native支持systemd是MySQL 5.7的新特性之一,我们之前在《MySQL 5.7.17 Group Replication部署实践》中编译安装MySQL时并没有开启这个特性。 本篇记录一下编译安装MySQL5.7并开启systemd的一些注意事项。

MySQL 5.7编译的选项可以参考MySQL Source-Configuration Options

1cmake . -DCMAKE_INSTALL_PREFIX=/usr/local/mysql \
2-DMYSQL_DATADIR=/var/lib/mysql \
3-DSYSCONFDIR=/etc \
4-DDOWNLOAD_BOOST=1 \
5-DWITH_BOOST=<boost_source_dir> \
6-DWITH_SYSTEMD=1
  • 通过编译选项-DWITH_SYSTEMD=1开启了systemd

MySQL Source-Configuration Options中描述了SYSTEMD_PID_DIR选项的默认值为/var/run/mysqld

而/var/run(即/run)是一个临时文件系统,存储系统启动以来的信息。当系统重启时,这个目录下的内容会被清楚。 因此我们编译安装的开启了systemd的MySQL,除了提供systemd的Unit文件外,还需要提供/usr/lib/tmpfiles.d中的mysql.conf的配置文件。

/usr/lib/tmpfiles.d/mysql.conf:

1d /var/run/mysqld 0755 mysql mysql  -

/etc/systemd/system/mysqld.service:

 1[Unit]
 2Description=MySQL Server
 3Documentation=man:mysqld(8)
 4Documentation=https://dev.mysql.com/doc/refman/5.7/en/using-systemd.html
 5After=network.target
 6After=syslog.target
 7
 8[Install]
 9WantedBy=multi-user.target
10
11[Service]
12User=mysql
13Group=mysql
14
15Type=forking
16
17PIDFile=/var/run/mysqld/mysqld.pid
18
19# Disable service start and stop timeout logic of systemd for mysqld service.
20TimeoutSec=0
21
22# Execute pre and post scripts as root
23PermissionsStartOnly=true
24
25# Needed to create system tables
26ExecStartPre=/usr/local/mysql/bin/mysqld_pre_systemd
27
28# Start main service
29ExecStart=/usr/local/mysql/bin/mysqld --daemonize --pid-file=/var/run/mysqld/mysqld.pid $MYSQLD_OPTS
30
31# Use this to switch malloc implementation
32EnvironmentFile=-/etc/sysconfig/mysql
33
34# Sets open_files_limit
35LimitNOFILE = 5000
36
37Restart=on-failure
38
39RestartPreventExitStatus=1
40
41PrivateTmp=false

参考