enhance: Refine param init for MmapDirPath (#35181)

Signed-off-by: Wei Liu <wei.liu@zilliz.com>

internal/util/initcore/init_core.go

@@ -173,13 +173,6 @@ func InitRemoteChunkManager(params *paramtable.ComponentParam) error {
 
 func InitMmapManager(params *paramtable.ComponentParam) error {
 	mmapDirPath := params.QueryNodeCfg.MmapDirPath.GetValue()
-	if len(mmapDirPath) == 0 {
-		paramtable.Get().Save(
-			paramtable.Get().QueryNodeCfg.MmapDirPath.Key,
-			path.Join(paramtable.Get().LocalStorageCfg.Path.GetValue(), "mmap"),
-		)
-		mmapDirPath = paramtable.Get().QueryNodeCfg.MmapDirPath.GetValue()
-	}
 	cMmapChunkManagerDir := C.CString(path.Join(mmapDirPath, "/mmap_chunk_manager/"))
 	cCacheReadAheadPolicy := C.CString(params.QueryNodeCfg.ReadAheadPolicy.GetValue())
 	defer C.free(unsafe.Pointer(cMmapChunkManagerDir))

pkg/util/paramtable/component_param.go

@@ -19,6 +19,7 @@ package paramtable
 import (
 	"fmt"
 	"os"
+	"path"
 	"strconv"
 	"strings"
 	"sync"
@@ -2496,6 +2497,12 @@ This defaults to true, indicating that Milvus creates temporary index for growin
 		DefaultValue: "",
 		FallbackKeys: []string{"queryNode.mmapDirPath"},
 		Doc:          "The folder that storing data files for mmap, setting to a path will enable Milvus to load data with mmap",
+		Formatter: func(v string) string {
+			if len(v) == 0 {
+				return path.Join(base.Get("localStorage.path"), "mmap")
+			}
+			return v
+		},
 	}
 	p.MmapDirPath.Init(base.mgr)
 

pkg/util/paramtable/component_param_test.go

@@ -443,6 +443,7 @@ func TestComponentParam(t *testing.T) {
 		assert.Equal(t, 3*time.Second, Params.LazyLoadRequestResourceRetryInterval.GetAsDuration(time.Millisecond))
 
 		assert.Equal(t, 4, Params.BloomFilterApplyParallelFactor.GetAsInt())
+		assert.Equal(t, "/var/lib/milvus/data/mmap", Params.MmapDirPath.GetValue())
 	})
 
 	t.Run("test dataCoordConfig", func(t *testing.T) {