, ElementsAre(collection))), _))
         .WillOnce([](::grpc::ServerContext*, const FlushRequest*, FlushResponse* response) {
-            response->mutable_status()->set_error_code(::milvus::proto::common::ErrorCode::UnexpectedError);
+            response->mutable_status()->set_code(::milvus::proto::common::ErrorCode::UnexpectedError);
             return ::grpc::Status{};
         });
 
diff --git a/test/it/TestGetPartitionStatistics.cpp b/test/it/TestGetPartitionStatistics.cpp
index e328e54..6f81076 100644
--- a/test/it/TestGetPartitionStatistics.cpp
+++ b/test/it/TestGetPartitionStatistics.cpp
@@ -77,7 +77,7 @@ TEST_F(MilvusMockedTest, GetPartitionStatisticsWithFlushFailure) {
 
     EXPECT_CALL(service_, Flush(_, AllOf(Property(&FlushRequest::collection_names, ElementsAre(collection))), _))
         .WillOnce([](::grpc::ServerContext*, const FlushRequest*, FlushResponse* response) {
-            response->mutable_status()->set_error_code(::milvus::proto::common::ErrorCode::UnexpectedError);
+            response->mutable_status()->set_code(::milvus::proto::common::ErrorCode::UnexpectedError);
             return ::grpc::Status{};
         });
 
diff --git a/test/it/TestGetQuerySegmentInfo.cpp b/test/it/TestGetQuerySegmentInfo.cpp
index 85cf78f..c5c261e 100644
--- a/test/it/TestGetQuerySegmentInfo.cpp
+++ b/test/it/TestGetQuerySegmentInfo.cpp
@@ -61,6 +61,7 @@ TEST_F(MilvusMockedTest, GetQuerySegmentInfoFoo) {
                 info->set_state(milvus::SegmentStateCast(info_exp.State()));
                 info->set_index_name(info_exp.IndexName());
                 info->set_indexid(info_exp.IndexID());
+                // TODO: nodeid deprecated
                 info->set_nodeid(info_exp.NodeID());
             }
             return ::grpc::Status{};
diff --git a/test/it/TestLoadCollection.cpp b/test/it/TestLoadCollection.cpp
index aa2dcb3..ced16a7 100644
--- a/test/it/TestLoadCollection.cpp
+++ b/test/it/TestLoadCollection.cpp
@@ -70,6 +70,7 @@ TEST_F(MilvusMockedTest, LoadCollectionFooWithProgress) {
             response->add_collection_ids(1);
             response->add_collection_names("dummy");
             response->add_created_utc_timestamps(10000);
+            // TODO: deprecated
             response->add_inmemory_percentages((++called_times) * 10);
             return ::grpc::Status{};
         });
diff --git a/test/it/TestLoadPartitions.cpp b/test/it/TestLoadPartitions.cpp
index a21dc91..1c56b46 100644
--- a/test/it/TestLoadPartitions.cpp
+++ b/test/it/TestLoadPartitions.cpp
@@ -68,7 +68,7 @@ TEST_F(MilvusMockedTest, LoadPartitionsFailure) {
                                      Property(&LoadPartitionsRequest::partition_names_size, partitions.size())),
                                _))
         .WillOnce([](::grpc::ServerContext*, const LoadPartitionsRequest*, milvus::proto::common::Status* response) {
-            response->set_error_code(::milvus::proto::common::ErrorCode::UnexpectedError);
+            response->set_code(::milvus::proto::common::ErrorCode::UnexpectedError);
             return ::grpc::Status{};
         });
 
@@ -128,6 +128,7 @@ TEST_F(MilvusMockedTest, LoadPartitionsWithQueryStatusSuccess) {
                 // time 7: 80%, 100%, 100%, 100%, 100%  -->{4, 5}
                 // time 8: 90%, 100%, 100%, 100%, 100%  -->{4, 5}
                 // time 9: 100%, 100%, 100%, 100%, 100% -->{5, 5}
+                // TODO: deprecated
                 response->add_inmemory_percentages(std::min(index * 10 * show_partitions_called, 100));
             }
             return ::grpc::Status{};
@@ -175,9 +176,10 @@ TEST_F(MilvusMockedTest, LoadPartitionsWithQueryStatusOomFailure) {
                     response->add_partition_names(partition);
                     response->add_partitionids(0);
                     response->add_created_timestamps(0);
+                    // TODO: deprecated
                     response->add_inmemory_percentages(10);
                 }
-                response->mutable_status()->set_error_code(::milvus::proto::common::ErrorCode::OutOfMemory);
+                response->mutable_status()->set_code(::milvus::proto::common::ErrorCode::OutOfMemory);
                 return ::grpc::Status{};
             });
 
