Hi,

I have a (at least for me) quite complex problem to solve:

At the moment we have 3 servers in 3 different locations, which synchronize their data at night via a rsync job.

What i would like is that the servers synchronize their filesystems in realtime and also act as a local cache for the location.

To make it a little clearer what i mean here's an example:

There are Servers A B in Location 1 2.
These 2 servers somehow (I don't know how, thats exactly my question) have their filesystems sychronized.
The server are on a 1Gbit LAN and connected to each other over a 34Mbit WAN.
The client X is in Location 1 and Y in Location 2.

Now client X in L1 uploads a huge file to Server A.
Shortly after the upload is finished, client Y in L2 wants to download this file from Server B. Server B is not yet finished with the synchronization and should transparently now get the file from Server A and serve it to the client while continuing the synchronization.
Of course this transfer is slow for Client Y cause he effectively only has 34mbit - but at least he doesn't have to worry about which server to get the file from.
After some time then the servers are 100% synchronized again and all clients get their LAN bandwidth.


Is there any software / filesystem / cluster solution / whatever that you know of that does exactly this?