mysqld_safe在my.cnf中做了什么？

Question

下面是我的MySQL配置文件.我试图了解它是如何工作的.有什么意义[mysqld_safe]？还没有[mysqld]启动MySQL？为什么之后的日志错误和pid文件设置呢？

[mysqld]
# Settings user and group are ignored when systemd is used (fedora >= 15).
# If you need to run mysqld under different user or group, 
# customize your systemd unit file for mysqld according to the
# instructions in http://fedoraproject.org/wiki/Systemd
user=mysql

datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock

# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0

# Semisynchronous Replication
# http://dev.mysql.com/doc/refman/5.5/en/replication-semisync.html
# uncomment next line on MASTER
;plugin-load=rpl_semi_sync_master=semisync_master.so
# uncomment next line on SLAVE
;plugin-load=rpl_semi_sync_slave=semisync_slave.so

# Others options for Semisynchronous Replication
;rpl_semi_sync_master_enabled=1
;rpl_semi_sync_master_timeout=10
;rpl_semi_sync_slave_enabled=1

# http://dev.mysql.com/doc/refman/5.5/en/performance-schema.html
;performance_schema

innodb_strict_mode=on
sql_mode=TRADITIONAL
;sql_mode=STRICT_TRANS_TABLES,NO_ZERO_DATE,NO_ZERO_IN_DATE
character-set-server=utf8
collation-server=utf8_general_ci

[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

Answer 1

您可以使用mysqld或启动MySQL服务器mysqld_safe.mysqld_safe可能本身mysqld也会尝试执行但也可能不执行.请参阅文档(Google中 mysqld_safe,btw 的第一个结果):

mysqld_safe是在Unix和NetWare上启动mysqld服务器的推荐方法.mysqld_safe添加了一些安全功能,例如在发生错误时重新启动服务器并将运行时信息记录到错误日志文件中.特定于NetWare的行为将在本节后面列出.

部分[mysqld_safe]配置文件中是当你使用应用的设置mysqld_safe启动MySQL服务器,而不是mysqld.