diff --git a/.clang-tidy b/.clang-tidy
index 1f7850efe7c624ae8a22700f247c10126f160d10..1695fa668541bf56dbed074b8860347985116218 100644
--- a/.clang-tidy
+++ b/.clang-tidy
@@ -18,8 +18,10 @@
 Checks:          'clang-diagnostic-*,clang-analyzer-*,-clang-analyzer-alpha*,google-*,modernize-*,readability-*'
 # produce HeaderFilterRegex from cpp/build-support/lint_exclusions.txt with:
 # echo -n '^('; sed -e 's/*/\.*/g' cpp/build-support/lint_exclusions.txt | tr '\n' '|'; echo ')$'
-HeaderFilterRegex: '^(.*cmake-build-debug.*|.*cmake-build-release.*|.*cmake_build.*|.*src/thirdparty.*|.*src/core/thirdparty.*|.*src/grpc.*|)$'
+HeaderFilterRegex: '^(.*cmake-build-debug.*|.*cmake-build-release.*|.*cmake_build.*|.*src/core/thirdparty.*|.*thirdparty.*|.*easylogging++.*|.*SqliteMetaImpl.cpp|.*src/grpc.*|.*src/core.*|.*src/wrapper.*)$'
 AnalyzeTemporaryDtors: true
+ChainedConditionalReturn: 1
+ChainedConditionalAssignment: 1
 CheckOptions:
   - key:             google-readability-braces-around-statements.ShortStatementLines
     value:           '1'
diff --git a/cpp/build.sh b/cpp/build.sh
index 69fd4f0f29469b67caeb8eabee9b255ad66ed30f..deda35ab275672a83d735c0c5a220dbdce4d4bfa 100755
--- a/cpp/build.sh
+++ b/cpp/build.sh
@@ -111,14 +111,14 @@ if [[ ${RUN_CPPLINT} == "ON" ]]; then
         exit 1
     fi
     echo "clang-format check passed!"
-#
-#    # clang-tidy check
-#    make check-clang-tidy
-#    if [ $? -ne 0 ]; then
-#        echo "ERROR! clang-tidy check failed"
-#        exit 1
-#    fi
-#    echo "clang-tidy check passed!"
+
+    # clang-tidy check
+    make check-clang-tidy
+    if [ $? -ne 0 ]; then
+        echo "ERROR! clang-tidy check failed"
+        exit 1
+    fi
+    echo "clang-tidy check passed!"
 else
     # compile and build
     make -j 4 || exit 1
diff --git a/cpp/src/cache/CpuCacheMgr.h b/cpp/src/cache/CpuCacheMgr.h
index fbc4f6dfb38bb2c9b876acbecfa27cac4a77e998..ad6087de7c42104f36d233d107d5691b603bd630 100644
--- a/cpp/src/cache/CpuCacheMgr.h
+++ b/cpp/src/cache/CpuCacheMgr.h
@@ -32,7 +32,7 @@ class CpuCacheMgr : public CacheMgr<DataObjPtr> {
     CpuCacheMgr();
 
  public:
-    // TODO: use smart pointer instead
+    // TODO(myh): use smart pointer instead
     static CpuCacheMgr*
     GetInstance();
 
diff --git a/cpp/src/core/test/kdtree.cpp b/cpp/src/core/test/kdtree.cpp
index 0b63e657e1f465a1dffef4e76afb3d30e6b6367f..b3de8f345c650c9d06b811490dbfeed1a08ae964 100644
--- a/cpp/src/core/test/kdtree.cpp
+++ b/cpp/src/core/test/kdtree.cpp
@@ -44,7 +44,7 @@ DatasetPtr
 generate_queries(int64_t n, int64_t d, int64_t k, int64_t base) {
     size_t size = sizeof(float) * n * d;
     auto v = (float *) malloc(size);
-    // TODO: check malloc
+    // TODO(lxj): check malloc
     for (auto i = 0; i < n; ++i) {
         for (auto j = 0; j < d; ++j) {
             v[i * d + j] = float(base + i);
diff --git a/cpp/src/core/test/test_ivf.cpp b/cpp/src/core/test/test_ivf.cpp
index 1eeb1f9872cc65fa1b0ade750b8d260ba3e4e3dc..7196fe15e44fc7ee35ae6ae8a294e72cc4895576 100644
--- a/cpp/src/core/test/test_ivf.cpp
+++ b/cpp/src/core/test/test_ivf.cpp
@@ -694,4 +694,4 @@ TEST_F(GPURESTEST, TrainAndSearch) {
 
