replicating, balanced web-server with *write* access?
Much is written about High-Availability servers but I still didn't find a
good solution how to build two load-balanced webservers _without_
connecting them both to one RAID (single point of failure).
The problem with balancing between two servers is that the might host
web-servers that could write a file on system A and then reading this file
(status file or whatever) on system B immediately before e.g. rsync could
transfer it. In the worst case writing/reading could happen for two different
connection so that even connection based balancing wouldn't work.
For now I have three ideas:
1. forget about load balancing and do one-way balancing i.e. having one
primary and one minutely synced backup. In a case of a failure the
backup would take over the service and even if there's a little loss it
only occures at failures.
2. use network attached storage. To avoid another single point of failure
you then would have to take two file servers and a protocol (NFS wont
need) to realize this. Maybe at least IP takeover and forced reconnection
3. Forget about writing anything to disk - apart from FTP uploads
everything will have to be written to database. But tell that your
The ideal solution would be a network filesystem like www.inter-mezzo.org
but it does not appear to be really mature and tested in real life
So any idea?
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