fix: [Cherry-pick] accesslog can not print search expression (#28931)

relate: https://github.com/milvus-io/milvus/issues/28893
pr: https://github.com/milvus-io/milvus/pull/28899

---------

Signed-off-by: aoiasd <zhicheng.yue@zilliz.com>

configs/milvus.yaml

@@ -200,18 +200,18 @@ proxy:
   ginLogging: true
   maxTaskNum: 1024 # max task number of proxy task queue
   accessLog:
-    enable: true
+    enable: false
     # Log filename, set as "" to use stdout.
-    filename: "" 
+    # filename: "" 
     # define formatters for access log by XXX:{format: XXX, method:[XXX,XXX]}
     formatters:
       # "base" formatter could not set methods
       # all method will use "base" formatter default
       base: 
         # will not print access log if set as ""
-        format: "[$time_now] [ACCESS] <$user_name: $user_addr> $method_name [status: $method_status] [code: $error_code] [msg: $error_msg] [traceID: $trace_id] [timeCost: $time_cost]"
+        format: "[$time_now] [ACCESS] <$user_name: $user_addr> $method_name [status: $method_status] [code: $error_code] [sdk: $sdk_version] [msg: $error_msg] [traceID: $trace_id] [timeCost: $time_cost]"
       query: 
-        format: "[$time_now] [ACCESS] <$user_name: $user_addr> $method_name [status: $method_status] [code: $error_code] [msg: $error_msg] [traceID: $trace_id] [timeCost: $time_cost] [database: $database_name] [collection: $collection_name] [partitions: $partition_name] [expr: $method_expr]"
+        format: "[$time_now] [ACCESS] <$user_name: $user_addr> $method_name [status: $method_status] [code: $error_code] [sdk: $sdk_version] [msg: $error_msg] [traceID: $trace_id] [timeCost: $time_cost] [database: $database_name] [collection: $collection_name] [partitions: $partition_name] [expr: $method_expr]"
           # set formatter owners by method name(method was all milvus external interface)
           # all method will use base formatter default
           # one method only could use one formatter

internal/proxy/accesslog/info.go

@@ -88,11 +88,8 @@ func (i *GrpcAccessInfo) SetResult(resp interface{}, err error) {
 
 func (i *GrpcAccessInfo) Get(keys ...string) []string {
 	result := []string{}
-	metricMap := map[string]string{}
 	for _, key := range keys {
-		if value, ok := metricMap[key]; ok {
-			result = append(result, value)
-		} else if getFunc, ok := metricFuncMap[key]; ok {
+		if getFunc, ok := metricFuncMap[key]; ok {
 			result = append(result, getFunc(i))
 		}
 	}
@@ -108,6 +105,7 @@ func (i *GrpcAccessInfo) Write() bool {
 	if !ok {
 		return false
 	}
+
 	_, err := _globalW.Write([]byte(formatter.Format(i)))
 	return err == nil
 }
@@ -256,10 +254,15 @@ func getPartitionName(i *GrpcAccessInfo) string {
 
 func getExpr(i *GrpcAccessInfo) string {
 	expr, ok := requestutil.GetExprFromRequest(i.req)
-	if !ok {
-		return unknownString
+	if ok {
+		return expr.(string)
 	}
-	return expr.(string)
+
+	dsl, ok := requestutil.GetDSLFromRequest(i.req)
+	if ok {
+		return dsl.(string)
+	}
+	return unknownString
 }
 
 func getSdkVersion(i *GrpcAccessInfo) string {

internal/proxy/accesslog/info_test.go

@@ -45,7 +45,7 @@ type GrpcAccessInfoSuite struct {
 	info     *GrpcAccessInfo
 }
 
-func (s *GrpcAccessInfoSuite) SetupSuite() {
+func (s *GrpcAccessInfoSuite) SetupTest() {
 	s.username = "test-user"
 	s.traceID = "test-trace"
 
@@ -130,6 +130,24 @@ func (s *GrpcAccessInfoSuite) TestSdkInfo() {
 	s.Equal(info.SdkType+"-"+info.SdkVersion, result[0])
 }
 
+func (s *GrpcAccessInfoSuite) TestExpression() {
+	result := s.info.Get("$method_expr")
+	s.Equal(unknownString, result[0])
+
+	testExpr := "test"
+	s.info.req = &milvuspb.QueryRequest{
+		Expr: testExpr,
+	}
+	result = s.info.Get("$method_expr")
+	s.Equal(testExpr, result[0])
+
+	s.info.req = &milvuspb.SearchRequest{
+		Dsl: testExpr,
+	}
+	result = s.info.Get("$method_expr")
+	s.Equal(testExpr, result[0])
+}
+
 func TestGrpcAccssInfo(t *testing.T) {
 	suite.Run(t, new(GrpcAccessInfoSuite))
 }

pkg/util/paramtable/component_param.go

@@ -1062,7 +1062,7 @@ please adjust in embedded Milvus: false`,
 	p.AccessLog.Filename = ParamItem{
 		Key:          "proxy.accessLog.filename",
 		Version:      "2.2.0",
-		DefaultValue: "milvus_access_log.log",
+		DefaultValue: "",
 		Doc:          "Log filename, leave empty to use stdout.",
 		Export:       true,
 	}