<服务>Inotify

时间：Nov. 29, 2016 分类：Linux服务

Inotify

rsync的核心算法是对目标文件进行对比，只进行差异同步，对于大数据量对比是非常耗时的，并且低效，Inotify的作用是获取client端目录文件的变化，然后执行rsync命令同步数据。 Inotify从kernel内核2.6.13起对Inotify的支持。

Inotify的组件

Inotify 效果大概为300个文件/s
sersync 效果大概为150个文件/s
lsyncd
Inotify使用

检查内核版本

[root@sersync why]# uname -r
2.6.32-431.el6.x86_64

Inotify配置

[root@nfs data1]# ll /proc/sys/fs/inotify/
总用量 0
-rw-r--r-- 1 root root 0 11月 27 05:02 max_queued_events
-rw-r--r-- 1 root root 0 11月 27 05:02 max_user_instances
-rw-r--r-- 1 root root 0 11月 27 05:02 max_user_watches

max_queued_events监控队列的最大值，默认为16384。监控的执行的命令放到队列里，如果出现堵塞可以调大该值。
max_user_instances用户实例
max_user_watches用户watch

Inotify

下载Inotify http://github.com/downloads/rvoicilas/inotify-tools/inotify-tools-3.14.tar.gz 使用wget下不下来。

[root@nfs ~]# tar xf inotify-tools-3.14.tar.gz 
[root@nfs ~]# cd inotify-tools-3.14
[root@nfs inotify-tools-3.14]# ./configure --prefix=/usr/local/inotify-tools-3.14
[root@nfs inotify-tools-3.14]# make && make install
[root@nfs inotify-tools-3.14]# ln -s /usr/local/inotify-tools-3.14/ /usr/local/inotify-tools

Inotify目录

[root@nfs inotify-tools-3.14]# cd !$
cd /usr/local/inotify-tools
[root@nfs inotify-tools]# ll
总用量 16
drwxr-xr-x 2 root root 4096 11月 27 05:55 bin
drwxr-xr-x 3 root root 4096 11月 27 05:55 include
drwxr-xr-x 2 root root 4096 11月 27 05:55 lib
drwxr-xr-x 4 root root 4096 11月 27 05:55 share

Inotify参数

[root@nfs inotify-tools]# ./bin/inotifywait --help
inotifywait 3.14
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>.      #排除文件或目录，不区分大小写
    --excludei <pattern>
                    Like --exclude but case insensitive.
    -m|--monitor    Keep listening for events forever.  Without
                    this option, inotifywait will exit after one
                    event is received.      #保持事件监听状态
    -d|--daemon     Same as --monitor, except run in the background
                    logging events to a file specified by --outfile.
                    Implies --syslog.
    -r|--recursive  Watch directories  recursively.        #递归查询
    --fromfile <file>
                    Read files to watch from <file> or `-' for stdin.
    -o|--outfile <file>
                    Print events to <file> rather than stdout.
    -s|--syslog     Send errors to syslog rather than stderr.
    -q|--quiet      Print less (only print events).        #打印监控事件信息
    -qq             Print nothing (not even events).
    --format <fmt>  Print using a specified printf-like format
                    string; read the man page for more details.       #输出格式字符串
    --timefmt <fmt> strftime-compatible format string for use with
                    %T in --format string.      #时间格式
    -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.
# 指定监控事件
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       #文件或目录被封闭，无法读或者写
    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      #文件或目录被移动至另一个目录或者从另一个目录移植当前目录
    create      file or directory created within watched directory        #文件或目录被创建在当前目录
    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     #文件系统被卸载

Inotify手动测试

启动监听create事件

启动监听

[root@nfs inotify-tools]# ./bin/inotifywait -mrq --timefmt '%d/%m/%y/ %H:%M:%S' --format '%T %w%f' -e create /data1/

重启一个tty终端

[root@nfs data1]# touch 1
[root@nfs data1]# touch 2
[root@nfs data1]# touch 3
[root@nfs data1]# mkdir 4
[root@nfs data1]# mkdir 5

