inotifyrsync -- 用inotify和rsync实现多机文件实时同步

对于热备的机器，需要实时把文件目录的修改从master同步到slave上。用crontab加rsync的方式能够实现几分种延迟内的同步，但用对于文件数目很大的情况，每次rsync都会有很多计算，比较耗费CPU资源。下面的脚本用inotify和rsync实现实时同步。为了保险起见，最好还是设置一个crontab来定时跑整个目录的rsync，不过定时间隔可以稍微长一点，以免占用太多系统资源。

github上的链接：https://github.com/gaopenghigh/inotifyrsync

直接上代码：

README

Use rsync and inotify to sync files and directories from one host to other hosts
  
  Include 2 files:
  sync.sh
  do_sync.py
  
  RUN:
  0. Make sure source host can ssh into destination hosts without password
  1. Do some setting in file do_sync.py
  2. run sync.sh

sync.sh

#!/bin/bash
  
  LOG=`cat $(dirname $0)/do_sync.py | grep "LOG_FILE = " | head -n 1 | awk '{print $3}' | tr -d \'`
  BASE_DIR=`cat $(dirname $0)/do_sync.py | grep "BASE_DIR = " | head -n 1 | awk '{print $3}' | tr -d \'`
  tester=`/bin/ps aux | grep -v grep | grep do_sync.py`
  if [[ ! -z $tester ]];then
      echo "sync.sh already running"
  else
      echo "/usr/bin/inotifywait -mrq --format '%w%f' -e modify,delete,create,move $BASE_DIR | $(dirname $0)/do_sync.py > $LOG &"
      /usr/bin/inotifywait -mrq --format '%w%f' -e modify,delete,create,move $BASE_DIR | $(dirname $0)/do_sync.py > $LOG &
  fi

do_sync.py

  #!/usr/bin/python
  # -*- coding: utf-8 -*-
  # Author: [e-mail]
  
  import sys
  import os
  import commands
  import threading
  import time
  
  ### CONFIGS, YOU CAN CHANGE SETTINGS HERE ###
  THREAD_NUM = 2                # how many threads do the rsync job
  SLEEP_TIME = 3                # if nothing to sync, just sleep, second
  MERGE_NUM = 25                # try to sync dirs instead of files in the same dir
  BASE_DIR = '/home/admin/run'  # root dir you want to sync, anything out of this dir will not sync
  LOG_FILE = '/home/admin/out/sync.log'  # log file, set to '/dev/null' if no log file needed
  DESTS = [                     # Destination Hosts
          'hz-wsbuyblog-web1',
          'hz-wsbuyblog-web2',
          'hz-ws-buyblog-web3'
          ]
  DESTS = ['hz-wsbuyblog-web1',]
  ### END OF CONFIGS ###
  
  
  class WorkThread(threading.Thread):
      ''' working thread in thread pool'''
      def __init__(self, work_set, **kwargs):
          threading.Thread.__init__(self, kwargs=kwargs)
          self.work_set = work_set
          self.setDaemon(True)
          self.start()
  
      def run(self):
          '''always trying to get rsync job, if nothing to sync, sleep SLEEP_TIME seconds'''
          while True:
              try:
                  # if too many files need to sync, try rsync dir of these files
                  set_size = len(self.work_set)
                  while set_size > MERGE_NUM:
                      last_size = set_size
                      merge(self.work_set)
                      set_size = len(self.work_set)
                      # Can not merge any more
                      if last_size == set_size:
                          break
                  f = self.work_set.pop()
                  if not f.startswith(BASE_DIR):
                      continue
                  if os.path.isdir(f):
                      dest_file = os.path.dirname(f)
                  else:
                      dest_file = f
                  for d in DESTS:
                      cmd = '/usr/bin/rsync -az --delete %s %s:%s' % (f, d, dest_file)
                      res = commands.getstatusoutput(cmd)
                      if res[0] != 0:
                          flag = 'FAIL'
                      else:
                          flag = 'OK'
                      print '[%s] [WAITING:%s] [%s] %s ---> %s:%s' % (time.strftime('%Y-%m-%d_%H:%M:%S'), len(self.work_set), flag, f, d, dest_file)
              except KeyError:
                  time.sleep(SLEEP_TIME)
              except:
                  print sys.exc_info()
                  raise
  
  
  class ThreadPool:
      # thread pool
      def __init__(self, work_set, thread_num = 10):
          self.work_set = work_set
          self.threads = []
          self.thread_num = thread_num
          self._create_thread_pool()
  
      def _create_thread_pool(self):
          self.threads = []
          for i in range(self.thread_num):
              t = WorkThread(self.work_set)
              self.threads.append(t)
  
  
  def merge(file_set):
      '''
      if more thanfiles in the same dir, use dir instead of these files to make file_set smaller
      '''
      print '### MERGE %s' % len(file_set),
      tmp_set = file_set.copy()
      dir_dic = {}
      for f in tmp_set:
          dir = '/'.join(f.split('/')[:-1])
          if dir in dir_dic:
              dir_dic[dir] += [f,]
          else:
              dir_dic[dir] = [f,]
      for d, fs in dir_dic.items():
          if len(fs) > 1:
              for f in fs:
                  file_set.remove(f)
              file_set.add(d)
      print '---> %s' % len(file_set)
  
  
  def review(file_set):
      '''delete unnecessary files'''
      all_files = file_set.copy()
      for f in all_files:
          # added dir
          if os.path.isdir(f):
              # do not need rsync files in the dir
              tmp_set = file_set.copy()
              for xf in tmp_set:
                  if xf.startswith(f) and xf != f:
                      file_set.remove(xf)
      all_files = file_set.copy()
      for f in all_files:
          # deleted file or dir
          if not os.path.isfile(f) and not os.path.isdir(f):
              file_set.remove(f)
              father = '/'.join(f.split('/')[:-1])
              while not os.path.isdir(father):
                  father = '/'.join(father.split('/')[:-1])
              file_set.add(father)
              tmp_set = file_set.copy()
              for xf in tmp_set:
                  if xf.startswith(father) and xf != father:
                      file_set.remove(xf)
  
  
  def main():
      file_set = set([])
      tp = ThreadPool(file_set, THREAD_NUM)
      if not tp:
          print "create thread pool failed"
          return False
      while True:
          line = sys.stdin.readline()
          ignore = False
          if not line:
              break
          line = line.strip()
          file_set_tmp = file_set.copy()
          for exist_file in file_set_tmp:
              if line.startswith(exist_file) and line != exist_file:
                  ignore = True
                  break
          if ignore:
              continue
          file_set.add(line)
          review(file_set)
  
  
  if __name__ == '__main__':
      main()