 
 
-// TODO(linxj): Add exception test
+// TODO(lxj): Add exception test
diff --git a/cpp/src/core/test/test_kdt.cpp b/cpp/src/core/test/test_kdt.cpp
index fce233aca7f0272422e9f69dd4e4b90dd50a5c95..3780f655cca17b3b17c0d4ca7c462d488e9faa8e 100644
--- a/cpp/src/core/test/test_kdt.cpp
+++ b/cpp/src/core/test/test_kdt.cpp
@@ -85,7 +85,7 @@ void PrintResult(const DatasetPtr &result,
     std::cout << "dist\n" << ss_dist.str() << std::endl;
 }
 
-// TODO(linxj): add test about count() and dimension()
+// TODO(lxj): add test about count() and dimension()
 TEST_F(KDTTest, kdt_basic) {
     assert(!xb.empty());
 
diff --git a/cpp/src/core/thirdparty/SPTAG/AnnService/src/Core/MetadataSet.cpp b/cpp/src/core/thirdparty/SPTAG/AnnService/src/Core/MetadataSet.cpp
index 2eefcea68f3c4ace8bc9e3614236e71eca123186..a5d410ce5e9490eedc99c817cce9886e4b132222 100644
--- a/cpp/src/core/thirdparty/SPTAG/AnnService/src/Core/MetadataSet.cpp
+++ b/cpp/src/core/thirdparty/SPTAG/AnnService/src/Core/MetadataSet.cpp
@@ -179,13 +179,13 @@ FileMetadataSet::SaveMetadata(const std::string& p_metaFile, const std::string&
 
 ErrorCode
 FileMetadataSet::SaveMetadataToMemory(void **pGraphMemFile, int64_t &len) {
-    // TODO: serialize file to mem?
+    // TODO(lxj): serialize file to mem?
     return ErrorCode::Fail;
 }
 
 ErrorCode
 FileMetadataSet::LoadMetadataFromMemory(void *pGraphMemFile) {
-    // TODO: not support yet
+    // TODO(lxj): not support yet
     return ErrorCode::Fail;
 }
 
diff --git a/cpp/src/db/DBImpl.cpp b/cpp/src/db/DBImpl.cpp
index 2e6955a81d7e80fbeadc5ef44983b6d161fcf9ca..10cdf60b5ab41e9336bb1622a7affd194d11885a 100644
--- a/cpp/src/db/DBImpl.cpp
+++ b/cpp/src/db/DBImpl.cpp
@@ -242,7 +242,7 @@ DBImpl::GetTableRowCount(const std::string& table_id, uint64_t& row_count) {
 }
 
 Status
-DBImpl::InsertVectors(const std::string& table_id_, uint64_t n, const float* vectors, IDNumbers& vector_ids_) {
+DBImpl::InsertVectors(const std::string& table_id, uint64_t n, const float* vectors, IDNumbers& vector_ids) {
     //    ENGINE_LOG_DEBUG << "Insert " << n << " vectors to cache";
     if (shutting_down_.load(std::memory_order_acquire)) {
         return Status(DB_ERROR, "Milsvus server is shutdown!");
@@ -250,7 +250,7 @@ DBImpl::InsertVectors(const std::string& table_id_, uint64_t n, const float* vec
 