原tty终端显示

[root@nfs inotify-tools]# ./bin/inotifywait -mrq --timefmt '%d/%m/%y/ %H:%M:%S' --format '%T %w%f' -e create /data1/
27/11/16/ 09:05:34 /data1/1
27/11/16/ 09:05:36 /data1/2
27/11/16/ 09:05:38 /data1/3
27/11/16/ 09:05:42 /data1/4
27/11/16/ 09:05:44 /data1/5

gif展示

多种监控事件

启动监听

[root@nfs inotify-tools]# ./bin/inotifywait -mrq --timefmt '%d/%m/%y/ %H:%M:%S' --format '%T %w%f' -e create,delete /data1/

新tty终端删除

[root@nfs data1]# rm -f {1,2,3}

原tty终端显示

[root@nfs inotify-tools]# ./bin/inotifywait -mrq --timefmt '%d/%m/%y/ %H:%M:%S' --format '%T %w%f' -e create,delete /data1/
27/11/16/ 09:06:35 /data1/1
27/11/16/ 09:06:35 /data1/2
27/11/16/ 09:06:35 /data1/3

监控事件重复

启动监听

[root@nfs inotify-tools]# ./bin/inotifywait -mrq --timefmt '%d/%m/%y/ %H:%M:%S' --format '%T %w%f' -e create,delete,close_write /data1/

新tty终端创建

[root@nfs data1]# touch 1

原tty终端显示

[root@nfs inotify-tools]# ./bin/inotifywait -mrq --timefmt '%d/%m/%y/ %H:%M:%S' --format '%T %w%f' -e create,delete,close_write /data1/
27/11/16/ 09:10:23 /data1/1
27/11/16/ 09:10:23 /data1/1

create和close_write同时监听到，所以显示两次。

新tty终端写入

[root@nfs data1]# echo 1 > 1

原tty终端显示

[root@nfs inotify-tools]# ./bin/inotifywait -mrq --timefmt '%d/%m/%y/ %H:%M:%S' --format '%T %w%f' -e create,delete,close_write /data1/
27/11/16/ 09:10:23 /data1/1
27/11/16/ 09:10:23 /data1/1
27/11/16/ 09:11:00 /data1/1

不显示时间

[root@nfs inotify-tools]# ./bin/inotifywait -mrq --format '%w%f' -e create,delete,close_write /data1/
/data1/2
/data1/2

脚本推送

#!/bin/sh
cmd=/usr/local/inotify-tools/bin/inotifywait
$cmd -mrq --format '%w%f' -e create,delete,close_write /data1 | \
while read line
do
    rsync -az --delete /data1/  rsync://rsync_backup@192.168.0.184/why --password-file=/etc/rsync.password
done

参数调优

默认值

[root@sersync inotify]# cat max_queued_events 16384 [root@sersync inotify]# cat max_user_instances 128 [root@sersync inotify]# cat max_user_watches 8192

调优值

max_queued_events = 327679
max_user_watches = 5000000
性能极限

一般在50~500k大小的文件进行同步时，可以达到200~300的并发。

脚本优化

#!/bin/sh
cmd=/usr/local/inotify-tools/bin/inotifywait
$cmd -mrq --format '%w%f' -e create,close_write /data1 | \
while read line
do
    rsync -az $line  rsync://rsync_backup@192.168.0.184/why --password-file=/etc/rsync.password
done


$cmd -mrq --format '%w%f' -e delete /data1 | \
while 
do
    rsync -az --delete /data1  rsync://rsync_backup@192.168.0.184/why --password-file=/etc/rsync.password
done

因为在推送的过程中，一旦文件数量特大，每次都要做推送整个目录的比对，效率太低，只推送状态和改变的即可。或者添加判断。

#!/bin/sh
cmd=/usr/local/inotify-tools/bin/inotifywait
$cmd -mrq --format '%w%f' -e create,close_write /data1 | \
while read line
do
    [ ! -e "$line" ] && continue
    rsync -az --delete $line rsync://rsync_backup@192.168.0.184/why --password-file=/etc/rsync.password
done

火眼征信大数据工程师闫大佬

Inotify

Inotify的组件

Inotify使用

检查内核版本

Inotify配置

Inotify

Inotify目录

Inotify参数

Inotify手动测试

启动监听create事件

启动监听

重启一个tty终端

原tty终端显示

gif展示

多种监控事件

启动监听

新tty终端删除

原tty终端显示

监控事件重复

启动监听

新tty终端创建

原tty终端显示

新tty终端写入

原tty终端显示

不显示时间

脚本推送

参数调优

默认值

调优值

性能极限

脚本优化