From 51f6ed9bff03e29079d9a7774905312877e2fa0a Mon Sep 17 00:00:00 2001
From: ti-srebot <66930949+ti-srebot@users.noreply.github.com>
Date: Wed, 9 Feb 2022 14:03:35 +0800
Subject: [PATCH] [logutil]: Fix `MaxDays` and `MaxBackups` not working for
 slow-query-logger (#27625) (#30171)

ref pingcap/tidb#25716
---
 util/logutil/slow_query_logger.go | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/util/logutil/slow_query_logger.go b/util/logutil/slow_query_logger.go
index c64333afd9baf..cf03dd34e6b80 100644
--- a/util/logutil/slow_query_logger.go
+++ b/util/logutil/slow_query_logger.go
@@ -15,17 +15,15 @@ var _pool = buffer.NewPool()
 
 func newSlowQueryLogger(cfg *LogConfig) (*zap.Logger, *log.ZapProperties, error) {
 
-	// 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
+	// copy the global log config to slow log config
+	// if the filename of slow log config is empty, slow log will behave the same as global log.
 	sqConfig := cfg.Config
 	// level of the global log config doesn't affect the slow query logger which determines whether to
 	// log by execution duration.
 	sqConfig.Level = LogConfig{}.Level
 	if len(cfg.SlowQueryFile) != 0 {
-		sqConfig.File = log.FileLogConfig{
-			MaxSize:  cfg.File.MaxSize,
-			Filename: cfg.SlowQueryFile,
-		}
+		sqConfig.File = cfg.File
+		sqConfig.File.Filename = cfg.SlowQueryFile
 	}
 
 	// create the slow query logger