     Status status;
     zilliz::milvus::server::CollectInsertMetrics metrics(n, status);
-    status = mem_mgr_->InsertVectors(table_id_, n, vectors, vector_ids_);
+    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);
     //    double average_time = double(time_span.count()) / n;
@@ -295,15 +295,17 @@ DBImpl::CreateIndex(const std::string& table_id, const TableIndex& index) {
     // for IDMAP type, only wait all NEW file converted to RAW file
     // for other type, wait NEW/RAW/NEW_MERGE/NEW_INDEX/TO_INDEX files converted to INDEX files
     std::vector<int> file_types;
-    if (index.engine_type_ == (int)EngineType::FAISS_IDMAP) {
+    if (index.engine_type_ == static_cast<int32_t>(EngineType::FAISS_IDMAP)) {
         file_types = {
-            (int)meta::TableFileSchema::NEW, (int)meta::TableFileSchema::NEW_MERGE,
+            static_cast<int32_t>(meta::TableFileSchema::NEW), static_cast<int32_t>(meta::TableFileSchema::NEW_MERGE),
         };
     } else {
         file_types = {
-            (int)meta::TableFileSchema::RAW,       (int)meta::TableFileSchema::NEW,
-            (int)meta::TableFileSchema::NEW_MERGE, (int)meta::TableFileSchema::NEW_INDEX,
-            (int)meta::TableFileSchema::TO_INDEX,
+            static_cast<int32_t>(meta::TableFileSchema::RAW),
+            static_cast<int32_t>(meta::TableFileSchema::NEW),
+            static_cast<int32_t>(meta::TableFileSchema::NEW_MERGE),
+            static_cast<int32_t>(meta::TableFileSchema::NEW_INDEX),
+            static_cast<int32_t>(meta::TableFileSchema::TO_INDEX),
         };
     }
 
diff --git a/cpp/src/db/Utils.cpp b/cpp/src/db/Utils.cpp
index 2055ff391c1813bd6c4db5644894188250de67c9..d9e500f84ae5b9453acd7b2c31c0a2ab1d1146cd 100644
--- a/cpp/src/db/Utils.cpp
+++ b/cpp/src/db/Utils.cpp
@@ -228,7 +228,7 @@ ParseMetaUri(const std::string& uri, MetaUriInfo& info) {
         info.port_ = pieces_match[5].str();
         info.db_name_ = pieces_match[6].str();
 
-        // TODO: verify host, port...
+        // TODO(myh): verify host, port...
     } else {
         return Status(DB_INVALID_META_URI, "Invalid meta uri: " + uri);
     }
diff --git a/cpp/src/db/engine/ExecutionEngineImpl.cpp b/cpp/src/db/engine/ExecutionEngineImpl.cpp
index 52b4992dab098d40595070759bfc4838889bb19e..2a239ddbea58114a4e31789e6c8801d59de75aa7 100644
--- a/cpp/src/db/engine/ExecutionEngineImpl.cpp
+++ b/cpp/src/db/engine/ExecutionEngineImpl.cpp
@@ -342,8 +342,9 @@ Status
 ExecutionEngineImpl::Init() {
     server::Config& config = server::Config::GetInstance();
     Status s = config.GetDBConfigBuildIndexGPU(gpu_num_);
-    if (!s.ok())
+    if (!s.ok()) {
         return s;
+    }
 
     return Status::OK();
 }
diff --git a/cpp/src/db/meta/MySQLConnectionPool.cpp b/cpp/src/db/meta/MySQLConnectionPool.cpp
index 2d09874d3f4b62fdc9522b763e9089c9b0a50ae5..6c9312010790cab25e9cf5ba67b0405c12cb30f4 100644
--- a/cpp/src/db/meta/MySQLConnectionPool.cpp
+++ b/cpp/src/db/meta/MySQLConnectionPool.cpp
@@ -68,7 +68,7 @@ MySQLConnectionPool::create() {
     try {
         // Create connection using the parameters we were passed upon
         // creation.
-        mysqlpp::Connection* conn = new mysqlpp::Connection();
+        auto conn = new mysqlpp::Connection();
         conn->set_option(new mysqlpp::ReconnectOption(true));
         conn->connect(db_.empty() ? 0 : db_.c_str(), server_.empty() ? 0 : server_.c_str(),
                       user_.empty() ? 0 : user_.c_str(), password_.empty() ? 0 : password_.c_str(), port_);
diff --git a/cpp/src/db/meta/MySQLMetaImpl.cpp b/cpp/src/db/meta/MySQLMetaImpl.cpp
index e9654c78669537c59874b88b1229d7d818449693..db93ce9ec6900861c59080ac5ebad3ceddb4987e 100644
--- a/cpp/src/db/meta/MySQLMetaImpl.cpp
+++ b/cpp/src/db/meta/MySQLMetaImpl.cpp
@@ -50,11 +50,11 @@ HandleException(const std::string& desc, const char* what = nullptr) {
     if (what == nullptr) {
         ENGINE_LOG_ERROR << desc;
         return Status(DB_META_TRANSACTION_FAILED, desc);
-    } else {
-        std::string msg = desc + ":" + what;
-        ENGINE_LOG_ERROR << msg;
-        return Status(DB_META_TRANSACTION_FAILED, msg);
     }
+
+    std::string msg = desc + ":" + what;
+    ENGINE_LOG_ERROR << msg;
+    return Status(DB_META_TRANSACTION_FAILED, msg);
 }
 
 class MetaField {
@@ -324,7 +324,7 @@ MySQLMetaImpl::Initialize() {
     return Status::OK();
 }
 
