Deterministic datasource selection was enabled in Tungsten Cluster 6.0.3.
Within composite clusters, both Composite Active/Passive and Composite Active/Active, the
selection of datasources can be made to be deterministic by specifying
the list of datasources within the
configuration. The configuration is based on an ordered, comma-separated
list of services to use which are then selected in order.
The format of the speecification is as follows:
The specification operates on the following rules:
List of service names in order
If the service name has a dash prefix it is always explicitly excluded from the list of available datasources
If a datasource is not specified, it will always be picked last
For example, in a setup made of three data service,
europe using the following
app_user secret usa,asia,-europe
Will select data sources in data service
usa is not available, in
asia is not availble, then
connection will not succeed since
europe has been negated.