The architecture which you should be looking at will be:
2-Node Shared Application tier with 2-Node DB (RAC 11gR2).
Additionally Configure PCP to ensure higher availability and better performance of concurrent processing.
Documents to follow:
Sharing The Application Tier File System in Oracle E-Business Suite Release 12.0 and 12.1 (Doc ID 384248.1)
Using Oracle Real Application Clusters 11g Release 2 with Oracle E-Business Suite Release 12 (Doc ID 823587.1)
Concurrent Processing - How To Ensure Load Balancing Of Concurrent Manager Processes In PCP-RAC Configurations (Doc ID 762024.1)
How To Activate Parallel Concurrent Processing In R12 (Doc ID 1525233.1)
Some points to consider:
1. You will be applying all the pacthes to APPL_TOP(adpatch) or 10.1.2/3 Homes only once
2. Autoconfig needs to be run on all nodes
3. DNS/Hardware Load balancing can be used for better performance
Vishnu and Srini, Thanks for the reply.
Could you please share some docs/links the for steps to apply patch (both DB and application) in multi node architecture and what are the main issues in multi node.
The information about applying patches on a Multi-Node system is available below:
See Section: Applying Patches to a Multi-Node System
For Database Patching:
Oracle Real Application Clusters Patching