@@ -220,6 +222,7 @@ TEST_F(MilvusMockedTest, LoadPartitionsWithQueryStatusTimeout) {
                     response->add_partition_names(partition);
                     response->add_partitionids(0);
                     response->add_created_timestamps(0);
+                    // TODO: deprecated
                     response->add_inmemory_percentages(0);
                 }
                 return ::grpc::Status{};
diff --git a/test/it/TestReleasePartitions.cpp b/test/it/TestReleasePartitions.cpp
index bb086d6..de2ea4a 100644
--- a/test/it/TestReleasePartitions.cpp
+++ b/test/it/TestReleasePartitions.cpp
@@ -52,7 +52,7 @@ TEST_F(MilvusMockedTest, ReleasePartitionsFailure) {
                                         Property(&ReleasePartitionsRequest::partition_names_size, partitions.size())),
                                   _))
         .WillOnce([](::grpc::ServerContext*, const ReleasePartitionsRequest*, milvus::proto::common::Status* response) {
-            response->set_error_code(::milvus::proto::common::ErrorCode::UnexpectedError);
+            response->set_code(::milvus::proto::common::ErrorCode::UnexpectedError);
             return ::grpc::Status{};
         });
 
diff --git a/test/it/TestSearch.cpp b/test/it/TestSearch.cpp
index c6f5345..3771b3c 100644
--- a/test/it/TestSearch.cpp
+++ b/test/it/TestSearch.cpp
@@ -20,6 +20,7 @@
 #include <memory>
 #include <nlohmann/json.hpp>
 #include <thread>
+#include <utility>
 
 #include "TypeUtils.h"
 #include "mocks/MilvusMockedTest.h"
@@ -40,7 +41,7 @@ using ::testing::UnorderedElementsAre;
 
 namespace {
 struct TestKv {
-    TestKv(const std::string& key, const std::string& value) : key_(key), value_(value) {
+    TestKv(std::string key, std::string value) : key_(std::move(key)), value_(std::move(value)) {
     }
     std::string key_;
     std::string value_;
@@ -115,7 +116,7 @@ DoSearchVectors(testing::StrictMock<::milvus::MilvusMockedService>& service_,
             EXPECT_EQ(json_params["nprobe"].get<int>(), 10);
 
             // check placeholder
-            auto placeholder_group_payload = request->placeholder_group();
+            const auto& placeholder_group_payload = request->placeholder_group();
             milvus::proto::common::PlaceholderGroup placeholder_group;
             placeholder_group.ParseFromString(placeholder_group_payload);
             EXPECT_EQ(placeholder_group.placeholders_size(), 1);
@@ -129,7 +130,7 @@ DoSearchVectors(testing::StrictMock<::milvus::MilvusMockedService>& service_,
                 EXPECT_EQ(test_vector, vector);
             }
 
-            response->mutable_status()->set_error_code(milvus::proto::common::ErrorCode::Success);
+            response->mutable_status()->set_code(milvus::proto::common::ErrorCode::Success);
             auto* results = response->mutable_results();
             results->set_top_k(10);
             results->set_num_queries(2);
diff --git a/test/it/TestShowPartitions.cpp b/test/it/TestShowPartitions.cpp
index 8773c2f..c69abdb 100644
--- a/test/it/TestShowPartitions.cpp
+++ b/test/it/TestShowPartitions.cpp
@@ -45,6 +45,7 @@ TEST_F(MilvusMockedTest, ShowPartitionsQueryAll) {
                 response->add_partition_names(partition.Name());
                 response->add_partitionids(partition.Id());
                 response->add_created_timestamps(partition.CreatedUtcTimestamp());
+                // TODO: deprecated
                 response->add_inmemory_percentages(partition.InMemoryPercentage());
             }
             return ::grpc::Status{};
@@ -79,6 +80,7 @@ TEST_F(MilvusMockedTest, ShowPartitionsQueryLoadingPercent) {
                 response->add_partition_names(partition.Name());
                 response->add_partitionids(partition.Id());
                 response->add_created_timestamps(partition.CreatedUtcTimestamp());
+                // TODO: deprecated
                 response->add_inmemory_percentages(partition.InMemoryPercentage());
             }
             return ::grpc::Status{};
diff --git a/test/st/MilvusServerTest.h b/test/st/MilvusServerTest.h
index 5a8b40a..11d8f5f 100644
--- a/test/st/MilvusServerTest.h
+++ b/test/st/MilvusServerTest.h
@@ -37,13 +37,13 @@ waitMilvusServerReady(const PythonMilvusServer& server) {
     auto client = milvus::MilvusClient::Create();
     auto param = server.TestClientParam();
     client->Connect(*param);
-    auto status = client->HasCollection("nosuchcollection", has);
+    auto status = client->HasCollection("no_such", has);
 
