logrotate对MySQL日志轮替的实例分享

发布时间:2019-08-14编辑:脚本学堂
本文介绍下,在linux中,使用logrotate工具对mysql日志进行轮替的配置方法,有需要的朋友可以参考下。

linux下,使用logratate进行日志轮替,比较适用于具有固定文件名的日志文件,比如mysql的出错日志、常规查询日志、慢查询日志等。

本文介绍下logratate实现自动轮替的原理和用法。

默认情况下,logrotate部署为每天运行的cron job,可以在目录/etc/cron.daily里找到名为logrotate的配置文件。
那么它是在每天的上面时候运行的呢?

打开文件/etc/crontab即知晓,类似:
 

复制代码 代码示例:

shell=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
MAILTO=root
HOME=/

# run-parts
01 * * * * root run-parts /etc/cron.hourly
02 4 * * * root run-parts /etc/cron.daily
22 4 * * 0 root run-parts /etc/cron.weekly
42 4 1 * * root run-parts /etc/cron.monthly

/etc/cron.daily是在每天凌晨4:02执行。即每天4:02分/etc/cron.daily/logrotate将会自动执行,内容:
 

复制代码 代码示例:

#!/bin/sh

/usr/sbin/logrotate /etc/logrotate.conf
EXITVALUE=$?
if [ $EXITVALUE != 0 ]; then
    /usr/bin/logger -t logrotate "ALERT exited abnormally with [$EXITVALUE]"
fi
exit 0

从以上可以知道,logratate默认的配置文件是/etc/logratate.conf,内容:
 

复制代码 代码示例:

EXITVALUE=$?
if [ $EXITVALUE != 0 ]; then
    /usr/bin/logger -t logrotate "ALERT exited abnormally with [$EXITVALUE]"
fi
exit 0
[root@jbxue /etc/cron.daily ]# cat /etc/logrotate.conf
# see "man logrotate" for details
# rotate log files weekly
weekly

# keep 4 weeks worth of backlogs
rotate 4

# create new (empty) log files after rotating old ones
create

# uncomment this if you want your log files compressed
#compress

# RPM packages drop log rotation information into this directory
include /etc/logrotate.d

# no packages own wtmp -- we'll rotate them here
/var/log/wtmp {
    monthly
    minsize 1M
    create 0664 root utmp
    rotate 1
}

/var/log/btmp {
    missingok
    monthly
    minsize 1M
    create 0600 root utmp
    rotate 1
}

这个默认的配置文件将读取目录/etc/logrotate.d,所以只要把自己写的配置文件放到该目录下即可。

MySQL本省提供了一个rotate的参考配置文件,在support-files目录下,文件名为mysql-log-rotate,内容如下:
 

复制代码 代码示例:

# This logname can be set in /etc/my.cnf
# by setting the variable "err-log"
# in the [safe_mysqld] section as follows:
#
# [safe_mysqld]
# err-log=/opt/mysql/data/mysqld.log
#
# If the root user has a password you have to create a
# /root/.my.cnf configuration file with the following
# content:
#
# [mysqladmin]
# password = <secret>
# user= root
#
# where "<secret>" is the password.
#
# ATTENTION: This /root/.my.cnf should be readable ONLY
# for root !

/opt/mysql/data/mysqld.log {
        # create 600 mysql mysql
        notifempty
        daily
        rotate 3
        missingok
        compress
    postrotate
        # just if mysqld is really running
        if test -x /opt/mysql/bin/mysqladmin &&
           /opt/mysql/bin/mysqladmin ping &>/dev/null
        then
           /opt/mysql/bin/mysqladmin flush-logs
        fi
    endscript
}
 

logrotate常见选项:
选项 含义
compress 压缩日志文件的所有非当前版本
copy 复制当前的日志文件,忽略create参数
 
copytruncate 复制当前的日志文件,并置空当前文件
daily 每天轮日志文件i
dateext 轮换的日志后缀为-YYYYMMDD格式
delaycompress 压缩除了当前和最近之外的所有其他版本
missingok 如果日志不存在,不会报错
notifempty 如果日志为空,则不轮换
rotate n 在轮换方案中包含n个版本的日志
size=logsize 如果日志文件大于logsize才轮换

只要根据自己的需要,修改相应配置即可。

例子:
1)创建MySQL root密码文件
vi /root/.my.cnf
 

复制代码 代码示例:
[mysqladmin]
password = ***
user= root
chmod 600 /root/.my.cnf

2)把mysql-log-rotate拷贝至/etc/logrotate.d目录下,修改其内容为:
 

复制代码 代码示例:
/data/mysql/log/slow.log
/data/mysql/log/alert.log {
        create 600 mysql mysql
        notifempty
        daily
        rotate 7
        missingok
        # compress
    postrotate
        # just if mysqld is really running
        if test -x /opt/mysql/bin/mysqladmin &&
           /opt/mysql/bin/mysqladmin ping &>/dev/null
        then
           /opt/mysql/bin/mysqladmin flush-logs
        fi
    endscript
}

3)执行命令测试
 

复制代码 代码示例:
/usr/sbin/logrotate -f /etc/logrotate.d/mysql-log-rotate