enhance: Use an individual buffer size parameter for imports (#31833)

Use an individual buffer size parameter for imports and set buffer size
to 64MB.

issue: https://github.com/milvus-io/milvus/issues/28521

---------

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

configs/milvus.yaml

@@ -506,6 +506,7 @@ dataNode:
   import:
     maxConcurrentTaskNum: 16 # The maximum number of import/pre-import tasks allowed to run concurrently on a datanode.
     maxImportFileSizeInGB: 16 # The maximum file size (in GB) for an import file, where an import file refers to either a Row-Based file or a set of Column-Based files.
+    readBufferSizeInMB: 16 # The data block size (in MB) read from chunk manager by the datanode during import.
 
 # Configures the system log output.
 log:

internal/datanode/importv2/scheduler.go

@@ -150,7 +150,7 @@ func (s *scheduler) handleErr(task Task, err error, msg string) {
 }
 
 func (s *scheduler) PreImport(task Task) []*conc.Future[any] {
-	bufferSize := paramtable.Get().DataNodeCfg.FlushInsertBufferSize.GetAsInt()
+	bufferSize := paramtable.Get().DataNodeCfg.ReadBufferSizeInMB.GetAsInt() * 1024 * 1024
 	log.Info("start to preimport", WrapLogFields(task,
 		zap.Int("bufferSize", bufferSize),
 		zap.Any("schema", task.GetSchema()))...)
@@ -241,7 +241,7 @@ func (s *scheduler) readFileStat(reader importutilv2.Reader, task Task, fileIdx
 }
 
 func (s *scheduler) Import(task Task) []*conc.Future[any] {
-	bufferSize := paramtable.Get().DataNodeCfg.FlushInsertBufferSize.GetAsInt()
+	bufferSize := paramtable.Get().DataNodeCfg.ReadBufferSizeInMB.GetAsInt() * 1024 * 1024
 	log.Info("start to import", WrapLogFields(task,
 		zap.Int("bufferSize", bufferSize),
 		zap.Any("schema", task.GetSchema()))...)

pkg/util/paramtable/component_param.go

@@ -3209,6 +3209,7 @@ type dataNodeConfig struct {
 	// import
 	MaxConcurrentImportTaskNum ParamItem `refreshable:"true"`
 	MaxImportFileSizeInGB      ParamItem `refreshable:"true"`
+	ReadBufferSizeInMB         ParamItem `refreshable:"true"`
 
 	// Compaction
 	L0BatchMemoryRatio ParamItem `refreshable:"true"`
@@ -3477,6 +3478,16 @@ func (p *dataNodeConfig) init(base *BaseTable) {
 	}
 	p.MaxImportFileSizeInGB.Init(base.mgr)
 
+	p.ReadBufferSizeInMB = ParamItem{
+		Key:          "datanode.import.readBufferSizeInMB",
+		Version:      "2.4.0",
+		Doc:          "The data block size (in MB) read from chunk manager by the datanode during import.",
+		DefaultValue: "16",
+		PanicIfEmpty: false,
+		Export:       true,
+	}
+	p.ReadBufferSizeInMB.Init(base.mgr)
+
 	p.L0BatchMemoryRatio = ParamItem{
 		Key:          "datanode.compaction.levelZeroBatchMemoryRatio",
 		Version:      "2.4.0",

pkg/util/paramtable/component_param_test.go

@@ -441,6 +441,7 @@ func TestComponentParam(t *testing.T) {
 		t.Logf("maxConcurrentImportTaskNum: %d", maxConcurrentImportTaskNum)
 		assert.Equal(t, 16, maxConcurrentImportTaskNum)
 		assert.Equal(t, int64(16), Params.MaxImportFileSizeInGB.GetAsInt64())
+		assert.Equal(t, 16, Params.ReadBufferSizeInMB.GetAsInt())
 		params.Save("datanode.gracefulStopTimeout", "100")
 		assert.Equal(t, 100*time.Second, Params.GracefulStopTimeout.GetAsDuration(time.Second))
 	})