Free OS memory in QueryNode and IndexNode (#14305)

Signed-off-by: bigsheeper <yihao.dai@zilliz.com>

internal/core/src/indexbuilder/index_c.cpp

@@ -10,6 +10,7 @@
 // or implied. See the License for the specific language governing permissions and limitations under the License
 
 #include <string>
+#include <malloc.h>
 #include "index/knowhere/knowhere/index/vector_index/adapter/VectorAdapter.h"
 #include "indexbuilder/IndexWrapper.h"
 #include "indexbuilder/index_c.h"
@@ -46,6 +47,7 @@ void
 DeleteIndex(CIndex index) {
     auto cIndex = (milvus::indexbuilder::IndexWrapper*)index;
     delete cIndex;
+    malloc_trim(0);
 }
 
 CStatus

internal/core/src/segcore/collection_c.cpp

@@ -10,6 +10,7 @@
 // or implied. See the License for the specific language governing permissions and limitations under the License
 
 #include <iostream>
+#include <malloc.h>
 #include "segcore/collection_c.h"
 #include "segcore/Collection.h"
 
@@ -24,6 +25,7 @@ void
 DeleteCollection(CCollection collection) {
     auto col = (milvus::segcore::Collection*)collection;
     delete col;
+    malloc_trim(0);
 }
 
 const char*

internal/querynode/mock_test.go

@@ -49,7 +49,7 @@ import (
 // ---------- unittest util functions ----------
 // common definitions
 const ctxTimeInMillisecond = 500
-const debug = false
+const debugUT = false
 
 const (
 	dimKey        = "dim"

internal/querynode/query_node_test.go

@@ -177,7 +177,7 @@ func newQueryNodeMock() *QueryNode {
 
 	var ctx context.Context
 
-	if debug {
+	if debugUT {
 		ctx = context.Background()
 	} else {
 		var cancel context.CancelFunc

internal/querynode/task.go

@@ -21,6 +21,7 @@ import (
 	"errors"
 	"fmt"
 	"math/rand"
+	"runtime/debug"
 	"strconv"
 	"time"
 
@@ -793,6 +794,8 @@ func (r *releaseCollectionTask) Execute(ctx context.Context) error {
 	}
 	r.node.historical.removeGlobalSegmentIDsByCollectionID(r.req.CollectionID)
 
+	debug.FreeOSMemory()
+
 	log.Debug("ReleaseCollection done", zap.Int64("collectionID", r.req.CollectionID))
 	return nil
 }