MySQL 5.7時間表示変更(log_timestamps UTC)

MySQL 5.7バージョンでは、ログ記録時間が変化し、UTC方式でログ時間を記録しています.つまり、これは世界統一時間であり、私たちがよく使うローカル時間とは調和していません.そのため、MySQL 5.7を初期化した後、以下のように調整する必要があります.
一、エラーログの時間フォーマット

    
[robin@ydq-mnt ~]$ more /etc/redhat-release
CentOS Linux release 7.5.1804 (Core) 

[robin@ydq-mnt ~]$ mysql -V
mysql  Ver 14.14 Distrib 5.7.22, for Linux (x86_64) using  EditLine wrapper

[root@ydq-mnt ~]#  date  ###    
2018  07  25      12:53:32 CST

[root@ydq-mnt ~]# more /var/log/mysqld.log   ###mysql       
2018-07-25T07:50:40.575098Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. 
Please use --explicit_defaults_for_timestamp server option (see do
cumentation for more details).
2018-07-25T07:50:40.576375Z 0 [Note] /usr/sbin/mysqld (mysqld 5.7.22-17-57-log) starting as process 9268 ...
2018-07-25T07:50:40.578287Z 0 [Warning] No argument was provided to --log-bin, and --log-bin-index was not used; 
so replication may break when this MySQL serve
r acts as a master and has his hostname changed!! Please use '--log-bin=ydq-mnt-bin' to avoid this problem.
2018-07-25T07:50:40.578320Z 0 [Note] WSREP: Setting wsrep_ready to false
2018-07-25T07:50:40.578330Z 0 [Note] WSREP: No pre-stored wsrep-start position found. Skipping position initialization.
2018-07-25T07:50:40.578335Z 0 [Note] WSREP: wsrep_load(): loading provider library '/usr/lib64/galera3/libgalera_smm.so'
2018-07-25T07:50:40.582014Z 0 [Note] WSREP: wsrep_load(): Galera 3.22(r8678538) by Codership Oy  loaded successfully.
    ，        mysql          。

二、システム変数log_timestamps

This variable controls the timestamp time zone of error log messages, and of general query log
and slow query log messages written to files. It does not affect the time zone of general query log
and slow query log messages written to tables (mysql.general_log, mysql.slow_log). Rows
retrieved from those tables can be converted from the local system time zone to any desired time
zone with CONVERT_TZ() or by setting the session time_zone system variable.
Permitted log_timestamps values are UTC (the default) and SYSTEM (local system time zone).
Timestamps are written using ISO 8601 / RFC 3339 format: YYYY-MM-DDThh:mm:ss.uuuuuu plus
a tail value of Z signifying Zulu time (UTC) or  hh:mm (an offset from UTC).
This variable was added in MySQL 5.7.2. Before 5.7.2, timestamps in log messages were written
using the local system time zone by default, not UTC. If you want the previous log message time
zone default, set log_timestamps=SYSTEM.

上記の説明から分かるように、この変数はMySQL 5.7.2に追加されています.デフォルトはUTCです.デフォルトタイムゾーンの時間を使用する場合は、このパラメータの値をSYSTEMに変更します.
三、修正と検証

mysql> set global log_timestamps='SYSTEM';
Query OK, 0 rows affected (0.00 sec)

[root@ydq-mnt mysql]# vim /etc/percona-xtradb-cluster.conf.d/mysqld.cnf
log_timestamps=SYSTEM

[root@ydq-mnt ~]# systemctl restart mysql
2018-07-25T07:52:41.543983Z 0 [Note] Beginning of list of non-natively partitioned tables
2018-07-25T07:52:41.544128Z 0 [Note] WSREP: Member 0.0 (ydq-mnt) synced with group.
2018-07-25T07:52:41.544138Z 0 [Note] WSREP: Shifting JOINED -> SYNCED (TO: 4163)
2018-07-25T07:52:41.550738Z 8 [Note] WSREP: Synchronized with group, ready for connections
2018-07-25T07:52:41.550755Z 8 [Note] WSREP: This node is synced, setting wsrep_ready to true
2018-07-25T07:52:41.550761Z 8 [Note] WSREP: wsrep_notify_cmd is not defined, skipping notification.
2018-07-25T07:52:41.582207Z 0 [Note] End of list of non-natively partitioned tables
2018-07-25T07:52:43.178826Z 0 [Note] InnoDB: Buffer pool(s) load completed at 171218 15:52:43
2018-07-25T16:24:23.588881+08:00 0 [Note] WSREP: Received shutdown signal. Will sleep for 10 secs before initiating shutdown.
pxc_maint_mode switched to SHUTDOWN
2018-07-25T16:24:33.591354+08:00 0 [Note] WSREP: Stop replication
2018-07-25T16:24:33.591408+08:00 0 [Note] WSREP: Closing send monitor...
2018-07-25T16:24:33.591429+08:00 0 [Note] WSREP: Closed send monitor.
2018-07-25T16:24:33.591453+08:00 0 [Note] WSREP: gcomm: terminating thread
2018-07-25T16:24:33.591477+08:00 0 [Note] WSREP: gcomm: joining thread
2018-07-25T16:24:33.591700+08:00 0 [Note] WSREP: gcomm: closing backend

再起動と検証、時間表示はシステム時間と一致します.