-// PXU TODO: Temp solution. Will fix later
+// TODO(myh): Delete single vecotor by id
 Status
 MySQLMetaImpl::DropPartitionsByDates(const std::string& table_id, const DatesT& dates) {
     if (dates.empty()) {
@@ -1379,7 +1379,7 @@ MySQLMetaImpl::GetTableFiles(const std::string& table_id, const std::vector<size
     }
 }
 
-// PXU TODO: Support Swap
+// TODO(myh): Support swap to cloud storage
 Status
 MySQLMetaImpl::Archive() {
     auto& criterias = options_.archive_conf_.GetCriterias();
@@ -1984,9 +1984,8 @@ MySQLMetaImpl::DropAll() {
 
         if (dropTableQuery.exec()) {
             return Status::OK();
-        } else {
-            return HandleException("QUERY ERROR WHEN DROPPING ALL", dropTableQuery.error());
         }
+        return HandleException("QUERY ERROR WHEN DROPPING ALL", dropTableQuery.error());
     } catch (std::exception& e) {
         return HandleException("GENERAL ERROR WHEN DROPPING ALL", e.what());
     }
diff --git a/cpp/src/db/meta/SqliteMetaImpl.cpp b/cpp/src/db/meta/SqliteMetaImpl.cpp
index 471b182981df2d5a183f78b6f1d72064088e4067..accad0be7098530e609ba08f4fada49e6da1d13e 100644
--- a/cpp/src/db/meta/SqliteMetaImpl.cpp
+++ b/cpp/src/db/meta/SqliteMetaImpl.cpp
@@ -155,7 +155,7 @@ SqliteMetaImpl::Initialize() {
     return Status::OK();
 }
 
-// PXU TODO: Temp solution. Will fix later
+// TODO(myh): Delete single vecotor by id
 Status
 SqliteMetaImpl::DropPartitionsByDates(const std::string &table_id,
                                       const DatesT &dates) {
@@ -885,7 +885,7 @@ SqliteMetaImpl::GetTableFiles(const std::string &table_id,
     }
 }
 
-// PXU TODO: Support Swap
+// TODO(myh): Support swap to cloud storage
 Status
 SqliteMetaImpl::Archive() {
     auto &criterias = options_.archive_conf_.GetCriterias();
diff --git a/cpp/src/metrics/SystemInfo.cpp b/cpp/src/metrics/SystemInfo.cpp
index 4647b1435b202d592dce56f9f04569d215daf279..98822945ca67261376e5edc7b88b358f2bce1020 100644
--- a/cpp/src/metrics/SystemInfo.cpp
+++ b/cpp/src/metrics/SystemInfo.cpp
@@ -31,8 +31,9 @@ namespace server {
 
 void
 SystemInfo::Init() {
-    if (initialized_)
+    if (initialized_) {
         return;
+    }
 
     initialized_ = true;
 
@@ -45,9 +46,10 @@ SystemInfo::Init() {
     last_user_cpu_ = time_sample.tms_utime;
     file = fopen("/proc/cpuinfo", "r");
     num_processors_ = 0;
-    while (fgets(line, 128, file) != NULL) {
-        if (strncmp(line, "processor", 9) == 0)
+    while (fgets(line, 128, file) != nullptr) {
+        if (strncmp(line, "processor", 9) == 0) {
             num_processors_++;
+        }
         if (strncmp(line, "physical", 8) == 0) {
             num_physical_processors_ = ParseLine(line);
         }
@@ -80,7 +82,9 @@ SystemInfo::ParseLine(char* line) {
     // This assumes that a digit will be found and the line ends in " Kb".
     int i = strlen(line);
     const char* p = line;
-    while (*p < '0' || *p > '9') p++;
+    while (*p < '0' || *p > '9') {
+        p++;
+    }
     line[i - 3] = '\0';
     i = atoi(p);
     return static_cast<uint64_t>(i);
@@ -105,7 +109,7 @@ SystemInfo::GetProcessUsedMemory() {
     constexpr uint64_t KB_SIZE = 1024;
     char line[line_length];
 
