Josef Pospisil wrote:
i have a problem. I want to loadbalance several webservers. But there is
also a MYSQL database. And i want to have the same content in all
databases (for example if a user writes a news or something i want to
have it in all databases). Of course i could use one MYSQL database for
all webservers but i would loose the redundancy. Somebody told me i
could do that with Distributed Filesystem. But what exactly is
distributed filesystem and how does it work? Or is there any other way
to keep all databases up to date?
You can't just access the same DB from all web servers? It's far easier
to add redundant web servers than redundant databases, if you care about
If you really need several databases, you'll have to look into
replication. MySQL has some form of it (I'm not sure of the details).
PostgreSQL has Slony. All of the big db vendors have replication.
A distributed filesystem will not help with a db.
I think there are also things that send the same UPDATE/DELETE commands
to all databases, but pulls SELECTS from whichever one is least loaded.
You are not guaranteed the data will remain in sync.