More performance considerations
Picking up on a thread from QAT’s blog about performance considerations when moving from a CBD approach to a J2EE approach within Gen, its also worth noting that moving between platforms can cause a significant difference to performance.
Tuning the application and performance testing is a must, especially if changing the middleware (moving from, say, Client Manager to Direct TCP connections, or more radically from Tuxedo to Transaction Enabler).
Notable things to consider and be mindful of are memory requirements for the load modules, and the calculation of how much should be allocated to the application and how much to the OS, for example. Possible changes in the way the database engines work (assume you are changing database too!) will change the performance profile of the application – online and batch applications often have different performance curves.
The issues can be resolved – by performance testing and tuning early on, and before even that – considering the performance of the existing application on the existing platform and working out the differences in architecture on the new platform to see at least WHERE the effects will be felt if not what they are.
