The Oracle E-Business Suite architecture comprises a client tier, an application tier with one or more nodes, and a database tier with one or more nodes. The different tiers can run on various hardware and operating systems, together often referred to as the platform.
Many customers standardize on a single platform for both the application and database tiers. This has the advantage that they only need to follow maintenance guidelines from a single vendor.
However, some customers choose to deploy the EBS application and database tiers on different platforms. This deployment is referred to as mixed platforms or database tier only platform or split tier configuration. There can be various reasons for doing this, for example to run the Oracle Database on a platform to which the applications code was not ported.
For releases earlier than EBS 12.2, it was also supported to deploy mixed platforms in a multi-node application tier environment. However, it is important to be aware that using different platforms for the application tier is not supported in EBS Release 12.2, where key architectural features need the application code to be common (shared) across all nodes.
Most notably, the use of the adop patching utility in EBS 12.2 is optimized by running patching activities on the primary node, with remote processes triggered on secondary nodes as applicable. This distributed patching mechanism requires all the binaries to run on the same hardware and operating system.