log file write sync problem

[cw-20020752]

I'm using zap to write the audit log file, and I'm writing both to the console output and to a file in the aws filesystem called efs.
I am writing the log in json format, and it is normally output to the console, but an abnormal log is sometimes output to the log file in the file system.
(
I have two pods running with kubernetes.
)
Can you tell me why?

Below is my code.

---

package logger
import (
 ...
)

var logger *zap.Logger
var InfoLogChannel chan DefaultLog
var ErrorLogChannel chan DefaultLog
var mu sync.Mutex

func getWriteSyncer() zapcore.WriteSyncer {
	logFile := config.RuntimeConf.Log.Path + utils.GetLocalTimeNowFormat("2006010215") + ".log"
	lumlog := &lumberjack.Logger{
		Filename: logFile,
		MaxAge:   7, // days
	}
	return zapcore.AddSync(lumlog)
}

func init() {

	encoderConfig := map[string]string{
		"levelEncoder": "capital",
		"timeKey":      "timestamp",
		"timeEncoder":  "iso8601",
	}
	data, _ := json.Marshal(encoderConfig)
	var encCfg zapcore.EncoderConfig
	if err := json.Unmarshal(data, &encCfg); err != nil {
		panic(err)
	}
	core := zapcore.NewTee(
		zapcore.NewCore(zapcore.NewJSONEncoder(encCfg), getWriteSyncer(), zap.InfoLevel),
		zapcore.NewCore(zapcore.NewJSONEncoder(encCfg), zapcore.AddSync(os.Stdout), zap.InfoLevel),
	)

	logger = zap.New(core)

}

func SetDefaultLog(defaultLog DefaultLog) (*zap.Logger, error) {
	logger := logger.With(
		zap.String("URI", defaultLog.URI),
		zap.String("method", defaultLog.Method),
		zap.Any("request", defaultLog.Request),
	)
	return logger, nil
}

func PrintInfoLog(log DefaultLog) {
	mu.Lock()
	logger, _ := SetDefaultLog(log)
	logger.Info("",
		zap.String("type", "audit"),
	)
	defer logger.Sync()
	defer mu.Unlock()
}

func PrintErrorLog(log DefaultLog) {
	mu.Lock()
	logger, _ := SetDefaultLog(log)
	logger.Error("",
		zap.String("type", "except"),
	)
	defer logger.Sync()
	defer mu.Unlock()
}

[sywhang]

I am writing the log in json format, and it is normally output to the console, but an abnormal log is sometimes output to the log file in the file system.

Can you elaborate what you mean by "abnormal log"?