-    while (fgets(line, line_length, file) != NULL) {
+    while (fgets(line, line_length, file) != nullptr) {
         if (strncmp(line, "VmRSS:", 6) == 0) {
             result = ParseLine(line);
             break;
@@ -118,9 +122,12 @@ SystemInfo::GetProcessUsedMemory() {
 
 double
 SystemInfo::MemoryPercent() {
-    if (!initialized_)
+    if (!initialized_) {
         Init();
-    return (double)(GetProcessUsedMemory() * 100) / (double)total_ram_;
+    }
+
+    double mem_used = static_cast<double>(GetProcessUsedMemory() * 100);
+    return mem_used / static_cast<double>(total_ram_);
 }
 
 std::vector<double>
@@ -174,8 +181,9 @@ SystemInfo::getTotalCpuTime(std::vector<uint64_t>& work_time_array) {
 
 double
 SystemInfo::CPUPercent() {
-    if (!initialized_)
+    if (!initialized_) {
         Init();
+    }
     struct tms time_sample;
     clock_t now;
     double percent;
@@ -233,7 +241,7 @@ SystemInfo::CPUTemperature() {
     for (int i = 0; i <= num_physical_processors_; ++i) {
         std::string path = "/sys/class/thermal/thermal_zone" + std::to_string(i) + "/temp";
         FILE* file = fopen(path.data(), "r");
-        if (file == NULL) {
+        if (file == nullptr) {
             perror("Could not open thermal file");
             return result;
         }
@@ -269,7 +277,7 @@ SystemInfo::Octets() {
     std::ifstream file(filename);
     std::string lastline = "";
     std::string line = "";
-    while (file) {
+    while (true) {
         getline(file, line);
         if (file.fail()) {
             break;
diff --git a/cpp/src/scheduler/ResourceMgr.cpp b/cpp/src/scheduler/ResourceMgr.cpp
index eefa30560cf5b867d56ecf2fde0917a9c6325630..ce9fcc9fb9abecf2b705718f90681e910772b9de 100644
--- a/cpp/src/scheduler/ResourceMgr.cpp
+++ b/cpp/src/scheduler/ResourceMgr.cpp
@@ -75,7 +75,7 @@ ResourceMgr::Connect(const std::string& name1, const std::string& name2, Connect
     auto res2 = GetResource(name2);
     if (res1 && res2) {
         res1->AddNeighbour(std::static_pointer_cast<Node>(res2), connection);
-        // TODO: enable when task balance supported
+        // TODO(wxy): enable when task balance supported
         //        res2->AddNeighbour(std::static_pointer_cast<Node>(res1), connection);
         return true;
     }
diff --git a/cpp/src/scheduler/ResourceMgr.h b/cpp/src/scheduler/ResourceMgr.h
index 05393041bfdb5438fea693961155ea65b7bef6d3..531491066f8ac6336d726ccb7c7c98889efecaa2 100644
--- a/cpp/src/scheduler/ResourceMgr.h
+++ b/cpp/src/scheduler/ResourceMgr.h
@@ -65,7 +65,7 @@ class ResourceMgr {
         return disk_resources_;
     }
 
-    // TODO: why return shared pointer
+    // TODO(wxy): why return shared pointer
     inline std::vector<ResourcePtr>
     GetAllResources() {
         return resources_;
@@ -90,7 +90,7 @@ class ResourceMgr {
     GetNumGpuResource() const;
 
  public:
-    // TODO: add stats interface(low)
+    // TODO(wxy): add stats interface(low)
 
  public:
     /******** Utility Functions ********/
diff --git a/cpp/src/scheduler/SchedInst.cpp b/cpp/src/scheduler/SchedInst.cpp
index 5c04eeb93150ff255334f97152664dd9b6f623e7..cdeb834f5711e32e8e75e6d3f16d862e83865203 100644
--- a/cpp/src/scheduler/SchedInst.cpp
+++ b/cpp/src/scheduler/SchedInst.cpp
@@ -147,7 +147,7 @@ load_advance_config() {
     //        }
     //    } catch (const char *msg) {
     //        SERVER_LOG_ERROR << msg;
-    //        // TODO: throw exception instead
+    //        // TODO(wxy): throw exception instead
     //        exit(-1);
     ////        throw std::exception();
     //    }
diff --git a/cpp/src/scheduler/Scheduler.cpp b/cpp/src/scheduler/Scheduler.cpp
index 5cffa9996889acba406a2dfa08ae79aeefae7640..8272bf621947edfb0421fae080fa45aa23df8810 100644
--- a/cpp/src/scheduler/Scheduler.cpp
+++ b/cpp/src/scheduler/Scheduler.cpp
@@ -93,7 +93,7 @@ Scheduler::Process(const EventPtr& event) {
     process_event(event);
 }
 
