How to gracefully realize regular backup of MySQL database (glory Collection Edition)

Catalog

Preface

One 、mysqldump Command backup data

1、mysqldump Common operation examples

2、 Restore MySQL Backup content

3、 To write BASH Maintain a fixed number of backup files

3.2、cron service

3.3、crontab grammar

3.5、 establish cron Script

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Preface

In the process of manipulating data , May cause data errors , Even the database crashed , And effective scheduled backup can well protect the database . This article mainly describes several methods to MySQL Back up the database regularly .

One 、mysqldump Command backup data

stay MySQL It provides a convenient tool for command line to export database data and files mysqldump, We can directly export the database content through the command line dump, First of all, let's have a brief understanding of mysqldump Command usage :

#MySQLdump Commonly used 
mysqldump -u root -p --databases  database 1  database 2 > xxx.sql

1、mysqldump Common operation examples

1. Back up the data and structure of all databases

mysqldump -uroot -p123456 -A > /data/mysqlDump/mydb.sql

2. Back up the structure of all databases （ Add -d Parameters ）

mysqldump -uroot -p123456 -A -d > /data/mysqlDump/mydb.sql

3. Back up all database data ( Add -t Parameters )

mysqldump -uroot -p123456 -A -t > /data/mysqlDump/mydb.sql

4. Back up the data and structure of a single database (, Database name mydb)

mysqldump -uroot-p123456 mydb > /data/mysqlDump/mydb.sql

5. Backing up the structure of a single database

mysqldump -uroot -p123456 mydb -d > /data/mysqlDump/mydb.sql

6. Backing up data from a single database

mysqldump -uroot -p123456 mydb -t > /data/mysqlDump/mydb.sql

7. Backing up data and structure of multiple tables （ data , The separate backup method of the structure is the same as above ）

mysqldump -uroot -p123456 mydb t1 t2 > /data/mysqlDump/mydb.sql

8. Backing up multiple databases at a time

mysqldump -uroot -p123456 --databases db1 db2 > /data/mysqlDump/mydb.sql

2、 Restore MySQL Backup content

There are two ways to restore , The first is in MySQL Command line , The second is to use SHELL Line complete restore

1. On the system command line , Enter the following to restore ：

mysql -uroot -p123456 < /data/mysqlDump/mydb.sql

2. Log in to mysql In the system , adopt source Command to find the file in the corresponding system to restore ：

mysql> source /data/mysqlDump/mydb.sql

stay Linux in , Usually use BASH The script writes what needs to be executed , Plus regular command execution crontab Realize automatic log generation .

The following code functions are for mysql Make a backup , coordination crontab, The backup content is about one month （31 God ） Every day in mysql Database records .

3、 To write BASH Maintain a fixed number of backup files

stay Linux in , Use vi perhaps vim Write the script and name it ：mysql_dump_script.sh

#!/bin/bash

# Save the number of backup , Backup 31 Day data 
number=31
# Backup save path 
backup_dir=/root/mysqlbackup
# date 
dd=`date +%Y-%m-%d-%H-%M-%S`
# Backup tools 
tool=mysqldump
# user name 
username=root
# password 
password=TankB214
# The database to be backed up 
database_name=edoctor

# If the folder does not exist, create 
if [ ! -d $backup_dir ];
then     
    mkdir -p $backup_dir;
fi

# Simple writing  mysqldump -u root -p123456 users > /root/mysqlbackup/users-$filename.sql
$tool -u $username -p$password $database_name > $backup_dir/$database_name-$dd.sql

# Write create backup log 
echo "create $backup_dir/$database_name-$dd.dupm" >> $backup_dir/log.txt

# Find the backup that needs to be deleted 
delfile=`ls -l -crt $backup_dir/*.sql | awk '{print $9 }' | head -1`

# Determine whether the current number of backups is greater than $number
count=`ls -l -crt $backup_dir/*.sql | awk '{print $9 }' | wc -l`

if [ $count -gt $number ]
then
  # Delete the earliest generated backup , Only keep number Number of backups 
  rm $delfile
  # Write delete file log 
  echo "delete $delfile" >> $backup_dir/log.txt
fi

The main meaning of the above code is as follows ：

1. First, set the parameters , for example number The maximum number of backups required , Backup path , user name , Password etc. .

2. perform mysqldump Command save backup file , And print the operation to log.txt Mark the operation log in .

3. Define files to delete ： adopt ls Command to get the ninth column , That is, the list of documents , Then define the file to be deleted with the latest operation time through the implementation .

4. Define the number of backups ： adopt ls Command plus , Statistics to sql The number of lines in the ending file .

5. If the file exceeds the limit size , Delete the first sql file

3.1、 Use crontab Execute backup scripts on a regular basis

stay Linux in , Periodic tasks are usually performed by cron This daemons will handle [ps -ef|grep cron].cron Read one or more configuration files , These configuration files contain the command line and its call time .

cron The configuration file for is called “crontab”, yes “cron table” Abbreviation .

