> We have a mission critical PHP based system that uses a Firebird SQL
> back-end. Works brilliantly and has for many years. This is hosted on
> a CentOS server with FB 1.5 (will update FB versions soon to later
> releases).
>
> Due to high demand, we are going to need to create multiple server
> 'nodes' for the system using a DNS load balanced setup. As a result,
> servers that run PHP will be located in different geographic regions,
> sometimes in different countries. The DNS failover capability will
> ensure that at least one server is available for any incoming request.
>
> Although this is relatively painless to setup for general PHP/Apache
> operation, it isn't as simple with the database. I'd like to adopt a
> common approach that MySQL databases& high demand PHP apps seem to do,
> and that is that updates to the database are immediately replicated to
> all node systems, which have their own separate Firebird database on
> them. In this way, each node is self-contained. If a node is down,
> however, I need to find a way to identify changes that were made to a
> 'master' server, that didn't complete replication to a number of slave
> node servers.
>
> Is anyone doing this sort of thing in similar technologies that we use?
> If so, how have you chosen to do it? Should I build all of this
> technology myself, or are there any pre-written systems that do
> replication that already are considered 'bullet proof' that I should be
> considering evaluation?

Various customers are using the redo facility in our IB LogManager
product family for maintaining one or more slave databases as logical
standby copies of the production database. With the help of a big
customer running such an environment, we improved the redo facility in
V2.11 of IB LogManager a lot. A video on the redo stuff is available here:
http://www.iblogmanager.com/download/demos/iblm/iblm_hotstandby.htm


--
With regards,

Thomas Steinmaurer
Upscene Productions
http://www.upscene.com
http://blog.upscene.com/thomas/

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