Rsync+inotyfy realize real-time synchronization of single data monitoring

One , environmental information
1, Usage environment
CentOS Linux release 7.5.1804 (Core)
Update source ：192.168.21.131
Target source ：192.168.21.132

2, Check Rsync Whether to install （ If not, directly yum Can be installed ）
rpm -qa | grep rsync
2.1, I use rsync edition
rsync-3.1.2-6.el7_6.1.x86_64
2.2,rsync Common parameters of
-v –verbose Detailed mode output .
-a –archive Archiving mode , Indicates that files are transferred recursively , And keep all file attributes unchanged .
-l Keep soft links
-R Keep relative path
-H Keep hard links
-p,-o,-g,-A Reserve permissions separately , Belong to , Generic group ,acl etc. , But if you add -a, These include
-z, –compress Compress the backup files during transmission .
-D be equal to –devices --specials Express support b,c,s,p Files of type
–delete Delete those DST Exist in SRC Files not in .
–progress Show the progress during the transfer
Two , Configuration of the target server ,Rsync Server side （192.168.21.132）
3, Definition Rsync The configuration file
vim /etc/rsyncd.conf
uid = tongbu # Daemon user
gid = tongbu # Daemon Group
use chroot = no # Do not apply chroot
max connections = 100 # maximum connection ,0 For no limit
port = 873 # The default port is 873
timeout = 600 # Appoint IP Timeout for
pid file = /var/run/rsyncd.pid #Pid Storage location
lock file = /var/run/rsyncd.lock # Lock file storage location , The default is /var/run/rsync.lock
log file = /var/log/rsyncd.log # The location of the log file
Log format = %t %a %m %f %b # Custom log file fields
syslog facility = local3 # Define log levels , The default is daemon

# Module parameters 
[web1]								# Authentication module name , stay client End needs to be specified 							
path = /home							# Directory to be mirrored 
ignore errors							# Ignore irrelevant IO error 
comment = backup web				# Comment information of the module 
read only = no						# Whether to allow customers to upload files 
list = no								# Column file not allowed 
hosts allow = 192.168.21.0/255.255.255.0	# Allowed host network segments 
auth users = tongbu					# Authenticated user name , If there is no such line, it means anonymity , This user has nothing to do with the system 
secrets file = /etc/tongbu.pwd			# User and password comparison table 

3.1, Be careful
Wrong content ：rsync: failed to set times on “xxxx”: Operation not permitted
here uid And gid It needs to be consistent with the users and groups of the synchronized directory , Otherwise, an error will be reported

4, Create authentication file
echo “tongbu:Admin123” >> /etc/tongbu.pwd

5, Set permissions
chmod 600 /etc/{tongbu.pwd,rsyncd.conf}

6, establish motd file （rsync Welcome to , Fill in as you like ）
echo “Welcome to use the rsync services!” >> /var/rsyncd.motd

7, start-up Rsync（ Start with daemons ）
/usr/bin/rsync –daemon

8, Join auto start
echo “/usr/bin/rsync --daemon” >> /etc/rc.local
3、 ... and , Update server configuration ,Rsync client （192.168.21.131）
1, install inotify-tools
1.1, Be careful
In the installation inotify-tools Please confirm your linux Whether the kernel hits 2.6.13, And it turns on at compile time CONFIG_INOTIFY Options , You can also use the following command to detect
1.2, command （ The following three appear MAX It's on ）
ls /proc/sys/fs/inotify
max_queued_events max_user_instances max_user_watches
1.3, install inotify-tools
tar -zxf inotify-tools-3.14.gz
cd inotify-tools-3.14
./confifure
Make && make install
1.4, inotifywait Several parameters of
-m namely –monitor, Indicates that the event listening state is always maintained .
-r namely –recursive, Represents a recursive query directory .
-q namely –quiet, Indicates that the monitoring event is printed out .
-e namely –event, This parameter allows you to specify the event to be monitored , Common events are modify、delete、create、attrib etc.
–timefmt： The output format of the specified time
–format： Specify the details of the change file

2, Write real-time monitoring script
vim /root/rsync.sh
#!/bin/bash
UNISON=ps -ef |grep -v grep|grep -c inotifywait
if [ ${UNISON} -lt 1 ];then
HOST1=192.168.21.132
SRC=/home/tongbu
DES1=web1
USER1=tongbu

    /usr/local/bin/inotifywait -mrq --timefmt '%d/%m/%y %H:%M' --format  '%T %w%f' -e modify,delete,create,attrib ${SRC} |
    while read file
    do
            rsync -vzrtopg --delete --progress ${SRC} ${USER1}@${HOST1}::${DES1} --password-file=/etc/tongbu.pwd &&
            echo "${file} was rsynced" >> /tmp/rsync.log 2>&1
            echo "---------------------------------------------------------------------------"  
    done

fi
2.1, If you don't need real-time monitoring, you only need to do a scheduled task
30 1 * * * /usr/bin/rsync -vzrtopg --delete --progress /home/tongbu/ [email protected]::web1 --password-file=/etc/tongbu.pwd >/dev/null 2>&1 &

3, Create authentication file
echo “tongbu:Admin123” >> /etc/tongbu.pwd

4, Set permissions
chmod 600 /etc/tongbu.pwd

5, Check the startup
5.1, Syntax check
/usr/bin/bash -n /root/rsync.sh
5.2, Background start
chmod +x /root/rsync.sh
nohup /usr/bin/sh /root/rsync.sh &

6, You can use the command line to test before the script
rsync -vzrtopg --delete --progress /home/tongbu/ [email protected]::web1 --password-file=/etc/tongbu.pwd

When you don’t know what to do, just settle down and study！