-// TODO: refactor the function
+// TODO(wxy): refactor the function
 void
 Scheduler::OnLoadCompleted(const EventPtr& event) {
     auto load_completed_event = std::static_pointer_cast<LoadCompletedEvent>(event);
diff --git a/cpp/src/scheduler/Scheduler.h b/cpp/src/scheduler/Scheduler.h
index e72e40d1bad07067d420299b37c4a09335aae95f..58cb4cbce81d5d76374c29eba586a58cbfd7dbe2 100644
--- a/cpp/src/scheduler/Scheduler.h
+++ b/cpp/src/scheduler/Scheduler.h
@@ -32,7 +32,7 @@ namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
-// TODO: refactor, not friendly to unittest, logical in framework code
+// TODO(wxy): refactor, not friendly to unittest, logical in framework code
 class Scheduler {
  public:
     explicit Scheduler(ResourceMgrWPtr res_mgr);
diff --git a/cpp/src/scheduler/TaskCreator.cpp b/cpp/src/scheduler/TaskCreator.cpp
index 4f8979703f6733f466d7c0bf95c647154588dba2..cfcb0eb448605500ae5a591673fafd9ecdf71bfd 100644
--- a/cpp/src/scheduler/TaskCreator.cpp
+++ b/cpp/src/scheduler/TaskCreator.cpp
@@ -33,7 +33,7 @@ TaskCreator::Create(const JobPtr& job) {
             return Create(std::static_pointer_cast<DeleteJob>(job));
         }
         default: {
-            // TODO: error
+            // TODO(wxy): error
             return std::vector<TaskPtr>();
         }
     }
diff --git a/cpp/src/scheduler/TaskTable.h b/cpp/src/scheduler/TaskTable.h
index eb6a69324d64b05206e124a986e7bdf860b9ef63..80c8438eb1d468a3582ce266d834ddeb1fb9d3c9 100644
--- a/cpp/src/scheduler/TaskTable.h
+++ b/cpp/src/scheduler/TaskTable.h
@@ -126,7 +126,7 @@ class TaskTable {
     Get(uint64_t index);
 
     /*
-     * TODO(wxyu): BIG GC
+     * TODO(wxy): BIG GC
      * Remove sequence task which is DONE or MOVED from front;
      * Called by ?
      */
@@ -174,7 +174,7 @@ class TaskTable {
  public:
     /******** Action ********/
 
-    // TODO: bool to Status
+    // TODO(wxy): bool to Status
     /*
      * Load a task;
      * Set state loading;
diff --git a/cpp/src/scheduler/action/PushTaskToNeighbour.cpp b/cpp/src/scheduler/action/PushTaskToNeighbour.cpp
index 4cafffa3659c167944ee1dead7b5368e98842b5b..6fb861c8f3e6ca651613724e25206d09c359e314 100644
--- a/cpp/src/scheduler/action/PushTaskToNeighbour.cpp
+++ b/cpp/src/scheduler/action/PushTaskToNeighbour.cpp
@@ -83,7 +83,7 @@ Action::PushTaskToNeighbourRandomly(const TaskPtr& task, const ResourcePtr& self
         }
 
     } else {
-        // TODO: process
+        // TODO(wxy): process
     }
 }
 
diff --git a/cpp/src/scheduler/resource/Node.h b/cpp/src/scheduler/resource/Node.h
index 0713dafa2d6f0baa7a1aba9ce042520347a0feec..588eef5f2eb2849d97f9bcbf216892c166cb1956 100644
--- a/cpp/src/scheduler/resource/Node.h
+++ b/cpp/src/scheduler/resource/Node.h
@@ -41,7 +41,7 @@ struct Neighbour {
     Connection connection;
 };
 
