util/logutil: Remove useless grpc log in production

util/logutil/log.go

@@ -42,8 +42,6 @@ const (
 	DefaultRecordPlanInSlowLog = 1
 	// DefaultTiDBEnableSlowLog enables TiDB to log slow queries.
 	DefaultTiDBEnableSlowLog = true
-	// GRPCLogDebugVerbosity enables max verbosity when debugging grpc code.
-	GRPCLogDebugVerbosity = 99
 )
 
 // EmptyFileLogConfig is an empty FileLogConfig.
@@ -111,12 +109,33 @@ func InitLogger(cfg *LogConfig) error {
 		return errors.Trace(err)
 	}
 
-	// init logger for grpc debugging
+	err = initGRPCLogger(cfg)
+	if err != nil {
+		return errors.Trace(err)
+	}
+
+	return nil
+}
+
+func initGRPCLogger(cfg *LogConfig) error {
+	// copy Config struct by assignment
+	config := cfg.Config
+	// hack: force stdout
+	config.File.Filename = ""
 	if len(os.Getenv("GRPC_DEBUG")) > 0 {
-		// more information for verbosity: https://github.com/google/glog#verbose-logging
-		gzap.ReplaceGrpcLoggerV2WithVerbosity(gl, GRPCLogDebugVerbosity)
+		config.Level = "debug"
+		l, _, err := log.InitLogger(&cfg.Config, zap.AddStacktrace(zapcore.DebugLevel))
+		if err != nil {
+			return errors.Trace(err)
+		}
+		gzap.ReplaceGrpcLoggerV2WithVerbosity(l, 999)
 	} else {
-		gzap.ReplaceGrpcLoggerV2(gl)
+		config.Level = "error"
+		l, _, err := log.InitLogger(&cfg.Config, zap.AddStacktrace(zapcore.FatalLevel))
+		if err != nil {
+			return errors.Trace(err)
+		}
+		gzap.ReplaceGrpcLoggerV2(l)
 	}
 
 	return nil

util/logutil/slow_query_logger.go

@@ -15,9 +15,9 @@ var _pool = buffer.NewPool()
 
 func newSlowQueryLogger(cfg *LogConfig) (*zap.Logger, error) {
 
-	// reuse global config and override slow query log file
+	// copy global config and override slow query log file
 	// if slow query log filename is empty, slow query log will behave the same as global log
-	sqConfig := &cfg.Config
+	sqConfig := cfg.Config
 	if len(cfg.SlowQueryFile) != 0 {
 		sqConfig.File = log.FileLogConfig{
 			MaxSize:  cfg.File.MaxSize,
@@ -26,7 +26,7 @@ func newSlowQueryLogger(cfg *LogConfig) (*zap.Logger, error) {
 	}
 
 	// create the slow query logger
-	sqLogger, prop, err := log.InitLogger(sqConfig)
+	sqLogger, prop, err := log.InitLogger(&sqConfig)
 	if err != nil {
 		return nil, errors.Trace(err)
 	}