Logrotate in Linux to cut logs (Nginx,mysql)

Logrotate Introduction
log rotation is especially useful for log files with fixed file names, such as MySQL error log, regular query log, slow query log, and so on. Linux system has a very easy to use according to Logratate can achieve automatic rotation, this article describes its principle and usage.

Logrotate is the tool for managing log files, in CentOS systems, where commands are located in/usr/sbin/logrotate, commonly used operations such as:
-D,--debug Don ' t do anything, just test (IMPLIES-V)
-F,--force force file rotation
Note: the-d parameter does not produce a new log.

Logrotate is typically run once a day by cron. The standard profile is/etc/logrotate.conf, and the/ETC/LOGROTATE.D directory is the location where the configuration file is saved.

Logrotate Common options:
/-----------------------------------------------
Options          |        meaning
-----------------------------------------------
compress    |    All non-current versions of the compressed log file
copy    |    Copy the current log file, ignore the Create parameter
copytruncate    |    Copy the current log file, and empty the current file
daily     |    Daily Wheel log file I
dateext    |    rotation log suffix is-YYYYMMDD format
delaycompress    |    compresses all but the current and most recent versions of
missingok    |     If the log does not exist, there is no error
notifempty    |    If the log is empty, do not rotate
rotate n     |    contains n versions of the log in a rotation scheme
size=logsize    |    Rotate
-----------------------------------------------/

If the log file is larger than logsize

By default, Logrotate is deployed as a daily cronjob, and you can find a configuration file named Logrotate in the directory/etc/cron.daily. So it runs at the top of every day? Open the file/etc/crontab know, here is the situation on my machine:

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Shell=/bin/bash Path=/sbin:/bin:/usr/sbin:/usr/bin Mailto=root home=/ # Run-parts * * * * Root run-parts/etc/cron.hourly 4 * * * Root run-parts/etc/cron.daily 4 * * 0 root run-parts/etc/cron.weekly 4 1 * * Root run-parts/etc/cron.monthly

From the above configuration we can know that the/etc/cron.daily is executed at 4:02 every day. That is, every day 4:02/etc/cron.daily/logrotate will be automatically executed, the following is its content:

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#!/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

From the above we can see that the default profile for Logratate is/etc/logrotate.conf, and here's what it does:

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# "Man logrotate" for details # Rotate log Files Weekly Weekly # Keep 4 weeks worth of backlogs Rotate 4 # Create new (empty) log files after the rotating old ones Create # Use date as a suffix of the rotated file Dateext # 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 and btmp--we'll rotate them here /var/log/wtmp { Monthly Create 0664 Root utmp MinSize 1M Rotate 1 } /var/log/btmp { Missingok Monthly Create 0600 Root utmp Rotate 1 } # System-specific logs may also is configured here.

As you can see from the/etc/logrotate.conf configuration, this default configuration file will read the directory/ETC/LOGROTATE.D, so we simply put our own configuration file into the/ETC/LOGROTATE.D directory.

MySQL Configuration Chapter

MySQL This province provides a rotate reference profile, in the MySQL installation directory in the Support-files directory, the file name is Mysql-log-rotate, which reads as follows:

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# This logname can is set in/etc/my.cnf # by setting the variable ' err-log ' # in ' [Safe_mysqld] section as follows: # # [safe_mysqld] # err-log=/usr/local/mysql/data/mysqld.log # # If The root user has a PASSW Ord you have to create a #/root/.my.cnf configuration file with the following # content: # # [Mysqladmin] # password = <secret> # user= Root # # where ' <secret> ' is the password. # # attentio N:THIS/ROOT/.MY.CNF should be readable only # for Root! /usr/local/mysql/data/mysqld.log {         # create MySQL MySQL         notifempty         Daily         Rotate 3         Missingok         Compress     postrotate          # Just if Mysqld is really running         if Test-x/usr/local /mysql/bin/mysqladmin &&           /usr/local/ Mysql/bin/mysqladmin Ping &>/dev/null         then            /usr/local/mysql/bin/mysqladmin flush-logs          fi     endscript }

From the above annotation information you can see the steps:
1. Create MySQL root password file
Vi/root/.my.cnf
Edit the following content

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[Mysqladmin] Password = <secret> user= Root

Note: <secret> is your root password
2. Permission to read root
chmod 600/root/.my.cnf
3. Copy the mysql-log-rotate to the/ETC/LOGROTATE.D directory and modify the contents to read:

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/usr/local/mysql/data/*.log { Create MySQL MySQL Notifempty Daily Rotate 7 Missingok Compress Postrotate # http://www.111cn.net # Just if Mysqld is really running If Test-x/usr/local/mysql/bin/mysqladmin && /usr/local/mysql/bin/mysqladmin Ping &>/dev/null Then /usr/local/mysql/bin/mysqladmin Flush-logs Fi Endscript }

4. Perform the following command test

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/usr/sbin/logrotate-f/etc/logrotate.d/mysql-log-rotate

Nginx Configuration Chapter
Write the following code to/etc/logrotate.d/nginx

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/usr/local/ Nginx/log/*.log {         create www www.          notifempty         daily          Rotate 7         Missingok          Compress     postrotate         # Servic nginx Reload     endscript }