     while (!status.IsOk() && retry++ < max_retry) {
         std::this_thread::sleep_for(std::chrono::seconds{5});
         client = milvus::MilvusClient::Create();
         client->Connect(*param);
-        status = client->HasCollection("nosuchcollection", has);
+        status = client->HasCollection("no_such", has);
         std::cout << "Wait milvus start done, try: " << retry << ", status: " << status.Message() << std::endl;
     }
     std::cout << "Wait milvus start done, status: " << status.Message() << std::endl;
diff --git a/test/st/TestConnectWithTls.cpp b/test/st/TestConnectWithTls.cpp
index 8321bec..134d3c1 100644
--- a/test/st/TestConnectWithTls.cpp
+++ b/test/st/TestConnectWithTls.cpp
@@ -22,9 +22,6 @@
 #include <random>
 
 #include "MilvusServerTest.h"
-#include "milvus/MilvusClient.h"
-#include "milvus/Status.h"
-#include "milvus/types/ConnectParam.h"
 
 using testing::UnorderedElementsAre;
 using testing::UnorderedElementsAreArray;
@@ -73,7 +70,7 @@ class MilvusServerTestWithTlsMode : public MilvusServerTest {
     void
     SetUp() override {
         generate_certificates();
-        std::array<char, 256> path;
+        std::array<char, 256> path{};
         getcwd(path.data(), path.size());
         std::string pwd = path.data();
         server_.SetTls(Mode, pwd + "/certs/server.crt", pwd + "/certs/server.key", pwd + "/certs/ca.crt");
diff --git a/test/st/TestConnectWithUser.cpp b/test/st/TestConnectWithUser.cpp
index a7445e4..9c63aeb 100644
--- a/test/st/TestConnectWithUser.cpp
+++ b/test/st/TestConnectWithUser.cpp
@@ -19,7 +19,6 @@
 #include <random>
 
 #include "MilvusServerTest.h"
-#include "milvus/Status.h"
 
 using milvus::test::MilvusServerTest;
 using testing::UnorderedElementsAre;
diff --git a/test/ut/TestFieldData.cpp b/test/ut/TestFieldData.cpp
index f903c64..86a38a2 100644
--- a/test/ut/TestFieldData.cpp
+++ b/test/ut/TestFieldData.cpp
@@ -199,9 +199,9 @@ TEST_F(FieldDataTest, GeneralTesting) {
     }
 
     {
-        std::string name{"foo"};
+        std::string field_name{"foo"};
         const std::vector<std::string> elements{"\x01\x02", "\x03\x04"};
-        milvus::BinaryVecFieldData data{name, elements};
+        milvus::BinaryVecFieldData data{field_name, elements};
         std::vector<std::vector<uint8_t>> expected{{1, 2}, {3, 4}};
         EXPECT_EQ(data.DataAsUnsignedChars(), expected);
 
diff --git a/test/ut/TestHybirdTimestamp.cpp b/test/ut/TestHybirdTimestamp.cpp
index 6c5c20f..8b89a01 100644
--- a/test/ut/TestHybirdTimestamp.cpp
+++ b/test/ut/TestHybirdTimestamp.cpp
@@ -16,17 +16,17 @@
 
 #include <gtest/gtest.h>
 
-#include "milvus/types/HybirdTimestamp.h"
+#include "milvus/types/HybridTimestamp.h"
 
-class HybirdTimestampTest : public ::testing::Test {};
+class HybridTimestampTest : public ::testing::Test {};
 
-TEST_F(HybirdTimestampTest, GeneralTesting) {
-    milvus::HybirdTimestamp foo{};
+TEST_F(HybridTimestampTest, GeneralTesting) {
+    milvus::HybridTimestamp foo{};
     EXPECT_EQ(foo.Timestamp(), 0);
     EXPECT_EQ(foo.Logical(), 0);
     EXPECT_EQ(foo.Physical(), 0);
 