3.2、cron service

cron It's a Liunx Next The timing tool of , You can run a job without human intervention .

service crond start // Start the service 
service crond stop // Close the service 
service crond restart // Restart the service 
service crond reload // service crond reload 
service crond status // View service status 

3.3、crontab grammar

crontab The command is used to install 、 Delete or list for driving cron The table of the background process . The user places the sequence of commands to be executed in crontab File to get execution . Every user can have their own crontab file ./var/spool/cron Under the crontab Files cannot be created or modified directly . The crontab The document is passed crontab Command created .

stay crontab How to input the command and time to execute in the file . Each line in the file contains six fields , The first five fields specify when the command will be executed , The last domain is the command to be executed .

Separate each field with a space or tab .

The format is as follows ： 

minute hour day-of-month month-of-year day-of-week commands
 Legal value  00-59 00-23 01-31 01-12 0-6 (0 is sunday)

Besides numbers, there are several special symbols "*"、"/" and "-"、",",* Represents all numbers in the range of values ,"/" Represents the meaning of each ,"/5" each 5 A unit of ,"-" Represents from a number to a number ,"," Separate several discrete numbers .

-l Display the current... On the standard output crontab. 

-r Delete the current crontab file . 

-e Use VISUAL perhaps EDITOR The editor that the environment variable refers to edits the current crontab file . When the end editor leaves , The edited file will be installed automatically . 

3.5、 establish cron Script

First step ： Write cron Script files , Name it mysqlRollBack.cron.

15,30,45,59 * * * * echo "xgmtest....." >> xgmtest.txt  Express , every other 15 minute , Execute the print once command  

The second step ： Add timing task . Carry out orders “crontab crontest.cron”. Get it done  

The third step ："crontab -l" Check if the scheduled task is successful or check /var/spool/cron Whether to generate corresponding cron Script

Be careful ： This operation is to replace the user directly crontab, Instead of adding .

Execute the scheduled task script written on a regular basis （ Remember to give it first shell Script execution permission ）

0 2 * * * /root/mysql_backup_script.sh

Subsequent use crontab Command the timing script written by the periodic instruction

crontab mysqlRollback.cron

Then check whether the scheduled task has been created through the command ：

attach crontab Use example of ：

1. Every day in the morning 6 spot  

0 6 * * * echo "Good morning." >> /tmp/test.txt // Pay attention to simplicity echo, No output can be seen from the screen , because cron Put any output email To root The mailbox of .

2. Every two hours  

0 */2 * * * echo "Have a break now." >> /tmp/test.txt

3. evening 11 Point to morning 8 Every two hours between and eight in the morning  

0 23-7/2,8 * * * echo "Have a good dream" >> /tmp/test.txt

4. Monthly 4 And every Monday to Wednesday morning 11 spot  

0 11 4 * 1-3 command line

5.1 month 1 Day in the morning 4 spot  

0 4 1 1 * command line SHELL=/bin/bash PATH=/sbin:/bin:/usr/sbin:/usr/bin MAILTO=root // If something goes wrong , Or data output , The data is sent to this account as an email  HOME=/

6. Hourly execution /etc/cron.hourly Script inside

01 * * * * root run-parts /etc/cron.hourly

7. Daily execution /etc/cron.daily Script inside

02 4 * * * root run-parts /etc/cron.daily

8. Every week /etc/cron.weekly Script inside

22 4 * * 0 root run-parts /etc/cron.weekly

9. Every month /etc/cron.monthly Script inside  

42 4 1 * * root run-parts /etc/cron.monthly

Be careful : "run-parts" This parameter , If you remove this parameter , You can then write the name of a script to run , Not the folder name .　 

10. Every afternoon 4 spot 、5 spot 、6 Dot 5 min、15 min、25 min、35 min、45 min、55 min To execute an order . 

5,15,25,35,45,55 16,17,18 * * * command

11. Every Monday , 3、 ... and , Five afternoons 3：00 The system enters the maintenance state , Restart the system .

00 15 * * 1,3,5 shutdown -r +5

12. Hourly 10 branch ,40 Execute... In the user directory innd/bbslin This instruction ： 

10,40 * * * * innd/bbslink

13. Hourly 1 Execute... In the user directory bin/account This instruction ： 

Here's a screenshot of my test every minute , The corresponding code is as follows ：

* * * * * /root/mysql_backup_script.sh

Effect screenshots ：

Among them log.txt Record the detailed operation log of the backup ：

  Only when you start , You will reach your ideal and destination , Only when you work hard ,
You will achieve brilliant success , Only when you sow , You will gain something . Only pursue ,
To taste the taste of success , Sticking to yesterday is called foothold , Sticking to today is called enterprising , Sticking to tomorrow is called success . Welcome all friends to praise + Collection ！！！