linux 实时同步inotify

#实时同步inotify

1、inotify简介
inotify是一种强大的，细腻度的，异步的文件系统事件监控机制，linux内核从2.6.13起，加入了inotify支持，通过INOTIFY可以监控文件系统中添加、删除、修改、移动等各种事件，利用这个内核接口，第三方软件就可以监控文件系统下文件的各种变化情况，而inotify-tloos就是实施这样监控的软件。

2、inotify实施
检查rsync daemon服务是否服务正常，可以推送数据实施同步
ps -ef |grep rsync|grep -v grep
root 5959 1 0 18:52 ? 00:00:00 rsync --daemon
1)坚持当前系统是否支持inotify
uname -r 版本在2.6.13以上才支持
2.6.32-504.el6.x86_64
# ls -l /proc/sys/fs/inotify
-rw-r--r-- 1 root root 0 Apr 4 20:23 max_queued_events
-rw-r--r-- 1 root root 0 Apr 4 20:23 max_user_instances
-rw-r--r-- 1 root root 0 Apr 4 20:23 max_user_watches
#显示这三个文件则证明支持INOTIFY
proc/sys/fs/inotify/max_queued_evnets
表示调用inotify_init时分配给inotify instance中可排队的event的数目的最大值，超出这个值的事件被丢弃，但会触发IN_Q_OVERFLOW事件。

/proc/sys/fs/inotify/max_user_instances
表示每一个real user ID可创建的inotify instatnces的数量上限。

/proc/sys/fs/inotify/max_user_watches
表示每个inotify instatnces可监控的最大目录数量。如果监控的文件数目巨大，需要根据情况，适当增加此值的大小。
例如： echo 30000000 > /proc/sys/fs/inotify/max_user_watches

2)下载inotify源码包，编译安装
wget https://jaist.dl.sourceforge.net/project/inotify-tools/inotify-tools/3.13/inotify-tools-3.13.tar.gz
tar zxvf inotify-tools-3.13.tar.gz
cd inotify-tools-3.13
./configure --prefix=/usr/local/inotify-tools-3.13
make && make install
ln -s /usr/local/inotify-tools-3.13/ /usr/local/inotify
cd /usr/local/inotify

./inotifywait -help
inotifywait 3.13
Wait for a particular event on a file or set of files.
Usage: inotifywait [ options ] file1 [ file2 ] [ file3 ] [ ... ]
Options:
-h|--help Show this help text.
@<file> Exclude the specified file from being watched.
--exclude <pattern>
Exclude all events on files matching the
extended regular expression <pattern>.
--excludei <pattern>
Like --exclude but case insensitive. #排除文件或目录时，不区分大小写
-m|--monitor Keep listening for events forever. Without
this option, inotifywait will exit after one
event is received. #始终保持事件监听状态
-r|--recursive Watch directories recursively. #递归查询目录
--fromfile <file>
Read files to watch from <file> or - for stdin.
-q|--quiet Print less (only print events). #打印监控事件的信息
-qq Print nothing (not even events).
--format <fmt> Print using a specified printf-like format
string; read the man page for more details.
--timefmt <fmt> strftime-compatible format string for use with
%T in --format string. #指定时间输出的格式
-c|--csv Print events in CSV format.
-t|--timeout <seconds>
When listening for a single event, time out after
waiting for an event for <seconds> seconds.
If <seconds> is 0, inotifywait will never time out.
-e|--event <event1> [ -e|--event <event2> ... ]
Listen for specific event(s). If omitted, all events are
listened for. #通过此参数可以指定需要监控的事件，如下：

Exit status:
0 - An event you asked to watch for was received.
1 - An event you did not ask to watch for was received
(usually delete_self or unmount), or some error occurred.
2 - The --timeout option was given and no events occurred
in the specified interval of time.

Events:
access file or directory contents were read #文件或目录被读取
modify file or directory contents were written #文件或目录内容被修改
attrib file or directory attributes changed #文件或目录属性被修改
close_write file or directory closed, after being opened in
writeable mode
close_nowrite file or directory closed, after being opened in
read-only mode
close file or directory closed, regardless of read/write mode #文件或目录封闭，无论读/写模式
open file or directory opened #文件或目录被打开
moved_to file or directory moved to watched directory #文件或目录被移动至另外一个目录
moved_from file or directory moved from watched directory
move file or directory moved to or from watched directory #文件或目录被移动另一个目录或另一个目录移动到当前目录
create file or directory created within watched directory #文件或目录被创建
delete file or directory deleted within watched directory #文件或目录被删除
delete_self file or directory was deleted
unmount file system containing file or directory unmounted #文件或目录被卸载
实时监控命令：
/usr/local/inotify/bin/inotifywait -mrq --timefmt '%d%m%y %H:%M' --format '%T %w%f' -e create,delete,close_write,attrib /data

inotify缺点：
1)并发不能大于200个文件

实时监控inotify脚本

#!/bin/bash
#inotify jiankong
cmd="/usr/local/inotify/bin/inotifywait"
src="/data"
mod="test"
user="rsyncback"
ip=192.168.233.129
passfile="/etc/rsync.password"
rsyc="/usr/bin/rsync"
#judge
if [ -f "$cmd" ] && [ -e "$src" ] && [ -n "$user" ] && [ -n "$mod" ] && [ -f "$passfile" ] && [ -f "$rsyc" ];then
 echo "file path is ok"
else
  exit
fi
while true
do
$cmd -mrq --format '%w%f' -e create,delete,modify,attrib,close_write,move $src|\
while read line
do
   [ ! -e "$line" ] && break || \
   echo $line >> /root/inotiity.log
   $rsyc -az --delete $line ${user}@${ip}::$mod --password-file=$passfile
done
cd $src && $rsyc -az --delete ./ ${user}@${ip}::$mod --password-file=$passfile
done