5.5.6 The WAS database tier

Although it is outside of WAS, the database tier affects the behavior of WAS from an active-active performance and failover perspective, as discussed here.

If we have an active-passive configuration, then the data center with the active database has a shorter network path length so it responds quicker, which skews load balancing. In this case, a DB2 on AIX HADR configuration for the session database, application database, and persistent messaging database is not ideal.

Oracle supports clustering in a shared everything database environment with the cache fusion fast interconnect with Real Application Clustering (RAC) and Oracle 10GR2, which has been proven to fully support a fully active-active and shared load environment using the NAS configuration to avoid split-brain scenarios. It is believed a similar active-active and fully load balanced configuration can be achieved using the Gridscale product for DB2, although this was not tested for this document.

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