I have two servers , each server have a path to keep many files , these files in the path should be the same ( file name , file size , no of file , date of file ) , everything should be the same , there are some files will be write to these path from time to time , if I would like to compare these path to make sure the file is consistency anytime , can advise what can i do ? thx

1) you could use fuse to mount one file system remotely and run diff on the files. If there is a difference, an alert could be sent to tell you something is out of sync.
2) you could use a cron'd rsync to force syncronicity. In effect, this would push the files on the source server to the target server if the target gets out of sync.
3) Use something like "File Alteration Monitor" or iNotify, specifically iNotifyWatch to check for file system changes and then do something (like rsync). This would allow you to push in either direction, rather than from a designated "master".

Maybe you can share the directory between the servers? Have you considered setting up a NFS server on one of the servers, export the files and mount the share on the other server?

This way your servers would be in sync all the time

R.