-// TODO(linxj): return type void -> Status
+// TODO(lxj): return type void -> Status
 class Node {
  public:
     Node();
diff --git a/cpp/src/scheduler/resource/Resource.h b/cpp/src/scheduler/resource/Resource.h
index f6ba88c2c3ee5acea7398315f6a11f8cf329fbb9..2bffaae5cfb9d7d88f69440c497e1fe79106f755 100644
--- a/cpp/src/scheduler/resource/Resource.h
+++ b/cpp/src/scheduler/resource/Resource.h
@@ -39,7 +39,7 @@ namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
-// TODO(wxyu): Storage, Route, Executor
+// TODO(wxy): Storage, Route, Executor
 enum class ResourceType {
     DISK = 0,
     CPU = 1,
@@ -115,11 +115,11 @@ class Resource : public Node, public std::enable_shared_from_this<Resource> {
         return enable_executor_;
     }
 
-    // TODO: const
+    // TODO(wxy): const
     uint64_t
     NumOfTaskToExec();
 
-    // TODO: need double ?
+    // TODO(wxy): need double ?
     inline uint64_t
     TaskAvgCost() const {
         return total_cost_ / total_task_;
diff --git a/cpp/src/scheduler/task/SearchTask.h b/cpp/src/scheduler/task/SearchTask.h
index 872187a077e4f891e1745d966e1a5fb7f36a4000..a89df4637b97a6444c09a1e450b68dc37271690b 100644
--- a/cpp/src/scheduler/task/SearchTask.h
+++ b/cpp/src/scheduler/task/SearchTask.h
@@ -27,7 +27,7 @@ namespace zilliz {
 namespace milvus {
 namespace scheduler {
 
-// TODO: rewrite
+// TODO(wxy): rewrite
 class XSearchTask : public Task {
  public:
     explicit XSearchTask(TableFileSchemaPtr file);
diff --git a/cpp/src/sdk/examples/grpcsimple/main.cpp b/cpp/src/sdk/examples/grpcsimple/main.cpp
index 76c60ac1f807c044ae419b1c3ce4433df9ed03d9..c31f491afb2a8363dfbeaef874e7c7a03c1c8c1f 100644
--- a/cpp/src/sdk/examples/grpcsimple/main.cpp
+++ b/cpp/src/sdk/examples/grpcsimple/main.cpp
@@ -30,10 +30,10 @@ main(int argc, char* argv[]) {
     printf("Client start...\n");
 
     std::string app_name = basename(argv[0]);
-    static struct option long_options[] = {{"server", optional_argument, 0, 's'},
-                                           {"port", optional_argument, 0, 'p'},
-                                           {"help", no_argument, 0, 'h'},
-                                           {NULL, 0, 0, 0}};
+    static struct option long_options[] = {{"server", optional_argument, nullptr, 's'},
+                                           {"port", optional_argument, nullptr, 'p'},
+                                           {"help", no_argument, nullptr, 'h'},
+                                           {nullptr, 0, nullptr, 0}};
 
     int option_index = 0;
     std::string address = "127.0.0.1", port = "19530";
diff --git a/cpp/src/sdk/grpc/ClientProxy.cpp b/cpp/src/sdk/grpc/ClientProxy.cpp
index db4f717eaa094048c02c9fe2257cd3b5db8e4342..7e1955b04b319e2fca7b60a044b52f204c55e57e 100644
--- a/cpp/src/sdk/grpc/ClientProxy.cpp
+++ b/cpp/src/sdk/grpc/ClientProxy.cpp
@@ -29,10 +29,7 @@ namespace milvus {
 bool
 UriCheck(const std::string& uri) {
     size_t index = uri.find_first_of(':', 0);
-    if (index == std::string::npos) {
-        return false;
-    }
-    return true;
+    return (index != std::string::npos);
 }
 