-    milvus::HybirdTimestamp bar{1, 1};
+    milvus::HybridTimestamp bar{1, 1};
     EXPECT_EQ(bar.Timestamp(), (1 << 18) + 1);
     EXPECT_EQ(bar.Logical(), 1);
     EXPECT_EQ(bar.Physical(), 1);
@@ -43,12 +43,12 @@ TEST_F(HybirdTimestampTest, GeneralTesting) {
     EXPECT_EQ(bar.Logical(), 0);
     EXPECT_EQ(bar.Physical(), 2001);
 
-    bar = milvus::HybirdTimestamp::CreateFromUnixtime(1000);
+    bar = milvus::HybridTimestamp::CreateFromUnixTime(1000);
     EXPECT_EQ(bar.Logical(), 0);
     EXPECT_EQ(bar.Physical(), 1000);
 
-    milvus::HybirdTimestamp ts_a = milvus::HybirdTimestamp::CreateFromUnixtime(3);
-    milvus::HybirdTimestamp ts_b{ts_a.Timestamp()};
+    milvus::HybridTimestamp ts_a = milvus::HybridTimestamp::CreateFromUnixTime(3);
+    milvus::HybridTimestamp ts_b{ts_a.Timestamp()};
     EXPECT_EQ(ts_a.Logical(), ts_b.Logical());
     EXPECT_EQ(ts_a.Physical(), ts_b.Physical());
 }
diff --git a/test/ut/TestIndexDesc.cpp b/test/ut/TestIndexDesc.cpp
index 72f2d98..e4bc84e 100644
--- a/test/ut/TestIndexDesc.cpp
+++ b/test/ut/TestIndexDesc.cpp
@@ -41,17 +41,17 @@ TEST_F(IndexDescTest, GeneralTesting) {
 
 TEST_F(IndexDescTest, ValidationTestingPossitive) {
     for (const auto& test_data : {
-             std::make_tuple(milvus::IndexType::IVF_FLAT, milvus::MetricType::L2, "{\"nlist\": 1024}"),
-             std::make_tuple(milvus::IndexType::IVF_SQ8, milvus::MetricType::L2, "{\"nlist\": 1024}"),
-             std::make_tuple(milvus::IndexType::IVF_PQ, milvus::MetricType::L2, "{\"nlist\": 1024, \"m\": 8}"),
+             std::make_tuple(milvus::IndexType::IVF_FLAT, milvus::MetricType::L2, R"({"nlist": 1024})"),
+             std::make_tuple(milvus::IndexType::IVF_SQ8, milvus::MetricType::L2, R"({"nlist": 1024})"),
+             std::make_tuple(milvus::IndexType::IVF_PQ, milvus::MetricType::L2, R"({"nlist": 1024, "m": 8})"),
              std::make_tuple(milvus::IndexType::IVF_PQ, milvus::MetricType::L2,
-                             "{\"nlist\": 1024, \"m\": 8, \"nbits\": 12}"),
-             std::make_tuple(milvus::IndexType::HNSW, milvus::MetricType::L2, "{\"M\": 4, \"efConstruction\": 12}"),
+                             R"({"nlist": 1024, "m": 8, "nbits": 12})"),
+             std::make_tuple(milvus::IndexType::HNSW, milvus::MetricType::L2, R"({"M": 4, "efConstruction": 12})"),
              std::make_tuple(milvus::IndexType::IVF_HNSW, milvus::MetricType::L2,
-                             "{\"nlist\": 1024, \"M\": 4, \"efConstruction\": 12}"),
+                             R"({"nlist": 1024, "M": 4, "efConstruction": 12})"),
              std::make_tuple(milvus::IndexType::RHNSW_PQ, milvus::MetricType::L2,
-                             "{\"PQM\": 32, \"M\": 4, \"efConstruction\": 12}"),
-             std::make_tuple(milvus::IndexType::ANNOY, milvus::MetricType::L2, "{\"n_trees\": 12}"),
+                             R"({"PQM": 32, "M": 4, "efConstruction": 12})"),
+             std::make_tuple(milvus::IndexType::ANNOY, milvus::MetricType::L2, R"({"n_trees": 12})"),
              std::make_tuple(milvus::IndexType::BIN_IVF_FLAT, milvus::MetricType::JACCARD, ""),
              std::make_tuple(milvus::IndexType::BIN_IVF_FLAT, milvus::MetricType::TANIMOTO, ""),
              std::make_tuple(milvus::IndexType::BIN_IVF_FLAT, milvus::MetricType::HAMMING, ""),
@@ -68,13 +68,13 @@ TEST_F(IndexDescTest, ValidationTestingPossitive) {
 
