by looking at the number of packages and ART based objects you should check your application how it can be split up into meaningful chunks of code.
We are currently using a mix of the scenarios described by MR:
We are running 5 instances of IS sharing one central Broker(would become UM in newer installations):
- one IS is mostly using SAP-Adapter (mostly IDocs, few RFC) together with WebsphereMQ-Adapter.
- one IS is using SAP-Adapter (equal mix of IDocs and RFC) and WebServices.
- one IS is using WebServies, SFTP and some SAP RFC combined with WM JMS Provider (hosted on Broker).
- one IS is used/planned for internal tasks like Deployer and as a spare instance for upcoming applications.
- one IS is used as a WebService Provider for custom CAF UIs and Tasks.
All 5 ISes have the same components installed (even some of them do not really use them) for the ease of updating the installations and for moving the application parts from one instance to another when the performance indicates that this might make sense.
All 5 ISes are equipped a set of packages for common tasks like monitoring/archiving/logging and basic support services.
For your scenario I suggest at least the following installations:
- 1 IntegrationServer and 1 UM on Windows for those parts which really needs this.
- x IntegrationServer(s), 1 UM, 1 CentraSite and 1 MWS on AIX for all the rest.
- One central Database for all installations where needed (hosted on AIX)
Communication between the two parts will be only handled by the 2 UM installations.
If Terracotta is really needed depends on the size of your data and if you need to cluster IS instances for performance issues.
Higher number of packages increases startup time of the IntegrationServer and affects the heap size of the JVM in which the IntegrationServer is running.
There is no definitiv answer “do it this way or do it that way” as each customers landscape is different and needs apropriate analysis before decision.
You can try to get SAG Consulting involved to help you with this analysis.
I assume you are preparing a migration from an older version?
If so, SAG Consulting provides specific migration support services.