 Status
@@ -99,7 +96,7 @@ ClientProxy::CreateTable(const TableSchema& param) {
         schema.set_table_name(param.table_name);
         schema.set_dimension(param.dimension);
         schema.set_index_file_size(param.index_file_size);
-        schema.set_metric_type((int32_t)param.metric_type);
+        schema.set_metric_type(static_cast<int32_t>(param.metric_type));
 
         return client_ptr_->CreateTable(schema);
     } catch (std::exception& ex) {
@@ -130,7 +127,6 @@ ClientProxy::DropTable(const std::string& table_name) {
 Status
 ClientProxy::CreateIndex(const IndexParam& index_param) {
     try {
-        // TODO: add index params
         ::milvus::grpc::IndexParam grpc_index_param;
         grpc_index_param.set_table_name(index_param.table_name);
         grpc_index_param.mutable_index()->set_index_type(static_cast<int32_t>(index_param.index_type));
@@ -274,7 +270,7 @@ ClientProxy::DescribeTable(const std::string& table_name, TableSchema& table_sch
         table_schema.table_name = grpc_schema.table_name();
         table_schema.dimension = grpc_schema.dimension();
         table_schema.index_file_size = grpc_schema.index_file_size();
-        table_schema.metric_type = (MetricType)grpc_schema.metric_type();
+        table_schema.metric_type = static_cast<MetricType>(grpc_schema.metric_type());
 
         return status;
     } catch (std::exception& ex) {
@@ -384,7 +380,7 @@ ClientProxy::DescribeIndex(const std::string& table_name, IndexParam& index_para
         grpc_table_name.set_table_name(table_name);
         ::milvus::grpc::IndexParam grpc_index_param;
         Status status = client_ptr_->DescribeIndex(grpc_table_name, grpc_index_param);
-        index_param.index_type = (IndexType)(grpc_index_param.mutable_index()->index_type());
+        index_param.index_type = static_cast<IndexType>(grpc_index_param.mutable_index()->index_type());
         index_param.nlist = grpc_index_param.mutable_index()->nlist();
 
         return status;
diff --git a/cpp/src/server/grpc_impl/GrpcRequestTask.cpp b/cpp/src/server/grpc_impl/GrpcRequestTask.cpp
index a76552b65b67580775117431e2622e7a35fdc9be..241e24e8f676ea759550a4c32e2a14d207e6da70 100644
--- a/cpp/src/server/grpc_impl/GrpcRequestTask.cpp
+++ b/cpp/src/server/grpc_impl/GrpcRequestTask.cpp
@@ -468,7 +468,7 @@ InsertTask::OnExecute() {
         // step 4: prepare float data
         std::vector<float> vec_f(insert_param_->row_record_array_size() * table_info.dimension_, 0);
 
-        // TODO: change to one dimension array in protobuf or use multiple-thread to copy the data
+        // TODO(yk): change to one dimension array or use multiple-thread to copy the data
         for (size_t i = 0; i < insert_param_->row_record_array_size(); i++) {
             if (insert_param_->row_record_array(i).vector_data().empty()) {
                 return Status(SERVER_INVALID_ROWRECORD_ARRAY, "Row record array data is empty");
diff --git a/cpp/unittest/db/db_tests.cpp b/cpp/unittest/db/db_tests.cpp
index 365fc3ab2dfd6c3954ebedc59bb10b144d703a87..0bb74437b013bc840ba4f4c523598d34f04bb883 100644
--- a/cpp/unittest/db/db_tests.cpp
+++ b/cpp/unittest/db/db_tests.cpp
@@ -291,7 +291,7 @@ TEST_F(DBTest, SEARCH_TEST) {
         ASSERT_TRUE(stat.ok());
     }
 
-    // TODO(linxj): add groundTruth assert
+    // TODO(lxj): add groundTruth assert
 }
 
 TEST_F(DBTest, PRELOADTABLE_TEST) {
diff --git a/cpp/unittest/server/cache_test.cpp b/cpp/unittest/server/cache_test.cpp
index 056d60185a68b8b8712168dc8349a78dc1408cfa..8fea11fa62d75a019c40b38494fdb27bf28a0a3f 100644
--- a/cpp/unittest/server/cache_test.cpp
+++ b/cpp/unittest/server/cache_test.cpp
@@ -193,7 +193,7 @@ TEST(CacheTest, GPU_CACHE_TEST) {
     ASSERT_EQ(gpu_mgr->ItemCount(), 0);
 
     for (auto i = 0; i < 3; i++) {
-        // TODO: use gpu index to mock
+        // TODO(myh): use gpu index to mock
         //each vector is 1k byte, total size less than 2G
         ms::engine::VecIndexPtr mock_index = std::make_shared<MockVecIndex>(256, 2000000);
         ms::cache::DataObjPtr data_obj = std::make_shared<ms::cache::DataObj>(mock_index);