 TEST_F(IndexDescTest, ValidationTestingNegative) {
     for (const auto& test_data : {
-             std::make_tuple(milvus::IndexType::IVF_FLAT, milvus::MetricType::JACCARD, "{\"nlist\": 1024}"),
-             std::make_tuple(milvus::IndexType::BIN_IVF_FLAT, milvus::MetricType::SUBSTRUCTURE, "{\"nlist\": 1024}"),
-             std::make_tuple(milvus::IndexType::IVF_FLAT, milvus::MetricType::IP, "{\"nlist\": 0}"),
-             std::make_tuple(milvus::IndexType::IVF_FLAT, milvus::MetricType::IP, "{\"nlist\": \"1024\"}"),
-             std::make_tuple(milvus::IndexType::IVF_FLAT, milvus::MetricType::IP, "{\"nlist\": 65537}"),
-             std::make_tuple(milvus::IndexType::ANNOY, milvus::MetricType::IP, "{\"nlist\": 65537}"),
-             std::make_tuple(milvus::IndexType::BIN_IVF_FLAT, milvus::MetricType::IP, "{\"nlist\": 1024}"),
+             std::make_tuple(milvus::IndexType::IVF_FLAT, milvus::MetricType::JACCARD, R"({"nlist": 1024})"),
+             std::make_tuple(milvus::IndexType::BIN_IVF_FLAT, milvus::MetricType::SUBSTRUCTURE, R"({"nlist": 1024})"),
+             std::make_tuple(milvus::IndexType::IVF_FLAT, milvus::MetricType::IP, R"({"nlist": 0})"),
+             std::make_tuple(milvus::IndexType::IVF_FLAT, milvus::MetricType::IP, R"({"nlist": "1024"})"),
+             std::make_tuple(milvus::IndexType::IVF_FLAT, milvus::MetricType::IP, R"({"nlist": 65537})"),
+             std::make_tuple(milvus::IndexType::ANNOY, milvus::MetricType::IP, R"({"nlist": 65537})"),
+             std::make_tuple(milvus::IndexType::BIN_IVF_FLAT, milvus::MetricType::IP, R"({"nlist": 1024})"),
          }) {
         milvus::IndexDesc index_desc{"foo", "index", std::get<0>(test_data), std::get<1>(test_data), 0};
         index_desc.ExtraParamsFromJson(std::get<2>(test_data));
diff --git a/test/ut/TestQueryArguments.cpp b/test/ut/TestQueryArguments.cpp
index d98a811..9c64524 100644
--- a/test/ut/TestQueryArguments.cpp
+++ b/test/ut/TestQueryArguments.cpp
@@ -23,7 +23,7 @@ class QueryArgumentsTest : public ::testing::Test {};
 TEST_F(QueryArgumentsTest, GeneralTesting) {
     milvus::QueryArguments arguments;
 
-    std::string empty_name = "";
+    std::string empty_name;
     std::string collection_name = "test";
     arguments.SetCollectionName(collection_name);
     EXPECT_FALSE(arguments.SetCollectionName(empty_name).IsOk());
diff --git a/test/ut/TestSearchArguments.cpp b/test/ut/TestSearchArguments.cpp
index 780b89b..bd1bd92 100644
--- a/test/ut/TestSearchArguments.cpp
+++ b/test/ut/TestSearchArguments.cpp
@@ -24,7 +24,7 @@ TEST_F(SearchArgumentsTest, GeneralTesting) {
     milvus::SearchArguments arguments;
     EXPECT_EQ(arguments.TargetVectors(), nullptr);
 
-    std::string empty_name = "";
+    std::string empty_name;
     std::string collection_name = "test";
     arguments.SetCollectionName(collection_name);
     EXPECT_FALSE(arguments.SetCollectionName(empty_name).IsOk());
diff --git a/test/ut/TestTypeUtils.cpp b/test/ut/TestTypeUtils.cpp
index 76761d9..8a47839 100644
--- a/test/ut/TestTypeUtils.cpp
+++ b/test/ut/TestTypeUtils.cpp
@@ -16,7 +16,6 @@
 
 #include <gmock/gmock.h>
 
-#include <functional>
 #include <vector>
 
 #include "TypeUtils.h"