Merge branch '0.5.0' into '0.5.0'

add log

See merge request megasearch/milvus!768

Former-commit-id: 67e0d114e0b653af7927219b481b4f84fab983d0

core/src/db/engine/ExecutionEngineImpl.cpp

@@ -164,6 +164,9 @@ ExecutionEngineImpl::HybridLoad() const {
         quantizer_conf->mode = 1;
         quantizer_conf->gpu_id = best_device_id;
         auto quantizer = index_->LoadQuantizer(quantizer_conf);
+        if (quantizer == nullptr) {
+            ENGINE_LOG_ERROR << "quantizer is nullptr";
+        }
         index_->SetQuantizer(quantizer);
         auto cache_quantizer = std::make_shared<CachedQuantizer>(quantizer);
         cache::GpuCacheMgr::GetInstance(best_device_id)->InsertItem(key, cache_quantizer);

core/src/wrapper/VecIndex.h

@@ -26,6 +26,7 @@
 #include "knowhere/common/Config.h"
 #include "knowhere/index/vector_index/Quantizer.h"
 #include "utils/Status.h"
+#include "utils/Log.h"
 
 namespace milvus {
 namespace engine {
@@ -101,6 +102,7 @@ class VecIndex : public cache::DataObj {
     ////////////////
     virtual knowhere::QuantizerPtr
     LoadQuantizer(const Config& conf) {
+        ENGINE_LOG_ERROR << "LoadQuantizer virtual funciton called.";
         return nullptr;
     }